Endocrine and Nervous System

Question 1

What processes does the endocrine system influence?

Answer 1

Metabolism, growth and reproduction

Question 2

What mediators does the endocrine system release?

Answer 2

Hormones

Question 3

What is a Hormone?

Answer 3

Chemical messenger released by endocrine glands to regulate activity of cells in other parts of body

Question 4

What do circulating hormones do?

Answer 4

Secreted by endocrine cells into bloodstream, travel through bloodstream to target cells
Exert effect via receptors expressed on target cells

Question 5

What organ inactivates circulating hormones?

Answer 5

Liver

Question 6

What organ excretes circulating hormones?

Answer 6

Kidneys

Question 7

What do local hormones do?

Answer 7

Secreted by one cell type into extracellular fluid to affect surrounding cells
Exert effect via receptors expressed on surrounding cells

Question 8

Examples of local hormones

Answer 8

Paracrine hormones e.g. Histamine
Autocrine hormones- e.g. Interleukin 2 (IL-2)
local hormones that act of the same cell that secreted them

Question 9

What are the two types of ways hormone can be transported around the body?

Answer 9

Water soluble hormones

Lipid soluble hormones

Question 10

What are water soluble hormones?

Answer 10

Hormones that circulate freely within the blood

Question 11

What are lipid soluble hormones?

Answer 11

Hormones that are bound to proteins, which are temporarily water soluble

Question 12

Are hormones specific or non-specific?

Answer 12

Specific- can only affect specific target cells

Only target cells for a specific hormone will express receptors for that hormone

Question 13

Where are hormone receptors located?

Answer 13

Within the target cell or on the target cell membrane

Question 14

What happens after the lipid soluble hormones bind to receptors within target cells?

Answer 14

Activated-receptor hormone complex alters gene expression

mRNA directs synthesis of a new protein (enzyme) which alters cell’s activity

Question 15

Where do water soluble hormones bind?

Answer 15

Receptors on cell membrane

Question 16

What happens when the water soluble hormones bind to the receptors?

Answer 16

Hormone-receptor complex activates a G-protein

Question 17

What happens after the G-protein is activated by the water soluble hormone?

Answer 17

Activates a cascade of events which amplify the reaction

Cellular proteins are activated or inhibited, and a physiological response is produced

Question 18

What feedback loop does the endocrine system take?

Answer 18

Negative feedback loop

Question 19

What is the nervous system?

Answer 19

A regulatory system composed brain, spinal cord and nerves

Question 20

What does the Central Nervous System control?

Answer 20

Controls movement, intellectual and physiological function, detects and processes sensory information

Question 21

What mediators do the Nervous System release?

Answer 21

Neurotransmitters

Question 22

What is a neurotransmitter?

Answer 22

Chemical messengers released by neurones to regulate activity of other neurones, glands and muscles

Question 23

What releases neurotransmitters?

Answer 23

Neurone releases it into a synapse

Question 24

What is a synapse?

Answer 24

Region where communication occurs between a neurone and an effector cell (muscle or gland) or another neurone

Question 25

What happens after a Neurotransmitters (NTs) released into chemical synapse?

Answer 25

NTs diffuse through synaptic cleft and bind to specific receptors on target cell NT binding to receptor activates one of many pathways Like hormones , can activate a G-protein cascade which produces a physiological response

Question 26

How do electrical synapses release neurotransmitters?

Answer 26

Ions flow directly between adjacent cells through a gap | Gap junction connects cytosol of two cells together

Question 27

Where are gap junctions found?

Answer 27

Smooth muscle, cardiac muscle and developing embryo

Question 28

What neuropeptides are released from nerves in hypothalamus?

Answer 28

Oxytocin | Vasopressin

Question 29

What do the endocrine and nervous system have in common?

Answer 29

Both associated with the brain Same molecules can be both neurotransmitters and hormones Two systems work simultaneously to regulate critical body processes

Question 30

What are the differences between the nervous and endocrine systems?

Answer 30

Endocrine secretes hormones that are transported in the bloodstream Nervous system secretes neurotransmitters released directly onto target cells Nervous system- activates targets quickly not long lasting Endocrine system- longer lasting effects

Question 31

What are hormones physiological functions?

Answer 31

``` Temperature control Thirst Hunger Mood Sex drive ```

Question 32

What is paracrine signalling?

Answer 32

Cell-cell signalling

Question 33

What is synaptic signalling?

Answer 33

Between cells with a synapse in between

Question 34

What is autocrine signalling?

Answer 34

Cell secretes hormone/messenger

Question 35

What is contact-dependent cell signalling?

Answer 35

Close contact signalling