Structure of the nervous system

Question 1

what are the functions of the spinal cord

Answer 1

mediates info between brain and body below the neck
coordinating certain reflexes
pathway fir sensory *travel up sc) and motor (travel down sc) information

Question 2

explain the structure of the spinal cord

Answer 2

protected by 24 vertebra
consists of grey matter srounded by white matter
dorsal is the back
ventral is the front
spinal nerves split into dorsal and ventral roots before entering the spinal cord

Question 3

what do afferent neurons do?

Answer 3

afferent neurons axons enter through dorsal root and terminate in dorsal horn
towards brain

Question 4

what do efferent neurons do?

Answer 4

efferent neurones have a cell body in ventral horn and axons leave cord in ventral root
away from brain

Question 5

How many nerves pairs are in the PNS,

how many are cranial and how many are spinal

Answer 5

43 pairs
12 cranial (10 connect to brainstem and 2 connect to forebrain
31 spinal

Question 6

what is the function of cranial nerves

Answer 6

resonsible for infomration between brain and body above the neck
exception being the vagus nerve

Question 7

spinal nerve function

Answer 7

each spinal nerve is connected with a particular segment of the spinal cord creating different functions.
spinal nerves can contain sensory and motor fibres

Question 8

function of somatic nervous system

afferent/efferent

excitatory or inhibitory?

Answer 8

voluntary movement via skeletal muscles
receives info and controls spinal nerves that innervate skin, joints, and muscles.

afferent carry sensory info from skin.
efferent neurons control skeletal muscles via motor neurons.

neurones are excitatory

Question 9

Autonomic NS

efferent/afferent

excitatory or inhibitory

Answer 9

involunary functions

Afferent neurons carry sensory info from internal organs to CNS
Efferent neurons control smooth muscle, cardiac muscle, glands and carry from CNS to these.

Neurons can be excitatory or inhibitory

Question 10

what does the autonomic split into including there functions

Answer 10

1. sympathetic NS= fight or flight
2. PSNS= rest and relax response e.g. decreased hr
3. ENS(ENTERIC)- ‘second brain’ - controls digestion, from swallowing to the release of enzymes to breakdown to the control of blood flow to help with nutrient absorption and elimination

Question 11

Sensory neurone structure and function

Answer 11

part of PNS
Function= sends info about sensory changes to CNS
Structure= contains sensory receptors to detect sensory changes/ the cell body is in the PNS/ axon of sensory neurone enters CNS as axon terminals are located here and so terminates in dorsal horn.

Question 12

motor neurons structure and function

Answer 12

part of pns
function- synapses to skeletal muscle to command movement or onto glands to release hormones . It relays signals from CNS to PNS.
Structure- dendrites and cell body live within CNS, axon enters PNS and terminal buttons are near muscle cells

Question 13

Interneuron structure and function

Answer 13

In the CNS
function- receives info from sensory neurons to motor neurones. So they integrate and change signal.
Integrate means it inputs are from multiple neurons so may combine multiple afferent neurons for example
change means interneurons can provide excitatory or inhibitory signals e.g. pupils change size in light.

Question 14

what info is carried via dorsal roots?

where dorsal root ocated

Answer 14

somatosensory

posterior

Question 15

what info is carried via ventral roots?

where is ventral root located

Answer 15

motor

anterior