Neurophysiology

Question 1

What are three components of the brain?

Answer 1

Cerebrum (cortex), cerebellum, brain stem

Question 2

What are purposes of Gyrus and Sulci

Answer 2

Increase surface area of brain, thus, allowing for greater concentration of neurons, as skull size cannot increase

Question 3

What are the lobes of the cerebrum?

Answer 3

Frontal lobe, Temporal lobe, Parietal lobe, Occipital lobe, Insula lobe

Question 4

State purpose of frontal lobe + symptoms of damage

Answer 4

Frontal lobe is responsible for higher cognitive function (executive thinking), and Motor function (voluntary movement)
If damaged: Weakness to one side of body, Inability to plan or problem solve, Impaired judgement, difficulty controlling emotion

Question 5

What is purpose of temporal lobe + symptoms if damaged

Answer 5

Temporal lobe is responsible for processing auditory information, understanding language, memory encoding, face recognition, object recognition, and perception
If damaged: Difficulty understanding spoken words, difficulty with identification and categorisation of objects, difficulty learning and retaining new information, impaired memory

Question 6

What is purpose of parietal lobe + symptoms if damaged

Answer 6

Responsible for integrating sensory information, including touch, temperature, pressure, and pain
If damaged: Patient may have difficulty finding way around new or familiar places, may disrupt a persons ability to understand spoken articular written language

Question 7

What is purpose of Occipital lobe + symptoms if damaged

Answer 7

Responsible for vision perception, including colour, form, motion
If damaged: Vision impairments such as blindness or blindspots, visual distortions, and poor spatial analysis

Question 8

What is purpose of Insula lobe (DEEP within cerebrum) + symptoms if damaged

Answer 8

Responsible for taste, processing our environment for movement. Contains vestibular link which is link between brain and inner ear which helps maintain balance and proprioception.
If damaged: Dizziness, feeling off-balance, feeling as if you are floating or world is spinning

Question 9

What are main gyrus and sulci of cerebrum

Answer 9

The central sulcus, which seperates the primary motor cortex (pre-central gyrus) from the primary somatosensory cortex (post central gyrus)

Question 10

What joins left and right side of brain

Answer 10

Corpus callosum - mediates information between left and right side

Question 11

What is purpose of cerebellum + symptoms if damaged

Answer 11

Cerebellum is responsible for smooth and refined movements (voluntary movement) , including balance and coordinating eye movement
If damaged: Inability to judge distance, Inability to perform rapid alternating movements, Movement tremors, Staggering or wide base walking

Question 12

What are parts of brain stem

Answer 12

Midbrain, pons, medulla oblongata (involuntary movements)

Question 13

Purpose of midbrain?

Answer 13

Regulates eye movement, plays a role in motor movement and audio/visual processing - works with occipital lobe and cerebellum

Question 14

Purpose of Pons?

Answer 14

Coordinates facial movement, hearing, and balance

Question 15

Purpose of Medulla oblongata?

Answer 15

Assists in regulation of breathing, heart rhythms, BP, and swallowing

Question 16

What are meninges of brain and spinal cord?

Answer 16

Three protective membranes that cover brain and spinal cord:
Dura mater (most superficial)
Arachnoid mater
Sub-arachnoid space (CSF flows in this space)
Pia mater

Question 17

What are three regions of the brain

Answer 17

Forebrain (cerebrum and regions that run deeper), Midbrain (one part of brain stem), Hindbrain (cerebellum, pons, medulla oblongata)

Question 18

What is contained in Diencephalon?

Answer 18

Epithalamus (links limbic system to other parts of brain), Thalamus (All information of body senses except smell are processed through thalamus before being interpreted by cortex- also plays a role in sleep, wakefullness, conciousness, learning and memory)
Hypothalamus (horemone production, maintain homeostasis)

Question 19

What is anatomy at end of spinal cord

Answer 19

Conus medullaris (cone shaped structure at end of spinal cord), cauda equina (loosely packed collection of nerve roots), Filum terminale ( singular fibre entending from conus medullaris to sacrum)

Question 20

What are two types of nerve roots

Answer 20

Ventral (motor/effector and are anterior), Dorsal (sensory/affector, and are posterior - contain ganglia)

Question 21

Difference between CNS and PNS

Answer 21

CNS is brain and spinal cord and have neurons (conducting cells) and helping cells called glial cells (keep neurons healthy, give nutrients)

PNS is neurons outside brain and spinal cord. PNS has Ganlia (collection of neuron bodies), plexus, and sensory receptions (pick up info such as temp, touch, hearing, balance, chemical and light)

Question 22

What are the glial cell types

Answer 22

Astrocytes (CNS), Oligodendrocytes (CNS- myelin sheath), Microglia (immune cell of CNS), Shwann cell (Myelin sheath of PNS), Satelite ( wrap bodies found in ganglia of PNS)

Question 23

What is nerve structure

Answer 23

Nerve (surrounded by epineurium), Fascial (surrounded by perineurium), and axon (endoneurium covering)

Question 24

What are two structures of PNS

Answer 24

Somatic NS - Voluntary movement, skeletal muscle movement only. Efferent motor nerves send signal from CNS to voluntarily contract muscle

Autonomic NS (involuntary movement)
Enteric NS - innervate the gut (smooth muscle only)
Sympathetic NS - innervates “fight or flight” response (smooth and cardiac muscle)
Parasympathetic NS - Recovery from “fight or flight” response (smooth and cardiac only, return body to homeostasis)

Question 25

What are types of general sensory receptors

Answer 25

Thermoreceptors- Detect temp stimuli
Noiciceptors- Detect pain stimuli
Mechanoreceptors - Touch, pressure, vibration
Baroreceptors - Detect BP
Proprioception - detect change in body position (conscious and unconscious)

Question 26

What is receptor transduction

Answer 26

Refers to the conversion of energy from stimulus to an action potential.
E.G. energy in form of mechanical information resulting from stimulus causes mechanical-gates Na+ ion channels to open, depolarising membrane, sending AP down sensory fibre

Question 27

What are receptive fields

Answer 27

A receptive field is an area of skin surface that is monitored by a single touch receptor - smaller field size allows much finer discrimination

Question 28

What is receptor adaptation (and two types)

Answer 28

Refers to receptors actually stopping signalling when faced with constant stimulus

Slowly adapting- responds to signals considered to be a threat
Rapidly adapting - responds to situations considered not to be a threat (stops signalling after sending initial signal

Question 29

Name the 4 sensory pathways

Answer 29

1. Posterior column-medial lemniscus
2. Spinothalamic
3. Spinocerebellar
4. Trigemino-thalamic

Question 30

Describe posterior column-medial lemniscus sensory pathway

Answer 30

Spinal tract: Fasciculus Gracillis and fasciculus cuneatus
Decussion region: medulla
Order of neurons: 3
Info conducted: Touch, pressure, vibration, proprioception (conscious)

Question 31

Describe spinothalamic sensory pathway

Answer 31

Spinal tract: lateral spinothalamic and anterior spinothalamic
Decussion region: spinal segment
Order of neurons: 3
Info conducted: Pain, temp, tickle, and itch

Question 32

Describe spinocerebellar sensory pathway

Answer 32

Spinal tract: anterior spinocerebellar and posterior spinocerebellar
Decussion region: No decussation
Order of neurons: 2
Info conducted: unconscious proprioception

Question 33

Trigemino-thalamic

Answer 33

Spinal tract: Ventral trigemino-thalamic, dorsal trigemino-thalamic
Decussion region: Medulla or pons
Order of neurons: 3
Info conducted: Specific to face- pressure, vibration, pain, temp, tickle, itch