The Nervous system

Question 1

how does the nervous system ensure homeostasis is preserved

Answer 1

detects stimuli occuring inside and outside the body

responds to these changes
coordiantes activities in the organ systems

Question 2

what are the 3 main functions of the Nervous System

Answer 2

sensory
integrative
motor function

Question 3

what does the sensory function of the nervous system involve

Answer 3

detects sensory input

sends sensory input to the control centre

Question 4

what does the integrative function of the nervous system involve

Answer 4

analyses and interprets sensory input
determines approprriate response
generates motor output that causes response

Question 5

what does the motor function of the nervous system involve

Answer 5

issues motor output to activate an effector

Question 6

what stimuli do nociceptors detect

Answer 6

pain

Question 7

what do tactile receptors detect

Answer 7

touch, pressure and vibration

Question 8

what do baroreceptors detect

Answer 8

change in BP

Question 9

What do proprioreceptors detect

Answer 9

body position

Question 10

what do photoreceptors detect

Answer 10

light

Question 11

what do chemoreceptors detect

Answer 11

chemicals in solution ( taste and smell)

Question 12

what do mechanorecptors detect

Answer 12

hearing and balance

Question 13

list the 2 divisions of the nervous system

Answer 13

Central and peripheral

Question 14

what does the CNS consist of

Answer 14

brain and spinal cord

Question 15

the control centre performs what main function

Answer 15

integration

Question 16

what are the 2 main divisions of the motor division

Answer 16

autonomic and somatic

Question 17

conveys somatic motor output from the _______ to the skeletal muscles

Answer 17

CNS

Question 18

the autonomic motor output control involuntary activities such as: (5)

Answer 18

heart rate
resp. 
food digestion 
urination/ defication
BV and pupil diameter

Question 19

name the 2 functional divisions of the autonomic nervous system

Answer 19

sympathetic and parasympathetic

Question 20

neural tissue mostly consists of 2 cell types, name them

Answer 20

neuroglia

neurons

Question 21

name the 2 types of neuroglia that can be found in the PNS

Answer 21

satellite cells

schwann cells

Question 22

name the 4 different types of neuroglia that can be found in the CNS

Answer 22

ependymal cells
astrocytes
oligodendrocytes
microglia

Question 23

what do neurons require for survival

Answer 23

oxygen and glucose

Question 24

what is the main function of neurons

Answer 24

communication

Question 25

name the 4 parts most neurons consist of

Answer 25

dendrites cell body axon axon terminals

Question 26

Dendrites are the main _____ input region of a neuron

Answer 26

input

Question 27

what does the cell body contain

Answer 27

nucleus and organelles

Question 28

what are the 2 main function of the cell body

Answer 28

receive info from other neurons and converts this info into a graded potential. integrates info and conveys it towards the initial segment of the axon

Question 29

what is the axon covered by

Answer 29

myelin sheath

Question 30

where is the myelin sheath produced

Answer 30

schwann cells and oligodendrocytes

Question 31

what is the function of myelin

Answer 31

increases the speed of signal conduction

Question 32

what are the gaps in the segments called

Answer 32

nodes of ranvier

Question 33

destruction of myelin in the CNS results in which condition

Answer 33

MS

Question 34

What do axon terminals contain?

Answer 34

synaptic vesicles

Question 35

what do synaptic vesicles store and release

Answer 35

neurotransmitters

Question 36

what is the function of neurotransmitters

Answer 36

chemicals that carry info from a neuron to another cell

Question 37

neuron cell bodies are organised into clusters called: in the CNS in the PNS

Answer 37

nuclei | ganglia

Question 38

neuron axons are bundled together to form in the CNS in the PNS

Answer 38

tracts | nerves

Question 39

what are the 3 classifications of neurons

Answer 39

- multipolar - bipolar - unipolar

Question 40

particles can be ____/____ charged

Answer 40

positively or negatively

Question 41

for neurons to generate an electrical signal, their plasma mem must:

Answer 41

- exhibit a resting membrane potential (RMP) | - contain protein channels which allow specific ions to diffuse down their concentration gradient

Question 42

compare leakage channels and gated channels

Answer 42

leakage: always open gated: open and close in response to a specific stimulus

Question 43

where would chemically gated channels be located

Answer 43

along the plasma membrane of the dendrites and cell body

Question 44

where would one find mechanically gated channels

Answer 44

along the plasma membrane of dendrites

Question 45

where are voltage gated channels found

Answer 45

along the PM of the axon and axon terminals

Question 46

what is a resting membrane potential

Answer 46

voltage across the plasma membrane of a resting cell.

Question 47

what causes a RMP to exist

Answer 47

uneven distribution of positive ions across the plasma membrane creates a charge difference across the membrane

Question 48

what is the approximate voltage of a RMP

Answer 48

-70mV

Question 49

what is depolarisation

Answer 49

occurs when the membrane potential becomes less negative

Question 50

what happens when a stimuls opens sodium gated channels

Answer 50

- influx of sodium ions into the ICF - ICF gains postive ions - cell interior becomes less negative - membrane potential becomes less negative

Question 51

what is hyperpolarisation

Answer 51

membrane potential becomes more negative

Question 52

what happens when a stimulus opens potassium gated channels"

Answer 52

- efflux of potassium ions out of the ICF - ICF looses positive ions - cell interior becomes more negative - membrane potential becomes more negative

Question 53

what are the 2 types of electrical singnals that the nervous system generates

Answer 53

- graded potentials | - action potentials

Question 54

what are the graded potentials

Answer 54

small changes in the membrane potential

Question 55

where do graded potentials originate

Answer 55

in the dendrites or cell body when a stimulus opens chemically gated or mechanically gated channels.

Question 56

state the length of graded potentials

Answer 56

short

Question 57

describe the process of a graded potential

Answer 57

- travel to the initial segment of an axon - depolarise the initial segment to -55 stimulates voltage gated sodium channels to open - generates an AP

Question 58

compare continuous conduction with saltatory conduction with regards to: - where it occurs - whether the action potentials are generated - conduction speed

Answer 58

unmyelinated axons // myelinated axons voltage gated channels along the length of the axon // generated at the nodes of ranvier < 2m/s // >100m/s

Question 59

explain how a local anesthetic blocks pain

Answer 59

- block voltage gated sodium channels - no action potential - no conduction of pain signal to the brain - no sensation of pain

Question 60

why does the cold and pressure reduce pain

Answer 60

impairs signal conduction

Question 61

what is a chemical synapse

Answer 61

junction that mediates the transfer of info

Question 62

what process occurs at a chemical synapse between 2 neurons

Answer 62

- neurons sending the info - presynaptic neuron - neuron receiving the info - postsynaptic neuron - presynaptic and postsynaptic membranes and seperated by synaptic cleff. - signal transmission involves chemical neurotransmitters.