Lecture 2 - Gross Anatomy (HARC 1)

Question 1

Function of Kidney

Answer 1

1.) Excrete waste products of metabolism as urine 2.) Water and electrolyte balance in the body 3.) Maintain acid-base balance of blood

Question 2

What is the peritoneum?

Answer 2

A continuous transparent membrane which lines the abdominal cavity and covers the abdominal organs (or viscera).

Question 3

Where do the kidneys sit?

Answer 3

Lie behind peritoneum high on posterior abdominal wall either side of the vertebral column

Question 4

Why is the right kidney lower?

Answer 4

Liver

Question 5

Which ribs cover left kidney?

Answer 5

Ribs 11 and 12

Question 6

Which ribs cover right kidney?

Answer 6

Rib 12

Question 7

Answer 7

Question 8

Answer 8

Question 9

What is a renal calyx?

Answer 9

• Calyces are chambers of the kidney through which urine passes
• Minor calyces surround the apex of the renal pyramids.
• Two or three minor calyces converge to form a major calyx

Question 10

Answer 10

Question 11

Flow of Urine

Answer 11

Collecting Ducts → Minor Calyx → Major Calyx → Renal Pelvis → Ureter

Question 12

Answer 12

Question 13

Glomerulus

Answer 13

• Tuft of capillaries
• Blood enters via afferent arteriole
• Leaves via efferent arteriole
• Plasma filtrate passes over B’s C epithelium and enters proximal tubule.
• Controlled by juxtaglomerular cells (smooth muscle)

Question 14

Answer 14

Question 15

Kidney Blood Flow

Answer 15

Question 16

Urine Formation

Answer 16

1. Filtration
2. Reabsorption
3. Secretion
4. Excretion

Question 17

How much fluid do kidneys filter every day?

Answer 17

180 Litres

Question 18

How much of filtrate is reabsorbed in PCT and Loop of Henle?

Answer 18

Over 70%

Question 19

What solutes are actively transported out of PCT?

Answer 19

Glucose, Amino Acids, Bicarbonate

Question 20

Where is Sodium reabsorbed?

Answer 20

PCT (60%), Loop of Henle (30%), DCT (10%)

Roughly

Question 21

What is Vasopressin?

Answer 21

Antidiuretic Hormone

(Increases DCT and Collecting Duct permeability to water)

Question 22

Secretion

Answer 22

• Post filtration, kidney continues to secrete additional substances into tubular fluid.
• Enhances kidney’s ability to eliminate certain toxins and wastes.
• Essential to plasma concetrations and pH.

Question 23

Excretion

Answer 23

Final composition of urine

Question 24

Ureter

Answer 24

Carries urine from renal pelvis to bladder

Question 25

Ureter Position

Answer 25

* Descends inferiorly and medially along lumbar transverse processes * Over sacroiliac joint to enter bladder at level of ischial spine

Question 26

Ureter Blood Supply

Answer 26

Question 27

Ureteric Constrictions

Answer 27

Question 28

Macula Densa Cells

Answer 28

Thickening of the distal tubule (where it meets glomerulus) which regulates the GFR (glomerular filtration rate) as part of a feedback loop

Question 29

Mesangial Cells

Answer 29

* Central position in glomerulus * Characteristics of modified smooth muscle cells * Can alter GFR (along with macula & juxtagomerular cells) * Generate prostaglandin & mediators of inflammation * Production & breakdown of basement membrane * Synthesis of cytokines * Uptake of macromolecules, including immune complexes.

Question 30

Podocytes

Answer 30

* Pedicels of podocytes interdigitate and leave slits between them for filtration * Slits covered by slit diaphragms which restrict passage of macromolecules * Ensure macromolecules remain in bloodstream * E.G. * Nephrin (cell-surface protein) restricts serum albumin and gamma globulin

Question 31

Answer 31

Question 32

Answer 32

Question 33

Answer 33

Question 34

Answer 34

Question 35

Answer 35