Endocrine

Question 1

What is the definition of a hormone?

Answer 1

A chemical produced by an endocrine organ and transported in the bloodstream

Question 2

Do hormones initiate new processes?

Answer 2

No they modify existing process

Question 3

What are paracrine signals?

Answer 3

Signals that affect nearby cells

Question 4

What are autocrine signals?

Answer 4

Signals that act on cells that secreted them

Question 5

What are the four main chemical classes of hormones?

Answer 5

• Amino acids
• Fatty acids
• Peptide/proteins
• Steroids

Question 6

How are protein hormones synthesised and released?

Answer 6

Synthesised in the cell, stored in granules and secreted by exocytosis in response to a signal

Question 7

How are steroid hormones synthesis and released?

Answer 7

Synthesised from cholesterol and immediately released upon stimulation they are not stored

Question 8

How are protein and peptide hormones transported in the blood?

Answer 8

They are hydrophilic and dissolve directly in plasma

Question 9

How are steroid and thyroid hormones transported?

Answer 9

They bind to transport proteins which restrict diffusion but prolong hormone action by slowing degradation

Question 10

Why are hormone effects specific and localised?

Answer 10

Only target cells have specific receptors with high affinity for particular hormones

Question 11

Where are the receptors for steroid hormones?

Answer 11

In the cytoplasm or nucleus

Question 12

Where are the receptors for protein hormones located?

Answer 12

On the plasma membrane

Question 13

What are the three components of a homeostatic feedback system?

Answer 13

• Receptors
• Control center
• Effectors

Question 14

What is the set point in a feedback loop?

Answer 14

Is the target value or range that a physiological parameter is regulated around

Question 15

What happens if hormone production is too high or too low?

Answer 15

Can disrupt homeostasis and cause physiological dysfunction or disease

Question 16

What is the hypothalamic-hypophyseal tract?

Answer 16

The neural connection between the hypothalamus and posterior pituitary

Question 17

What happens at the hypothalamic-hypophyseal tract?

Answer 17

Axons from the paraventricular and supraoptic nuclei terminate

Question 18

What two hormones are released by the posterior pituitary?

Answer 18

• ADH
• Oxytocin

Question 19

What is another name for vasopressin?

Answer 19

ADH

Question 20

What are the functions of oxytocin?

Answer 20

• ilk ejection
• Uterine contraction
• Sperm transport
• Prolactin synthesis
• Release of PGF₂α from corpus luteum and endometrium

Question 21

What are 5 things that stimulates ADH secretion?

Answer 21

• Pain
• Nicotine
• Acetylcholine
• Morphine
• Chloroform

Question 22

What inhibits ADH secretion?

Answer 22

Alcohol

Question 23

What is the function of ADH?

Answer 23

Helps the body conserve water by increasing water reabsorption in the kidneys

Question 24

What happens when ADH is too low?

Answer 24

Causes diabetes insipidus

Question 25

What is diabetes insipidus?

Answer 25

Large volumes of dilute urine and inability to conserve water

Question 26

What are the two types of diabetes insipidus?

Answer 26

- Central - Nephrogenic

Question 27

What is central diabetes insipidus?

Answer 27

When no ADH is secreted

Question 28

What is nephrogenic diabetes insipidus?

Answer 28

When ADH is secreted but kidneys do not respond

Question 29

What happens when ADH is too high?

Answer 29

Idiopathic ADH syndrome

Question 30

What does idiopathic ADH syndrome lead to?

Answer 30

- Increased water retention - Hyponatremia (low Na) - Hypoosmolality (low electrolytes)

Question 31

Where are the neurons that produce ADH and oxytocin located?

Answer 31

Paraventricular and supraoptic nuclei of the hypothalamus