Bio 202 Beginning Through Pituatary Readings

Question 1

Down regulation

Answer 1

If a hormone is present in excess, the number of Target cell receptors May decrease

This makes a Target cell less sensitive to a hormone

Question 2

Up regulation

Answer 2

When a hormone is deficient the number of receptors may increase

This makes a Target cell more sensitive to a hormone

Question 3

Circulating hormones

Answer 3

Most endocrine hormones are these

They pass from the secretory cells that make them into interstitial fluid and then into the blood

Question 4

Local hormones

Answer 4

Hormones that act locally on neighboring cells or on the same cell that secreted them without entering the bloodstream

Question 5

Paracrine hormones

Answer 5

Local hormones that act on neighboring cells

Question 6

Autocrine hormones

Answer 6

Local hormones that act on the same cell that secreted them

Question 7

Two chemical classes of hormones

Answer 7

Those that are soluble in lipids and those that are soluble in water

Question 8

What are the four types of lipid soluble hormones

Answer 8

Steroid hormones
Thyroid hormones
Nitric oxide
Ecosanoid hormones

Question 9

Steroid hormones

Answer 9

Are derived from cholesterol

Each is unique due to the presence of different chemical groups attached to various sites on the four rings at the core of its structure

This allows for a large diversity of functions

Question 10

Thyroid hormones

Answer 10

T3 and t4 are synthesized by attaching iodine to the amino acid tyrosine

The presence of two benzene rings with a t3 or t4 molecule makes these molecules very lipidsoluble

Question 11

Nitric oxide

Answer 11

Is both a hormone and a neurotransmitter it synthesis is catalyzed by the enzyme nitric oxide synthase

Question 12

Ecosanoid hormones

Answer 12

Are derived from arachidonic acid a 20 carbon fatty acid

The two major types include prostaglandins and lucatrines

They are important local hormones and they may act as circulating hormones as well

Question 13

What are the two types of water-soluble hormones?

Answer 13

Amine hormones and peptide hormones

Question 14

Amine hormones

Answer 14

Are synthesized by decarboxylating meaning removing a molecule of CO2 And otherwise modifying certain amino acids

They are called amines because they retain an amine group

The catecholamines, epinephrine norepinephrine dopamine are synthesized by modifying the amino acid tyrosine

Histamine is synthesized from the amino acid histidine by mast cells and platelets

Serotonin and melanin are derived from tryptophan

Question 15

Peptide hormones and protein hormones

Answer 15

Water soluble hormones that are amino acid polymers

The smaller peptide hormones consist of chains of 3 to 49 amino acids larger 50 to 200

Examples are antidiuretic, hormone and oxytocin

Protein hormones include growth, hormone and insulin

Several of the protein hormones such as thyroid stimulating hormone have attached carbohydrate groups and thus are glycoprotein hormones

Question 16

The responsiveness of a Target cell to a hormone depends on what three things in hormone interactions

Answer 16

The hormones concentration in the blood

The abundance of the target cell’s hormone receptors

Influences exerted by other hormones

Question 17

What is the permissive effect of a hormone interaction

Answer 17

The actions of some hormones on target cells require a simultaneous or recent exposure to a second hormone

For example, epinephrine alone only weakly stimulates lipolysis but when small amounts of thyroid hormones are present the same amount of epinephrine stimulates lipolysis much more powerfully

Sometimes the permissive hormone increases the number of receptors for the other hormone and sometimes it promotes the synthesis of an enzyme required for the expression of the other hormones affects

Question 18

What is the synergistic effect in hormone interactions

Answer 18

The effect of two hormones acting together is greater than the sum of their individual effects

For example, glucagon and epinephrine increase blood glucose concentration and when both are present, the increase in blood glucose concentration is greater than the sum of the individual hormone responses

Question 19

What is the antagonistic effect in hormone interactions

Answer 19

When one hormone opposes the actions of another hormone

Question 20

What factors regulate hormone secretion

Answer 20

Signals from the nervous system

Chemical changes in the blood

Other hormones

Question 21

Do most hormonal regulatory systems work via positive feedback or negative feedback?

Answer 21

Negative feedback

Question 22

What is seasonal affective disorder

Answer 22

A type of depression that afflicts some people during the winter months when daily this short

It is thought to be due in part over production of melatonin

Full spectrum bright light therapy repeated doses of several hours of exposure to artificial light as bright as sunlight provides relief for some people

Question 23

What type of therapy can help jet lag

Answer 23

Can help jet lag? 3 to 6 hours of exposure to Bright light appears to speed recovery from jet lag

The fatigue suffered by travelers who quickly cross several time zones

Question 24

What is non-steroidal anti-inflammatory drugs?

Answer 24

nsaids such as ibuprofen inhibit cyclohenase a key enzyme involved in prostaglandin synthesis

They are used to treat a wide variety of inflammatory disorders for rheumatoid arthritis to tennis elbow

They are successful in reducing fever, pain and inflammation

Question 25

Define eustress

Answer 25

A stress that prepares us to meet certain challenges and is thus helpful

Question 26

Define distress

Answer 26

Other stress that is not helpful but harmful

Question 27

What is a stressor

Answer 27

Any stimulus that produces a stress response? It may be almost any disturbance of the human body Heat or cold? Environmental poisons Toxins from bacteria Heavy bleeding Strong emotions Can be pleasant or unpleasant

Question 28

Define stress response

Answer 28

Also called general adaptation syndrome Your body's homeostatic mechanisms attempt to counteract stress. If the stress is extreme, unusual or long-lasting, these normal mechanisms may not be enough A variety of stressful conditions or noxers agents elicit a similar sequence of bodily changes. This is called the stress response

Question 29

What are the three stages of the stress response

Answer 29

Initial fight or flight response A slower resistance reaction Exhaustion

Question 30

What happens during the fight or flight response

Answer 30

Nerve impulses from the hypothalamus to the sympathetic part of the ANS Mobilizes the body's resources for immediate physical activity, bringing glucose and oxygen to the organs. Most active in warding off danger, including the brain skeletal muscles and heart Digestive urinary and reproductive activities are inhibited

Question 31

What is the resistance reaction

Answer 31

It is initiated in large part by hypothalamic releasing hormones and is a lot longer lasting reaction Hormones involved are CRH, ghrh, and trh Crh stimulates anterior pituitary to release ACTH which stimulates super renal cortex to increase release of cortisol Ghrh causes interior pituitary to release GH which stimulates lipolysis glycogenolysis Trh stimulates anterior pituitary to secrete TSH TSH promotes secretion of thyroid hormones which stimulate the increased use of glucose for ATP production This stage helps the body continue fighting a stressor long after the fight-or-flight response dissipates and is why your heart continues to pound for several minutes even after the stressor is removed

Question 32

What is the exhaustion stage of the stress response

Answer 32

The body's resources may eventually become so depleted. They cannot sustain the resistance stage Prolonged exposure to high levels of cortisol and other hormones involved in the resistance reaction cause wasting a muscle suppression of the immune system ulceration of the digestive canal and failure of pancreatic beta cells Pathological changes may occur because resistance reactions persist after the stressor has been removed