unit 3 aos 1a

Question 1

central nervous system

Answer 1

receives information from PNS, processes a response and then responds. made up of brain and spinal cord.

Question 2

brain

Answer 2

part of the CNS. regulates vital bodily functions (BREATHING). it is responsible for higher order thinking and receiving information then coordinating appropriate responses.

Question 3

spinal cord

Answer 3

part of CNS. column of nerve fibres that extend from lower back to base of brain. passes sensory information from PNS to brain and motor information from brain to PNS

Question 4

peripheral nervous system

Answer 4

network of neutrons located outside CNS comprising of muscles glands and organs. carries information from sensory organs to the CNS. conveys information from CNS to muscles glands and organs. contains somatic and autonomic nervous systems

Question 5

somatic nervous system

Answer 5

part of PNS. controls voluntary movement and responses by transmitting information from receptor sites on the sensory organs to CNS and carries information from CNS to muscles that control movement

Question 6

autonomic nervous system

Answer 6

part of CNS. responsible for involuntary movement and body functions. contains sympathetic and parasympathetic

Question 7

sympathetic nervous system

Answer 7

part of autonomic NS. activates internal muscles, organs and glands to prepare the body for vigorous activity or stressful situations. releases adrenaline, increases heart rate and respiration. activates FFF response

Question 8

parasympathetic nervous system

Answer 8

part of autonomic NS. keeps the body functioning effectively. counterbalances the sympathetic nervous system by returning the body to a state of calm and maintains homeostasis

Question 9

steps of neural transmission

Answer 9

1. neurotransmitters are stored in synaptic vesicles. 2. when action potential reaches axon terminal, synaptic vesicles move to surface of membrane and release neurotransmitters. 3. the. neurotransmitter will carry the chemical message across the synapse to the receptor site on the dendrite of the post synaptic neuron, altering activity on the post synaptic neuron.

Question 10

action potential

Answer 10

an electrical impulse initiated by the soma and travels along the axon to the axon terminal, prompting the release of neurotransmitters. it is an all or nothing event

Question 11

neurotransmitters

Answer 11

a chemical substance formed within a presynaptic neuron. when a neurotransmitter is released it finds the receptor on the post synaptic neuron. each neurotransmitter binds with its specific type of receptor.

Question 12

effect of neurotransmitters on post synaptic neuron

Answer 12

neurotransmitters have 2 basic effects on post synaptic neuron. to excite the neuron and increase activity or inhibit the neuron and decrease activity.

Question 13

excitatory neurotransmitters

Answer 13

cause a neuron to fire and stimulate a response. increases amount of activity at the neuron. (glutamate is a primary excitatory neurotransmitter involved in memory formation)

Question 14

inhibitory neurotransmitters

Answer 14

stop a neuron from firing and inhibit a response. decreases amount of activity at neuron. (gamma amino butyric acid involved in regulating anxiety)

Question 15

spinal reflex

Answer 15

an automatic response initiated by neurons in the spinal cord, instead of the brain. whilst a spinal reflex/reflex arc is initiated, sensory messages continue to the brain. pain cannot be felt until messages has reached the brain although the motor response has already occurred.

Question 16

interneuron

Answer 16

located in the CNS, primarily the spinal cord. forms a connection between motor and sensory neurons. allows for an instant response.

Question 17

monosynaptic reflex arc

Answer 17

involves only 1 synapse. affector neuron brings sensation from receptors in the body and an effector neuron carries motor messages to the muscles

Question 18

polysynaptic reflex arc

Answer 18

involving interneurons connecting the affector and effector. involving at least 2 synapses

Question 19

dendrite

Answer 19

an extension of the neurons that detects and receives information. can branch and rebranch forming numerous sites where connections can be made with adjacent neurons

Question 20

soma

Answer 20

the main cellular body of the neuron and contains the cell nucleus. where incoming neural information collected from multiple neurons may be integrated.

Question 21

nucleus

Answer 21

contains the neurons genetic material in the form of chromosomes. coordinates the cells metabolism ,growth and repair

Question 22

axon

Answer 22

a single tube like structure that transmits neural information to other neurons. can have several branches, which enables the neuron to send it’s message to many other neurons simultaneously

Question 23

myelin sheath

Answer 23

a fatty white substance that forms an insulating layer around the axon. supports rapid movement of a neural message through the neuron without interruption or distortion

Question 24

node of ranvier

Answer 24

a small, unmyelinated gap in the protective insulation around the axon. neural messages jump across this site which assists in speeding up neural transmission

Question 25

terminal buttons

Answer 25

a small swelling at the end of an axon collateral. contains synaptic vesicles that store and release neurotransmitters into the synaptic gap.

Question 26

sensory neurons

Answer 26

detect and respond to energy from external environments. 1-sensory info about environment is detected by receptor cells in our sensory organs. 2-info is transmitted by sensory neurons in PNS inwards to spinal cord, then up afferent tracts towards brain for higher processing

Question 27

motor neurons

Answer 27

carry motor messages related to movement from CNS to the rest of the body. these messages affect the activity level of internal organs so a specific response can be enacted. 1-once the brain has decided On an appropriate response to sensory info, motor message is relayed to motor neurons located. in efferent tracts of spinal cord. 2-info is transmitted to motor neurons within the bodys relevant muscles glands and organs so a response can be enacted

Question 28

receptor sites

Answer 28

tiny areas on the cell membrane that are sensitive to certain neurotransmitters.

Question 29

lock and key

Answer 29

a neurotransmitter has distinct molecular shape that fits perfectly into its specific receptor site. receptor sites will ignore all neurotransmitters except for its one particular neurotransmitter. once a neurotransmitter has attached to its specific receptor site, it is then able to influence the neurons activity level.