Lecture one

Question 1

The kidneys perform a variety of functions aimed at maintaining

Answer 1

homeostasis

Question 2

How do the kidneys maintain homeostasis

Answer 2

1. Maintaining stable volume, electrolyte composition, and osmolarity (solute concentration) of the ECF
2. Maintain water and electrolyte balance within the narrow range
3. Adjust for variations in ingestion of water, salt, and other electrolytes, but also adjust urinary output of these ECF constituents

Question 3

To maintain homeostasis, urine

Answer 3

composition varies greatly

Question 4

Other kidney homeostasis mechanisms

Answer 4

• Eliminate the ECF surplus water or a particular electrolyte in the urine
• Can limit urinary losses of the material in short supply and thus conserve it
• Compensate more efficiently for excesses than for deficits
• In some instances the kidneys cannot halt the loss of a valuable substance in the urine
  E.g. water deficit
• The main route for eliminating potentially toxic metabolic wastes and foreign compounds
• Water eliminated in the urine is derived from the blood plasma

Question 5

Functions of the kidneys [10]

Answer 5

Maintaining water (H2O) balance in the body
Maintaining the proper osmolarity of body fluids, primarily through regulating H2O balance
Regulating the quantity and concentration of most ECF ions
Maintaining proper plasma volume
Helping maintain the proper acid–base balance
Excreting (eliminating) the end products (wastes) of bodily metabolism
Excreting many foreign compounds
Producing renin
Producing erythropoietin
Converting vitamin D into its active form

Question 6

Anatomic considerations

Answer 6

Question 7

https://www.youtube.com/watch?v=1NtPjzm1-74&t=73s

Question 8

The functional unit of the kidney

Answer 8

The Nephron

Question 9

The arrangement of nephrons within the kidneys gives rise to two distinct regions:

Answer 9

Renal Cortex
Renal Medulla

Question 10

Each nephron consists of 2 components

Answer 10

vascular component
tubular component

Question 11

Question 12

The dominant part of the nephron’s vascular component is the

Answer 12

glomerulus

Question 13

Vascular Component of the Nephron blood supply

Answer 13

The renal artery subdivides to form many small vessels known as afferent arterioles
The afferent arteriole delivers blood to the glomerulus

Question 14

Blood that was not filtered into the tubular component leaves the glomerulus via

Answer 14

the efferent arteriole

Question 15

The efferent arteriole subdivides into a second set of capillaries,

Answer 15

the peritubular capillaries

Question 16

The peritubular capillaries re-join to form venules that

Answer 16

ultimately drain into the renal vein, by which blood leaves the kidney

Question 17

A hollow fluid-filled tube

Answer 17

Tubular Component of the Nephron

Question 18

Tubular Component of the Nephron is Divided into various segments based on differences in structure and function along its length:

Answer 18

Bowman’s capsule
Proximal tubule
Loop of Henle
Descending loop
Ascending loop
Juxtaglomerular apparatus
Distal tubule
Collecting duct or tubule

Question 19

Answer 19

Question 20

Two types of nephrons:

Answer 20

Cortical nephrons
Juxtamedullary nephrons

Question 21

Cortical nephrons

Answer 21

– glomeruli lie in the outer layer of the cortex

Question 22

Juxtamedullary nephrons

Answer 22

– glomeruli lie in the inner layer of the cortex

Question 23

The two nephron types differ most markedly in their

Answer 23

loops of Henle

Question 24

Question 25

Question 26

https://www.youtube.com/watch?v=2PEohSqpp_E