Week 10 - Hormones and Behaviour

Question 1

What are hormones?

Answer 1

Chemical substances, formed in a specialized gland or group of cells, released into the blood that affect target cells in another organ.
Hormones reach all parts of the body, but only target cells have receptors for that hormone.

Question 2

The endocrine system refers to what?

Answer 2

a set of glands that produce chemical messengers called hormones.

Question 3

What does the pituitary gland regulate?

Answer 3

“Master Gland” that regulates all other EndocrineGlands, also releases growth hormone.

Question 4

What does the thyroid gland regulate?

Answer 4

Metabolism, body heat, bone growth.

Question 5

What do the parathyroids regulate?

Answer 5

Use of Calcium and Phosphorous.

Question 6

What does the hypothalamus gland regulate?

Answer 6

Links nervous system to endocrine system.

Question 7

What does the adrenal gland regulate?

Answer 7

Response in emergency or stressful situations, metabolism, blood pressure, salt balance.

Question 8

What are the activational effects of hormones?

Answer 8

Short-term, reversible effects that occur in the fully developed organism (e.g. alteration of transmission in neural networks that respond to certain aspects of the environment).

Question 9

What are the organisational effects of hormones?

Answer 9

Long-term, irreversible effects on tissue differentiation and development (e.g. brain, ovary) that can either directly (brain) or indirectly (ovary) influence behaviour.

Question 10

What are the two major classes of hormones the endocrine system produces?

Answer 10

protein hormones and steroid hormones.

Question 11

What are protein hormones?

Answer 11

These comprise amino acids. They exert their effect by binding to the membrane receptor of the target cell.

Question 12

What are steroid hormones?

Answer 12

These are derived from cholesterol from the diet and exert their effects in two ways:

i) They bind directly to membrane receptors.
ii) As they are fat-soluble they pass through cell membranes where they attach to receptors in the cytoplasm. Here they determine gene expression.

Question 13

Differentiate peptide hormones and polypeptide hormones.

Answer 13

Both are protein hormones comprising of amino acids. those that are only several amino acids in length are called peptide hormones, whereas larger ones are called polypeptide hormones.

Question 14

What are the three main types of protein hormones?

Answer 14

insulin, glucagons, and leptin.

Question 15

What is insulin?

Answer 15

A protein hormone, made in the pancreas, it increases the entry of glucose into the cells and regulates fat storage.

Question 16

What are glucagons?

Answer 16

A protein hormone, made in the pancreas, are responsible for increasing the conversion of stored fats to blood glucose.

Question 17

What is leptin?

Answer 17

A protein hormone, produced by the fat cells, informs the brain how much fat is contained in the body.

Question 18

How does leptin relate to appetite?

Answer 18

When leptin levels are high appetite is decreased. When leptin levels are low appetite is increased and bodily activity is reduced.

Question 19

What are the main types of steroid hormones?

Answer 19

corticoids and sex steroids.

Question 20

What are the main types of corticoids (explain them)?

Answer 20

Glucocorticoids(principally cortisol) are released by the adrenal glands in response to stress. They increase the breakdown of fats and proteins into glucose to trigger escape or defence (“fight or flight”).
Mineralocorticoids(e.g. aldosterone) are also produced by the adrenal glands and reduce salt secretion in the kidneys.

Question 21

What are the three sex steroids?

Answer 21

Androgens, estrogens, and progesterone.

Question 22

What is androgen?

Answer 22

Testosterone, is produced in large amounts in males and has masculinising and defeminising effects; maintaining male secondary sexual characteristics (sex distinguishing features that are not directly related to reproduction) and promoting courtship, aggressive and sexual behaviours.

Question 23

What is estrogen?

Answer 23

Estradiolis produced in large amounts in females and has feminising effects, promoting female secondary sexual characteristics, water retention, calcium metabolism, sexual behaviour and maternal behaviours.

Question 24

What is progesterone?

Answer 24

prepares uterus and breasts for pregnancy and regulates the stages of pregnancy.

Question 25

True or false: sex steroids are sex-specific?

Answer 25

False, both males and females produce androgens and estrogens though their relative concentrations differ.

Question 26

True or false: Individual differences in behaviour and physiology reflect differences in hormone concentration?

Answer 26

False, While overall concentration is indeed important, of equal importance is the receptivity of the cells to the hormone. A high hormone concentration will have little effect if cells lack receptivity. An excellent example of this is Androgen Insensitivity Syndrome.

Question 27

What two key structures control hormone release?

Answer 27

The hypothalamus and the pituitary gland.

Question 28

What is the primary purpose of the hypothalamus?

Answer 28

To maintain homeostasis.

Question 29

The DNA molecule is packaged into thread-like structures called what?

Answer 29

Chromosomes.

Question 30

In humans, each cell nucleus contains how many pairs of chromosomes?

Answer 30

23 for a total of 46.

Question 31

What are autosomes?

Answer 31

The first 22 pairs of chromosomes not including the sex chromosome.

Question 32

What is Y?

Answer 32

The male sex chromosome for many species.

Question 33

Differentiate the Wolffian system from the Mullerian system.

Answer 33

Wolffian system – male system. Mullerian system – female system. All babies begin with both sets of ducts, differentiation happens in the third month.

Question 34

Later in pregnancy, females secret large amounts of hormones like oxytocin and prolactin, what is the purpose of these hormones?

Answer 34

Prolactin is necessary for milk production. Oxytocin is associated with maternal behaviour and social attachment.