CNS S1 Flashcards

(91 cards)

1
Q

CNS

A

Brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

PNS

A

Made up of neurons and parts of neurons outside of CNS. Somatic and autonomic nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Somatic nervous system

A

Controls voluntary action via skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Autonomic nervous system

A

Visceral functions such as heart rate, breathing, digestion (enteric nervous system)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many nervous are in the CNS/PNS

A

86 billion in brain, 1 billion in spinal cord. 100-600 million in PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

CNS and CSF route

A

3rd ventricle between lateral ventricles > 4th ventricle > central canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Grey matter

A

Nerve cell bodies, unmyelinated axons and dendrites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cell body organization

A

Organized in clusters called nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

White matter

A

Myelinated axons running in bundles called tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

PNS neuron clusters and axons nomenclature

A

Clusters of neurons are ganglia and bundles of axons are nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How many neurons are fired at any moment?

A

4%, only one AP fires every 6s in the cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Spinal cord

A

31 segments, each with a pair of spinal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Dorsal root

A

Carries afferent (incoming sensory) signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ventral root

A

Carries efferent (outgoing) motor signals from CNS to body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Grey matter in the spinal cord

A

Mainly in the middle and consists of a dorsal and ventral horn. Have motor and sensory nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Dorsal horn

A

Contain sensory nuclei. Somatic nuclei get signals from skin, visceral nuclei get signals from internal organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Ventral horn

A

Efferent nuclei. Autonomic send commands to glands and smooth muscle, somatic to skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

White matter in spinal cord + tract components (3)

A

Consist of tracts

1) ascending tracts: sensory signals to brain (dorsal)
2) descending tracts: signals from brain (ventral)
3) propriospinal: stay in spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Brain stem

A

Medulla, pons and midbrain Control centre for many autonomic functions and reflexes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Cranial nerves

A

Nerves that enter or leave the brain. 3-10 and 12 are in brain stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Diencephalon

A

Made up of thalamus, hypothalamus, pituitary and pineal gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Thalamus and hypothalamus

A

Thalamus: processes information to and from cerebral cortex
Hypothalamus: regulates behaviour and endocrine/autonomic homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Cerebrum

A

2 hemispheres connected by the corpus callosum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cerebral grey matter

A

Cortex, limbic system (motivation and memory) and basal ganglia (movement)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Left and right hemisphere functions
left: speech, writing, language, math right: analysis by touch, spatial analysis
26
Limbic system
Cingulate gyrus, amygdala, hippocampus
27
Senses
9 senses. 5 special and 4 somatic
28
Special senses
Vision, hearing, equilibrium, taste, smell. Have a sense organ that isn't skin
29
Somatic senses
Touch, temperature, proprioception and nociception (pain and itch)
30
Transduction
The process of converting stimuli into electrical signals
31
Chemoreceptors
Respond to specific molecules or ions
32
Mechanoreceptors
Respond to mechanical energy such as pressure, vibration, gravity, sound
33
Photoreceptors
Respond to light
34
Thermoreceptors
Temperature
35
Perceptual threshold
The weakest stimulus that will cause conscious perception in the organism
36
Labelled lines modality
The modality is revealed by which axons carry the signal
37
Population coding of intensity
Represents stimulus intensity by the number of active neurons
38
Phasic cells
Respond briefly to any change and then cease firing. Ex, retinal cells
39
Tonic cells
Maintain activity when the stimulus isn't changing
40
Phasic-tonic
React to change but don't return all the way to zero firing when stimulus is constant
41
Temporal changes
Changes through time, between one moment and the next
42
Spatial changes
Differences between neighbouring regions in space
43
Edges
Edges convey information between two different areas conveying different stimuli. Can be accentuated by lateral inhibition
44
Thalamus exception
Olfactory pathways are the only ones that don't project through thalamus
45
Equilibrium pathways
Project mainly to the cerebellum
46
Lens
Transparent disk that focuses light and is suspended by ligaments called zonules
47
Anterior chamber
The front of the lens and is filled with aqueous humour
48
Vitreous chamber
Filled with a vitreous body which helps maintain eye shape
49
Cornea
Transparent bulge at the front of the eye that is continuous with the sclera. Lights enter through cornea
50
Pupil
A hole in the iris that changes in response to light. Controlled by the pupillary muscle
51
Refraction
Allows us to obtain a bright, infocus image. The bending of light.
52
Refractive index
Light bends when it enters a different medium. Air and collagen of the eye are different so light bends to make a right angle
53
Lens composition
Mesh of long cells without nuclei, packed by crystallin proteins
54
Convex lens
Fatter in the middle and thinner at edges. Makes light converge at a focal point
55
Concave lenses
Thinner in the middle and fatter at edges. Disperse light
56
Accommodation
The process of changing the lens to alter the amount of refraction. Round lens bends light more, closer focal point. Skinnier lens bends light less, further focal point
57
Focal point
Must fall on the retina. To bring a closer object into focus, the lens is rounder
58
Ciliary muscle
Ring-shaped. Parasympathetic nerves contract the ring, making lens rounder and sympathetic signals relax the muscle, making lens flatter
59
Presbyopia
Lens stiffening, hindering accommodation
60
Hyperopia
Far-sightedness caused by focal point falling behind retina. Convex lens fixes it
61
Myopia
Near-sightedness caused by a focal point in front of the retina. Solved by a concave lens
62
How many cones and rods are in the retina
6 million cones and 120 million rods
63
Structure of rods and cones
Outer segment: disk-like layers of membrane that contain visual pigment Inner segment: contains nucleus and organelles Basal layer: found in inner segment and contain synapse
64
Photoreceptor mechanism
Pigment molecules change shape when light hits, hyperpolarizing the cells and reducing glutamate
65
Pigment in rods and cones
Rhodopsin in rods, 3 other pigments in 3 types of cones
66
Photoreceptor distribtuion
Most densely packed in the macula found in the fovea
67
Cones vs rods
Cones are for bright light, rods are for dim. Cones are less sensitive and can distinguish colours
68
Cone and rod distribution
Cones are almost exclusively in the fovea, peripheral retina contains rods
69
Bipolar cells
Have center-surround receptive fields, with a round center region and.a hoop surround
70
On-center cells
Excited by light in the center of the field, inhibited by light in the surround
71
Off-center cells
Inhibited by light in the center and excited by light in the surround
72
Bipolar cell projection
Project onto retinal ganglion cells which have center-surround receptive fields
73
Magnocellular ganglion cells
Provide information used by the brain to infer movement of objects. Phasic
74
Parvocellular ganglion cells
Provide information used to infer form and fine detail
75
Melanopsin ganglion cells
Photoreceptors with their own visual pigment, melanopsin
76
Optic nerve
Cranial nerve II. When each nerve reaches the optic chiasm, half cross to the other side of the brain (nasal half)
77
Why do optic fibers cross
For information from the right hemifield to come together in the left cerebral hemisphere and vice versa
78
Optic tracts
Nerve bundles emerging from the chiasm and end in the 2 lateral geniculate nuclei in the thalamus
79
What wavelengths do humans see
400nm (violet) to 700nm (red) and powerful infrared light
80
Three types of cones
Red, green and blue
81
Blue cones
Peak at 420nm and prefer blue light
82
Rhodopsin
Peak at 498nm and prefers blue-green light. Doesn't contribute to colour vision
83
Green cones
Peaks at 533nm and prefers yellow-green light
84
Red cones
Peak at 564m, and prefers yellow light
85
Spectral colours
Colours that can be evoked by a light of a single wavelength (rainbow colours)
86
Extraspectral colours
Can only be evoked by a mix of wavelength
87
R + G cells
Ganglion cells excited by red and green to make yellow
88
R - G cells
Ganglion cells excited by red and inhibited by green
89
B - R - G cells
Excited by blue and inhibited by red or green
90
Daltonism
Red-green colourblindness. Rarely occurs in women
91
Reflectance
A surfaces tendency to reflect a certain wavelength of light and absorb others. Doesn't change