Lecture 28: OVERVIEW AND GROSS STRUCTURE OF THE KIDNEY

Question 1

What portion of a male is water?

Answer 1

60%

Question 2

What portion of a female is water?

Answer 2

55%

Question 3

What is the reason for the differences in water content between males and females?

Answer 3

Males have more muscle which holds water while females have more adipose which holds less water

Question 4

What is the total body water made up of?

Answer 4

1/3 extracellular fluid and 2/3 intracellular fluid

Question 5

What is crucial?

Answer 5

Balance of water (and solutes) in the body

Question 6

How does the urinary system maintain balance?

Answer 6

By filtering the blood and expelling:

• excess water
• excess salts
• wastes of metabolism
• many toxins and drugs

Question 7

How much blood flows through the kidney per minute?

Answer 7

1200 ml

Question 8

How much urine is produced by a typical person in a day?

Answer 8

800-2000ml

Question 9

What is urine?

Answer 9

Waste product excreted to maintain balance within the body

Question 10

What is found in normal urine?

Answer 10

Water, salts, urea, metabolites, hormones and small proteins

Question 11

Is urine pH regulated?

Answer 11

No, not tightly (4.6-8) as it is influenced by what is being excreted

Question 12

What is urine useful for?

Answer 12

A diagnostic tool for disease states

Question 13

What is in abnormal urine?

Answer 13

Large proteins (too big to be filtered), RBC’s (too big to be filtered) and glucose (filtered but completely reabsorbed)

Question 14

What does the urinary system need to be effective?

Answer 14

• delivery system for blood
• selective filtration system (based largely on size)
• filtrate recovery mechanism (reabsorption)
• system to return recovered, filtered fluid to the body
• system to remove filtrate from the body
• protection
• ability to communicate with relevant parts of the body
• adaptable to meet the body’s changing needs

Question 15

What are the main components of the urinary system?

Answer 15

2 kidneys, 2 ureters, urinary bladder and urethra

Question 16

What does the structure of the kidney allow?

Answer 16

• blood to be brought into close proximity with the nephron for filtering
• blood that has been filtered to leave the kidney
• a pathway for urine to be removed from the kidney, stored and then excreted
• protection

Question 17

What vertebra are the kidneys between?

Answer 17

T12 and L3

Question 18

What ribs are the kidneys near?

Answer 18

11th and 12th

Question 19

Where does the convex side of the kidney face?

Answer 19

Laterally

Question 20

What does the medial surface of the kidney have?

Answer 20

A concave notch called the hilum

Question 21

What enters and exits the hilum of the kidneys?

Answer 21

renal blood vessels, lymphatics, nerves and the ureter

Question 22

Are kidneys intra or retroperitoneal?

Answer 22

Retroperitoneal - located on the posterior abdominal wall, covered on the anterior side by peritoneum

Question 23

What surrounds, supports and protects the kidneys?

Answer 23

Fat

Question 24

What kidney is found slightly lower?

Answer 24

The right kidney because the liver is found on that side and pushes it down slightly

Question 25

What are the three regions of the kidney?

Answer 25

Cortex, medulla and pelvis

Question 26

What surrounds the kidney?

Answer 26

A fibrous capsule

Question 27

What is the structure of inner medulla?

Answer 27

Divided into pyramids with each medullary pyramid ending in a papilla

Question 28

What is the structure of the outer cortex?

Answer 28

Continuous layer with renal columns

Question 29

What do the cortex and medulla form?

Answer 29

Functional lobes

Question 30

How many lobes per kidney?

Answer 30

5-11

Question 31

What does a lobe consist of?

Answer 31

One medullary pyramid and all the cortex that surrounds it (including the renal columns)

Question 32

What is the kidney lobes largely made of?

Answer 32

Nephrons - tiny tubes that filter from blood and create urine (thousands of these)

Question 33

Where does urine drain?

Answer 33

From each papilla and collects in a calyx

Question 34

What do calyces do?

Answer 34

Join to form the renal pelvis

Question 35

What does the pelvis do as it exits the hilum?

Answer 35

Narrows to become the ureter

Question 36

What is the path of urine travel?

Answer 36

papilla > minor calyx > major calyx > renal pelvis > ureter

Question 37

What does a pyelogram show?

Answer 37

Where urine is present in the body

Question 38

How is urine produced?

Answer 38

By filtering waste from blood into the nephron

Question 39

What part of the kidney does filtration occur in?

Answer 39

The cortex

Question 40

What does the renal artery arise from?

Answer 40

The abdominal aorta and enters at the hilum

Question 41

What do branching arteries do?

Answer 41

Get smaller and smaller until they reach the cortex

Question 42

What area of the kidneys contains no vessels?

Answer 42

The medullary pyramids

Question 43

What do veins do?

Answer 43

Return filtered blood from the cortex into the renal vein to the inferior vena cava

Question 44

What is the path of blood supply into the cortex to be filtered?

Answer 44

Abdominal aorta > renal artery > series of arteries > afferent arteriole which delivers blood from the arteries to the glomerulus where filtration occurs > glomerular capillaries

Question 45

What is the glomerulus made up of?

Answer 45

Glomerular capillaries

Question 46

What is the path of blood supply away from the cortex after being filtered?

Answer 46

Glomerular capillary > efferent arteriole carries blood from the glomerulus to the > peritubular capillaries > series veins > renal vein > inferior vena cava

Question 47

What is the innervation of the kidneys from?

Answer 47

A network of autonomic nerves and ganglia called the renal plexus

Question 48

What do sympathetic nerves do?

Answer 48

Act to adjust the diameter of renal arterioles and therefore regulate blood flow

Question 49

What is a nephron?

Answer 49

A microscopic functional unit of the kidneys

Question 50

What is the bulk of the kidney made up of?

Answer 50

Nephrons

Question 51

What does the nephron do?

Answer 51

Filters blood, selectively reabsorbs or secretes and produces urine

Question 52

What are the components of the nephron?

Answer 52

Renal corpuscle (glomerulus capsule and glomerulus), proximal convoluted tube, nephron loop, distal convoluted tube, collecting duct