Chapter 16: Reproductive System & Development
Part C: Menstrual cycle, Pregnancy
1. Menstrual (uterine) cycle
a. Overview
i. Cyclic changes of the endometrium
ii. Regulated by cyclic production of estrogens and progesterone
iii. FSH and LH regulate the production of estrogens and progesterone
iv. Both female cycles are about 28 days in length
v. Ovulation typically occurs about midway through cycle on day 14
1. However, variations occur
b. Stages
i. Menstrual phase
1. Days 1-5
2. Functional layer of the endometrium is sloughed
3. Bleeding occurs for 3-5 days
4. By day 5, growing ovarian follicles are producing more estrogen
ii. Proliferative stage
1. Days 6-14
2. Regulation of functional layer of the endometrium
3. Estrogen levels rise
4. Ovulation occurs in the ovary at the end of this stage
iii. Secretory stage
1. Days 15-28
2. Progesterone levels rise and increase the blood supply to the endometrium
3. Endometrium increases in size and readies for implantation
4. If fertilization does occur
a. Embryo produces a hormone a hormone (HCG) that causes the corpus luteum to continue producing its hormones
5. If fertilization does not occur
a. Corpus luteum degenerates as LH blood levels decline
c. Hormones produced by ovaries
i. Estrogen
1. Produced by follicle cells
2. Cause secondary sex characteristics:
a. Enlargement of accessory organs
b. Development of breasts
c. Appearance of axillary and pubic hair
d. Increase in fat beneath the skin, particularly in hips and breasts
e. Widening and lightening of the pelvis
f. Onset of menses (menstrual cycle)
ii. Progesterone = the hormone of pregnancy
1. Produced by the corpus luteum
2. Production continues until LH diminishes in the blood
3. Does not contribute to the appearance of secondary sex characteristics
4. Helps maintain pregnancy
5. Prepares breasts for milk productions
6. Feedback
d. Mammary glands
i. Present in
1. Modified
ii. Function is
iii. Stimulated by
Wednesday, May 25, 2011
Chapter 16, Reproductive System, Part B
Chapter 16: Reproductive System
Part B: Female System
1. Overview
a. Ovaries (2)—produce eggs and female sex hormones
b. Duct system: (transportation)
i. Fallopian tubes (2)—egg transport
ii. Uterus (1)—embryo/fetal development
iii. Vagina (1)—copulation, birth canal
c. External genitalia—copulation
2. Ovaries
a. Composed of ovarian follicles (sac-like structures):
i. Oocyte (immature egg)
ii. Follicular cells—surround the oocyte
iii. Follicular stages
1. Primary follicle—contains an immature oocyte
2. Graafian (vesicular) follicle—growing follicle with a maturing oocyte
3. Ovulation—when the egg is mature, the follicle ruptures (about every 28 days).
4. The ruptured follilcle is transformed into a Corpus luteum
b. Support
i. Suspensory ligaments—secure ovary to lateral walls of the pelvis
ii. Ovarian ligaments—attach to uterus
iii. Broad ligament—a fold of the peritoneum, encloses suspensory ligament
3. Duct system
a. Fallopian tubes
i. Receive the ovulated oocyte
ii. Provide a site for fertilization
iii. Attach to the uterus
iv. Little or no contact between ovaries and uterine tubes
v. Supported and enclosed by the broad ligament
vi. Anatomy & physiology
1. Fimbriae
a. Finger-like projections at the distal end of the uterine tube
b. Receive the oocyte from the ovary
2. Cilia
a. Located inside the uterine tube
b. Slowly move the oocyte towards the uterus (takes 3-4 days)
3. Fertilization occurs inside the uterine tube since oocyte lives about 24
b. Uterus
i. Located between the urinary bladder and rectum
ii. Hollow organ—pear shape
iii. Functions
1. Receives a fertilized egg
2. Retains the fertilized egg
3. Nourishes the fertilized egg
iv. Support
1. Broad
2. Round
3. Uterosacral
v. Regions of
1. Body—main portion
2. Fundus—superior rounded region above where uterine tube enters
3. Cervix—narrow outlet that protrudes into the vagina
vi. Walls of
1. Endometrium
a. Inner layer
b. Allows for implantation of a fertilized egg
c. Sloughs off if no pregnancy occurs (menses)
2. Myometrium—middle layer of smooth muscle
3. Perimetrium (visceral peritoneum)—outermost serous layer of the uterus
c. Vagina
i. Extends from
ii. Located between
iii. Serves as
iv. Receives
v. Hymen
4. External genitalia = vulva
a. Mons pubis
i. Fatty area
ii. Covered with
b. Labia =
i. Majora
ii. Minora
iii. Corresponds to
iv. Majora encloses vestibule
1. Contains external openings of
c. Clitoris
i. Contains
ii. Corresponds to
1. Hooded
2. Composed of
3. Becomes swollen
d. Greater vestibular glands
i. One found on
ii. Secretes
e. Perineum
i. Diamond-shaped defined by:
1. Anterior:
2. Posterior:
3. Lateral:
ii. Urethral orifice
iii. Vaginal orifice
5. Oogenesis and ovarian cycle
a. Total supply of eggs are present at birth
b. Ability to release eggs begins at puberty
c. Reproductive ability ends at menopause
d. Oocytes are matured in developing ovarian follicles
e. The process and steps of oogenesis
i. Oogonia—female stem cells found in a developing fetus
ii. Oogonia undergo mitosis to produce primary oocytes
iii. Cells surrounding primary oocytes that form primary follicles in the ovary
iv. Oogonia no longer exist by the time of birth
v. Primary oocytes are inactive until puberty
vi. Follicle stimulating hormone (FSH) causes some primary follicles to mature each month
vii. Cyclic monthly changes constitute the ovarian cycle
f. Meiosis
i. Starts inside maturing follicle
ii. Produces a secondary oocyte and the first polar body
iii. Development to mature stage takes about 14 days
iv. Secondary oocyte ovulates with the release of luteinizing hormone (LH).
1. Surrounded by a corona radiate (nurturing cells)
v. Is completed
1. Ovum = egg
2. Two additional
vi. Zygote (fertilized egg) =
vii. If no fertilization
viii. Comparison
1. Males
2. Females
ix. Sperm and egg comparison
1. Sperm
2. Egg
Part B: Female System
1. Overview
a. Ovaries (2)—produce eggs and female sex hormones
b. Duct system: (transportation)
i. Fallopian tubes (2)—egg transport
ii. Uterus (1)—embryo/fetal development
iii. Vagina (1)—copulation, birth canal
c. External genitalia—copulation
2. Ovaries
a. Composed of ovarian follicles (sac-like structures):
i. Oocyte (immature egg)
ii. Follicular cells—surround the oocyte
iii. Follicular stages
1. Primary follicle—contains an immature oocyte
2. Graafian (vesicular) follicle—growing follicle with a maturing oocyte
3. Ovulation—when the egg is mature, the follicle ruptures (about every 28 days).
4. The ruptured follilcle is transformed into a Corpus luteum
b. Support
i. Suspensory ligaments—secure ovary to lateral walls of the pelvis
ii. Ovarian ligaments—attach to uterus
iii. Broad ligament—a fold of the peritoneum, encloses suspensory ligament
3. Duct system
a. Fallopian tubes
i. Receive the ovulated oocyte
ii. Provide a site for fertilization
iii. Attach to the uterus
iv. Little or no contact between ovaries and uterine tubes
v. Supported and enclosed by the broad ligament
vi. Anatomy & physiology
1. Fimbriae
a. Finger-like projections at the distal end of the uterine tube
b. Receive the oocyte from the ovary
2. Cilia
a. Located inside the uterine tube
b. Slowly move the oocyte towards the uterus (takes 3-4 days)
3. Fertilization occurs inside the uterine tube since oocyte lives about 24
b. Uterus
i. Located between the urinary bladder and rectum
ii. Hollow organ—pear shape
iii. Functions
1. Receives a fertilized egg
2. Retains the fertilized egg
3. Nourishes the fertilized egg
iv. Support
1. Broad
2. Round
3. Uterosacral
v. Regions of
1. Body—main portion
2. Fundus—superior rounded region above where uterine tube enters
3. Cervix—narrow outlet that protrudes into the vagina
vi. Walls of
1. Endometrium
a. Inner layer
b. Allows for implantation of a fertilized egg
c. Sloughs off if no pregnancy occurs (menses)
2. Myometrium—middle layer of smooth muscle
3. Perimetrium (visceral peritoneum)—outermost serous layer of the uterus
c. Vagina
i. Extends from
ii. Located between
iii. Serves as
iv. Receives
v. Hymen
4. External genitalia = vulva
a. Mons pubis
i. Fatty area
ii. Covered with
b. Labia =
i. Majora
ii. Minora
iii. Corresponds to
iv. Majora encloses vestibule
1. Contains external openings of
c. Clitoris
i. Contains
ii. Corresponds to
1. Hooded
2. Composed of
3. Becomes swollen
d. Greater vestibular glands
i. One found on
ii. Secretes
e. Perineum
i. Diamond-shaped defined by:
1. Anterior:
2. Posterior:
3. Lateral:
ii. Urethral orifice
iii. Vaginal orifice
5. Oogenesis and ovarian cycle
a. Total supply of eggs are present at birth
b. Ability to release eggs begins at puberty
c. Reproductive ability ends at menopause
d. Oocytes are matured in developing ovarian follicles
e. The process and steps of oogenesis
i. Oogonia—female stem cells found in a developing fetus
ii. Oogonia undergo mitosis to produce primary oocytes
iii. Cells surrounding primary oocytes that form primary follicles in the ovary
iv. Oogonia no longer exist by the time of birth
v. Primary oocytes are inactive until puberty
vi. Follicle stimulating hormone (FSH) causes some primary follicles to mature each month
vii. Cyclic monthly changes constitute the ovarian cycle
f. Meiosis
i. Starts inside maturing follicle
ii. Produces a secondary oocyte and the first polar body
iii. Development to mature stage takes about 14 days
iv. Secondary oocyte ovulates with the release of luteinizing hormone (LH).
1. Surrounded by a corona radiate (nurturing cells)
v. Is completed
1. Ovum = egg
2. Two additional
vi. Zygote (fertilized egg) =
vii. If no fertilization
viii. Comparison
1. Males
2. Females
ix. Sperm and egg comparison
1. Sperm
2. Egg
Chapter 16, Reproductive System, Part A
Chapter 16: Reproductive System
Part A: Male System
1. Gonads
a. Primary sex organs
i. Males = testes
ii. Females = ovaries
b. Produce gametes (sex cells) and secrete hormones
i. Males = sperm (male gametes)
ii. Females = ova/eggs (female gametes)
2. Male reproductive system overview
a. Testes (2)
b. Duct system—transport sperm:
i. Epididymis (2)
ii. Ductus deferens = vas deferens (2)
iii. Urethra (1)
c. Accessory organs
i. Seminal vesicles (2)
ii. Prostate (1)
iii. Bulbourethral glands (2)
d. External genitalia
i. Penis
ii. Scrotum
3. Specialized structures
a. Testes
i. Coverings
1. Tunica albuginea—capsule that surrounds each testis
2. Septa (singular = septum)—extensions of the capsule; divide testes into lobules
ii. Internal structure
1. Lobules contain one to four seminiferous tubules
a. Tightly coiled structures
b. Function as sperm-forming factories
2. Sperm travels through the rete teswtis to the epididymis
3. Interstitial cells in the s.t.’s produce androgens (testosterone)
a. Castration—removal of testes
b. Duct system
i. Epididymis
1. Comma shaped, tightly coiled tube
2. Functions to mature and store sperm cells (at least 20 days)
3. Expels sperm with the contraction of muscles in walls to the vas deferens
ii. Vas deferens
1. Carries sperm from the epididymis to the ejaculatory duct
2. Passes through the inguinal canal and over the bladder
3. Moves sperm by peristalsis
4. Spermatic cord—ductus deferns, blood vessels, and nerves in a connective tissue sheath
5. Ends in the ejaculatory duct which unites with the urethra
6. Ejaculation—smooth muscle in the walls of the vas create peristaltic waves to squeeze sperm foward
7. Vasectomy—cutting of the ductus deferens at the level of the testes to prevent transportation of sperm
iii. Urethra
1. Extends from the base of the urinary bladder to the tip of the penis
2. Carries both urine and sperm
3. Sperm enters from the ejaculatory duct
c. Semen
i. Mixture of and accessory gland secretions
ii. Advantages of accessory gland secretions:
1. Fructose provides energy for sperm cells
2. Alkalinity of semen helps neutralize the acidic envioronment of vagina
3. Semen inhibits bacteria
4. Elements of semen enhance sperm motility
d. Accessory organs
i. Seminal vesicle
1. Located at the base of the bladder
2. Produces thick, yellowish secretion (60% of semen)
3. Contains:
a. Fructose (sugar)
b. Vitamin C
c. Other substances that nourish and activate sperm
ii. Prostate
1. Encircles the upper part of the urethra
2. Secretes milky fluid that helps to activate sperm, enters the urethra through several small ducts
3. Enlarged prostate constricts flow through urethra
iii. Bulbourethral gland
1. Pea-sized gland inferior to the prostate
2. Produces thick, clear mucus that
a. Cleanses the urethra of acidic urine
b. Serves as a lubricant during sexual intercourse
c. Secreted into the penile urethra
e. External genitalia
i. Scrotum
1. Divided sac of skin outside the abdomen
2. Maintains testes at 3oC (5oF) lower than normal body temperature to protect sperm viability
ii. Penis
1. Delivers sperm into the female reproductive tract
2. Regions of the penis
a. Shaft—with erectile tissue
b. Glans penis (enlarged tip)--sensitivity
c. Prepuce = foreskin
i. Folded cuff of skin around proximal end
ii. Often removed
3. Internal
a. Three areas of spongy tissue
b. Erections occur
4. Spermatogenesis
a. Overview
i. Production of sperm
ii. Begins at puberty and continues throughout life
iii. Occurs in the seminiferous tubules
b. Spermatogonia = stem cells undergo rapid mitosis to produce more stem cells before puberty
i. Follicle-stimulating hormone (FSH) modifies cell division
1. One cell produced is a stem cell, called a type A daughter cell
2. The other cell produced becomes a primary spermatocyte, called a type B daughter cell
ii. Primary spermatocytes undergo meiosis
1. One primary spermatocyte produces four haploid spermatids
2. Spermatids—23 chromosomes (half as much material as other body cells)
c. Human life cycle
i. Union of a sperm (n or 23 chromosomes) with an egg (23 chromosomes) creates a zygote (2n or 46 chromosomes)
1. N + N =
d. Spermiogenesis
i. Late spermatids develop distinct regions:
ii. Sperm cells result
iii. Entire spermatogenesis process
e. Sperm cell anatomy
i. The only
ii. Three parts
1. Head
a. Contains
b. Acrosome
c. Breaks down and releases
2. Midpiece
3. Tail
f. Testosterone production
i. The most important
ii. Produced in
iii. Luteinizing hormone (LH)
1. This causes
iv. Functions of testosterone
1. Stimulates
2. Underlies
3. Causes
a. Deepening
b. Increased
c. Enlargement
d. Thickening
Part A: Male System
1. Gonads
a. Primary sex organs
i. Males = testes
ii. Females = ovaries
b. Produce gametes (sex cells) and secrete hormones
i. Males = sperm (male gametes)
ii. Females = ova/eggs (female gametes)
2. Male reproductive system overview
a. Testes (2)
b. Duct system—transport sperm:
i. Epididymis (2)
ii. Ductus deferens = vas deferens (2)
iii. Urethra (1)
c. Accessory organs
i. Seminal vesicles (2)
ii. Prostate (1)
iii. Bulbourethral glands (2)
d. External genitalia
i. Penis
ii. Scrotum
3. Specialized structures
a. Testes
i. Coverings
1. Tunica albuginea—capsule that surrounds each testis
2. Septa (singular = septum)—extensions of the capsule; divide testes into lobules
ii. Internal structure
1. Lobules contain one to four seminiferous tubules
a. Tightly coiled structures
b. Function as sperm-forming factories
2. Sperm travels through the rete teswtis to the epididymis
3. Interstitial cells in the s.t.’s produce androgens (testosterone)
a. Castration—removal of testes
b. Duct system
i. Epididymis
1. Comma shaped, tightly coiled tube
2. Functions to mature and store sperm cells (at least 20 days)
3. Expels sperm with the contraction of muscles in walls to the vas deferens
ii. Vas deferens
1. Carries sperm from the epididymis to the ejaculatory duct
2. Passes through the inguinal canal and over the bladder
3. Moves sperm by peristalsis
4. Spermatic cord—ductus deferns, blood vessels, and nerves in a connective tissue sheath
5. Ends in the ejaculatory duct which unites with the urethra
6. Ejaculation—smooth muscle in the walls of the vas create peristaltic waves to squeeze sperm foward
7. Vasectomy—cutting of the ductus deferens at the level of the testes to prevent transportation of sperm
iii. Urethra
1. Extends from the base of the urinary bladder to the tip of the penis
2. Carries both urine and sperm
3. Sperm enters from the ejaculatory duct
c. Semen
i. Mixture of and accessory gland secretions
ii. Advantages of accessory gland secretions:
1. Fructose provides energy for sperm cells
2. Alkalinity of semen helps neutralize the acidic envioronment of vagina
3. Semen inhibits bacteria
4. Elements of semen enhance sperm motility
d. Accessory organs
i. Seminal vesicle
1. Located at the base of the bladder
2. Produces thick, yellowish secretion (60% of semen)
3. Contains:
a. Fructose (sugar)
b. Vitamin C
c. Other substances that nourish and activate sperm
ii. Prostate
1. Encircles the upper part of the urethra
2. Secretes milky fluid that helps to activate sperm, enters the urethra through several small ducts
3. Enlarged prostate constricts flow through urethra
iii. Bulbourethral gland
1. Pea-sized gland inferior to the prostate
2. Produces thick, clear mucus that
a. Cleanses the urethra of acidic urine
b. Serves as a lubricant during sexual intercourse
c. Secreted into the penile urethra
e. External genitalia
i. Scrotum
1. Divided sac of skin outside the abdomen
2. Maintains testes at 3oC (5oF) lower than normal body temperature to protect sperm viability
ii. Penis
1. Delivers sperm into the female reproductive tract
2. Regions of the penis
a. Shaft—with erectile tissue
b. Glans penis (enlarged tip)--sensitivity
c. Prepuce = foreskin
i. Folded cuff of skin around proximal end
ii. Often removed
3. Internal
a. Three areas of spongy tissue
b. Erections occur
4. Spermatogenesis
a. Overview
i. Production of sperm
ii. Begins at puberty and continues throughout life
iii. Occurs in the seminiferous tubules
b. Spermatogonia = stem cells undergo rapid mitosis to produce more stem cells before puberty
i. Follicle-stimulating hormone (FSH) modifies cell division
1. One cell produced is a stem cell, called a type A daughter cell
2. The other cell produced becomes a primary spermatocyte, called a type B daughter cell
ii. Primary spermatocytes undergo meiosis
1. One primary spermatocyte produces four haploid spermatids
2. Spermatids—23 chromosomes (half as much material as other body cells)
c. Human life cycle
i. Union of a sperm (n or 23 chromosomes) with an egg (23 chromosomes) creates a zygote (2n or 46 chromosomes)
1. N + N =
d. Spermiogenesis
i. Late spermatids develop distinct regions:
ii. Sperm cells result
iii. Entire spermatogenesis process
e. Sperm cell anatomy
i. The only
ii. Three parts
1. Head
a. Contains
b. Acrosome
c. Breaks down and releases
2. Midpiece
3. Tail
f. Testosterone production
i. The most important
ii. Produced in
iii. Luteinizing hormone (LH)
1. This causes
iv. Functions of testosterone
1. Stimulates
2. Underlies
3. Causes
a. Deepening
b. Increased
c. Enlargement
d. Thickening
Chapter 15, Urinary System, Part B
Chapter 15: The Urinary System
Part B
1. Urinary structures
a. Ureters
i. Slender tubes attach each kidney to the bladder
ii. Run from renal pelvis to the posterior aspect of the bladder
iii. Behind the peritoneum
iv. Peristalsis aids gravity in urine transport
b. Urinary bladder
i. Smooth, collapsible, muscular sac
ii. Temporary stores urine
iii. Trigone—triangular region of the bladder base
iv. Three openings
1. Two from the ureters
2. One to the urethra
v. In males, Prostate gland surrounds the neck of the bladder (and urethra)
vi. Bladder wall
1. Three layers of smooth muscle called Detrusor muscle
2. Mucosa made of transitional epithelium
3. Walls are thick and folded in an Empty bladder
4. Bladder expansion, bladder can expand significantly without increasing internal pressure
vii. Capacity
1. Moderately full bladder is about 5 inches long and holds about 500 mL of urine
2. Maximum of holding twice that amount of urine
c. Urethra
i. Thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis
ii. Urine release is controlled by two sphincters:
1. Internal urethral sphincter
a. Involuntary and made of smooth muscle
2. External urethral sphincter
a. Voluntary and made if skeletal muscles
iii. Gender differences
1. Length: females more likely to get bladder infections
a. Females is 3-4 cm (1 inch)
b. Males is 20 cm (8 inches)
2. Location
a. Female—along wall of the vagina
b. Male—through the prostate and penis
3. Function
a. Female—only carries urine
b. Male—carries urine and is a passageway for sperm cells
2. Micturition = peeing
a. Both sphincters muscles must open to allow voiding
b. Internal urethral sphincter sphincter is relaxed after stretching of the bladder
c. Pelvic nerves pelvic nerves initiate bladder to go into reflex contractions
d. Urine is forced past the internal urethra sphincter and the person feels the urge to void
e. External urethral sphincter must be voluntarily relaxed to void
3. Fluid, electrolyte, acid-base balance
a. Blood composition: depends on three factors:
i. Diet
ii. Cellular metabolism
iii. Urine output
iv. Four roles of kidneys in maintaining blood composition:
1. Excretion of nitrogen-containing wastes (previously discussed)
2. Maintain water balance of the blood
3. Maintain electrolyte balance of the blood
4. Ensure proper blood pH
b. Water balance
i. Normal amount in body by mass
1. Young adult female = 50%
2. Young adult male = 60%
3. Babies = 75%
4. The elderly = 45%
5. Universal solvent
ii. Distribution of body fluid
1. Intracellular (ICF)
a. Fluid inside cells
b. About two-thirds of body fluid
2. Extracellular (ECF)
a. Fluid outside cells
b. Interstitial fluid
c. Blood plasma
iii. Link between water and salt
1. Solutes in the body include electrolytes like sodium, potassium, and calcium ions
2. Changes in electrolyte balance causes water to move from one compartment to another (osmosis)
a. Alters blood volume and blood pressure
b. Impairs the activity of cells
iv. Water in = water out
1. Sources for water intake
a. Ingested foods and fluids
b. Water produced from metabolic processes (~10%)
c. Thirst mechanism is the driving force for water intake
2. Sources for water output
a. Vaporization out of the lungs
b. Lost in perspiration
c. Leaves the body in the feces
d. Urine production
3. Dilute urine is produced if water intake is excessive
4. Concentrated urine (less urine) is produced if large amounts of water are lost
5. Proper Electrolyte concentrations must be present
v. Regulation of water and electrolyte reabsorption
1. Osmoreceptors: (cells in the hypothalamus)
a. React to changes in blood composition by becoming more active
2. Hormones
a. ADH = Antidiuretic hormone
i. Prevents excessive water loss in urine
ii. Causes the kidney’s collecting ducts to reabsorb more water
iii. Alcohol suppresses ADH, causing urination
iv. Diabetes insipidus
1. When ADH is not released
2. Causes huge outputs of dilute urine
b. Aldosterone
i. From adrenal cortex
ii. Regulates sodium ion content of ECF
1. Sodium is the electrolyte most responsible for osmotic water flows
iii. Promotes reabsorption of sodium ions
1. Water follows salt
c. Rennin-angiotensin mechanism
i. Juxtaglomerular (JG) apparatus
1. Cells stimulated by
2. Rennin produces
3. Angiotensin II causes
4. Results in
c. Maintaining acid-base balance in blood
i. Blood pH between
1. Alkalosis =
2. Acidosis =
3. Physiological acidosis =
ii. Body acids
1. P , L, A
2. Carbon dioxide
3. Ammonia
4. Acid-base control systems/organs
a. Kidneys
b. Respiration
c. Blood buffers
i. Acids =
ii. Strong acids =
iii. Weak acids =
iv. Bases =
v. Strong bases =
vi. Weak bases =
vii. Action
1. Bind to H+
2. Release H+
viii. Three major systems
1. Protein
2. Phosphate
3. Bicarbonate
a. H2CO3 and NaHCO3
b. Carbonic acid
c. Bicarbonate ions
d. HCl + NaHCO3 H2CO3 + NaCl
4. Developmental aspects of the urinary system
a. Early life
i. Functional kidneys
ii. Newborn
1. Bladder
2. Urine
3. Void
iii. Young children
1. Control of voluntary sphincter
2. Nighttime control
3. Bladder infections
iv. Elderly
1. Bladder changes
2. Associated problems
a. Urgency
b. Frequency
c. Nocturia
d. Incontinence
e. Urinary retention
Part B
1. Urinary structures
a. Ureters
i. Slender tubes attach each kidney to the bladder
ii. Run from renal pelvis to the posterior aspect of the bladder
iii. Behind the peritoneum
iv. Peristalsis aids gravity in urine transport
b. Urinary bladder
i. Smooth, collapsible, muscular sac
ii. Temporary stores urine
iii. Trigone—triangular region of the bladder base
iv. Three openings
1. Two from the ureters
2. One to the urethra
v. In males, Prostate gland surrounds the neck of the bladder (and urethra)
vi. Bladder wall
1. Three layers of smooth muscle called Detrusor muscle
2. Mucosa made of transitional epithelium
3. Walls are thick and folded in an Empty bladder
4. Bladder expansion, bladder can expand significantly without increasing internal pressure
vii. Capacity
1. Moderately full bladder is about 5 inches long and holds about 500 mL of urine
2. Maximum of holding twice that amount of urine
c. Urethra
i. Thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis
ii. Urine release is controlled by two sphincters:
1. Internal urethral sphincter
a. Involuntary and made of smooth muscle
2. External urethral sphincter
a. Voluntary and made if skeletal muscles
iii. Gender differences
1. Length: females more likely to get bladder infections
a. Females is 3-4 cm (1 inch)
b. Males is 20 cm (8 inches)
2. Location
a. Female—along wall of the vagina
b. Male—through the prostate and penis
3. Function
a. Female—only carries urine
b. Male—carries urine and is a passageway for sperm cells
2. Micturition = peeing
a. Both sphincters muscles must open to allow voiding
b. Internal urethral sphincter sphincter is relaxed after stretching of the bladder
c. Pelvic nerves pelvic nerves initiate bladder to go into reflex contractions
d. Urine is forced past the internal urethra sphincter and the person feels the urge to void
e. External urethral sphincter must be voluntarily relaxed to void
3. Fluid, electrolyte, acid-base balance
a. Blood composition: depends on three factors:
i. Diet
ii. Cellular metabolism
iii. Urine output
iv. Four roles of kidneys in maintaining blood composition:
1. Excretion of nitrogen-containing wastes (previously discussed)
2. Maintain water balance of the blood
3. Maintain electrolyte balance of the blood
4. Ensure proper blood pH
b. Water balance
i. Normal amount in body by mass
1. Young adult female = 50%
2. Young adult male = 60%
3. Babies = 75%
4. The elderly = 45%
5. Universal solvent
ii. Distribution of body fluid
1. Intracellular (ICF)
a. Fluid inside cells
b. About two-thirds of body fluid
2. Extracellular (ECF)
a. Fluid outside cells
b. Interstitial fluid
c. Blood plasma
iii. Link between water and salt
1. Solutes in the body include electrolytes like sodium, potassium, and calcium ions
2. Changes in electrolyte balance causes water to move from one compartment to another (osmosis)
a. Alters blood volume and blood pressure
b. Impairs the activity of cells
iv. Water in = water out
1. Sources for water intake
a. Ingested foods and fluids
b. Water produced from metabolic processes (~10%)
c. Thirst mechanism is the driving force for water intake
2. Sources for water output
a. Vaporization out of the lungs
b. Lost in perspiration
c. Leaves the body in the feces
d. Urine production
3. Dilute urine is produced if water intake is excessive
4. Concentrated urine (less urine) is produced if large amounts of water are lost
5. Proper Electrolyte concentrations must be present
v. Regulation of water and electrolyte reabsorption
1. Osmoreceptors: (cells in the hypothalamus)
a. React to changes in blood composition by becoming more active
2. Hormones
a. ADH = Antidiuretic hormone
i. Prevents excessive water loss in urine
ii. Causes the kidney’s collecting ducts to reabsorb more water
iii. Alcohol suppresses ADH, causing urination
iv. Diabetes insipidus
1. When ADH is not released
2. Causes huge outputs of dilute urine
b. Aldosterone
i. From adrenal cortex
ii. Regulates sodium ion content of ECF
1. Sodium is the electrolyte most responsible for osmotic water flows
iii. Promotes reabsorption of sodium ions
1. Water follows salt
c. Rennin-angiotensin mechanism
i. Juxtaglomerular (JG) apparatus
1. Cells stimulated by
2. Rennin produces
3. Angiotensin II causes
4. Results in
c. Maintaining acid-base balance in blood
i. Blood pH between
1. Alkalosis =
2. Acidosis =
3. Physiological acidosis =
ii. Body acids
1. P , L, A
2. Carbon dioxide
3. Ammonia
4. Acid-base control systems/organs
a. Kidneys
b. Respiration
c. Blood buffers
i. Acids =
ii. Strong acids =
iii. Weak acids =
iv. Bases =
v. Strong bases =
vi. Weak bases =
vii. Action
1. Bind to H+
2. Release H+
viii. Three major systems
1. Protein
2. Phosphate
3. Bicarbonate
a. H2CO3 and NaHCO3
b. Carbonic acid
c. Bicarbonate ions
d. HCl + NaHCO3 H2CO3 + NaCl
4. Developmental aspects of the urinary system
a. Early life
i. Functional kidneys
ii. Newborn
1. Bladder
2. Urine
3. Void
iii. Young children
1. Control of voluntary sphincter
2. Nighttime control
3. Bladder infections
iv. Elderly
1. Bladder changes
2. Associated problems
a. Urgency
b. Frequency
c. Nocturia
d. Incontinence
e. Urinary retention
Chapter 15, Urinary System, Part A
Chapter 15: Urinary System
Part A: Kidneys & Urine
1. Functions of the urinary system
a. Elimination of waste products:
i. Nitrogenous wastes: urea, uric acid, ammonia
ii. Toxins—harmful or fatal in small doses
iii. Drugs—have specific and significant effects on the cells
b. Regulate aspects of homeostasis
i. Water balance—osmosis
ii. Electrolytes: ions such as Na, Ca, Mg, Cl
iii. Acid-base balance in the blood
iv. BP = blood pressure
v. RBC = red blood cell production
vi. Activation of vitamin D
2. Organs of the system
a. Kidneys—where blood is actively processed
i. Renal=kidney
b. Ureters—tubes draining kidneys
c. Urinary bladder—urine storage
d. Urethra—from bladder to exterior of body
3. Kidneys
a. Location
i. Retroperitoneal = against the dorsal body wall
ii. Level of the T12 to L3 vertebrae
iii. Right kidney is slightly lower than the left (due to the position of the liver)
b. Features
i. Shape
ii. Renal hilum—a medical indentation where several structures enter or exit the kidney (ureters, renal blood vessels, and nerves)
iii. Adrenal gland sits atop each kidney
c. Coverings
i. Fibrous capsule
• Surrounds each kidney—connective tissue
ii. Perirenal fat capsule
• Surrounds the kidney and cushions against blows
iii. Renal fascia
• Outermost capsule that helps hold the kidney in place against the muscles of the trunk wall
d. Anatomical regions – renal:
i. Cortex—outer region
ii. Medulla—inside the cortex
iii. Pelvis—inner collecting tube, like a funnel
e. Internal structures
i. Renal or medullary pyramids—triangular regions of tissue in the medulla
ii. Renal columns—extensions of cortex-like material inward that separates the pyramids
iii. Renal calyces (calyx)—cup-shaped structures that funnel urine towards the renal pelvis
f. Blood supply
i. 25% of the total blood supply of the body passes through the kidneys each minute
ii. Renal artery provides each kidney with arterial blood supply
iii. Arterioles and capillary beds – details below
• Renal artery divides
4. Nephrons
a. Structural and functional units of the kidneys
b. Over a million in each kidney
c. Responsible for forming urine
d. Main structures of the nephrons:
i. Glomerulus—ball of capillaries
ii. Renal tubule—kidney filtering tubes
e. Anatomy (Glomerulus)
i. Knot of capillaries
ii. Capillaries are covered with Podocytes from the renal tube
iii. Glomerulus sits within a glomerular (Bowman’s) capsule (the first part of the renal tubule)
iv. Renal tubule extends from glomerular capsule and ends at the collecting duct:
• Glomerular (Bowman’s) capsule
• Proximal convoluted tubule (PCT)
• Loop of Henle—deep into medulla
• Distal convoluted tubule (DCT)
f. Types
i. Cortical nephrons
• Located entirely in the cortext
• Includes most nephrons
ii. Juxtamedullary nephrons
• Found at the boundary of the cortex and medulla
• Extend deeper into kidney
g. Collecting ducts
i. Receives urine from many nephrons
ii. Runs through the medullary pyramids
iii. Delivers urine into the calyces and renal pelvis
h. Capillary beds (2 sets)
i. Glomerulus
• Arterioles leading in and out
a. Afferent arteriole—comes in
b. Efferent arteriole—goes out
• Specialized for filtration
• High pressure forces fluid and solutes out of blood and into the glomerular capsule
ii. Peritubular
• Arise from efferent arteriole of the glomerulus
• Normal, low Pressure capillaries
• Adapted for absorption instead of filtration
• Cling close to the renal tubule
5. Urine formation
a. Glomerular filtration
i. Nonselective passive process
ii. Water and solutes smaller than proteins are forced through capillary walls
iii. Proteins and blood cells are normally too large to pass through the filtration membrane
iv. Filtrate is collected in the glomerular capsule and leaves via the renal tubule
b. Tubular reabsorption
i. Peritubular capillaries reabsorb useful substances:
• Water
• Glucose
• Amino Acids
• Ions
ii. Some reabsorption is passive, most is active
iii. Most reabsorption occurs in the proximal convoluted tubule
iv. Materials not reabsorbed
• Nitrogenous waste products:
a. Urea—protein breakdown
b. Uric acid—nucleic acid breakdown
c. Creatinine—associated with creatine metabolism in muscles
c. Tubular secretion = reabsorption in reverse
i. Movement from the peritubular capillaries into the renal tubules
ii. Examples
• Hydrogen and potassium ions
• Creatinine
• H+, K+, creatinine, drugs, pH control
iii. Materials left in the renal tubule move toward the ureter
d. Urine
i. Characteristics
• Yellow color due to the pigment urochrom (from the destruction of hemoglobin) and solutes
a. Concentration
• Odor—slightly aromatic
• Sterile—kills many bacteria becase
• Normal pH of around 6
• Specific gravity = density
a. 1.001 to 1.035
• Normal production in 24 hours, about 1.0 to 1.8 liters of urine are produced
• Urine vs. filtrate
a. Filtrate = contains everything that blood plasma does (except proteins)
b. Urine = is what remains after the filotrate has lost most of its water, nutrients, and necessary ions.
ii. Contains substances less valuable or harmful to the body:
• Nitrogenous wastes
iii. Does not contain things that are valuable or are too large to diffuse through membranes:
Part A: Kidneys & Urine
1. Functions of the urinary system
a. Elimination of waste products:
i. Nitrogenous wastes: urea, uric acid, ammonia
ii. Toxins—harmful or fatal in small doses
iii. Drugs—have specific and significant effects on the cells
b. Regulate aspects of homeostasis
i. Water balance—osmosis
ii. Electrolytes: ions such as Na, Ca, Mg, Cl
iii. Acid-base balance in the blood
iv. BP = blood pressure
v. RBC = red blood cell production
vi. Activation of vitamin D
2. Organs of the system
a. Kidneys—where blood is actively processed
i. Renal=kidney
b. Ureters—tubes draining kidneys
c. Urinary bladder—urine storage
d. Urethra—from bladder to exterior of body
3. Kidneys
a. Location
i. Retroperitoneal = against the dorsal body wall
ii. Level of the T12 to L3 vertebrae
iii. Right kidney is slightly lower than the left (due to the position of the liver)
b. Features
i. Shape
ii. Renal hilum—a medical indentation where several structures enter or exit the kidney (ureters, renal blood vessels, and nerves)
iii. Adrenal gland sits atop each kidney
c. Coverings
i. Fibrous capsule
• Surrounds each kidney—connective tissue
ii. Perirenal fat capsule
• Surrounds the kidney and cushions against blows
iii. Renal fascia
• Outermost capsule that helps hold the kidney in place against the muscles of the trunk wall
d. Anatomical regions – renal:
i. Cortex—outer region
ii. Medulla—inside the cortex
iii. Pelvis—inner collecting tube, like a funnel
e. Internal structures
i. Renal or medullary pyramids—triangular regions of tissue in the medulla
ii. Renal columns—extensions of cortex-like material inward that separates the pyramids
iii. Renal calyces (calyx)—cup-shaped structures that funnel urine towards the renal pelvis
f. Blood supply
i. 25% of the total blood supply of the body passes through the kidneys each minute
ii. Renal artery provides each kidney with arterial blood supply
iii. Arterioles and capillary beds – details below
• Renal artery divides
4. Nephrons
a. Structural and functional units of the kidneys
b. Over a million in each kidney
c. Responsible for forming urine
d. Main structures of the nephrons:
i. Glomerulus—ball of capillaries
ii. Renal tubule—kidney filtering tubes
e. Anatomy (Glomerulus)
i. Knot of capillaries
ii. Capillaries are covered with Podocytes from the renal tube
iii. Glomerulus sits within a glomerular (Bowman’s) capsule (the first part of the renal tubule)
iv. Renal tubule extends from glomerular capsule and ends at the collecting duct:
• Glomerular (Bowman’s) capsule
• Proximal convoluted tubule (PCT)
• Loop of Henle—deep into medulla
• Distal convoluted tubule (DCT)
f. Types
i. Cortical nephrons
• Located entirely in the cortext
• Includes most nephrons
ii. Juxtamedullary nephrons
• Found at the boundary of the cortex and medulla
• Extend deeper into kidney
g. Collecting ducts
i. Receives urine from many nephrons
ii. Runs through the medullary pyramids
iii. Delivers urine into the calyces and renal pelvis
h. Capillary beds (2 sets)
i. Glomerulus
• Arterioles leading in and out
a. Afferent arteriole—comes in
b. Efferent arteriole—goes out
• Specialized for filtration
• High pressure forces fluid and solutes out of blood and into the glomerular capsule
ii. Peritubular
• Arise from efferent arteriole of the glomerulus
• Normal, low Pressure capillaries
• Adapted for absorption instead of filtration
• Cling close to the renal tubule
5. Urine formation
a. Glomerular filtration
i. Nonselective passive process
ii. Water and solutes smaller than proteins are forced through capillary walls
iii. Proteins and blood cells are normally too large to pass through the filtration membrane
iv. Filtrate is collected in the glomerular capsule and leaves via the renal tubule
b. Tubular reabsorption
i. Peritubular capillaries reabsorb useful substances:
• Water
• Glucose
• Amino Acids
• Ions
ii. Some reabsorption is passive, most is active
iii. Most reabsorption occurs in the proximal convoluted tubule
iv. Materials not reabsorbed
• Nitrogenous waste products:
a. Urea—protein breakdown
b. Uric acid—nucleic acid breakdown
c. Creatinine—associated with creatine metabolism in muscles
c. Tubular secretion = reabsorption in reverse
i. Movement from the peritubular capillaries into the renal tubules
ii. Examples
• Hydrogen and potassium ions
• Creatinine
• H+, K+, creatinine, drugs, pH control
iii. Materials left in the renal tubule move toward the ureter
d. Urine
i. Characteristics
• Yellow color due to the pigment urochrom (from the destruction of hemoglobin) and solutes
a. Concentration
• Odor—slightly aromatic
• Sterile—kills many bacteria becase
• Normal pH of around 6
• Specific gravity = density
a. 1.001 to 1.035
• Normal production in 24 hours, about 1.0 to 1.8 liters of urine are produced
• Urine vs. filtrate
a. Filtrate = contains everything that blood plasma does (except proteins)
b. Urine = is what remains after the filotrate has lost most of its water, nutrients, and necessary ions.
ii. Contains substances less valuable or harmful to the body:
• Nitrogenous wastes
iii. Does not contain things that are valuable or are too large to diffuse through membranes:
Chapter 14, Digestive System, Part B
Chapter 14: Digestive System & Nutrition: Part B
1. Accessory organs
a. Teeth
b. Salivary glands
c. Pancreas
d. Liver
e. Gall bladder
2. Teeth classification
a. Incisors - cutting
b. Canines – tearing or piercing
c. Premolars - grinding
d. Molars - grinding
3. Salivary glands – three pairs of salivary glands empty secretions into the mouth:
a. Parotid glands – largest, near ear
b. Submandibular glands – under jaw
c. Sublingual glands – under tongue
d. Saliva
i. Mixture of mucus and serous fluids
1. Mucus
2. Serous
ii. Helps to form a food bolus
iii. Contains salivary amylases to begin starch digestion
iv. Dissolves chemicals so they can be tasted
4. Deglutition = swallowing
a. Buccal phase
i. Voluntary
ii. Occurs in the mouth
iii. Food is formed into a bolus
iv. The bolus is forced into the pharynx by the tongue
b. Pharyngeal-esophageal phase
i. Involuntary transport of the bolus
ii. Passageways blocked (except to the stomach)
iii. Tongue blocks off the mouth
iv. Soft palate (uvula) blocks the nasopharynx
v. Epiglottis blocks the larynx
vi. Peristalsis moves the bolus towards the stomach
vii. Cardio-esophageal sphincter
5. Pancreas
a. Posterior to the parietal peritoneum
b. Extends across the abdomen from the spleen to the duodenum
c. Produces a wide spectrum of digestive enzymes that break down all categories of food
d. Enzymes are secreted into the duodenum
e. Alkaline fluid (basic) introduced with enzymes neutralizes acidic chime coming from stomach
f. Hormones produced by the pancreas:
i. Insulin – lower blood sugar; sugar into cells
ii. Glucagon – raises blood sugar; liver; glycogen
6. Liver
a. Size – largest gland in the body
b. Location – located on the right side of the body under the diaphragm
c. Consists of four lobes suspended from the diaphragm and abdominal wall
d. Connected to the gallbladder via the common hepatic duct
e. Produces bile
i. Salts
ii. Pigments
iii. Function
7. Gall bladder
a. Structure & location
i. Sac found in hollow fossa of liver
b. When no digestion is occurring, bile backs up the cystic duct for storage in the gallbladder.
c. When digestion of fatty food is occurring, bile is introduced into the duodenum from the gallbladder
d. Gallstones are crystallized cholesterol which can cause blockages
8. Functions to accomplish digestion
a. Ingestion—getting food into the mouth
b. Propulsion—moving foods from one region of the digestive system to another
c. Peristalsis—alternating waves of contraction and relaxation that squeezes food along the GI (gastro intestinal) tract
d. Segmentation—moving materials back and forth to aid with mixing in the small intestine
e. Food breakdown as Mechanical digestion
i. Examples:
1. Mixing food in the mouth by the tongue
2. Churning food in the stomach
3. Segmentation in the small intestine
4. Mechanical digestion exposes surface area of food for further breakdown by enzymes
f. Chemical digestion
i. Enzymes break down food molecules into their building blocks
ii. Each major food group uses different enzymes:
1. Carbohydrates are broken to simple sugars
2. Proteins are broken to amino acids
3. Lipids are broken to fatty acids and alcohols
g. Absorption
i. End products of digestion are absorbed in the blood or lymph capillaries (thin walls)
h. Defecation
i. Elimination of indigestible substances from the GI tract in the form of feces
ii. Also: bacteria, bile pigments
9. Nutrition
a. Nutrients (food)—substance used by the body for growth, maintenance, and repair
i. Major nutrients
1. Carbohydrates: sugars, starches: energy
2. Lipids: fats, oils, waxes: energy, structure
3. Proteins: energy, structure, enzymes
4. Water : no energy, body solvent
ii. Minor nutrients
1. Vitamins: coenzymes, metaabolism
2. Minerals: inorganic, assist physiology, anatomy
b. USDA food guide pyramid
1. Accessory organs
a. Teeth
b. Salivary glands
c. Pancreas
d. Liver
e. Gall bladder
2. Teeth classification
a. Incisors - cutting
b. Canines – tearing or piercing
c. Premolars - grinding
d. Molars - grinding
3. Salivary glands – three pairs of salivary glands empty secretions into the mouth:
a. Parotid glands – largest, near ear
b. Submandibular glands – under jaw
c. Sublingual glands – under tongue
d. Saliva
i. Mixture of mucus and serous fluids
1. Mucus
2. Serous
ii. Helps to form a food bolus
iii. Contains salivary amylases to begin starch digestion
iv. Dissolves chemicals so they can be tasted
4. Deglutition = swallowing
a. Buccal phase
i. Voluntary
ii. Occurs in the mouth
iii. Food is formed into a bolus
iv. The bolus is forced into the pharynx by the tongue
b. Pharyngeal-esophageal phase
i. Involuntary transport of the bolus
ii. Passageways blocked (except to the stomach)
iii. Tongue blocks off the mouth
iv. Soft palate (uvula) blocks the nasopharynx
v. Epiglottis blocks the larynx
vi. Peristalsis moves the bolus towards the stomach
vii. Cardio-esophageal sphincter
5. Pancreas
a. Posterior to the parietal peritoneum
b. Extends across the abdomen from the spleen to the duodenum
c. Produces a wide spectrum of digestive enzymes that break down all categories of food
d. Enzymes are secreted into the duodenum
e. Alkaline fluid (basic) introduced with enzymes neutralizes acidic chime coming from stomach
f. Hormones produced by the pancreas:
i. Insulin – lower blood sugar; sugar into cells
ii. Glucagon – raises blood sugar; liver; glycogen
6. Liver
a. Size – largest gland in the body
b. Location – located on the right side of the body under the diaphragm
c. Consists of four lobes suspended from the diaphragm and abdominal wall
d. Connected to the gallbladder via the common hepatic duct
e. Produces bile
i. Salts
ii. Pigments
iii. Function
7. Gall bladder
a. Structure & location
i. Sac found in hollow fossa of liver
b. When no digestion is occurring, bile backs up the cystic duct for storage in the gallbladder.
c. When digestion of fatty food is occurring, bile is introduced into the duodenum from the gallbladder
d. Gallstones are crystallized cholesterol which can cause blockages
8. Functions to accomplish digestion
a. Ingestion—getting food into the mouth
b. Propulsion—moving foods from one region of the digestive system to another
c. Peristalsis—alternating waves of contraction and relaxation that squeezes food along the GI (gastro intestinal) tract
d. Segmentation—moving materials back and forth to aid with mixing in the small intestine
e. Food breakdown as Mechanical digestion
i. Examples:
1. Mixing food in the mouth by the tongue
2. Churning food in the stomach
3. Segmentation in the small intestine
4. Mechanical digestion exposes surface area of food for further breakdown by enzymes
f. Chemical digestion
i. Enzymes break down food molecules into their building blocks
ii. Each major food group uses different enzymes:
1. Carbohydrates are broken to simple sugars
2. Proteins are broken to amino acids
3. Lipids are broken to fatty acids and alcohols
g. Absorption
i. End products of digestion are absorbed in the blood or lymph capillaries (thin walls)
h. Defecation
i. Elimination of indigestible substances from the GI tract in the form of feces
ii. Also: bacteria, bile pigments
9. Nutrition
a. Nutrients (food)—substance used by the body for growth, maintenance, and repair
i. Major nutrients
1. Carbohydrates: sugars, starches: energy
2. Lipids: fats, oils, waxes: energy, structure
3. Proteins: energy, structure, enzymes
4. Water : no energy, body solvent
ii. Minor nutrients
1. Vitamins: coenzymes, metaabolism
2. Minerals: inorganic, assist physiology, anatomy
b. USDA food guide pyramid
Chapter 14, Digestive System, Part A
Chapter 14: Digestive System
1. System functions:
a. Ingestion – taking in food
b. Digestion – breaking down food both physically and chemically
c. Absorption – movement of nutrients into the bloodstream
d. Defecation – rids the body of indigestible waste
2. Two groups of organs:
a. Alimentary canal – (gastrointestinal or GI tract): continuous coiled hollow tube
i. Mouth
ii. Pharynx (throat)
iii. Esophagus (long tube)
iv. Stomach
v. Small intestine (small in width)
vi. Large intestine (large in diameter)
vii. Anus
b. Accessory organs – branches off of alimentary canal
i. Salivary glands
ii. Pancreas
iii. Liver
iv. Gall bladder
3. Mouth – oral cavity
a. Anatomy
i. Lips (labia) – protect the anterior opening
ii. Cheeks – form the lateral walls
iii. Hard palate – forms anterior roof
iv. Soft palate – forms posterior roof
v. Uvula – fleshy projection of the soft palate
vi. Vestibule – space between lips and externally and teeth and gums internally
vii. Oral cavity proper – area contained by the teeth
viii. Tongue – attached at hyoid bone and styloid processes of the skull, and by the lingual frenulum to the floor of the mouth
ix. Tonsils – bacteria filters
1. Palatine – on palate
2. Lingual – base of tongue
b. Physiology
i. Mastication – (chewing) of food
ii. Mixing masticated food with liquid
iii. Tongue
1. Initiation of swallowing by the tongue
2. Allows for the sense of taste- function?
4. Pharynx = throat
a. Where food is propelled to
b. Anatomy
i. Nasopharynx – not part of the digestive system
ii. Oropharynx – posterior to oral cavity
iii. Laryngopharynx- below the oropharynx and connected to esophagus
c. Physiology
i. Mixed passageway: serves as a passageway for air and food
ii. Food movement is propelled to the esophagus by two muscle layers
1. Circular layer (outer layer)
2. Longitudinal inner layer
3. Peristalsis: food movement is by alternating contractions of the muscle layers
5. Esophagus
a. Anatomy
i. Length
ii. Runs from
b. Physiology
i. Peristalsis
ii. Food only
6. Common structure of alimentary canal organs
a. Four layers
i. Mucosa (innermost layer)
- Moist membrane consisting of
1. Surface epithelium- for absorption or secretion
2. Small amounts of connective tissue
3. Small smooth muscle layer
ii. Submucosa
- Just beneath the mucosa
- Soft connective tissue with blood vessels, nerve endings, glands, and lymphatics
iii. Muscularis externa- smooth muscle
- Inner circular layer
- Outer longitudinal layer
iv. Serosa- outermost layer of the wall contains fluid-producing cells:
1. Visceral peritoneum- outermost layer that is continuous with the innermost layer
2. Parietal peritoneum- innermost layer that lines the abdominopelvic cavity
7. Nervous system control
a. Two divisions of the autonomic nervous system serves the alimentary canal (autonomic nervous system)
- Function is to regulate mobility and secretory activity of the GI tract organs in coordinated way
i. Submucosal nerve plexus
ii. Myenteric nerve plexus
8. Stomach
a. Anatomy
i. Located on the left side of the abdominal cavity
ii. Cardioesophageal sphincter (where food enters)
iii. Pyloric sphincter (where food empties into the small intestine)
iv. Regions
1. Cardiac – near the heart
2. Fundus – expanded portion lateral to the cardiac region
3. Body - midportion
4. Pylorus – funnel-shaped terminal end
5. Rugae – internal folds of the mucosa
6. External
a. Greater curvature – convex lateral surface
b. Lesser curvature – concave medial surface
7. Peritoneum attachment: layers of peritoneum attached to the stomach:
a. Lesser omentum – attaches the liver to the lesser curvature
b. Greater omentum – attaches the greater curvature to the posterior body wall:
i. Contains fat to insulate, cushion, and protect abdominal organs
ii. Has lymph nodules containing macrophages
b. Physiology
i. Food & water storage
1. Temporary storage tank for food (1-3 hours)
ii. Site of Water and some chemical absorption
iii. Mechanical digestion – food mixed and churned
iv. Chemical digestion – breakdown of protein begins
1. Stomach mucosa
v. Delivers Chyme (processed food) to the small intestine
c. Stomach mucosa
i. Mucosa structure: is simple columnar epithelium
ii. Mucous neck cells – produce a sticky alkaline mucus
iii. Gastric glands – situated in gastric pits and secrete gastric juice
1. Chief cells – produce protein-digesting enzymes (pepsinogen pepsin)
2. Parietal cells – produce hydrochloric acid
3. Enteroendocrine cells – produce (hormone) gastrin
9. Small intestine
a. Overview
i. Body’s main organ for
ii. Site of
iii. Muscular tube
iv. Suspended from posterior abdominal wall
b. Subdivisions
i. Duodenum
ii. Jejunum
iii. Ileum
c. Chemical digestion – enzymes from:
i. Intestinal glands
ii. Pancreas
iii. Liver/gall bladder
d. Surface area increase mainly for absorption
e. Three structural modifications that increase surface area:
i. Villi (villus) – fingerlike structures formed by the mucosa
1. Capillaries & lacteals – for absorption (absorb food)
ii. Microvilli – tiny projections of the plasma membrane (create a brush borer appearance
iii. Plicae circulares (circular folds) – deep folds of mucosa and submucosa
10. Large intestine
a. Anatomy
i. Large = in diameter, but shorter min length, than the small intestine
ii. Frames the internal abdomen
iii. No villi present – absorb water through walls
iv. Goblet cells produce alkaline mucus which lubricates the passage of feces
v. Muscularis externa = teniae coli (three bands of muscle)
1. These bands cause the wall to pucker into haustra (pocket-like sacs)
vi. Two common problems
1. Diarrhea – food moves through too fast
2. Constipation – food moves through too slowly
b. Cecum – saclike first part of the large intestine
c. Appendix – no real function (vestigial):
i. Hangs from the cecum
ii. Accumulation of lymphatic tissue that sometimes becomes inflamed (appendicitis)
iii. Vestigial
iv. Location
v. Fatty tissue
d. Colon
i. Ascending – travels up the right side of the abdomen
ii. Transverse – travels across the abdominal cavity
iii. Descending – travels down the left side
iv. Sigmoid – enters the pelvis
e. Rectum – where feces is stored
f. Anus – opening of the large intestine:
i. External anal sphincter – skeletal muscle (voluntary control)
ii. Internal anal sphincter – formed by smooth muscle (involuntary)
iii. These sphincters are normally closed except during defecation
1. System functions:
a. Ingestion – taking in food
b. Digestion – breaking down food both physically and chemically
c. Absorption – movement of nutrients into the bloodstream
d. Defecation – rids the body of indigestible waste
2. Two groups of organs:
a. Alimentary canal – (gastrointestinal or GI tract): continuous coiled hollow tube
i. Mouth
ii. Pharynx (throat)
iii. Esophagus (long tube)
iv. Stomach
v. Small intestine (small in width)
vi. Large intestine (large in diameter)
vii. Anus
b. Accessory organs – branches off of alimentary canal
i. Salivary glands
ii. Pancreas
iii. Liver
iv. Gall bladder
3. Mouth – oral cavity
a. Anatomy
i. Lips (labia) – protect the anterior opening
ii. Cheeks – form the lateral walls
iii. Hard palate – forms anterior roof
iv. Soft palate – forms posterior roof
v. Uvula – fleshy projection of the soft palate
vi. Vestibule – space between lips and externally and teeth and gums internally
vii. Oral cavity proper – area contained by the teeth
viii. Tongue – attached at hyoid bone and styloid processes of the skull, and by the lingual frenulum to the floor of the mouth
ix. Tonsils – bacteria filters
1. Palatine – on palate
2. Lingual – base of tongue
b. Physiology
i. Mastication – (chewing) of food
ii. Mixing masticated food with liquid
iii. Tongue
1. Initiation of swallowing by the tongue
2. Allows for the sense of taste- function?
4. Pharynx = throat
a. Where food is propelled to
b. Anatomy
i. Nasopharynx – not part of the digestive system
ii. Oropharynx – posterior to oral cavity
iii. Laryngopharynx- below the oropharynx and connected to esophagus
c. Physiology
i. Mixed passageway: serves as a passageway for air and food
ii. Food movement is propelled to the esophagus by two muscle layers
1. Circular layer (outer layer)
2. Longitudinal inner layer
3. Peristalsis: food movement is by alternating contractions of the muscle layers
5. Esophagus
a. Anatomy
i. Length
ii. Runs from
b. Physiology
i. Peristalsis
ii. Food only
6. Common structure of alimentary canal organs
a. Four layers
i. Mucosa (innermost layer)
- Moist membrane consisting of
1. Surface epithelium- for absorption or secretion
2. Small amounts of connective tissue
3. Small smooth muscle layer
ii. Submucosa
- Just beneath the mucosa
- Soft connective tissue with blood vessels, nerve endings, glands, and lymphatics
iii. Muscularis externa- smooth muscle
- Inner circular layer
- Outer longitudinal layer
iv. Serosa- outermost layer of the wall contains fluid-producing cells:
1. Visceral peritoneum- outermost layer that is continuous with the innermost layer
2. Parietal peritoneum- innermost layer that lines the abdominopelvic cavity
7. Nervous system control
a. Two divisions of the autonomic nervous system serves the alimentary canal (autonomic nervous system)
- Function is to regulate mobility and secretory activity of the GI tract organs in coordinated way
i. Submucosal nerve plexus
ii. Myenteric nerve plexus
8. Stomach
a. Anatomy
i. Located on the left side of the abdominal cavity
ii. Cardioesophageal sphincter (where food enters)
iii. Pyloric sphincter (where food empties into the small intestine)
iv. Regions
1. Cardiac – near the heart
2. Fundus – expanded portion lateral to the cardiac region
3. Body - midportion
4. Pylorus – funnel-shaped terminal end
5. Rugae – internal folds of the mucosa
6. External
a. Greater curvature – convex lateral surface
b. Lesser curvature – concave medial surface
7. Peritoneum attachment: layers of peritoneum attached to the stomach:
a. Lesser omentum – attaches the liver to the lesser curvature
b. Greater omentum – attaches the greater curvature to the posterior body wall:
i. Contains fat to insulate, cushion, and protect abdominal organs
ii. Has lymph nodules containing macrophages
b. Physiology
i. Food & water storage
1. Temporary storage tank for food (1-3 hours)
ii. Site of Water and some chemical absorption
iii. Mechanical digestion – food mixed and churned
iv. Chemical digestion – breakdown of protein begins
1. Stomach mucosa
v. Delivers Chyme (processed food) to the small intestine
c. Stomach mucosa
i. Mucosa structure: is simple columnar epithelium
ii. Mucous neck cells – produce a sticky alkaline mucus
iii. Gastric glands – situated in gastric pits and secrete gastric juice
1. Chief cells – produce protein-digesting enzymes (pepsinogen pepsin)
2. Parietal cells – produce hydrochloric acid
3. Enteroendocrine cells – produce (hormone) gastrin
9. Small intestine
a. Overview
i. Body’s main organ for
ii. Site of
iii. Muscular tube
iv. Suspended from posterior abdominal wall
b. Subdivisions
i. Duodenum
ii. Jejunum
iii. Ileum
c. Chemical digestion – enzymes from:
i. Intestinal glands
ii. Pancreas
iii. Liver/gall bladder
d. Surface area increase mainly for absorption
e. Three structural modifications that increase surface area:
i. Villi (villus) – fingerlike structures formed by the mucosa
1. Capillaries & lacteals – for absorption (absorb food)
ii. Microvilli – tiny projections of the plasma membrane (create a brush borer appearance
iii. Plicae circulares (circular folds) – deep folds of mucosa and submucosa
10. Large intestine
a. Anatomy
i. Large = in diameter, but shorter min length, than the small intestine
ii. Frames the internal abdomen
iii. No villi present – absorb water through walls
iv. Goblet cells produce alkaline mucus which lubricates the passage of feces
v. Muscularis externa = teniae coli (three bands of muscle)
1. These bands cause the wall to pucker into haustra (pocket-like sacs)
vi. Two common problems
1. Diarrhea – food moves through too fast
2. Constipation – food moves through too slowly
b. Cecum – saclike first part of the large intestine
c. Appendix – no real function (vestigial):
i. Hangs from the cecum
ii. Accumulation of lymphatic tissue that sometimes becomes inflamed (appendicitis)
iii. Vestigial
iv. Location
v. Fatty tissue
d. Colon
i. Ascending – travels up the right side of the abdomen
ii. Transverse – travels across the abdominal cavity
iii. Descending – travels down the left side
iv. Sigmoid – enters the pelvis
e. Rectum – where feces is stored
f. Anus – opening of the large intestine:
i. External anal sphincter – skeletal muscle (voluntary control)
ii. Internal anal sphincter – formed by smooth muscle (involuntary)
iii. These sphincters are normally closed except during defecation
Subscribe to:
Posts (Atom)