Central NS Flashcards
1
Q
what brain regions make up the diencephalon
A
- thalamus
- hypothalamus
- pineal gland
- pituitary gland
2
Q
what brain regions make up the brainstem
A
midbrain
pons
medulla oblongata
3
Q
function of medulla oblongata
A
- transmit info b/t spine + brain
- contains CV centre + respiratory rhythmicity centre
4
Q
functions of CV + respiratory rhythmicity centres in medulla oblongata
A
CV = adjusts HR, heart contractions + blood flow
Resp. rhyth = regulates breathing rate
5
Q
function of pons + what structures it links
A
- links cerebellum w/ midbrain, diencephalon, cerebrum + spinal cord
-has nuclei + tracts that process info sent to + from the cerebellum - location of nuclei which control the activity of resp rhythm. centres in MO.
6
Q
function of midbrain
A
- process + regulate auditory + visual info
- controls alertness
7
Q
function of superior colliculi in midbrain
A
- process visual info
- control reflex for eye, head + neck movement for visual stimuli tracking
8
Q
function of inferior colliculi in brain stem
A
- receives auditory info from medulla oblongata + pons
- control reflex of head neck + torso for aud. stimuli tracking
9
Q
function of cerebellum
A
coordinates movement at subconscious level
- maintains balance+ eq. / monitors proprioception
- fine tunes learned movements
10
Q
3 functions of thalamus
A
- filters ascending info to cerebral cortex
- relays info from cerebellum to cerebral cortex
- recognises pain, temp + pressure
11
Q
functions of hypothalamus
A
- homeostasis
- autonomic function control
- coordinates NS + endocrine systems
- body temp regulation
- circadian rhythms
- emotions + behaviour
12
Q
functions of limbic system
A
- est. emotional states
- links conscious + autonomic functions
- facilitates memory storage + retrieval
13
Q
function of cerebrum
A
- controls conscious thoughts + intellectual function
- processes somatic sensory + motor info
14
Q
functions of special sensory nerves
A
carry sensations such as smell, sight, hearing + balance
15
Q
receptor defintion
A
specialised cell that monitors specific conditions in body or external environ.
16
Q
function of receptor
A
detects stimulus + converts to AP -> travel to CNS via sensory neurons
17
Q
how are receptors classified
A
- by the type of stimulus that excites them
eg. touh vs taste receptors
18
Q
function of nociceptor
A
detects pain + itch
19
Q
function of thermoreceptor
A
detects temperature
20
Q
function of chemoreceptors
A
detects chem. conc. eg. CO2
21
Q
function of mechanoreceptors
A
- detects tactile receptors: touch, pressure + vibration
- baroreceptors: organ pressure
- proprioceptors: muscle contraction + joint position
22
Q
describe the structure of simple sensory receptors eg. pain
A
- free nerve endings on both sides
- unmyelinated axon
23
Q
describe the structure of complex sensory receptors eg. touch
A
- enclosed nerve endings in connective tissue @ dendrites
- myelinated axon
24
Q
describe the structure of special sensory receptors eg. sight + hearing
A
- specialised receptor cell (hair cell)
-> separated from actual neuron -> releases neurotransmitters - myelinated axon
25
differentiate b/t a small + large receptive field
- small = provides detailed info -> fine touch + pressure tactile receptors eg. finger
- large = provides less detailed info -> crude touch + pressure eg. back
26
describe the concept of a 'labelled line'
- detected info follows specific neuronal pathway to cortical region of brain
- one type of receptor responds to one specific modality
- nerve attached to that type of receptor only carries that sensation
27
how does receptor adaptation occur
- changes in sensitivity occur in presence of continual stimulus
- peripheral adaptation occurs when activity amount changes
- central adaptation occurs once info in CNS -> activity along sensory pathway inhibited
28
describe the activity levels + adaptation rate of tonic receptors
- always active
- adapt slowly eg. pain
29
describe the activity levels + adaptation rate of phasic receptors
- rapidly adapting
- have reduced activity after desensitisation eg. entering cool room on hot day
30
how many neurons are in a somatosensory pathway + where are they located
3
- first order: info to CNS -> synapses w/ interneuron
- second order (interneuron): in spinal cord or brainstem / crosses to opposite side of CNS
- third order neuron: in thalamus, synapses with second order neuron
31
what info does the spinothalamic pathway carry
poorly localised touch
pressure
pain
temp
32
describe the pathway of the spinothalamic pathway
- anterior or lateral spinothalamic tract (in MO)
- midbrain
- cerebral cortex
33
what info does the posterior column pathway convey
precise touch
vibrations
proprioception
34
describe the structures involved in the posterior column pathway
- fasciculus gracilis + fasciculus cuneatus
- nucleus gracilis + nucleus cuneatus (in MO)
-medisal leminscus to midbrain
- ventral nuclei in thalamus
- cerebral cortex
35
what info does the spinocerebellar pathway carry
muscle, tendon + joint positions
36
describe the structures involved in the spinocerebellar pathway
- anterior + posterior cerebellar tracts (spinocerebellar pathway) in spinal cord
- MO
- pons
- cerebrum
37
differentiate b/t the fast + slow pain pathways of nociceptors
- A-delta fibres = fast pain pathway (sharp)
- C fibres = slow pain pathway (dull)
38
how do opioids work as analgesics
block the release of NTs from pre-synaptic neuron therefore post-syn neuron X activated
-> no interpretation of pain
39
compare + contrast the voluntary + involuntary motor pathways
both have sensory pathway of:
- depolarisation of sensory receptor by arriving stimulus
- AP generation
- propagation of AP to CNS
- CNS processing
involuntary pathway has immediate involuntary response
voluntary pathway undergoes perception then voluntary response
40
function of somatic sensory association area
integrate sensory info -> generate meaningful patterns of recognition + awareness
41
describe the function of primary motor cortex
control of skeletal muscle
42
describe the function of somatic motor association area
- communicate w/ other areas
- coordinate movement of several muscle groups
- controls learned skilled movements
- stores movement programs
43
how many neurons does the cortical spinal pathway have and what does it control
at least 2 motor neurons - upper + lower
- controls skeletal muscles
44
what 3 things protect the spinal cord
vertebral column bones
meninges - pia mater (closest), arachnoid mater, dura mater
CSF - chem. protection / waste removal
45
what 4 things protect the brain
bones of cranium
cranial meninges
cerebrospinal fluid
blood-brain barrier -(biochem.)
46
functions of CSF
- cushion delicate neural structures
- support brain
- transport nutrients, chem. messengers + waste products
47
functions of blood brain barrier
- isolate neural tissue from general circulation
- isolates brain from chem. that can disrupt neural function
48
how do molecules cross the blood brain barrier
- lipid soluble = diffuse across
- water + ions = channels
