Ch 10- Excretory & Skin Flashcards
“As is the case in other portal systems, the efferent arterioles then form a second capillary bed. These capillaries surround the loop of Henle and are known as
vasa recta
“Around the glomerulus is a cuplike structure known as
Bowman’s capsule”
Order of the tubules of the nephron
“proximal convoluted tubule, descending and ascending limbs of the Loop of Henle, the distal convoluted tubule, and the collecting duct.”
“The bladder has a muscular lining known as the
detrusor muscle
___________ activity causes the detrusor muscle to contract.”
Parasympathetic
“The internal urethral sphincter, consisting of smooth muscle, is contracted in its normal state. Because the internal sphincter is made of smooth muscle, it is under _________ control. The external urethral sphincter consists of skeletal muscle and is under ________ control. ”
Involuntary, Voluntary
What is the micturition reflex
“When the bladder is full, stretch receptors convey to the nervous system that the bladder requires emptying. This causes parasympathetic neurons to fire, and the detrusor muscle contracts. This contraction also causes the internal sphincter to relax.
“kidney function may be divided into the three different processes:
filtration, secretion, and reabsorption.
“The movement of fluid into Bowman’s space is governed by ________, which account for the pressure differentials in both hydrostatic and oncotic pressures between the blood and Bowman’s space”
Starling Forces
“The filtrate of bowman capsule is ________ to blood so that neither the capsule nor the capillaries swell”
isotonic
“ If blood cells or proteins are found in the urine, this indicates a health problem at the level of the __________.”
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
Glomerulus
“Small molecules dissolved in the blood will pass through the tiny pores (such as glucose, which is later reabsorbed), whereas large molecules such as proteins and blood cells will not.”
“the nephrons are able to secrete salts, acids, bases, and urea directly into the tubule by either _______ or ________ transport. ”
Active, passive
“The liver converts the ammonia to”
Urea (neutral compound)
“movement of solutes from blood to filtrate at Bowman’s capsule”
Filtration
“movement of solutes from blood to filtrate anywhere besides Bowman’s capsule”
Secretion
“movement of solutes from filtrate to blood”
Reabsorption
“Anything that makes it into the filtrate and that is not reabsorbed will be lost from the body in
Urine
“As a theme, note that segments that are horizontal in the diagram (Bowman’s capsule, the proximal convoluted tubule, and the distal convoluted tubule) are primarily focused on the _______ of the particles in the urine (keep what the body needs and lose what it doesn’t)”
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
Identity
“In contrast, the segments that are vertical in the diagram (the loop of Henle and collecting duct) are primarily focused on the volume and concentration of the urine (concentrate the urine to conserve water).”
the segments that are vertical in the diagram (the loop of Henle and collecting duct) are primarily focused on the _____ & ______ of the urine (concentrate the urine to conserve water).”
Volume and Concentration
“Major waste products excreted in the urine:
Dump the HUNK
H+
Urea
NH3
K+”
“Solutes that enter the interstitium—the connective tissue surrounding the nephron—are picked up by the _______ to be returned to the bloodstream for reuse within the body.”
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
Vasa Recta
“The descending limb is permeable only to
Water
“Together, the vasa recta and nephron create a
countercurrent multiplier system”
“What is meant by this is that the flow of filtrate through the loop of Henle is in the opposite direction from the flow of blood through the vasa recta. If the two flowed in the same direction, they would quickly reach equilibrium and the kidney would be unable to reabsorb as much water. By making the two flow in opposite directions, the filtrate is constantly being exposed to hypertonic blood, which allows maximal reabsorption of water.”
“The ascending limb is only permeable to ____ and is impermeable to_____”
Salts, Water
“Here the opposite occurs: at the deeper parts of the medulla, salt concentrations are high, but decrease as the ascending limb rises. Thus, increasing amounts of salt are removed from the filtrate as it travels up the loop of Henle.”
“At the transition from the inner to outer medulla, the loop of Henle becomes thicker in what is termed the”
Diluting Segment
“These cells contain large amounts of mitochondria, which allow the reabsorption of sodium and chloride by active transport”
“At the beginning of the loop of Henle, the filtrate is ________ to the interstitium. Thus, from the beginning of the loop of Henle to the end, there is a slight degree of _______.
”
Isotonic, Dilution
Far more important, however, is the fact that the volume of the filtrate has been significantly reduced, demonstrating a net reabsorption of a large volume of water.
