Chapter 17

Question 1

what is the Endocrine System (simple)

Answer 1

Hormones travel via bloodstream

Question 2

Autocrine

Answer 2

Secreted by cells in a local area. influences the activity of the same cell from which it was secreted.
eicosanoids (prostaglandins, thromboxanes, prostacyclins, leukotrienes)

Question 3

Paracrine

Answer 3

produced by a wide variety of tissues and secreted into extracellular fluid; has a localized effect on other tissues.
somatostatin, histamine, eicosanoids.

Question 4

Neurotransmitters

Answer 4

Produced by neurons; secreted into a synaptic cleft by presynaptic terminals; travels short distances; influences postsynaptic cells.
Acetylcholine, epinephrine

Question 5

Endocrine response is secreted into the

Answer 5

Secreted into the blood by specialized cells; travels some distance to target specific tissues

Question 6

Characteristics of the Endocrine System

Answer 6

Glands that secrete chemical messengers (hormones) into circulatory system (blood).
Regulates Activities (growth & reproduction) of body structures.

Question 7

Hormone Characteristics

Answer 7

1. produced in small quantities
2. secreted int intercellular space (outside of cell)
3. transported some distance in circulatory system
4. acts on target tissue elsewhere in the body (must posse receptors)

Question 8

Ligands

Answer 8

General term for chemical signals

Question 9

Similarities of Nervous and Endocrine System

Answer 9

1. Both systems associated with the brain. (hypothalamus - to control the pituitary gland. Epithalamus (pineal gland))
2. may use same chemical messenger as neurotransmitter and hormone. (epinephrine)
3. two systems are cooperative.

Question 10

Differences of Nervous & Endocrine System

Answer 10

1. mode of transport : nervous system uses axon of neurons via synapsis. Endocrine system uses blood stream
2. speed of response: Nervous system - instant/milliseconds. Endocrine system: Delayed/seconds.
   3.Duration of responses:
   Nervous system - milliseconds/seconds. Endocrine system: mintues/days.

Question 11

Duration of response nervous vs. endocrine system

Answer 11

The target cell/tissue produces a longer resonse with the endocrine system compared to the nervous system

Question 12

Lipid Soluble Hormones

Answer 12

absorbed/disolved by fat. hydrophobic (hates water).

Lipid soluble hormones have a longer half-life compared to water soluble hormones

Question 13

Water Soluble hormones

Answer 13

Absorbed/disolved by water - water loving/Hydrophilic.

water soluble hormones have a shorter half-life compared to lipid soluble hormones

Question 14

Lipid Soluble Vitamins

Answer 14

Vitamin A, D, E, K - can lead to toxicity if taken too much because they are harder to get rid of (stored in fats)

Question 15

Water soluble vitamins taken too much will lead to ___

Answer 15

if taken too much, kidneys can excrete excessive levels of water soluble vitamins

Question 16

what binding protein do water-soluble hormones need?

Answer 16

Water soluble hormones don’t need a binding protein when traveling in blood

Question 17

Patterns of Hormone Secretion

Answer 17

1. chronic hormone regulation - maitenance of relatively constant concentrations of hormone. (thyroid hormone regulates basal metabolism)
2. Acute hormone regulation - epinephrine in response to stress
3. episodic (cyclic) hormone regulation - female reproductive system

Question 18

Control of Hormone Secretion PTH

Answer 18

PTH Parathyroid hormone > stimulates osteoclasts (catastrophe bc they take calcium away from the bone and if stimulated too much may lead to osteoperiosis) > bone calcium levels decrease > blood calcium levels increase

Question 19

Control of Hormone Secretion Calcitonin

Answer 19

Calcitonin does oposite of PTH : secretion of calcitonin leads to stimulation of osteoblasts (bone building cells) causing an increase of calcium being added to the bone causing a decrease of blood calcium levels

Question 20

Negative Feedback

Answer 20

Ultimately turns off system. likes to maintain homeostasis (normal baseline, normal range, stable environment).

Question 21

Positive Feedback

Answer 21

It is a system that further deviates from normal baseline or homeostasis.

Question 22

Down-Regulation (Endocytosis)

Answer 22

takes away receptors on the cell membrane and decreases the cells response.

Question 23

Up-Regulation

Answer 23

adding more receptors to the cell membrane: exocytosis: increases cell response

Question 24

Overview of Hormone receptors and mechanisms of action Lipid Soluble and small molecules

Answer 24

Hormone

nuclear receptors

activates genes

synthesizes new proteins or enzymes

cell responds

Question 25

Hormone receptors and mechanisms of actions for Water soluble and large molecules

Answer 25

Membrane bound receptors receptors after the activity of G proteins Open of close Ion channels and activates existing enzymes cell responds OR Membrane bound receptors Receptors alter the activity of intracellular enzymes activate existing enzymes cell responds

Question 26

Hormone examples for Lipid Soluble

Answer 26

(receptor type : nuclear) ``` Steroid hormone testosterone estrogen progesterone aldosterone cortisol thyroid hormone vitamin D ```

Question 27

Hormone examples for water-soluble

Answer 27

(receptor type: membrane bound) ``` luteinizing hormone follicle-stimulating hormone thyroid stimulating hormone adrenocorticotropic hormone glucagon oxytocin antidiuretic hormone calcitonin parathyroid hormone epinephrine insulin growth hormone prolactin ```