week 4 Flashcards

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1
Q

what are the 2 parts of the nervous system

A
  • Centeral nervous system (CNS), contains brain and spinal cord
    Peripheral nervous system (PNS)
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2
Q

what is in the automatic nervous system

A
  • Parasympathetic: unconcious/ involuntary
    Sympathetic: concious/ voluntary
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3
Q

what are the cells of the nervous system

A

neuron / glial

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4
Q

draw or describe a neuron

A

Neuron: cell body (soma) which contains nucleus// around ccell body coming off is the dendrites which receive info and pass info along to the //axon (long log looking thing) // at the start of the axon is called axon hillock// at end of axon is the axon terminal which transmites neurotransmitters to other cells// the axon terminal contains visciles which conatins the neruorntransmitter around axon is myelin

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5
Q

what is multi polar neuron

A

a nureon that has lots of axon terminals and it present in:
motornurons
Interneurons

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6
Q

what is a bipolar nueron (sensory)

A

is very rare which is only found in the eye and in the ear

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7
Q

what is the last neutron

A

Pseudo-unipolar sensory neuron

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8
Q

what is Neuroglia

A

specialized cells found only in close association with neurons, don’t participate directly in information transfer.

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9
Q

Oligodendrocyte (CNS)

A

makes myolin for serveral axon at the same time

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10
Q

Schwann (PNS)

A

does one myolin one at a time but does faster thus most effiecent then the oligodendrocyte and more resistent to injury

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11
Q

Astrocytes (CNS)

A

provide nutrients and support for neuron in homostatis regulates synaptic connections and readts to injury (star shape)

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12
Q

Microstrecite (PNS)

A

provide nutrients and support for neuron

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13
Q

Microglia (CNS)

A

get pathogen and take into cell to eat it away via phagocytosis (immune cell to protect the brain)

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14
Q

Epenymal

A

provinding lining in the ventricles and are involved in production of Cerebro-spinal Fluid (CSF)

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15
Q

what helps in resisting membrane potential

A

1)Anions in cell
2) number of leak channels of potassium and sodium
3) Active pump to move K+ and Na+ (2 K+ into cell & 3Na+ out thus lose one + charge each time)

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16
Q

what is action potential

A

Normal potential=-70mV
Ligand gated channel needs a ligand to attach to receptor to open the door

- Ligand gated channel for Na+ opens at -55mV and closes at 30mV Ligand gated channel for K+ open 30mV closes -80mV so this decreases the postive charge inside the axon
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17
Q

what is depolarisation

A

The voltage gated sodium (Na+) channels in the neuronal membrane open and sodium flows into the cell, bringing positive electrical charge and so increasing membrane potential. This phase is called DEPOLARISATION.

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18
Q

what is repolarisation

A

When the membrane reaches a certain potential (around +30 to 40 mV), the voltage gated potassium (K+) channels open which leads to the exit of K+ ions out of the cell (so the membrane potential will decrease). This phase is called REPOLARISATION.

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19
Q

what is hyperpolarisation

A

Since the voltage gated potassium channels take time to close, K+ ions continue to leave the neuron, which causes the membrane potential to drop below the RMP (-70 mV) until it reaches around -90 mV.

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20
Q

what are the 2 types of synapses

A

Electrical: gap junction
chemical

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21
Q

what is an Electrical: gap junction synapse

A

Very fast connection present mainly in brain and heart

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22
Q

what is a chemical synapse

A

most common ones in mammals. Examples of chemical synapse locations include;
* Connection between Neuron- Neurons
* Neuromuscular junction: synapse between neuron and muscle
* Neuroglandular junction: synapse between neuron and gland

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23
Q

what are the 3 chemical synapses essential components

A
  • Pre-synaptic neuron with neurotransmitter housed in the pre-synaptic neuron in vesicles
  • Post-synaptic neuron with neurotransmitter binding sites
  • Cleft or gap with enzymes to degrade left over of neurotransmitters (such as Acetylcholinesterase degrading Acetylcholine)
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24
Q

how do neurotransmitters insynapse get out

A

1) Enzymes
2) Reuptake
3) Diffusion away

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25
Q

describe briefly the role of main neurotransmitters in the nervous system

A

Neurotransmitters are chemical messengers. They are released at presynaptic membrane (through EXOCYTOSIS) and bind to specific receptors at the postsynaptic neuronal membrane.

26
Q

Glutamate

A

Major excitatory neurotransmitter in CNS, role in learning and memory.
Act on both metabotropic and ionotropic (let enter Na+ and Ca++ in the cell) receptors

27
Q

GABA

A

Major inhibitory neurotransmitter in CNS.
Act on GABAergic receptors which are a ligand gated channel receptors. GABA, ethanol, benzodiazepine (anxiolitic) and barbiturate are ligands of these receptors which lead to entry of chloride (Cl-) ions, which have depressant effects

28
Q

Explain the general role of the protective systems of the brain

A

The brain is protected by meningeal layers made of:
* Dura Mater (“hard mother”): EXTERNAL Layer which is thick, tough, inelastic

  • Arachnoid Mater: thin cell layer with arachnoid trabeculae, which is web-like collagen projections to pia layer. Please note the subarachnoid space containing CSF (Cerebrospinal fluid)

Pia mater (“tender mother”): INTERNAL layer; thin, delicate, tightly covers all external contours of brain with blood vessels.

29
Q

Describe the structural components of the brain, including its major blood supply

A

The brain is organised with cortical areas (or cerebral cortex) and subcortical regions, which include:
DIENCEPHALON (thalamus and hypothalamus)
MIDBRAIN
PONS
MEDULLA OBLONGATA
CORPUS CALLOSUM
CEREBROSPINL FLUID

30
Q

DIENCEPHALON in the brain is responsible for what

A

Thalamus: relay and processing centers .
2) Hypothalamus:
* Highest center for autonomic control (HR, BP, respiration, digestion, thermoregulation),
* Control and integration center connected to the limbic system (emotion, behaviour, memory) and involved in appetite regulation,
* Hormonal regulation (pituitary for example to secrete FSH and LH which are going to stimulate secrete of sex hormones).

31
Q

the midbrain is associated with what

A

important region for motor control, sleep/wake, arousal (alertness), and temperature regulation and relay station for auditory and visual information.

32
Q

the PONS in the brain is associated with what

A

relays sensory information to cerebellum and thalamus and contains subconscious somatic and visceral centers.

33
Q

the MEDULLA OBLONGATA in the brain is associated with what

A

relays information and contains autonomic centers for regulation of visceral function (cardiovascular, respiratory and digestive activities).

34
Q

the CORPUS CALLOSUM in the brain does what

A

connects the two hemispheres (left and right) and is made of mainly nerve fibres

35
Q

what is the Cerebro Spinal fluid functions

A
  1. Cushions delicate neural structures
  2. Supports brain (oxygen, nutrients..)
  3. Transports chemical messengers, and waste products (maintains homeostasis)
    Brain blood supply
36
Q

Explain the structure and function of the cerebral cortex, including difference between grey and white matter

A

Grey matter= lots of cell bodies - info cell processing
White matter= axon- myolinated (myolin covers sections of axon-> speeds up action potential

37
Q

Frontal lobe

A

includes primary motor cortex, essential for motor control and language production

38
Q

Parietal lobe

A

includes somatosensory cortex, essential for perception of touch, pressure, pain, vibration, taste

39
Q

Occipital lobe

A

include visual cortex, essential for vision

40
Q

Temporal lobe

A

with auditory and olfactory cortices, essential for audition, olfaction and language comprehension.

41
Q

Explain the location and functions of the basal ganglia

A

group of nuclei located deep in the cerebral hemispheres
They are essential into motor planning and executing fine voluntary.

42
Q

Explain the location and functions of the CEREBELLUM

A

Called “little brain” at the back of the brain
This structure allows rapid co-ordination for movement, automatic adjustments to maintain balance and posture.
Is an automatic processing center which subconsciously co-ordinates both learned and reflexive patterns of muscle activity (e.g., swallowing)
PMA = premotor area

43
Q

wernicks area

A

Region responsible for language comprehension

44
Q

brocas area

A

Speech prodction

45
Q

Describe the structural components of the spinal cord

A

The spinal cord is a major column of nerve tissue extends from the foramen magnum to the lumbar vertebral column and ends level with the L1-L2 disc.

46
Q

Sensory pathways

A

sends information up to the brain to be processed
VIA DORSAL ROOT
Acsending= goes from PNS to CNS

47
Q

Motor pathways

A

sends signals down to muscles and organs movement and posture VIA VENTRAL ROOT.
Decending= goes from CNS to PNS

48
Q

Explain the pathways of nerve input (sensory) and output (motor) in and out of the brain and the general structure and function of the peripheral nerve

A

The nerves are bundle of axons in the body that transmit impulses of sensation to the brain or spinal cord, and impulses from these to the muscles and organs.
There are 31 pairs mixed nerves: 8 Cervical (C1-C8), 12 Thoracic (T1-T12), 5 Lumbar (L1 – L5), 5 Sacral (S1 – S5) and 1 Coccygeal.

49
Q

olfactory cranial nerve

A

motor: none
sensory: olfactory endings in nasal cavity

50
Q

optic cranial nerve

A

motor: none
sensory: retina (vision)

51
Q

oculomotor cranial nerve

A

motor: extraoccular and intraocular eye muscle
sensory: none

52
Q

trochlear cranial nerve

A

motor: extraoccular eye muscle
sensory: none

53
Q

trigeminal crasinial nerve

A

motor: mastication, some suprahyoid
sensory:general senses of anterior tongue, skin of face

54
Q

abducens cranial nerve

A

motor:extraoccular eye muscles
sensory: none

55
Q

facial cranial nerve

A

motor: facial expressions, middle ear, lacrimal and salivary glands
sensory: taste anterior 2/3 of tongue

56
Q

vestibulocochlear cranial nerve

A

motor: none
sensory: receptors inner ear - balance and hearing

57
Q

glossopharyngeal cranial neve

A

motor: pharynx, larynx, and soft palate
sensory: general sense larynx

58
Q

vagus cranial nerve

A

motor: organs of the thorax and abdomen
sensory: sensation from organs of thorax and abdomen

59
Q

accessory (to vagus) cranial nerve

A

motor: pharynx, larynx and soft palate
sensory: general sense larynx

60
Q

hypoglossal nerve cranial nerve

A

motor: the tongue
sensory: none

61
Q

what are the steps in action potential

A

1) Resting membrane potential (-70mV, Na+ outside, K+ & proteins inside)
2) Neurotransmitter ligand binds ligand gated Na+ channel -> open
3) Na+ moves down the gradient into axon -> membrane potential (coming closer to 0)
4) @threshold (-60mV) voltage gated Na+ channels open (all/ nothing)
5) Na+ moves down gradient into axon -> membrane potential
6) @ +30mV Na+ channels close, voltage gated K+ channels open
7) K+ moves down the gradient out of the axon-> membrane potential
8) @ -90mV K+ channel closes
9) Na/K pumps moves 3 Na+ out and 2K+ in -> resting membrane potential restored
10) Repeated propagating action potential to synapse
11) Voltage gated Ca+ channels open
12) Ca+ moves from igh conc outside to a low conc inside
13) Triggers release of neurotransmitters ( from vesicles which burst bc of Ca+ coming into cell) into synaptic cleft
Neurotrasmitters bind receptor ligand gated channels on postsynaptic membrane