Endocrine and Nervous System Flashcards Preview

Physiology and Neuroscience > Endocrine and Nervous System > Flashcards

Flashcards in Endocrine and Nervous System Deck (35):
1

What processes does the endocrine system influence?

Metabolism, growth and reproduction

2

What mediators does the endocrine system release?

Hormones

3

What is a Hormone?

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

4

What do circulating hormones do?

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

5

What organ inactivates circulating hormones?

Liver

6

What organ excretes circulating hormones?

Kidneys

7

What do local hormones do?

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

8

Examples of local hormones

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

9

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

Water soluble hormones
Lipid soluble hormones

10

What are water soluble hormones?

Hormones that circulate freely within the blood

11

What are lipid soluble hormones?

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

12

Are hormones specific or non-specific?

Specific- can only affect specific target cells
Only target cells for a specific hormone will express receptors for that hormone

13

Where are hormone receptors located?

Within the target cell or on the target cell membrane

14

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

Activated-receptor hormone complex alters gene expression
mRNA directs synthesis of a new protein (enzyme) which alters cell's activity

15

Where do water soluble hormones bind?

Receptors on cell membrane

16

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

Hormone-receptor complex activates a G-protein

17

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

Activates a cascade of events which amplify the reaction
Cellular proteins are activated or inhibited, and a physiological response is produced

18

What feedback loop does the endocrine system take?

Negative feedback loop

19

What is the nervous system?

A regulatory system composed brain, spinal cord and nerves

20

What does the Central Nervous System control?

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

21

What mediators do the Nervous System release?

Neurotransmitters

22

What is a neurotransmitter?

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

23

What releases neurotransmitters?

Neurone releases it into a synapse

24

What is a synapse?

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

25

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

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

26

How do electrical synapses release neurotransmitters?

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

27

Where are gap junctions found?

Smooth muscle, cardiac muscle and developing embryo

28

What neuropeptides are released from nerves in hypothalamus?

Oxytocin
Vasopressin

29

What do the endocrine and nervous system have in common?

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

30

What are the differences between the nervous and endocrine systems?

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

31

What are hormones physiological functions?

Temperature control
Thirst
Hunger
Mood
Sex drive

32

What is paracrine signalling?

Cell-cell signalling

33

What is synaptic signalling?

Between cells with a synapse in between

34

What is autocrine signalling?

Cell secretes hormone/messenger

35

What is contact-dependent cell signalling?

Close contact signalling