PSYCHOBIOLOGY: the CNS & brain

Question 1

what is sensory adaptation?

Answer 1

getting used to a specific stimulus - we only sense when things are changed

Question 2

how do we respond to changes in the environment?

Answer 2

specialised receptor cells connected to sensory neuron’s respond to changes in touch, smell, sight etc

Question 3

describe the process of signal transmission into the CNS from the body not including the head

Answer 3

sensory signals enter the CNS through the spinal cord via the dorsal root of spinal nerves

Question 4

describe the process of signal transmission into the CNS from the head

Answer 4

sensory signals send axons directly into the brain via cranial nerves

Question 5

describe the transmission of precisely localised information in the CNS

Answer 5

neurone which transmit precisely localised information eg fine touch send axons to the top of the spinal cord

Question 6

describe the transmission of poorly localised information in the CNS

Answer 6

neurons which transmit poorly localised information eg temp synapse immediately with other neurons upon entering the spinal cord

Question 7

describe the process of transmission in the visual system

Answer 7

• photoreceptors are hit by a photon
• a cascade of chemical changes in the photoreceptor triggers the bipolar neuron which triggers the ganglion cells
• axons of ganglion cells form a pathway into the thalamus
• neurons connect to thalamic neurons & axons are sent to the visual cortex in a process called optic radiation

Question 8

what is signal passing dependent on?

Answer 8

whether the pattern of input to a neutron is strong enough
- signal dies if input is too weak

Question 9

what is the hindbrain made up of?

Answer 9

medulla, pons & cerebellum

Question 10

structure & function of medulla and pons

Answer 10

structure = where spinal cord enters brain
function = contains several nuclei of the autonomic NS

Question 11

structure & function of cerebellum

Answer 11

structure = not part of brain stem
function = balance & motor

Question 12

function of the midbrain

Answer 12

combines information from different senses & directs attention

Question 13

name of hindbrain

Answer 13

rhombencephalon

Question 14

name of midbrain

Answer 14

mesencephalon

Question 15

name of forebrain

Answer 15

diencephalon (thalamus and hypothalamus) & telencephalon (cerebral hemisphere, basal ganglia, limbic system and cortex)

Question 16

structure & function of thalamus

Answer 16

structure = top of midbrain, deep in centre of brain
function = main relay station for sensory signals, receives input coming from higher areas

Question 17

structure & function of hypothalamus

Answer 17

structure = in front of & below thalamus, directly connected to pituitary gland
function = gateway to endocrine system

Question 18

structure of cerebral hemispheres

Answer 18

• 2 highly similar
• each covered in cerebral cortex
  grey matter = cortex & subcortical nuclei
  white matter = myelinated axons of neurons

Question 19

what is cerebral cortex?

Answer 19

stacked layers of neurons covering each hemisphere

Question 20

functions of cerebral hemispheres

Answer 20

• incoming signals from diencephalon go up the cerebrum
• each hemisphere mainly receives input from and sends output to the contralateral side of the body

Question 21

structure of the basal ganglia

Answer 21

subcortical nuclei surrounding the thalamus
- consists of globes pallidus, putamen & caudate (corpus striatum)

Question 22

function of the basal ganglia

Answer 22

motor control processes

Question 23

structure of the limbic system

Answer 23

subcortical = almost complete circle formed by fornix & hippocampus, ending in mammillary body & amygdala
cortical = cingulate cortex directly above corpus callosum, connected to hypothalamus & olfactory system

Question 24

function of the limbic system

Answer 24

memory & emotion

Question 25

structure of the corpus callosum

Answer 25

thick bundle of axons connecting the 2 hemispheres
- white matter
- main connection between 2 hemispheres
- gyrus = outward folds
- sulcus = inner folds

Question 26

what is longitudinal fissure?

Answer 26

largest sulcus, separates left & right hemispheres
(smaller sulcus - boundaries of cerebral cortex)

Question 27

function of cortex / corpus callosum

Answer 27

signal transfers between the cortices of the hemispheres

Question 28

location & function of occipital lobe

Answer 28

back
- visual perception

Question 29

location & function of temporal lobe

Answer 29

sides
- auditory perception

Question 30

location & function of parietal lobe

Answer 30

top
- somatosensory perception

Question 31

location & function of frontal lobe

Answer 31

front
- planning & motor output