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Homeostasis-Lecture 4 and 5 part 3

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winniesmith1's version from 2017-05-01 15:06

Section 1

Question Answer
Where does reabsorption occurin the proximal convoluted tubule
How is the yellow colour madepigment urobilin.
How is urobilin generatedin the kidneys from urobilinogens
What is the pH of normal urine4.5-8 (Average 6.0)
Specific gravity of normal urine1.003-1.030 same as water
Osmotic concentration of water855-1335 mOsm/L
What is the water content of normal urine93- 97%
What is the volume of normal urine700-2000 mL/day
What is the colour/odor of normal urineclear yellow/ varies with composition
What is the bacterial content of normal urinenone (sterile)??? incorrect?
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Section 2

Question Answer
What is the goal of urine productionTo maintain homeostasis: a) By regulating volume and composition of blood. b) Including excretion of metabolic waste products
Structures involved in urine transportMinor and major calyces, renal pelvis, ureters, urinary bladder, and the proximal portion of urethra (lined by transitional epithelium that undergoes cycles of distention and contraction). Urine is transported via the ureters, stored in the bladder, and eliminated through the urethra, aided by the micturiotion reflex.
Describe the uretersAre a pair of muscular tubes. Extend from kidneys to urinary bladder. Begin at renal pelvis. Pass over psoas major muscles. Are retroperitoneal, attached to posterior abdominal wall. Penetrate posterior wall of the urinary bladder . Pass through bladder wall at oblique angle. Shape helps prevent backflow of urine when urinary bladder contracts.
Describe the peristaltic contractionsBegin at renal pelvis, Sweep along ureter, Force urine toward urinary bladder, Every 30 seconds.
Describe the urinary bladder Is a hollow, muscular organ. Functions as temporary reservoir for urine storage. Full bladder can contain 1 liter of urine.
Describe the urethraExtends from the neck of urinary bladder, To the exterior of the body.
Describe the male urethraExtends from neck of urinary bladder to tip of penis (18–20 cm; 7-8 in.) . Prostatic urethra passes through center of prostate gland. Membranous urethra includes short segment that penetrates the urogenital diaphragm. Spongy urethra (penile urethra) extends from urogenital diaphragm to external urethral orifice.
Describe the female urethraIs very short (3–5 cm; 1-2 in.). Extends from bladder to vestibule. External urethral orifice is near the anterior wall of vagina.
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Section 3

Question Answer
(Micturition reflex & urination) What happens as the bladder fills with urineStretch receptors in urinary bladder stimulate sensory fibers in pelvic nerve. Stimulus travels from afferent fibers in pelvic nerves to sacral spinal cord.
(In micturition reflex & urination) What do efferent fibers in the pelvic nerves dostimulate ganglionic neurons in wall of bladder.
(In micturition reflex & urination) What do the postganglionic neuron in intramural ganglion stimulatedetrusor muscle contractions. The interneuron then relays sensation to thalamus.Projection fibers from thalamus deliver sensation to cerebral cortex. Voluntary relaxation of external urethral sphincter causes relaxation of internal urethral sphincter.
What begins the micturition reflexBegins when stretch receptors stimulate parasympathetic preganglionic motor neurons. Volume >500 mL triggers micturition reflex.
Which systems does the excretory system includeUrinary, integumentary, respiratory and digestive systems. All systems with excretory functions that affect body fluid composition.
Re cap powerpoint16PSA212 Urinary system (photos/diagrams may help)
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