Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Physiology 2 > Week Eleven > Flashcards

Week Eleven Flashcards

1
Q

What are the general functions of the kidneys?

A
  • filter blood to remove metabolic waste products
  • modify the blood plasma in order to maintain homeostasis of water & solute balance, electrolyte & acid-base balance, and blood pressure
  • regulate production of red blood cells by releasing the hormone erythropoietin
  • activate vitamin D
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the urinary tract composed of?

A

ureters, urinary bladder & urethra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do the ureters do?

A

transport filtrate from the kidneys to the bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the bladder do?

A

stores urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does urine exit the bladder?

A

through the urethra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the internal anatomy of the kidneys

A

divided up into the:
renal cortex
renal medulla
renal pelvis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the general function of the renal cortex and renal medulla?

A

where filtrate is collected and turned into urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the general function of the renal pelvis?

A

collects and drains the urine produced from the nephrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the functional unit of the kidney? How many are in each kidney?

A
  • the nephron
  • over 1 million in each kidney
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What makes up each nephron?

A

a renal corpuscle and renal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T or F: each nephron has its own little blood supply?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain the 13 steps of blood flow through the kidneys

A

renal artery → segmental artery → interlobar artery → arcuate artery → interlobular artery → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries → interlobular vein → arcuate vein → interlobar vein → renal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the micro anatomy of the nephron?

A

renal corpsucle (glomerulus & glomerular capsule) → proximal tubule → nephron loop (loop of henle) → distal tubule → collecting duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the job of the renal corpuscle? What are its two parts?

A
  • where blood filtrate enters into the kidney
  • glomerulus and glomerular capsule (bowman’s capsule)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the glomerulus?

A

group of looping fenestrated capillaries (very leaky capillaries with lots of gaps in the endothelium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the glomerular capsule?

A

double layered sheath of epithelial tissue (parietal and visceral layer) with capsular space in the middle that received all the filtrate in from the capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the visceral layer of the glomerular capsule made up of?

A

modified epithelial cells: podocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to newley formed filtrate that enters the renal tubule?

A

it is further modified in three structurally and functionally distinct regions: proximal tubule → nephron loop → distal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens once the collecting duct collects filtrate from the distal tubules of multiple neurons?

A

further modifies filtrate before it exits the kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When is filtrate considered urine?

A

once all the modification in the collecting duct is complete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the juxtaglomerular apparatus?

A
  • important area of regulation
  • made up of juxtaglomerular cells found in the walls of afferent and efferent arterioles AND macula dense cells that are found in the nephron tubule, right next to the glomerulus
  • regulates blood pressure and glomerular filtration rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is glomerular filtration rate?

A

amount of filtrate entering into both kidneys in one minute
- average: 125mL/min (the equivalent of filtering all 3 liters of blood plasma ~60x per day)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the 3 physiological processes carried out by the nephron?

A

glomerular filtration, tubular reabsorption, and tubular secretion

24
Q

Describe glomerular filtration

A

substances from the blood are filtered into the renal capsule based on size
- cells and larger proteins are too big and remain in the circulating blood
- small substances get through: water, electrolytes (Na+, K+), acids (H+), bases (HCO3-), other molecules and metabolic waste products

25
Q

Describe tubular reabsorption

A

filtrate is modified based on body’s needs
- most water, glucose, amino acids, and electrolytes are returned to blood
- nephron will further vary amount of different substances that is reabsorbed based on the body’s needs (mainly in distal tubule and collecting duct)

26
Q

Describe tubular secretion

A

more substances are added into the filtrate for excretion, as needed
- maintenance of electrolytes and acid-base homeostasis
- removal of toxins that were missed during filtration

27
Q

What is everything that enters the glomerular capsule by filtration called?

A

filtrate

28
Q

Where does glomerular filtration take place?

A

renal corpuscle

29
Q

What are the substances that are filtered into the glomerular capsule

A

water, ions, glucose, amino acids, very small proteins, nitrogenous waste (urea, ammonia, creatinine, uric acid)

30
Q

What are the 3 layers of filtration?

A
  1. fenestrated glomerular capillary endothelial cells
  2. basal lamina - a mesh work of collagen fibers
  3. podocytes - the visceral layer of epithelial cells of the glomerular capsule
31
Q

What is the filtration fraction?

A
  • the percentage of blood plasma that passes through the glomerular 3-ply filtration membrane to become filtrate
  • average filtration fraction: 20%
  • about 1/5 of the plasma that flows through the glomerulus enters into the capsular space (<1% is eventually excreted)
32
Q

What are the 3 forces that determine glomerular filtration rate?

A

glomerular hydrostatic pressure, capsular hydrostatic pressure, and glomerular colloid osmotic pressure

33
Q

What is glomerular hydrostatic pressure?

A
  • the force of the blood against the filtration membrane (mainly determined by the systemic blood pressure) → pushes plasma into the capsule
  • favor filtration and drive fluid out of the glomerular capillaries
34
Q

What is capsular hydrostatic pressure?

A
  • the force of the filtrate pushing back against the filtration membrane → pushes filtrate back into the glomerular capillaries
  • opposes filtration and drive fluid into the capillaries
35
Q

What is the glomerular colloid osmotic pressure?

A
  • the force created by the presence of proteins in the plasma, the protein concentration is higher in the capillary plasma than the filtrate → osmotic pressure → pulls water back into the capillaries
  • opposes filtration and drives fluid into the capillaries
36
Q

What are the 3 ways in which glomerular filtration rate is regulated?

A
  1. Autoregulation (regulation from within the kidneys)
    - myogenic
    - tubuloglomerular feedback
  2. Hormonal mechanisms
    - the renin-angiotensin-aldosterone system
    - atrial natriuretic peptide
  3. Neural mechanisms
    - sympathetic nervous system
37
Q

Describe autoregulation

A

enable the GFR to remain relatively constant even when systemic blood pressure fluctuates

38
Q

What is the myogenic mechanism?

A

the smooth muscle found in the afferent and efferent arterioles can vasoconstrict or vasodilation in response to changes in systemic BP in order to maintain constant GFR

39
Q

What is tubuloglomerular feedback?

A
  • as GFR increases, volume of filtrate flowing through the renal tubule and macula dense cells increases
  • the macula dense cells response by releasing paracrines that cause vasoconstriction of the afferent arteriole and vasodilation of efferent arteriole (opposite occurs when GFR decreases)
40
Q

What is the renin-angiotensin-aldosterone system?

A
  • primary goal is to maintain blood pressure (secondary goal: maintain GFR)
  • initiated by the release of renin from juxtaglomerular cells
  • there are three possible stimuli for renin release
41
Q

What are the three possible stimuli for renin release?

A
  • stimulation by the sympathetic NS
  • low glomerular hydrostatic pressure (due to low BP)
  • stimulation from the macula dense cells
42
Q

What is ACE?

A

angiotensin converting enzyme (from lungs)

43
Q

What is atrial natriuretic peptide?

A
  • a hormone released by cells in the atria of the heart
  • released in reponse to increased blood volume/blood pressure → increased GFR by causing vasodilation of afferent arterioles and vasoconstriction of efferent arterioles → increased excretion of urine (diuersis) → decreased blood volume (and blood pressure)
44
Q

What is Renin?

A

hormone secreted from juxtaglomerular cells of the afferent and efferent arterioles in response to decreased glomerular filtration rate. This is due to a drop in blood pressure

45
Q

Describe all the effects of angiotensin

A

Goal: systemic blood pressure increases
- promotes vasoconstriction of efferent arterioles (GFR returns to normal range)
- promotes vasoconstriction of systemic blood vessels
- promotes reabsorption of Na+ and Cl- from the proximal tubule and H2O follows
- promotes aldosterone release, leading to increasing Na+ and H2O reabsorption
- stimulates thirst center in hypothalamus, which may increase fluid intake

46
Q

Describe tubular reabsorption

A
  • paracellular transport between cells can fit small ions (simple diffusion) and water (osmosis)
  • transcellular transport: across cells, always by carrier-mediated transport (e.g. glucose, amino acids, Na+, K+, water)
  • most filtrate is immediately reabsorbed from the proximal tubule
  • water is reabsorbed by osmosis in the proximal tubule and nephron loop
  • more water and sodium can be reabsorbed if needed at distal tubule and collecting duct
47
Q

Describe the role of ADH and aldosterone at the distal tubule

A

ADH → stimulates water reabsorption at the distal tubule and collecting duct
Aldosterone → stimulates sodium reabsorption in distal tubule → water is reabsorbed by osmosis if ADH is also present

48
Q

Describe tubular secretion

A
  • always transcellular and by carrier-mediated transport
  • H+ (variable depending on pH of the blood), K+ and nitrogenous waste products
  • drugs e.g. antibiotics
49
Q

Describe the three steps of reabsorption of glucose in the proximal tubule

A
  1. Na+/K+ pumps move Na+ out of the proximal tubules cell into the interstitial fluid, creating a Na+ concentration gradient via primary active transport
  2. Na+ and glucose are moved into the cell from the filtrate by Na+/glucose symporters, using energy of the Na+ gradient
  3. glucose is transported from the proximal tubule cell to the interstitial fluid via facilitated diffusion, and then diffuses into the peritubular capillary
50
Q

Describe the 2 steps involved in reabsorption of water in the proximal tubule

A
  1. solutes passively diffuse or are actively transported into the tubule cell and interstitial fluid
  2. the resulting solute concentration gradient draws water into the tubule cell through the aquaporin channels via osmosis
51
Q

What happens to water reabsorption with maximal ADH present?

A

the collecting duct is freely permeable to water. Water leaves by osmosis and is carried away by the vasa recta capillaries. urine is concentrated

52
Q

What happens to water reabsorption in the absence of ADH?

A

the collecting duct is impermeable to water and the urine is dilute

53
Q

Describe the effect of aldosterone on sodium and water reabsorption

A

↓BP → + renin secretion → → ang II (or increased K+ concentration in blood) → aldosterone secretion from adrenal cortex → + K+ secretion & Na+ reabsorption (and water)

54
Q

Describe the role of atrial naturiuetic peptide on ADH and Aldosterone

A

ANP secreted by cells in the atria → ↓ADH and Aldosterone → ↑Na+ and H2O reabsorption → ***

55
Q

Describe the affect of ANP on increased Blood volume

A

ANP secreted by cells in the atria in response to ↑BP/ ↑BV → ↑GFR (and + vasodilation of afferent arterioles/ - vasoconstriction of efferent arterioles) → ↑execration of urine (diuresis) → ↓BV/↓BP

56
Q

What is the normal composition of urine?

A
  • water
  • sodium
  • postassium
  • chloride
  • hydrogen ion
  • phosphates
  • sulfates
  • metabolic wastes such as urea, creatinine, ammonia and uric acid
  • small amounts of bicarbonate, calcium, and magnesium may also be present

Human Physiology 2 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions