Lecture 1: The Nervous System

Question 1

Define physiology ?

Answer 1

The study of normal function of living organisms
Function

Question 2

Define anatomy?

Answer 2

The study of the body & how its parts are arranged
Structure

Question 3

Wnat are the 4 main types of tissues?

Answer 3

Nervous tissue
Muscle tissue
Connective tissues
Epithelial tissues

Question 4

Define nervous system?

Answer 4

A constellation of cells (neurons&glia) that are organised into functional neural circuits permit in (complex) neural control of an animals physiology & behaviour

Question 5

What are the 2 divisions of the nervous system?

Answer 5

1.) Central nervous system: brain & spinal cord
2.) peripheral nervous system
- autonomic nervous system:involuntary ( enteric NS
- somatic nervous system: motor voluntary control

Question 6

What are the 2 main types of cells?

Answer 6

1.) neurons: functional units of NS
2.) non-neuronal cells glia (or neuroglia): Astrocyte’s, oligodendrocytes, microglia & ependymal cells

Neurons communicate info from sensors to CNS store & integrate information, communicate commands to muscle to glands.
Gia support neurons modulate neuronal signalling insulate neuronal process: providing immunesystem

Question 7

What are the 2 primary function s of neurons?

Answer 7

1.) rapid transmission of information from specific sources to selected targets: done via action potential
2.) the integration of information / electrical activity from many sources

Question 8

StructureI anatomy of neurons?

Answer 8

Dendrites: receive information from other neurons “convergence”
Axon: transmits information to other neurons or non-neuronal cells ( e.gsmuscles)

Question 9

Basic structure of neurons?

Answer 9

Cell body (soma)
Dendrites
Axon terminal
Axon
Most neurons have 1 axon but con result in many axon terminals

Question 10

Do neurons have wide variety of forms?

Answer 10

Yes -→ morphology reflecting diff functionalities
2 neuronal types from brain:
→ purkinje cells
→ pyramidal cells

Question 11

2 types of glia?

Answer 11

Microglia: phagocytes cells → clean up after cellular damage
Macroglia: support & modulate the functions of neurons
Are motile ( more around environment)
First & major immune defense mechanism

Question 12

Define macroglia?

Answer 12

Support and modulate the functions of neurons

Question 13

Define astrocyte?

Answer 13

Support function for CNS neurons, contribute to the protective blood brain barrier (bbb), regulation of neurotransmitter modulation of neuronal activity

Question 14

Define oligo dendrocytes?

Answer 14

From myelin sheath around neuronal axons in CNS
→ each oligodendrocytes can myelinate - 40 axons
→ each Schwann cell myelinate a section - I axon

Question 15

Define ependymal cells ?

Answer 15

Specialised epithelial cells found in fluid-filled spaces of brain ventricles & central canal of the spinalcord
Produce & circulate cerebrospinal fluid (CSF)
posses microvinli which help circulate CSF around the CNS

Question 16

How does CNS develop?

Answer 16

From embryonic neural tube,
Anterior end of neural tube → folds & swells becoming.the major divisions of the brain.
3 expanded regions = become apparent the forebrain, midbrain & hindbrain
Remainder → (posterior end) of the tube becomes spinal cord

Question 17

What are the 3 main regions of the brain?

Answer 17

Forebrain: (prosencaphaton): cerebral hemisphere thalamus
Midbrain: (mesencephalon) superior & inferior collicular
Hindbrain: irhombsephalon cerebellum,pons medulla

Question 18

Localisation of functions in human brain?

Answer 18

Brocá’s area: initiates grammatical speech

Question 19

What is functional magnetic resonance imaging?

Answer 19

Detecting the functional activity of different brain areas
Indication of neural activity as measured via changes in oxygenated blood flow
More active more blood flow to that area

Question 20

what does fmri tell us ?

Answer 20

gives us an indication of neural activity measured through oxygenated blood flow :more active more blood flow to that area

Question 21

What is grey matter ?

Answer 21

contains larger number of cell bodies
distributed throughout he CNS ;discrete regions (nuclei

Question 22

what is a white matter ?

Answer 22

large number of myelinated nerve fibres/axons

Question 23

what does the PNS transmit ?

Answer 23

signals between CNS and receptors/effectors
nerves connect CNS to various parts of the body/periphery:
PNS consists both cranial nerves-(12 )connnects PNS to brain

Question 25

What is the spinal nerve?

Answer 25

Basic organisational pattern of the body is that of a series of segments.
31 pairs
→ cervical spinal nerve (8) [neck, shoulders arms, hands)
→thoracic
→ lumbar
→ sacral
Coccygeal

Question 26

How does the cross section of the spinal cord?

Answer 26

Repeating pattern:
Sensory (afferent) neuron axons form the dorsal roots of each succeeding segmental nerve;
Exiting (motor) efferent neurons form the ventral roots of each succeeding segmental nerve
??? May have to reword.

Question 27

Define reflexes?

Answer 27

A behavioural or physiological response that does not require conscious information processing: is autonomic
( involuntary reaction)
Spinal reflexes: convert afferrent input → efferent output without brain centres.

Question 28

What is monosynoptic?

Answer 28

2 neurons involved

Question 29

What is poly synaptic?

Answer 29

More then 3 neurons

Question 30

what does the efferent(motor) division of the PNS consist of ?

Answer 30

somatic (motor) nervous system-efferent intervention to skeletal( voluntary control )
controlling muscles of locomotion-movement, speech, breathing-sensory also
ANS-efferent innervation to tissues other than skeletal muscle (largely involuntary )

Question 31

Difference between the SNS and ANS between CNS and effector?

Answer 31

the no of neurons
SNS: 1 neuron connects CNS directly with effector muscle
ANS:2 neurons connect the CNS to effector target
1st-preganglionic neuron and 2nd:postganglionic neuron

Question 32

What are the 3 anatomically and functionally distinct parts ?

Answer 32

Sympathetic: Fight/flight
Parasympathetic: Rest/digest
—>these 2 have antagonistic effects in muscles, glands etc.
Enteric : autonomous nervous system (ENS)
second brain :2 nervous plexuses involved in gastrointestinal activity
Myenteric plexus :regulates motor activity
Submucosal plexus: regulates secretomotor activity

Question 33

slide 43 / lecture 1

Question 34

slide 45 ?

Question 35

define preganglionic neurons ?

Question 36

define postganglionic neuron ?

Question 37

what is the function of the adrenal medulla ganglion ?

Answer 37

autonomic ganglion of sympathetic division

Question 38

what is a noradrenergic neurons ?

Answer 38

preganglionic and postganglionic

Question 39

what are the neurotransmitters of sympathetic and parasympathetic respectively ?

Answer 39

-sympa &para PREGANGLIONIC = both CHOLINERGIC –>use Acetylcholine
- sympa POSTGANGLIONIC =mostly ADRENERGIC —>use noradrenaline/Norepinephrine
some use ACH:innervating nerve glands
some release co-transmitters (ATP,dopamine,neuropeptides)
-Para POSTGANGLIONIC= CHOLINERGIC use ACh
some use NA

Question 40

How does Ach act on postganglionic neurons ?

Answer 40

ACH acts on nictinic gated Ach receptors on post ganglionic neurons in automatic ganglia
-ligand gated ion channels ;when Ach binds ,channels open allowing influx of Na+ and K+ ions
eliciting fast changes in the membrane electric potential

Question 42

How can sympathetic & parasympathetic divisions be distinguished?

Answer 42

1.) anatomy organisation
2.) neurotransmitter
3.) actions (downstreams)

Question 43

What is antagonist control of involuntary functions ?

Answer 43

Heart rate
Blood flow
Respiration
Digestive activities
I

Question 44

What is the main division of the ans?

Answer 44

The ens → capable of sustaining the motility of GI tract in absence of input from the CNS
Contains rich, local interconnections between efferent & efferent & interneurons found in gut -wall.
Responds to stretch & chemical compositions