Neurobiology & Sensory Physiology

Question 1

Central nervous system

Answer 1

• Brain

* Spinal Cord

Question 2

Peripheral nervous system

Answer 2

•Nerves

Question 3

Nerve cells/neurons

Answer 3

• functional cell respo. for nervous system signaling.

* cells specialized for communication

Question 4

Function of neurons

Answer 4

•long distance: electrical signals
ie. Electrical impulses or action potentials

• short distance: chemical signals
• Higher order processing: brain & ganglia

Question 5

Multiple Sclerosis(MS)

Answer 5

• Autoimmune condition

* immune system attacks CNS=demyelination

Question 6

Neuron structure

Answer 6

1. Cell body
2. Dendrites
3. Axon
4. Axon hillock
5. Axon terminal
6. Pre & post synaptic cells

Question 7

Nerve structure in detail

Answer 7

•ENDONEURIUM: protective sheath
🔹axon+myelin sheath

• FASCICLE: group of ENDONEURIUMS
• PERINEURIUM: protective sheath of connective tissue around Fascicles

•EPINEURIUM: encloses
🔹several fascicles+blood supply+fatty tissueJ

Question 8

3 main functions of nervous system

Answer 8

• Sensory function
• Integrative function
• Motor function

Question 9

Types of nerve cells

Answer 9

1. Neurons

2. Glial cells

Question 10

Types of neurons

Answer 10

SIM

🔹sensory/afferent neurons

🔹interneurons

🔹motor/efferent neurons

Question 11

Types of glial cells

Answer 11

MAYO=CNS

🔺microglia= CNS

🔺 astrocyte=CNS

🔺ependymal cells=CNS

🔺oligodendrocytes=CNS

🔹Schwann cells= PNS

Question 12

Resting/graded/ membrane potential

Answer 12

“Ironic name as a lot of work is done to get it to rest”

•sodium channels
•potassium channels
NB. Passive channels therefore always open.

🔹sodium-potassium pump:
Co-transporter
•against [] gradient 
•uses ATP to maintain resting potential 
***think of revolving door 
AIM: 
-ve inside
\+ve  outside

Question 13

Action potential

Answer 13

• voltage gated channels
• action potential

🔹steps:

1. Resting state
2. Depolarization
3. Repolarization
4. Hyper polarization
5. resting state

Question 14

Conduction of action potential

Answer 14

Soma:Axon:Axon

a) depolarized:resting: resting
b) repolarize:depolarize: resting
c) resting:repolarize: depolarize

Node-node

*Saltatory(To jump or skip)conduction
•Increases speed of nerve impulse
•saves neuron energy by preventing slow inward leak of Na and K
•uses myelin as insulating layer(think of sweater)
•moves signal fast by trapping
+ve charge.
**prevents need for new action potential each time

Question 15

Synaptic transmission

Answer 15

1. Action potential reaches pre-synaptic membrane triggering opening of Ca2+ ions.
2. Ca2+ triggers exocytosis of neutransmitters in synaptic vessels.
3. Neurotransmitters diffuse across synaptic cleft
   * many neurotransmitters receptors=ligand gated.

***since synaptic cleft needs to be clear of neurotransmitters after signal has passed, remaining neurotransmitters:
•broken down by enzymes
•re-uptake in pre-synaptic neuron
•diffuse away from synaptic cleft where later destroyed
•taken up by glia cells for metabolic fuel

Question 16

Excitatory postsynaptic potentials(EPSPs)

Answer 16

🔺 in membrane potential=increases probability of action potential.

Question 17

Inhibitory postsynaptic potentials(IPSPs)

Answer 17

🔺 in membrane potential that decreases the probability of an action potential.

Question 18

Summation of post synaptic potentials

Answer 18

Can occur in 2 ways
•temporal summation
•spatial summation

Question 19

Response of postsynaptic cell to neurotransmitter depends on?

Answer 19

• type of neurotransmitters
• [] in synaptic cleft
• types of receptors & chemically sensitive ion channels in postsynaptic membrane

Question 20

Chemicals that function as neurotransmitters

Answer 20

• acetylcholine(ACh)-Alzheimer’s disease

* Biogenic anime’s (norepinephrine, epinephrine, dopamine,serotonin )

Question 21

Dopamine disorders

Answer 21

• ADHD(attention deficit hyperactivity disorder)
• Schizophrenia
• Amphetamines & cocaine
• LSD& mescaline

Question 22

Nervous system organization

Answer 22

• CNS

* PNS

Question 23

Central Nervous System

Answer 23

• *Brain: command Centre
• *Spinal cord: enclosed and protected

Derived from dorsal embryonic nerve cord

Question 24

Matter

Answer 24

Gray matter =neuron cell bodies
White matter= bundled axons

Brain=Gray over white(gray outside)—> signaling neurons for learning, emotions, senses etc

Spinal cord=white over gray(white outside)—>linking CNS and PNS

Question 25

Brain protection

Answer 25

1. Bone-skull 2. 3 layers of connective tissue-meninges) 3. Cerebrospinal Fluid(CSF)

Question 26

3layers of connective tissue protecting brain(meninges) | [DAP]

Answer 26

Duda mater(outer) Arachnoid(middle) Pia mater(inner)

Question 27

Cerebrospinal Fluid (CSF)

Answer 27

* In subarachnoid space(between middle and inner) * physical barrier-has cushioning effect * chemical barrier-isolates from infection * secreted from specialized capillaries into ventricles

Question 28

3 major anatomical divisions of brain

Answer 28

* forebrain (cerebral cortex) * midbrain * hindbrain

Question 29

4 functional lobes of cerebral cortex

Answer 29

* Frontal lobe * Parietal lobe * occipital lobe * temporal lobe

Question 30

What is lateralization?

Answer 30

When competing functions segregate and displace each other into left and right hemispheres during brain development after birth. LH: Adept at languages, maths, logical operations, sequences of information RH: Pattern and face recognition, spatial relations, non-verbal thinking, emotional processes

Question 31

Peripheral Nervous system

Answer 31

•structurally consists of left-right pairs of cranial and spinal nerves and associated ganglia. 1. 12 pairs of cranial nerves(connect directly to brain? 2. 31 pairs of spinal nerves(autonomic and somatic)

Question 32

Why do people feel hot when they eat chili food?

Answer 32

Capsaicin binds to vanilloid receptor inside mouth which =same receptor that detects temperature

Question 33

Freud Tore his Pants Off

Answer 33

``` Frontal lobe: Think of presentation in front of class You must do critical thinking , planning ``` Temporal lobe: Think of tempo of favorite musics Auditory processing Parietal lobe: Think of “piranha” fish biting you Sensation parietal would process. Occipital lobe: Think of octopus=many eyes Visual info

Question 34

Sensory receptors

Answer 34

Special cells that convert stimuli into electrical signals. * group of sensory receptors=sensory organ * AP generates by light striking eye is same as air vibrating in ear.

Question 35

Perception

Answer 35

Brain interprets sensation

Question 36

Types of sensations(6)

Answer 36

* visual * auditory * olfactory * gustatory * somatosensory * osmoreception

Question 37

Functions of sensory receptors(SATI)

Answer 37

Sensory transduction Amplification Transmission Integration

Question 38

Types of sensory receptors

Answer 38

* somatic sensations | * special senses