Endocrine System

Question 1

What is the endocrine system?

Answer 1

A system of glands that secrete hormones directly into the bloodstream.
( regulate the function of target organs and maintain homeostasis )

Question 2

What’s homeostasis?

Answer 2

Maintaining the internal environment within the body.

Question 3

What’s a hormone?

Answer 3

A chemical messenger that brings out changes in the body

Question 4

What is the pituitary gland split into?

Answer 4

Anterior and posterior lobes

Question 5

What does the pancreas produce?

Answer 5

• Hormones responsible for controlling blood glucose levels.

Question 6

What happens when blood glucose levels are high?

Answer 6

• Insulin is produced = by beta cells → in the ‘ islets of langerhans’
• insulin binds to liver & muscle cells → causes then to take in glucose & convert it into glycogen

( glucose → glycogen) = process= glycogenesis

Question 7

What happens when blood glucose levels are low?

Answer 7

• Glucagon produced by alpha cells = in ‘islets of langerhans’
• glucagon binds to liver & muscle cells = causes them to break down glycogen into glucose (glycogenolysis) & releases it into blood stream

Question 8

What is glycogenesis?

Answer 8

Process of converting glucose into glycogen for storage in the liver & muscle cells.
( glucose → glycogen = blood glucose too high)

Question 9

What is glycogenolysis?

Answer 9

Breakdown of glycogen into glucose, then released into bloodstream to increase blood glucose levels.
( breakdown glycogen → glucose =î levels)

Question 10

What’s negative feedback?

Answer 10

• Mechanism that restores a system to its original level by reversing any change.

Question 11

How do hormones transmit signals around the body?

Answer 11

• secretion of endocrine glands into bloodstream
• transports through blood
• cells with complementa receptors for specific hormone will respond to it.
• widespread effects.

Question 12

Where is insulin & glucagon made?

Answer 12

Pancreas

Question 13

How does ultrafiltration work?

Answer 13

( Process when small molecules are filtered out of blood and high pressure in glomerulus of kidney.)

-Blood inters glomerulus
- pressure forces wat, glucose & ions into bowman’s capsule.

Question 14

How does the loop of hence & collecting duct help reabsorb water?

Answer 14

• Creates a water potential gradient
• reabsorbs rate using the gradient ( duct passes through medulla )

Question 15

Name regions of the kidney

Answer 15

-Medulla
- pelvis
- cortex
-Ureter
-Renal artery
- renal vein

• nephrons are responsible for making urine

Question 16

Process of urine formation:

Answer 16

• During ultra filtration = molecules are filtered out
• glomerular filtrate = passes through proximal tubule where useful substances (glucose, water) = selectively reabsorbed =into peritubular capillaries
• filtrate passes through loop of hence = concentrates salts in medulla = create osmotic gradient
• filtrate passes through distal tubule & collecting duct = water reabsorbed into surrounding capillaries (down concentration gradient)

Question 17

What is ADH ?

Answer 17

Hormone responsible for controlling water content of blood = by negative feedback & enables more concentrated ruin to be formed.

Question 18

How is change in osmotic concentration found?

Answer 18

Detected by osmoreceptors = in the hypothalamus

Question 19

Where is ADH response coordinated?

Answer 19

Posterior lobe (brain) = pituitary gland

Question 20

Response in ADH when water levels fall.

Answer 20

• More water is secreted

Question 21

Response of ADH when water levels rise

Answer 21

• Less rate is secreted

Question 22

Where does ADH travel through?

Answer 22

• Blood & binds to receptors on plasma membranes

Question 23

What does ADH do to plasma membranes?

Answer 23

• more permeable to water.

Question 24

function of the kidney?

Answer 24

Excrete waste products & regulate the water potential of the blood.

Question 25

What is responsible for the formation of urine?

Answer 25

Nephrons

Question 26

Urine production summary:

Answer 26

- Urea is waste product made in the liver. - water content is controlled by kidneys. - urea + water = urine - urine travels down ureter & stored in bladder. - urine is excreted through urethra.

Question 28

How does urodynamic testing work?

Answer 28

- Record the length of time it takes a person to produce a urinary stream. - record volume of urine produced. - recording the ability or inability to stop the urine flow in midstream. ( cameras = for inside the bladder, pressure monitors )