1.4 Cell Physiology

Question 1

Which cells can release hormones that affect the parameter?

Answer 1

Only cells that monitor the parameter (ex: body temp, blood glucose, blood salinity)

Question 2

What must cells have to react to hormonal signals?

Answer 2

Correct hormone receptors

Question 3

Conceptual framework for Endocrine Control Systems

Answer 3

Sensor cells –> Integrator cells –> Effector cells–> Physiological parameter normalized

Question 4

Sensor cells

Answer 4

Assess parameter

Question 5

Integrator cells

Answer 5

Hi / lo?

Send out the messengers…

Question 6

Effector Cells

Answer 6

Target tissue function altered

Question 7

What do TRH neurons do?

Answer 7

Sense low body temp w/ thermoreceptors

Question 8

What does TRH do?

Answer 8

Causes TSH and Thyroid (T3, T4) hormones to be released which increases metabolism to release heat

Question 9

What do TRH neurons do if a high temp is sensed?

Answer 9

Suppress TRH

Question 10

What are the 3 ways to stimulate or inhibit hormone release?

Answer 10

Hormonal stimulation
Humoral stimulation
Nervous system stimulation

Question 11

Hormonal stimulation

Answer 11

Release of a hormone in response to another hormone (ex: TSH and TH)

Question 12

Humoral Stimulation

Answer 12

Release of a hormone in response to changes in level of nutrients or ions in the blood (ex: blood glucose levels and insulin)

Question 13

Nervous system stimulation

Answer 13

Release of a hormone in response to stimulation by the nervous system (ex: epinephrine and norepinephrine)

Question 14

How are hormones typically turned off?

Answer 14

Downregulating / removing a stimulator

Question 15

inhibition of hormone release by negative feedback on the stimulators occurs on what levels?

Answer 15

ALL possible anatomic levels

• Primary (gland releasing the effector hormone)
• Secondary (first order stimulating gland / hormone)
• Tertiary ( Second order stimulating gland / hormone)

Question 16

What are two major types of cellular communication?

Answer 16

Intercellular and intracellular

Question 17

Is endocrinology just about blood-bourns hormones?

Answer 17

No, it is a broadly applied term for any cell to cell or within cell communication outside the nervous system

Question 18

Intercellular messengers

Answer 18

“Cell to cell”; between cells and between tissues.. hormones, growth factors, cytokines carried by blood and interstitial fluid

Question 19

Intracellular messengers

Answer 19

“Within cell,” signal transduction within a single cell, all within the confines of the plasma membrane

Question 20

3 modes of intercellular communication

Answer 20

Endocrine
Paracrine
Autocrine

Question 21

Endocrine

Answer 21

Circulates via bloodstream, messenger “hormones”

Question 22

Paracrine

Answer 22

Diffuses locally to target cells

Question 23

Autocrine

Answer 23

Affects cell that releases it

Question 24

What are autocrine and paracrine messengers usually called?

Answer 24

Growth factors

Question 25

Another term for intracellular communication

Answer 25

Cell signaling pathways

Question 26

2 modes of intracellular communication

Answer 26

1) Lipid soluble hormones | 2) Water soluble hormones

Question 27

Lipid soluble hormones

Answer 27

- Diffuse through plasma membrane into the CYTOPLASM | - Interact with specific hormone receptor proteins inside the cell

Question 28

What are two main groups / hormones that are lipid soluble?

Answer 28

Steroids and thyroid hormones

Question 29

Process of estrogen and estrogen receptor

Answer 29

- ER binds to E, ER+E complex changes configuration to reveal a nuclear localization signal and shuttles to nucleus - ER + E complex behaves as a transcription factor... Find specific ERE DNA sequences to turn on

Question 30

Water soluble Hormones

Answer 30

- Insoluble in membranes, must bind extracellular domain of hormone receptors embedded in plasma membrane - Hormone receptors activate signal transduction pathway

Question 31

What do signal transduction pathways rely on

Answer 31

All rely on second messenger molecules or enzymes within the cell

Question 32

Protein Kinase A (PKA) Pathway

Answer 32

- Activated G protein causes activation of adenylate cyclase - Adenylate cyclase converts ATP molecules to cAMP - cAMP serves as "second messenger" by activating protein kinase A

Question 33

ADH is what kind of hormone?

Answer 33

Water soluble, peptide hormone

Question 34

LOOK AT ADH & PKC PATHWAY

Answer 34

SLIDES 16 17 18

Question 35

What does a PKA do?

Answer 35

It is a kinase that adds phosphate groups to activate proteins

Question 36

Hypothalamus

Answer 36

Homeostatic control center of the brain