WEEK 1- urinary system, anatomy+histology

Question 1

list some functions of the kidneys

Answer 1

-regulation of blood ionic comp, blood ph, blood volume, blood pressure.
-production of hormones
-activating vitamin D

Question 2

describe the location, tissue composition and function of the renal capsule

Answer 2

-it is the outermost layer of the kidney directly in contact with the kidney’s surface.
-consists of thing, tough layer of dense irregular connective tissue
-the function is to provode a protective barrier that shields the kidney from physical trauma and helps maintain its shape

Question 3

describe the location, tissue composition and function of the adipose capsule;

Answer 3

-it is located between the renal fascia and renal capsule
-this capsule is composed of fatty tissue, adipocytes and connective tissue
-function is to serve as a cushion to protect the kidneys from physical shock and trauma

Question 4

describe the location, tissue composition and function of the renal fascia

Answer 4

-surrounds the kidney and the adipose capsule
-this fascia is made of dense irregular connective tissue
-function is that this helps provide structural support and helps keep the kidney in place within the abdominal cavity and seperates the kidney from adjacent structures which helps limit spread of infections.

Question 5

describe the location, and function of the renal cortex

Answer 5

-this is the outer layer of the kidney located beneath the renal capsule, it is the outermost portion of the kidney

Question 6

describe the location, and function of the renal papilla

Answer 6

-is the tip or apex of each renal pyramid. it points towards the center of the kidney and projects into the minor calyx

Question 7

describe the location, tissue composition and function of the renal column

Answer 7

-the renal column are the extensions of the renal cortex that dip between the renal pyramids, running between them and extending into the medulla.
-they help in providing a pathway for blood vessels and interstitial tissue of the kidney

Question 8

describe the location, tissue composition and function of the renal pelvis

Answer 8

-located in the central part of the kidney, at the hilum where the kidney connects from the major calyces and channels it into the ureter. (collects urine from papilla)

Question 9

describe the location and tissue comp of the urethra

Answer 9

-is the tube that carries urine from the bladder to the outside of the body
-composed of transitional/stratified squamous epithelium, smooth muscle and connective tissue

Question 10

describe the location and tissue comp of the bladder

Answer 10

-is a pelvic cavity sac for urine storage; composed of transitional epithelium, smooth muscle and connective tissue

Question 11

describe the location and tissue comp of the ureters

Answer 11

-tube-like structures from the kidneys to bladder; composed of transitional epithelium, smooth muscle and connective tissue

Question 12

define transitional epithelium

Answer 12

it is a type of epithelial tissue specialized to accomodate flucuations in volume.
-this epithelium is typicially multilayered w/ cells that can vary in shape depending on degree of stretch

Question 13

define trigone

Answer 13

-it is a triangular area on the internal surface of the bladder it is defined by the openings of the ureters
-located at the based of the bladder
-it helps to ensure that urine is directed efficiently from the bladder into the urethra and prevents backflow of urine into the ureters.

Question 14

compare and contrast the male urethra and the female urethra

Answer 14

-both help urine leave the body from the bladder
-both exhibit changes in epithelial lining as they transition from the bladder to the external opening

-female urethra is much shorter (3-4cm long) and it extends from the bladder to external urethral oriface
-female urethra only serves as a conduit for urine and has no role in reproduction

-male urethra is longer (18-22cm long) and is divided into several parts
-male urethra coveys urine from bladder and also serves as a passage for semen therefore has a role in reproduction.

Question 15

what is a nephron

Answer 15

a functional unit of the kidney

Question 16

define the renal corpuscle and list the components of it

Answer 16

-is a crucial component of the nephron

-components include;
-glomerulus; which is a network of capillaries located within the renal corpuscle, function is to filter blood to form glomerular filtrate that will eventually become urine

-glomerular capsule; is a double walled cup-like structure that encloses the glomerulus, function is to collect filtrate that is pushes out of glomerulus and directs it into renal tubules.

Question 17

what is the filtration membrane? and list its three main components

Answer 17

this membrane is a criticial barrier that seperates blood in the glomerular capillaries from the filtrate in the bowman’s capsule

three main components include;
1) endothelium of glomerular capillaries; consist of single layer of endothelial cells that have small pores allowing passage of water, etc and blocking out blood cells and proteins

2)basement membrane; is a thick extracellular matrix located between the endothelium and podocytes. it acts as a selective fliter preventing passagae of larger proteins and allowing smaller molecules to pass thru

3)podocytes; are specialized epithelial cells with pedicels, podocytes help further refine the filtration process by preventing passage of medium sized proteins.

Question 18

define the renal artery

Answer 18

it branches directly from the abdominal aorta and suppplies blood to each kidney. it delivers oxygenated blood from the heart to the kidneys for filtration

Question 19

define the renal vein

Answer 19

drains blood from the kidneys into the inferior vena cava, carries deoxygenated blood away from the kidneys and back to the heart

Question 20

define segmental arteries

Answer 20

branch off from the renal artery and enter the kidney at the helium. function is to supply blood to different segments of the kidney

Question 21

define interlobar arteries/veins

Answer 21

run between the renal pyramids in the renal columns. the interlobar arteries branch from segmental arteries and supply blood to the renal cortex/medulla. the interlobar arteries drain blood from these area

Question 22

define arcuate arteries/veins

Answer 22

they each arch along the boundary between the renal cortex+medulla the arteries supply blood to the renal cortex and veins collect blood from the cortical radiate veins and drain into the interlobar veins

Question 23

define cortical radiate arteries/veins

Answer 23

these are found within the renal cortex, the arteries supply blood to glomeruli within nephron units the veins drain blood from pertubular capillaries

Question 24

define afferent arteriole

Answer 24

branch from the cortical radiate arteries and lead to the glomeruli, carry blood to the glomerular capillaries where filtration occurs

Question 25

define glomerular capillaries

Answer 25

network of capillares located within the glomerulus of each nephron this is where blood filteration takes place allowing water/small solutes to pass

Question 26

define efferent arteriole

Answer 26

they exit the glomerulus and carry blood away from glomerular capillaries. directs filtered blood from gomerulus to pertubular capillaries or vasa recta

Question 27

define pertubular capillaries

Answer 27

surround the nephron tubules in renal cortex. involved in reabsorption of water, ions, etc.

Question 28

comapre the visceral and parietal layers of the glomerular capsule

Answer 28

1)visceral layer- directly covers the glomerulus, consists of podocytes and their foot processes (pedicels) that create filtration slits. this layer is crucial for the filtration of blood as the podocytes play a key role in filtering out molecules 2)parietal layer-forms the outer wall of the glomerular capsule, composed of simple squamous epithelium this layer is primarily structural, providing a barrier that contains and directs the filtrate into renal tubules

Question 29

for the following nephron component describe their epithelium and relative location in the kidney/nephron; PCT

Answer 29

-proximal convoluted tubule; -has simple cuboidal epithelium -located after the glomerular capsule and first segment of the renal tubule in the nephron -located in the renal cortex in the kidney.

Question 30

for the following nephron component describe their epithelium and relative location in the kidney/nephron; descending limb of the nephron loop

Answer 30

-simple squamous epithelium -extends from proximal straight portion of the PCT in the nephron -located in the renal medulla in the kidney

Question 31

for the following nephron component describe their epithelium and relative location in the kidney/nephron; ascending limb of the nephron loop

Answer 31

-simple cubodial to columnar epithelial cells are thicker comapred to descending limb -begins at the end of decending limb and ascends back towards renal cortex in the nephron -transitions from medulla back the cortex in kidney

Question 32

for the following nephron component describe their epithelium and relative location in the kidney/nephron; DCT (distal convuluted tubule

Answer 32

-simple cubodial epithelium -the DCT is located after the ascending limb of the loop before connecting tubules in the nephron -located in the renal cortex in kidney

Question 33

describe in detail the arrangement of the renal corpuscle to include the relative positions of; afferent arteriole

Answer 33

location; enters the renal corpuscle and branches into the glomerular capillaries. funciton; supplies blood to the glomerulas

Question 34

for the following nephron component describe their epithelium and relative location in the kidney/nephron; collecting duct (CD)

Answer 34

-simple cubodial to columnar epithelium -channels into renal pelvis in the nephron -extends from renal cortex into renal medulla where it coverges into the renal pelvis

Question 35

describe in detail the arrangement of the renal corpuscle to include the relative positions of; efferent arteriole

Answer 35

location; exits the renal corpuscle, carrying blood away from the glomerulas after filtration. function; drains blood from the glomerular capillaries

Question 36

describe in detail the arrangement of the renal corpuscle to include the relative positions of; glomerular capillaries

Answer 36

location; located within the glomerulas these are the network of tiny blood vessels where filtration occurs function; filters blood allowing water and small solutes to pass into the bowmans capsule while retaining larger molecules and cells

Question 37

describe in detail the arrangement of the renal corpuscle to include the relative positions of; podocytes (visceral layer of the glomerular capsule)

Answer 37

location;visceral layer of the glomerular capsule directly covers the glomerular capillaaries function; podocytes form filtration slits that control passage of molecules

Question 38

describe in detail the arrangement of the renal corpuscle to include the relative positions of; parietal layer of the glomerular capsule

Answer 38

location; forms the outer wall of the bowmans capusle function; this layer helps support and helps direct the filtrate into the renal tubule

Question 39

describe in detail the arrangement of the renal corpuscle to include the relative positions of; ascending limb of the nephron loop

Answer 39

location; begins after the descending limb and ascends back towards the renal cortex

Question 40

describe in detail the arrangement of the renal corpuscle to include the relative positions of; macula densa

Answer 40

location; located in the distal convulted tubule where it comes in cotnact w/ the afferent and efferent arterioles function; moniters sodium chloride concen in the filtrate and signals juxtaglomerular cells to adjust blood pressure and filtration rate

Question 41

describe in detail the arrangement of the renal corpuscle to include the relative positions of; juxtaglomerular appartus/cells (JGA)

Answer 41

location; found in the region where the distal conc=vulted tubule contacts the afferent arteioles function; regulates blood pressure and glomerular filtration rate by rsponfing to changes in blood pressure and sodium concentration.

Question 42

describe in detail the arrangement of the renal corpuscle to include the relative positions of; mesangial cells

Answer 42

location; situated between the glomerular cappliaries within the glomerulas function; provides structural support helps regulate golmerular filtration by contrating + relaxing

Question 43

define renin

Answer 43

hormone prodcued by juxtaglomerular cells that regulates blood pressure by activating angiotensin

Question 44

compare and contrast gomerular filtration, tubular reabsorption and tubular secreation

Answer 44

glomerular filtration; movement of fluid and solutes from the blood into bowmans capsule tubular reabsorption; movement of substances from the tubular fluid back into the blood tubular secreation; movement of substances from the blood into the tubular fluid for excretion

Question 45

pressures involved in filtration; glomerular blood hydrostatic pressure (CBHP)

Answer 45

blood pressure in capillaries

Question 46

pressures involved in filtration; capsular hydrostatic pressure (CHP)

Answer 46

pressure exerted by fluid in the bowmans capsule

Question 47

pressures involved in filtration; blood colloid osomotic pressure (BCOP)

Answer 47

osmotic pressure from proteins in the blood

Question 48

pressures involved in filtration; capsular osomotic pressure

Answer 48

low osomotic pressure in the capsule

Question 49

passive vs active transport

Answer 49

active transport- requires energy (ATP) to move substances against their concen. gradient (from low to high concen) e.g sodium potassium pump passiventransport- does not require energy substances move down their concen. gradient (from high to low concen.) e.g simple diffusion, facillitated diffusion, osmosis.

Question 50

describe the permeability of the following molecules; small non polar gases, ions, large polar molecules.

Answer 50

small non polar gases; highly permeable, these molecules easily diffuse across the lipid bilayer ions- impermeable, ions cannot cross membrane freely and require specific channels or transporters because they are charged large, polar molecules; impermeable these molecules require facillitated diffusion via carrier proteins or active transport mechanisms

Question 51

what are channel transporters

Answer 51

-allow specific ions or molecules to pass thru membrane -passive allowing ions to flow down their concen. gradient -e.g na+ and k+ channels

Question 52

what are carrier proteins

Answer 52

-bind to specific molecules and undergo a conformational change to transport them -can be passive or active -e.g glucose transporters

Question 53

what are pump transporters

Answer 53

-active transporters that use ATP to move ions or molecules against their concen. gradient -e.g na+/k+ pump which moves 3 na+ out of the cell and 2 k+ into the cell

Question 54

what are pumps transporters

Answer 54

-active transporters that use ATP TO MOVE IONS or molecules against their concen. gradient -e.g is a na+/k+ pump

Question 55

what are symporter transporters

Answer 55

-move 2 or more substances in the same direction across the membrane -e.g na+/glucose symporter in the pct

Question 56

what are antiporters

Answer 56

Move two or more substances in opposite directions. Example: Na+/H+ antiporter, which moves Na+ into the cell while moving H+ out.

Question 57

describe the arrangement of ions around the cell membrane

Answer 57

Outside the cell: High concentration of Na+ and Cl- ions. Inside the cell: High concentration of K+ ions and negatively charged proteins. The sodium-potassium pump helps maintain this gradient by moving Na+ out and K+ in.

Question 58

paracellular vs transcellular transport

Answer 58

Paracellular Transport: Movement of substances between adjacent cells through tight junctions. Transcellular Transport: Movement of substances across the cell, through both the apical and basolateral membranes of the epithelial cells.

Question 59

what is the na+/glucose pathway

Answer 59

Sodium and glucose are reabsorbed together via a Na+/glucose symporter. Sodium moves down its gradient, providing energy for glucose to move against its gradient.

Question 60

h20 in the PCT

Answer 60

Water follows the reabsorption of sodium through osmosis, primarily via aquaporins (water channels).

Question 61

lipid soluble substances

Answer 61

Reabsorbed by simple diffusion as they can pass freely through the lipid bilayer of cells.

Question 62

how are cl-, ca2+, k+ and urea reabsorbed

Answer 62

Reabsorbed through both paracellular and transcellular pathways depending on their gradients.

Question 63

what is an aquaporin

Answer 63

Aquaporins are specialized water channels that facilitate the passive transport of water across the cell membrane.

Question 64

what is the renal medulla

Answer 64

-the inner region of the kidney beneath the renal cortex -plays role in concentrating urine and regulates water balance