Packet One - Kidney Overview

Question 1

Kidney Functions 6

Answer 1

Excretes wastes & foreign substances
Maintain blood pH, osmolarity, glucose 
Regulation of:
blood/ECF ionic composition
blood volume
blood pressure
Acts as endocrine organ

Question 2

Kidney acts as an endocrine organ by:

Answer 2

making renin, calcitriols, secreting renin

Question 3

The kidneys are _______ on the posterior wall of the abdomen

Answer 3

retroperitoneal

Question 4

Urine flows from the kidney to the _____ _____ through the _____
Urine is stored in the bladder until it is eliminated from the body via the _____

Answer 4

urinary bladder
ureters
urethra

Question 5

At rest, the kidneys receive _____% of resting cardiac output via the ____ _____ which branch off the abdominal aorta.
Most of this blood flows through the ____ _____
and then the ____ capillaries

Answer 5

20-25%
renal arteries
Glomerular capillaries
peritubular

Question 6

The filtered blood returns to the systemic circulation via the ____ ____ which empty into the inferior vena cava

Answer 6

renal veins

Question 7

Where does filtration of blood occur?

Answer 7

Glomerular capillaries

Question 8

Generally, where does reabsorption and secretion occur?

Answer 8

peritubular capillaries

Question 9

Arteriole capillaries that allow Glomerular capillaries to maintain higher pressure than other capillaries in the body?

Answer 9

afferent and efferent arterioles

Question 10

Which is required for adequate filtration of blood: High or low GC pressure?

Answer 10

High GC pressure

Question 11

Sympathetic vasomotor nerves and local (kidney) factors help regulate:

Answer 11

GC blood flow & pressure

Question 12

Part of the nephron that performs the first step of filtering blood is:

Answer 12

glomerulus

Question 13

A glomerulus receives its blood supply from an _____ arteriole of the renal circulation

Answer 13

afferent

Question 14

The glomerulus drains into an ____ arteriole rather than a venule

Answer 14

efferent

Question 15

A glomerulus and its surrounding Bowman’s capsule constitute a ____ _____, the basic filtration unit of the kidney.

Answer 15

renal corpuscle

Question 16

The rate at which blood is filtered through all of the glomeruli, and thus the measure of the overall renal function, is the _____ _____ _____.

Answer 16

glomerular filtration rate (GFR).

Question 17

The _______ contain negatively charge coat (glycocalyx) that limits filtration of negatively charge molecules such as serum albumin

Answer 17

Podocytes

Question 18

GFR = Kf [(PGC – PBS) – σ(πGC – πBS)]

Answer 18

`Kf= filtration coefficient
PGC= Hydrostatic pressure in glomerular capillary
PBS= Hydrostatic pressure in bowman’s space
σ= Reflection coefficient
πGC= Oncotic pressure in glomerular capillary
πBS = Oncotic pressure in bowman’s space

Question 19

The nephron performs 3 Basic Processes:

Answer 19

Glomerular Filtration
Tubular Reabsorption
Tubular Secretion

Question 20

Functional Unit of the Kidney

Answer 20

Nephron

Question 21

Blood-plasma filtered to produce filtrate is known as

Answer 21

Glomerular Filtration

Question 22

Substances transported from the filtrate back to the blood-plasma: this process is known as

Answer 22

Reabsorption

Question 23

Substances transported from the blood-plasma to filtrate is known as

Answer 23

Secretion

Question 24

processed filtrate becomes urine which is transported to the bladder then excreted from the body is known as

Answer 24

Excretion

Question 25

Excretion = Filtration + Secretion - ______

Answer 25

Reabsorption

Question 26

Two major nephrons of the kidney

Answer 26

cortical and juxtamedullary nephron

Question 27

80-85% of the ~ 1 million nephrons are ____ nephrons. Renal corpuscles are in outer cortex and loops of Henle are near the cortex

Answer 27

cortical

Question 28

15-20% of nephrons are _____ nephrons with renal corpuscles close to medulla and long loops of Henle extend deep into medulla with ___ ____ enabling the formation of dilute or concentrated urine

Answer 28

juxtamedullary | vasa recta

Question 29

_____ of bowman’s capsule are specialized to help produce the filtrate of plasma

Answer 29

Podocytes

Question 30

help regulate glomerular filtration rate (GFR)

Answer 30

Mesangial cells

Question 31

Podocytes & Mesangial cells surround different parts of the glomerular capillaries and form the ____ layer of Bowman’s capsule

Answer 31

visceral

Question 32

_____ layer cells contain the filtrate and channel it toward the proximate tubule

Answer 32

Parietal

Question 33

The Filtration Membrane has 3 layers:

Answer 33

Endothelial Cells Basement Membrane Podocytes

Question 34

Water and small molecules can easily pass through the filtration membrane but ____ cells and most ___ ____ cannot

Answer 34

blood | plasma proteins

Question 35

Cells of the proximal tubule are specialized for _____ and have an elaborate brush border to increase the ____ surface area

Answer 35

reabsorption | apical

Question 36

Nearly 100% of glucose, amino acids and other nutrients; and ~ 60-80% of water and salts are reabsorbed in the ___ _____

Answer 36

proximal tubule

Question 37

Histology of the Proximal Tubule: 5

Answer 37

``` simple cuboidal microvilli on luminal (apical) side Basal-end faces the basal lamina Tight junctions Large number of mitochondria (provides energy for active transport) ```

Question 38

Cells of the Loop of Henle are specialized for ____ _____ and transport. They help to produce the osmotic concentration gradient necessary to produce _____ urine

Answer 38

selective permeability | concentrated

Question 39

Histology of the Descending Limb : 4

Answer 39

simple squamous epithelium fewer microvilli on the luminal (apical) surface fewer mitochondria Permeable to water due to aquaporin water channels in both the apical and basolateral membranes

Question 40

Histology of the Ascending Limb

Answer 40

simple columnar epithelial cells not water permeable- Cells lack aquaporins on apical surface apical and basolateral membranes have many transmembrane ion transport molecules

Question 41

Ascending Limb reabsorbs:

Answer 41

Na+ and K+ as well as Cl-

Question 42

Ascending Limb ______ co-transporters sensitive to _____

Answer 42

Na-K-Cl | Furosemide

Question 43

Some cells of the Distal tubule and collecting ducts respond to hormones such as:

Answer 43

Aldosterone, ADH, ANP, PTH & others

Question 44

Histology of the Distal Tubule

Answer 44

Simple cuboidal small number of microvilli on apical surface Large numbers of mitochondria for the active reabsorption of Na+ and Cl-

Question 45

sodium-chloride symporter of Distal tubule are sensitive to:

Answer 45

Thiazide

Question 46

Histology of the Collecting Duct

Answer 46

Few microvilli on apical membrane | mitochondria for active reabsorption of Na+ and Cl- ; K+ secretion

Question 47

reabsorption of Na+ and Cl- ; K+ secretion in the collecting duct is regulated by:

Answer 47

aldosterone

Question 48

Both DT and CD cells are ___ sensitive

Answer 48

ADH

Question 49

______ hormone stimulates increase of aquaporins on apical membrane increasing the water permeability of collecting duct

Answer 49

antidiuretic