neuron and brain Flashcards
1
Q
Cells in the NS (2)
A
- neurons: nerve cells that conduct signals
- neuroglia: support cells for neurons, aka glial cells
2
Q
Neurons: how many? form?
A
- 100 billion neurons
- form connectios to other cells via synapses (10^15 synapses, each neuron has ~100 000 connections with other neurons)
3
Q
Nerve Cell Bodies - 2 names?
A
- nucleus: collection of nerve cell bodies within the CNS
- gangliaon: collection of NCBs in PNS
4
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5
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6
Q
Parts of a Neuron: axon collateral? Nissl bodies?
A
- AC: branches that come off axon: how
action potentials are amplified - NB: rough ER with ribosomes, protein manufacturing
7
Q
Classification of Neurons - three polarities?
A
- unipolar: one appendage from body, predominantly sensory fibres
- bipolar: one dendrite coming in, one axon leaving (ex found in eye, olfactory)
- multipolar: many different appendages off cell body - usually one axon, many dendrites
8
Q
Multipolar cell examples
A
- pyramidal cell
- purkinje cell
- stellate cell
- granule cell
- basket cell
9
Q
Neuroglia names - PNS vs CNS?
A
- PNS: satellite cells, Schwann cells
- CNS: oligodendrocytes, astrocytes, microglia, ependymal cells
10
Q
Satellite Cells
A
- neuroglia found in PNS
- surround neuron cell bodies in ganglia
- regulate O2, CO2, nutrient and neurotransmitter levels around neurons in ganglia - homeostasis
11
Q
Schwann Cells
A
- neuroglia in PNS
- surrounds all axons in PNS, responsible for myelination of peripheral axons, participates in repair process after injury
12
Q
Oligodendrocytes
A
- neuroglia in CNS (are like Schwann Cells)
- myelinate CNS axons, provide structural framework
13
Q
Astrocytes
A
- are like satellite cells, but for CNS
- maintain blood-brain barrier, structural support, regulate ion, nutrient, dissolved gas concentrations, absorb and recycle neurotransmitters, form scar tissue after injury (but prevents regrowth of axons)
14
Q
Microglia
A
- neuroglia in CNS
- removes cell debris, wastes and pathogens by phagocytosis
15
Q
Ependymal Cells
A
- neuroglia in CNS
- line inside of “tube” - ventricles in brain and central canal in spinal cavity
- assist in producing, circulatin and monitoring cerebrospinal fluid
16
Q
CNS protection - 2?
A
- meninges: cover and protect the CNS
- CNS floats in cerebrospinal fluid: buffers compression, but will still displace during significant trauma
17
Q
Meninges - 3?
A
- dura mater: tough outer layer, very dense, doesn’t tear
- arachnoid Mater: spider web like appearance, CSF cushion just under am, shiny, like saran wrap
- pia mater: intimate contact with brain, doesn’t really separate from brain
18
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19
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20
Q
Brain - 3 main parts?
A
- cerebrum - like a bum
- cerebellum - like a bell
- brain stem
21
Q
Cerebrum functions (5)
A
- higher cognitive functions: thought, intellect, planning, creativity
- language/speech: formulation and comprehension
- somatic motor function: regulates skeletal muscle activity, movement (basal ganglia)
- somatic sensory function: interprets stimuli from environment
- regulates emotional aspects of behaviour
22
Q
Structure of Cerebrum
A
- 2 hemispheres, 4 lobes, 3 poles, 3 major grooves
- many sulci and gyri
23
Q
Cerebrum structure: cerebral cortex vs medulla?
A
- cerebral cortex: outer covering, grey matter b/c of cell bodies
- medulla: inner, white matter, axons
24
Q
3 major grooves in cerebellum?
A
- Longitudinal/Interhemispheric Fissure: b/w left and right hemispheres
- central sulcus: frontal and parietal
- lateral sulcus: above temporal
25
3 Poles of cerebrum?
* frontal pole, occiptial pole (posterior), temporal pole at sides
26
Sulcus vs Gyrus?
* sulcus/sulci = groove
* gyrus/gyri = ridge of tissue between sulci
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4 Lobes of Brain?
1. Frontal: higher cognitive, planning, strategy, motor
2. Parietal: perception of self in space, sensory
3. Temporal: memory, learning, social, emotions, hearing
4. Occiptial: vision
30
Post/Precentral Gyrus?
* Precentral gyrus - in the front = motor (in frontal)
* postcentral gyrus - in the back = sensory (in parietal)
31
grey vs. white matter?
grey outside, cell bodies. white inside, axons b/c of myelin and fat
32
Fibre Tracts in Brain (3)
* projection: travel to and from cortex
* association: intrahemispheric connections, short or long
* commissural: interhemispheric connections - corpus callosum
33
Cerebellum - purpose? 3)
* acts as a comparator: inteded movement with evolving movement, corrects for errors
* ensures movements are smooth, coordinated, purposeful
* regulates posture and balance
34
Cerebellar Ataxia?
* disease of cerebellum
* intention tremor, lack of balance and coordination
35
Brainstem - 3 parts?
* midbrain
* pons
* medulla oblongata
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Brainstem: contains? (3) functions?
* motor and sensory pathways connecting cerebral cortex and thalamus to spinal cord
* houses cranial nerve nuclei (origins of CNs)
* contains reticular activating system: important for arousal of cortex and consciousness
* vital centres for regulating heart rate, breathing
* centers for regulating swallowing and gag reflex
39
Midbrain - two major components? cranial nerves?
* substantia nigra
* red nucleus
* relay centers for visual and auditory pathways
* crandial nerves III and iV attached
40
substantia nigra? red nucleus?
* SN: in midbrain, regulates motor activit, neuronal degeneration = Parkinson's disease
* red nucleus: regulates motor activity, activates flexors in upper extremities
41
Pons - purpose? nerves?
* bridge between cerebrum and cerebellum: lots of axonal input, so has a belly
* cranial nerves 5 to 8
42
Medulla Oblongata - contains? nerves?
* vital cardio-respiratory regulatory centers
* cranial nerves 9 to 12
