16.1-16.5 Endocrine System

Question 1

Coordinates and integrates activity of the body; Works with the nervous system
Influences metabolic activities via hormones

Answer 1

Endocrine system

Question 2

Chemical messengers secreted by cells into extracellular fluids
Travel through blood and lymph for long distances
Bind to cellular receptors
Regulate metabolic function of other cells

Answer 2

Hormones

Question 3

Study of hormones and endocrine organs

Answer 3

Endocrinology

Question 4

Endocrine system responses are _________ but _________ than nervous system responses
Acts at diffuse locations (anywhere blood can reach)

Answer 4

Slower, longer

Question 5

1. Reproduction
2. Growth and Development
3. Maintenance of electrolyte, water, nutrient balance
4. Regulation of cellular metabolism and energy balance
5. Mobilization of body defenses

Answer 5

What ES controls:

Question 6

One or more cells that make and secrete a product

Answer 6

Gland

Question 7

To secrete

Answer 7

-Crine

Question 8

Internal, within
External

Answer 8

Endo-

Question 9

Externally secreting
Produce non hormonal substances (ex. sweat, saliva)
Have ducts to carry secretion to membrane surface

Answer 9

Exocrine glands

Question 10

Internally secreting; Produce hormones; Lack ducts
(Some have functions of endo and exocrine ex. Pancreas)

Answer 10

Endocrine glands

Question 11

Chemicals that exert effects on same cells that secrete them
(not always considered part of ES)

Answer 11

Autocrine

Question 12

Act within same tissue produced, chemicals that affect cells other than those that secrete them
(not always considered part of ES)

Answer 12

Paracrine hormones

Question 13

First class of hormone; Amino acid derivatives, peptides, and proteins
Most hormones

Answer 13

Amino acid hormones

Question 14

Second class of hormone; Synthesized from cholesterol
Gonadal and adrenocortical hormones

Answer 14

Steroid hormones

Question 15

Possible third class

Answer 15

Eicosanoid hormones

Question 16

How do hormones act?

Answer 16

Through second messengers/activating genes

Question 17

Tissue with receptor for specific hormone
Hormones alter target cell activity
Response depends on type of target cell

Answer 17

Target cells

Question 18

1. Alters plasma membrane permeability
2. Stimulates synthesis of enzymes
3. Activates or deactivates enzymes
4. Induces secretory activity
5. Stimulates mitosis

Answer 18

Changes hormones make:

Question 19

First action of hormones; Cannot cross the plasma membrane to enter the cell
Act on plasma membrane receptors by binding to outside
Most use a secondary messenger mechanism
Most amino acid hormones (except thyroid)

Answer 19

Water-soluble hormones

Question 20

Second action hormones; Can cross the plasma membrane
Act on intracellular receptors inside
Receptor-hormone complex directly activates genes
Steroid and thyroid hormones

Answer 20

Lipid-soluble hormones

Question 21

1. Hormone (1st messenger) binds to receptor
2. Receptor activates G protein
3. G protein activates adenylate cyclase
4. Adenylate cyclase converts ATP to cAMP (2nd messenger)
5. cAMP activates protein kinases

Answer 21

Water soluble hormone mechanism

Question 22

1. Type of target cell
2. Specific protein kinase the cell contains
3. Substrates in the cell available for protein kinase to act upon

Answer 22

Motion by cAMP requirements:

Question 23

1. Steroid hormone diffuses through the plasma membrane and binds to intracellular receptor
2. Receptor-hormone complex enters the nucleus
3. The receptor-hormone complex binds a specific DNA region
4. Binding initiates transcription of the gene to mRNA
5. mRNA directs protein synthesis

Answer 23

Lipid-soluble mechanism

Question 24

Regulated by negative feedback; Causes blood levels of hormones to vary only within narrow, desirable range
Hormone secretion –> hormone levels rise –> effect occurs on target organ –> further hormone release is inhibited

Answer 24

Hormone release

Question 25

Endocrine gland stimuli; Changing blood levels of ions (Ca2+) and nutrients directly stimulate secretion of hormones Response: Parathyroid hormone released, increases blood Ca2+

Answer 25

Humoral stimuli

Question 26

Endocrine gland stimuli; Nerve fibers stimulate hormone release by action potential Response: Adrenal medulla cells secrete epinephrine and norepinephrine

Answer 26

Neural stimuli

Question 27

Endocrine gland stimuli; Hormones secreted by endocrine organs stimulate other endocrine organs to release their hormones; Chain reaction

Answer 27

Hormonal stimuli

Question 28

Hormones from final target organs inhibit release of anterior pituitary gland

Answer 28

Hypothalamic-pituitary-target endocrine feedback loop

Question 29

NS makes adjustments to hormone levels when needed NS can override normal endocrine controls and maintain homeostasis

Answer 29

Nervous system modulation

Question 30

1. Blood level of hormone 2. Relative number of receptors on/in target cell 3. Affinity of binding between receptor and hormone

Answer 30

Target cell activation:

Question 31

Target cells create more receptors in response to low hormone levels

Answer 31

Up-regulation

Question 32

Target cells lose receptors in response to high hormone levels

Answer 32

Down-regulation

Question 33

Concentration of circulating hormone in blood reflects:

Answer 33

1. Rate of release of hormone 2. Speed at which the hormone is inactivated

Question 34

Hormones are either bound to a protein carrier or float free?

Answer 34

True

Question 35

Kidneys Liver Degrading enzymes (target cells)

Answer 35

Things that remove hormones from blood:

Question 36

Time required for level of hormone in blood level to decrease by half

Answer 36

Half life

Question 37

***hormone fact sheet*** onset and duration

Question 38

Multiple hormones may act on same target at same time?

Answer 38

True

Question 39

1st hormone interaction; When one hormone cannot exert its effects without another hormone being present

Answer 39

Permissiveness

Question 40

2nd hormone interaction; When more than one hormone produces same effects on target cell, causing amplification of effects

Answer 40

Synergism

Question 41

3rd hormone interaction; When hormone opposes the action of another hormone

Answer 41

Antagonism