neural system

Question 1

what is contained in the CNS?

Answer 1

brain

spinal cord

Question 2

what is contained in the PNS?

Answer 2

12 pairs of cranial nerves
31 pairs of spinal nerves
- brain to effectors
- effectors to spinal cord

Question 3

does the neural system decline with age?

examples of diseases due to this?

Answer 3

yes, like most of the systems in the body

dementia, parkison’s and strokes

Question 4

what is the cerebrum?

Answer 4

4 lobes (FPOT)
big part of brain

Question 5

what is the cerebellum?

Answer 5

little brain

coordinates movement by cerebral cortex

Question 6

role of frontal lobe?

Answer 6

concentration and decision making and expression of emotions

Question 7

what is the diencephalon?

Answer 7

thalamus, hypothalamus, pituitary gland

sensory integration and homeostasis regulation

Question 8

role of parietal lobe?

Answer 8

object recognition

Question 9

role of temporal lobe?

Answer 9

equilibrium and motion detection and STM storage

Question 10

what is the brain stem?

Answer 10

connects brain to spinal cord

connection point of different systems

Question 11

role of motor function area and sensory area?

Answer 11

motor - initiation of voluntary movement (behind sensory area if looking at brain from front)

sensory - sensation from muscles and skin

Question 12

how to use MRI to understand brain injury?

Answer 12

can do MRI of brain to see which areas damaged and which areas of body they control

Question 13

which pairs in the cranial nerves are responsible for what?

Answer 13

1 (smell), 2 (vision) & 5 (touch and chewing) = sensory

3 (eyelid), 4 (eye movement), 5 (chewing), 6 (eye movement) = motor

Question 14

what are afferent nerves?

1/2 nerves in PNS

Answer 14

sensory neurons

- impulses from receptors to CNS

Question 15

what are efferent nerves?

1/2 nerves in PNS

Answer 15

motor neurons

- impulses from CNS to effectors

Question 16

what are baroreceptors?

Answer 16

stretch receptors

sensitive to changes in blood pressure

sensory neuron example

Question 17

what are chemoreceptors?

Answer 17

chemical receptors

chemical enviro of the blood

sensory neuron example

Question 18

what are mechano/proprioceptors?

Answer 18

muscle tension and length

sensory neuron example

Question 19

what are metaboreceptors?

Answer 19

skeletal muscle metabolites

sensory neuron example

Question 20

what are thermoreceptors?

Answer 20

temperature regulation

sensory neuron example

Question 21

what are nociceptors?

Answer 21

pain

sensory neuron example

Question 22

what are interneurons?

Answer 22

example through pain response:

analyse and store sensory info and make decisions

act as a shortcut by passing afferent transmission to efferent response without need to involve brain

spinal cord can contol simple motor reflexes
brain controls more complex and subconscious motor reactions

Question 23

describe the myotatic/stretch reflex?

Answer 23

stretch sensed by Muscle-Spindles

signal to afferent which sends signal to spinal cord

motor neurons send efferent impulses to agonist muscle to contract

interneurons block motor neurons signalling antagonist muscle to not contract

Question 24

what is the autonomc nervous system?

what it uses and function

Answer 24

involuntary processes

uses SNS and PNS

Question 25

what is the somatic nervous system? what it uses and function

Answer 25

uses motor neurons skeletal muscle function

Question 26

what is the sensory function of the neural system?

Answer 26

sense change in the internal and exetrnal enviro through sensory receptors afferent nerves

Question 27

what is the integrative function of the neural system?

Answer 27

analyse the sensory info, store some aspects and ake decisions interneurons

Question 28

what is the motor function of the neural system?

Answer 28

to respond to stimuli by initiation of action efferent nerves

Question 29

describe neurons?

Answer 29

functional units of nervous system | convert stimuli to nerve impulses

Question 30

what are neuroglia?

Answer 30

don't generate or conduct nerve impulses just protect and support neurons e.g astrocytes and oligodendrocytes and microglia and Schwann cells

Question 31

what are oligodendrocytes?

Answer 31

support cells in CNS type of neuroglia

Question 32

what are astrocytes?

Answer 32

regulate electrical transmission in brain type of neuroglia

Question 33

what are the 2 components and 3 types of the motor unit?

Answer 33

1. alpha-motor neurons (AMN) 2. muscle fibres innervated by the AMN 1) slow type 1 fibres 2) fatigue resistant type 2a fibres 3) fast fatiguing type 2x fibres 1 motor neuron innervates each single muscle cell

Question 34

role of dendrites, axon hillock, axon, synapses, myelin sheath and nodes of Ranvier? anatomy of the neuron

Answer 34

dendrites - picking up signals axon hillock - nerve impulse generated axon - carries electrical impulse away from cell body synapses - contact point myelin sheath - contains Schwann Cells and insulating, fatty sheath which surrounds nerve fibres Nodes of Ranvier - periodic breaks of myelin sheath

Question 35

what is the importance of the myelin sheath?

Answer 35

speeds up transmission of impulses

Question 36

what are the 3 groups of nerve fibres and their myelin status?

Answer 36

A group - alpha, beta and gamma - all myelinated B nerve fibres - moderate myelination C nerve fibres -unmyelinated

Question 37

when is the velocity of action potential the fastest?

Answer 37

amount of myelination - myelinated axon diameter - large diameter temperature - higher temperatures

Question 38

what are the 3 structural classifications of neurons? location of cell body in each?

Answer 38

1. multipolar - cell body at top 2. bipolar - cell body in middle so signal takes longer 3. unipolar - cell body separated and in middle

Question 39

what is an action potential?

Answer 39

sequence of rapidly occurring events that reverse the membrane potential and then restore to a resting state

Question 40

what is the membrane potential?

Answer 40

difference in amount of electrical charge inside and outside of cell (negative inside and positive outside)

Question 41

describe the resting membrane potential?

Answer 41

due to the concentration of ions inside and outside more potassium inside cell and more sodium outside it membrane permeability much greater for potassium inward flow of NA can't match outward flow of K Na/K pump removes Na as fast as it leaks in

Question 42

what are the K and Na thresholds of voltage gated channels?

Answer 42

Na - -55mV | K - 30mV

Question 43

what is depolaristion?

Answer 43

occurs when sufficient stimulus depolarises cell voltage gated Na open and sodium floods in

Question 44

what is repolarisation?

Answer 44

return to resting membrane potential Na channels close K leaves to cell through voltage gated K channels

Question 45

what is hyperpolarisation?

Answer 45

delay in closing of voltage gated K channels

Question 46

what is the speed of action potential propagation in each fibre type of the motor unit?

Answer 46

A fibres - fastest as myelinated B fibres - medium C fibres - slowest

Question 47

role of synaptic transmission?

Answer 47

allow neurons to communication via synaptic transmission

Question 48

examples of excitatory, inhibitory and both neurotransmitters?

Answer 48

excitatory - glutamate inhibitory - gamma aminobutyric acid both - noradrenaline

Question 49

what are the 2 types of synpase?

Answer 49

1. chemical | 2. electrical

Question 50

describe excitatory postsyaptic potential?

Answer 50

depolarisation via ligand gated Na channels

Question 51

describe inhibitory postsynaptic potential?

Answer 51

more negative or hyperpolarised via ligand gated CL or K channels

Question 52

what is spatial summation?

Answer 52

summation of effects of neurotrasmitters released from several end bulbs onto one neuron

Question 53

what is temporal summation?

Answer 53

summation of effect of neurotransmitters released from 2 or more in rapid succession

Question 54

what is meant by refractory period? absolute? relative?

Answer 54

excitable membrane needs recovery so during refractory period region can't be excited again absolute - unable to respond relative - stimulus must be substantially greater to evoke action potential