biological

Question 1

what is the role of the nervous system

Answer 1

• collect process and respond to information from the environment
• coordinate working organs and cells of the body

Question 2

where is the spinal cord located and what does it do

Answer 2

• connected via the brainstem
• controls reflex actions (e.g. pulling hand from hot plate)
• passes messages to and from the brain

Question 3

why is the control of the body contralateral

Answer 3

• left side controls right and vice versa

Question 4

what is the role of the thalamus

Answer 4

• receives info from senses and passes to appropriate areas of the cerebral cortex for higher level processing
• does some filtering on its own so acts as a gate or filter
• role in sleep and wakefulness

Question 5

what is the role of the hypothalamus

Answer 5

• controls motivational behaviours
• key role in bodys control of fight or flight
• maintains homeostasis in many bodily functions e.g. temperature
• regulates activity of the endocrine system

Question 6

what is the limbic system

Answer 6

• several structures related to memory and learning and to regulating emotion (amygdala)
• integrates cortical and sub-cortical areas of the brain

Question 7

what is the role of the cerebellum

Answer 7

• to coordinate posture balance and movement
• contains almost 50% of brains neurons but only 10% of the weight

Question 8

what is the role of the corpus callosum

Answer 8

• connects two hemispheres of the brain below the cerebral cortex
• critical as it gives the brain contralateral control of the body because it integrates activity of both sides of the body

Question 9

what is lateralisation

Answer 9

• hemispheres in the brain are almost structurally identical but have different functions

Question 10

what is localisation

Answer 10

• certain areas responsible for specific functions and behaviours

Question 11

what are the convolutions of the brain called and why are they important

Answer 11

• ridges are called gyri
• valleys are called sulci
• they increase cortexs surface area so give it more processing power

Question 12

what is the role of the frontal lobe

Answer 12

• controls high level cognitive functions like planning and decision making
• contains motor cortex one in each hemisphere each one controlling voluntary movements on the opposite sides of the body
• left frontal lobe contains broca’s area

Question 13

what is the role of the parietal lobes

Answer 13

• behind the central sulcus
• contain somatosensory cortex (processes info from the skin)
• area of the somatosensory cortex reflects that parts sensitivity to touch e.g. neurons from the face and hands take up over half of the cortex

Question 14

what is the role of the temporal lobes

Answer 14

• lie beneath
• contains auditory cortex
• process location volume and pitch of sounds so role in understanding language
• left temporal lobe has wernicke’s area

Question 15

what is the role of the occipital lobes

Answer 15

• at the back of the brain
• each one contains primary visual cortex

Question 16

what is Broca’s area

Answer 16

-Broca (surgeon) identified a small area in left frontal lobe responsible for speech production
- damage to this area causes Broca’s aphasia (slow laborious speech)

Question 17

what is Wernicke’s area

Answer 17

• wernicke described patients in their left temporal lobe
• they also had difficulty understanding language, producing fluent but meaningless speech (Wernicke’s aphasia)

Question 18

what is a neuron

Answer 18

• a nerve cell , the basic unit of the nervous system

Question 19

what is the cell body of a neuron

Answer 19

• also called the soma
• includes nucleus containing genetic material of the cell

Question 20

what are the dendrites of a neuron

Answer 20

• branch-like structures sticking out of the cell body , carry impulses from other neurons to the cell body

Question 21

what is the axon of a neuron

Answer 21

• a tube like structure , carries impulses away from the cell body down the length of the neuron

Question 22

what is the myelin sheath of a neuron

Answer 22

• in many neurons the axon is covered by a fatty layer formed from glial cells
• protects the axon and speeds up transmission of the impulse

Question 23

what are the nodes of ranvier of a neuron

Answer 23

• gaps in the myelin sheath that increase speed of transmission by forcing the impulses to jump across gaps along the length of the axon

Question 24

what are the terminal buttons of a neuron

Answer 24

• at the end of the axons, not physically connected to the next neuron but involved in communication across the synapse

Question 25

what is the role of a sensory neuron

Answer 25

• carry messages from sensory receptors along nerves in the PNS to the CNS
• they have long dendrites and short axons

Question 26

what is the role of the motor neuron

Answer 26

• carry messages from the CNS along nerves in the PNS to effectors such as muscles and glands
  (short dendrites , long axons)

Question 27

what is the role of a relay neuron

Answer 27

• connect sensory and motor neurons together and also connect to other relay neurons
• (short dendrites , short axons , only in CNS)

Question 28

How does a neuron work

Answer 28

• when sufficiently activated by a stimulus (reaches threshold) the neuron becomes depolarised ( positive for second )
• creates an action potential from the axon to the terminal buttons
• all or nothing event - if threshold not reached there is no AP - every AP is the same intensity regardless of the size of the stimulus

Question 29

describe synaptic transmission

Answer 29

• when AP reaches end of the neuron (presynaptic terminal button) it triggers the release of neurotransmitters from synaptic vesicles
• NT molecules cross the synaptic cleft and bind to specific receptors of the postsynaptic neuron
• the chemical signal converted back to electrical impulse in the postsynaptic neuron which may trigger another AP
• NT molecules that remain in the synapse are reabsorbed into presynaptic neuron (reuptake)

Question 30

what is a neurotransmitter

Answer 30

-chemical that diffuse across the synapse to the next neuron in the chain - they have specific functions and only fit into specific post synaptic receptors

Question 31

what is excitation

Answer 31

• dopamine causes excitation of the postsynaptic neuron by increasing its positive charge , making it more likely to fire

Question 32

what is inhibition

Answer 32

• serotonin inhibits the postsynaptic neuron making the neuron more negatively charged and less likely to fire

Question 33

what is summation

Answer 33

• the excitatory and inhibitory from the neural network are summed
• temporal or spatial summation
  -if net effect is inhibitory then neuron less likely to fire and vice versa
• firing of the postsynaptic neuron depends on summation

Question 34

How does cocaine affect the central nervous system

Answer 34

• blocks the reuptake of dopamine by binding to dopamine transporter molecules on the terminal buttons of the presynaptic neuron
• synapse becomes flooded with surplus quantities of dopamine all available for binding with postsynaptic receptors
• has a stimulant effect

Question 35

what are the long term effects of using cocaine

Answer 35

• dopamine receptors become downregulated (fewer receptors active, some are damaged and shut down and the quantity dopamine produced declines)
• higher doses needed to feel effect