Lec 22

Question 1

What differs between an endocrine and exocrine gland?

Answer 1

Endocrine glands secrete into the body and involve exocytosis into the blood.

Exocrine glands are secreted onto the skin and undergo exocytosis in a bulb formation.

Question 2

Compare and contrast the ANS and the endocrine system

Answer 2

The Ans is rapid, and the endocrine system is slow but longer lasting. The ANS uses neurons, and the endocrine system uses glands. The ANS uses neurotransmitters, the endocrine system uses hormones

Question 3

What are the 4 types of hormone movement systems?

Answer 3

-Classical endocrine system is where the hormone goes into the bloodstream and effects a response in another cell
-Autocrine systems effect themselves
-Paracrine the cell creating the hormone that isn’t released into the bloodstream but affects a close by cell.
-Neurocrine: A neuron releases a hormone into the bloodstream that effects an effector.

Question 4

What is a hormone?

Answer 4

It is a chemical substance that regulates metabolic activity

Question 5

What must hormones bind to to influence function?

Answer 5

Specific receptors

Question 6

What do the levels of target cell function relating to hormones depend on?

Answer 6

1. Hormone Concentration
2. target cell receptor content
3. the affinity of the hormone for the receptor

Question 7

What do hormones alter? (5)

Answer 7

They alter the levels of cell activity:
1. membrane permeability
2. synthesis of enzymes
3. enzyme activation/deactivation
4. Induction of secretory activity
5. Stimulation of mitosis

Question 8

What are the three structural classifications of hormones?

Answer 8

1. Amino acids, peptides, and proteins
2. Steroids
3. eicosanoids (COOH)

Question 9

What is the mechanism of action for proteins/peptides?

Answer 9

They are water soluble so they bind to a surface cell receptor and produce a 2nd messenger through a G protein

Question 10

Describe the mechanism of action in a steroid hormone

Answer 10

They are fat soluble so they can enter the nucleus and effect gene transcription. The hormone binds to a receptor and enters the nucleus where it initiates the transcription of the gene to mRNA which directs protein synthesis.

Question 11

Why don’t we need much hormone in our bodies?

Answer 11

Hormones are potent and the effects are amplified.

Question 12

What does the level of blood hormone depend on?

Answer 12

The rate of synthesis and the rate of clearance from the blood

Question 13

What is the half-life of a hormone?

Answer 13

Its measure of persistence, it varies between less than a minute or up to a week

Question 14

What affects the speed of onset of hormone activation?

Answer 14

If enzyme is activated it is rapid, if it is synthesized it can take hours to days.

Question 15

In terms of hormone levels, what is positive feedback and negative feedback?

Answer 15

Positive feedback would be releasing hormone to an end goal, and negative feedback would be the maintenance of a set level

Question 16

What are the three types of hormonal stimuli?

Answer 16

Humoral, neural, and hormonal

Question 17

What is humoral stimulus?

Answer 17

It is a hormone secretion in direct response to a change in blood levels i.e. PTH and calcium, insulin and glucose

Question 18

What is neural stimulus?

Answer 18

It is less common, it deals with the SNS and epinephrine release, or hypothalamic neurons and oxytocin release.

Question 19

What is hormonal stimulus?

Answer 19

It is a 3 tiered system that involves the hypothalamus, pituitary, and target endocrine gland.

Question 20

What is a common example of hormonal stimulus?

Answer 20

1. Thyroid releasing hormone is released from the hypothalamus
2. The hormone makes the anterior pituitary gland release thyroid stimulating hormone
3. This goes to the thyroid gland that releases T3 and T4

Question 21

What is the hypophyseal portal system?

Answer 21

It is a set of 2 capillary beds that connect the hypothalamus and the anterior pituitary.

Question 22

How can we describe the pituitary gland?

Answer 22

It is the size and shape of a pea.

Question 23

What is important about the posterior pituitary gland?

Answer 23

It consists of axons, and it can be thought of as a hormone storage area that holds antidiuretic hormone (SON) and oxytocin (PVN).

Question 24

What connects the pituitary gland with the hypothalamus?

Answer 24

The infundibulum

Question 25

What is the hormonal stimulus system that deals with the thyroid glands?

Answer 25

Hypothalamic Releasing Hormone = Thyroid releasing hormone
Anterior pituitary hormone = Thyroid stimulating hormone
Target gland = Thyroid gland

Question 26

What is the hormonal stimulus system that deals with the adrenal glands?

Answer 26

Hypothalamic Releasing Hormone = Corticotropin releasing hormone
Anterior pituitary hormone = Adrenocorticotropic hormone
Target gland = Adrenal Cortex

Question 27

What is the hormonal stimulus system that deals with the liver?

Answer 27

Hypothalamic Releasing/Inhibitory Hormone = Somatostatin (inhibitory) and GRH/GHRH (releasing)
Anterior pituitary hormone = Growth hormone
Target gland = Liver

Question 28

What is the hormonal stimulus system that deals with the gonads?

Answer 28

Hypothalamic Releasing Hormone = Gonadotropin releasing hormone (GNRH)
Anterior pituitary hormone = FSH/LH
Target gland = Ovaries/Gametes

Question 29

What is the hormonal stimulus system that deals with the breasts? lol

Answer 29

Hypothalamic Releasing/Inhibitory Hormone = Dopamine (inhibitory) oxytocin/TRH (releasing)
Anterior pituitary hormone = Prolactin
Target gland = boobs mammary glands boobs

Question 30

Bonus slide!

Answer 30