Urinary System

Question 1

Why must the internal environment of the body be maintained?

Answer 1

Must be maintained in specific limits in order for its chemical reactions and cellular activities to continue normally

Question 2

How does the body get rid of waste and how much?

Answer 2

Most waste, excess and toxic substances are eliminated from blood plasma through the kidneys and excreted from body in the urinary system. 200L a day

Question 3

How do the kidneys adjust blood chemistry?

Answer 3

By regulating levels of waste from cell metabolism, acid water balance, water balance, ion level, hormones (erythropoeitin and renin) and metabolises vitamin D

Question 4

What does the urinary system consist of?

Answer 4

2 kidneys (left higher than right), urinary bladder, 2 ureters and the urethra

Question 5

Define excretion or secretion.

Answer 5

the passage of substances and fluid from the blood into the nephron (the tubules and the collecting duct)

Question 6

Define reabsorption

Answer 6

passage of substances and fluid from the filtrate back into the blood (the peritubular capillaries or vasa recta)

Question 7

Where is the location of the kidneys?

Answer 7

Posterior to the abdominal peritoneum on either side of the vertebrae

Question 8

Where do the adrenal glands sit?

Answer 8

On top of the kidneys

Question 9

What colour are the kidneys?

Answer 9

Reddish brown

Question 10

What is the indentation on the kidney called and what does it contain?

Answer 10

It is called the hilus and is where the ureter, blood vessels, lymph vessels and nerves enter the renal pelvis.

Question 11

How does blood flow occur in the kidneys?

Answer 11

Blood flows in via the renal arteries (from abdominal aorta) and flows out via renal vein to inferior vena cava

Question 12

What does the renal capsule do?

Answer 12

Directly surrounds kidney

Question 13

What does the adipose capsule do?

Answer 13

Layer of fat to help cushion the kidney

Question 14

What does the renal fascia do?

Answer 14

covers adipose capsule and kidney. Also anchors kidney to surrounding structures

Question 15

What are the 2 main regions of the kidneys?

Answer 15

The cortex (reddish outer region )and the medulla (reddish brown inner region containing renal pyramids)

Question 16

How does the renal pyramids and the ureter connect?

Answer 16

Small tubules from the pyramids join together to form a large cavity called the renal pelvis. The urine from the renal pelvis passes into the ureter

Question 17

What is a nephron?

Answer 17

Functional unit of kidneys with more than a million in each kidney

Question 18

What are the 2 types of nephrons?

Answer 18

Juxtamedullary (extend deep into the medulla-urinary concentration) and Cortical (85% occasionally penetrate the medulla)

Question 19

What does each nephron consist of?

Answer 19

A dense network of capillaries called glomerulus surrounded by a cup shaped Bowmans capsule and the renal tubules.

Question 20

What do the glomerulus and the Bowmans capsule make up and where are they found?

Answer 20

A filtration system through which blood is filtered. Found in the cortex of kidney

Question 21

What are the 2 types of tubular secretion?

Answer 21

Active and passive

Question 22

What is active tubular secretion?

Answer 22

Sodium ions takes up 80% of our transport because its needed to produce energy (na/k pump) in order to power the other solutes as well as glucose, amino acids and vitamins

Question 23

What is passive (diffusion) tubular secretion?

Answer 23

Along the pressure gradient; H2O, fats K+, Cl, lipid soluble drugs are difficult to excrete because of above

Question 24

What is GFR?

Answer 24

The total amount of filtrate formed per minute by the kidneys

Question 25

What are factors governing filtration rate at the capillary bed?

Answer 25

Total surface area available for filtration, filtration membrane permeability and net filtration pressure

Question 26

What is normal GFR in both kidneys?

Answer 26

120-125 ml/min

Question 27

Why do the kidneys adjust their smooth muscle?

Answer 27

In response to changes of blood pressure. If blood vessels are stretched, smooth muscle contracts. If BP is too low, smooth muscle dilates

Question 28

What do the specific cells that are part of the juxtaglomerular apparatus do?

Answer 28

Surround distal tubule and monitor the concentration of NaCl in the filtrate. If concentration is high, smooth muscles of arterioles constrict and too low dilation occurs

Question 29

What occurs to the sympathetic nervous system under stress?

Answer 29

Noradrenaline released by sympathetic nervous system, adrenaline released by adrenal medulla, overall effect is constriction of afferent arterioles and inhibition of filtration and renin-angiotensin mechanism is stimulated

Question 30

What are the uteters?

Answer 30

Continuation of renal pelvis and enter bladder at angle so when bladder is full, ureters compressed to prevent backflow