anatomy of nervous system 1 Flashcards
1
Q
What are the two divisions of the nervous system
A
Central (CNS), and Peripheral (PNS)
2
Q
What does the CNS consist of
A
brain and spinal cord. Responsible for integrative and control centers
3
Q
What does PNS consist of
A
Cranial and spinal nerves for incoming/outgoing info, resp. for communication lines between the CNS and rest of body
4
Q
What are the two divisions of the PNS
A
Sensory (afferent) division, Motor (efferent) division
5
Q
What does sensory division of PNS consist of
A
Somatic and visceral sensory nerve fibers
Conducts impulses from receptors to brain (up)
6
Q
What does motor division of PNS consist of
A
Motor nerve fibers
Conducts impulses from CNS to effectors (muscles) (down)
7
Q
What are the two divisions of the Motor division of PNS
A
Somatic nervous system and Autonomic nervous system
8
Q
What is the Somatic nervous system
A
Contains somatic (voluntary) motor nerve fibers
Conducts impulses from the CNS to skeletal muscles
9
Q
What is the Autonomic nervous system
A
Contains visceral (involuntary) motor nerve fibers
Conducts impulses from CNS to cardiac, smooth muscle and glands
10
Q
What are the two divisions of the Autonomic nervous system
A
Sympathetic division
Parasympathetic division
11
Q
What is the Sympathetic division of ANS
A
Mobilizes body systems during activity, “Fight or Flight”
12
Q
What is the parasympathetic division of ANS
A
Conserves energy, promotes house-keeping functions during rest
13
Q
Nervous tissue is ____ cellular, ____ packed, _____ extracellular space
A
Highly cellular, tightly packed, little space
14
Q
What are the two principal nervous tissue cell types
A
Neuroglia - supporting cells
Neurons - nerve cells
15
Q
What are neuroglia and what are the 6 different types
A
Small cells that surround and wrap delicate neurons
1. Astrocytes (CNS)
2. Microglial (CNS)
3. Ependymal (CNS)
4. Oligodendrocytes (CNS)
5. Satellite (PNS)
6. Shwann cells (PNS)
16
Q
What are Astrocytes
A
Description: CNS, Star-shaped, most abundant; anchor neurons close to capillaries
Function: nutrient exchange, guide migration of young neurons, clean up environment (excess NT, K+ ions) , even shown to release NT
17
Q
What are Microglia
A
Description: CNS, thinner processes than astrocytes
Function: protective, touch neurons to monitor well-being; can transform into macrophages to engulf micro-organisms and/or cellular debris
18
Q
What are ependymal cells
A
Description: CNS. line cavities of brain and spinal cord
Function: form permeable barrier between cerebrospinal fluid (CSF) in cavities and tissue fluid bathing CNS cells
19
Q
What are Oligodendrocytes
A
Description: CNS. Few branches
Function: processes wrap CNS nerve fibers, forming insulating myelin sheaths
20
Q
What are the 2 neuroglia in the PNS
A
Satellite Cells and Schwann Cells
21
Q
What are satellite cells
A
surround neuron cell bodies in ganglia- do the same things as astrocytes in CNS
22
Q
What are satellite cells
A
form myelin sheath around larger neurons in the PNS.
23
Q
What are the special characteristics of neurons
A
- Extreme longevity; amitotic
- High metabolic rate: requires continuous supply of oxygen and glucose
24
Q
What are multipolar neurons
A
Many processes extend from the cell body. All are dendrites except for a single axon.
25
What are bipolar neurons
Two processes extend from the cell body. One is a fused dendrite, the other is an axon
26
What is a unipolar neuron
One process extends from the cell body and forms central and peripheral processes, which together comprise an axon
27
What are the 3 functional classifications of neurons
according to direction in which nerve impulse travels relative to CNS
1. Sensory
2. Motor
3. Interneurons
28
What are sensory neurons
carry impulses toward CNS.
Almost all primary sensory neurons (receptors) are unipolar,
Higher order sensory neurons are all multipolar and reside entirely in the CNS
29
What are motor neurons
Carry impulses away from CNS to effectors
Multipolar with most cell bodies in CNS (except some autonomic neurons)
30
What are interneurons
between motor and sensory neurons.
Integration of info;multipolar, most entirely within CNS, 99% of neurons in the body
31
Most multipolar neurons are _____neurons
interneurons
32
Most bipolar neurons are ____ neurons
sensory neurons
33
Most unipolar neurons are ____neurons
sensory neurons
34
What are the subdivisions of the brain
1. Cerebral hemispheres (left and right)
2. Diencephalon (thalamus, hypothalamus, epithalamus)
3. Brain stem (midbrain, Pons, medulla)
4. Cerebellum
35
What is the arrangement of gray and white matter in the spinal cord
central cavity surrounded by gray matter (non-myelated axons) and white matter (myelated axons)
36
What is the arrangement of gray and white matter in the brain
same design as spinal cord, but with additional regions of gray matter.
Cerebral hemispheres and cerebellum have outer "bark" of gray matter.
37
What are gyri
ridges of the brain
38
Sulci
shallow grooves of brain
39
fissures
deep grooves of brain
40
Longitudinal fissue
The longitudinal fissure is the deep groove that separates the two cerebral hemispheres of the vertebrate brain.
41
Transverse Cerebral fissure
divides the cerebrum from the cerebellum (anatomy of cerebral hemisphere)
42
What is the central sulcus and which part of the brain is it on
The central sulcus separates the frontal lobe from the parietal lobe, and more specifically separates the primary motor cortex anteriorly from the primary somatosensory cortex posteriorly. Anatomy of cerebral hemisphere
43
What is the precentral gyrus
a prominent gyrus on the surface of the posterior frontal lobe of the brain. It is the site of the primary motor cortex. Anatomy of cerebral hemisphere
44
What is postcentral gyrus
a prominent gyrus in the lateral parietal lobe of the human brain. It is the location of the primary somatosensory cortex, the main sensory receptive area for the sense of touch. Anatomy of cerebral hemisphere
45
What is parieto-occipital sulcus
shallow groove that seperates the parietal lobe of the cerebral hemisphere from the occipital lobe
46
What is the lateral sulcus
shallow groove that separates the frontal and parietal lobes of cerebral hemisphere from the temporal lobe.
47
What are the 5 lobes of the cerebral hemisphere
1. frontal
2. parietal
3. occipital
4. temporal
5. insula
48
What are the 3 basic regions of the cerebral hemisphere
1. Cerebral cortex of gray matter superficially
2. White matter internally
3. Basal nuclei deep within white matter
49
What is the function of the cerebral cortex
allows us to perceive, communicate, remember, understand, appreciate, initiate voluntary momvents.
TLDR: consious behaviour
50
What are brodmann areas
numbered areas according to subtle differences in thickness, linking to particular functions
51
What are the functional areas of the cerebral cortex
Motor, Sensory, Association
52
each hemisphere handles sensory and motor functions of the _______ side of body
contralateral (opposite)
53
What are 4 areas in the cerebral hemispheres involved in motor control
Primary motor cortex, premotor cortex, Broca's area, frontal eye field
54
Where is the primary motor cortex
Precentral gyrus of frontal love of each hemisphere
55
What neuron cells are involved in the primary motor cortex
pyramidal cells allow control of skeletal muscles, axons project to spinal cord and pyramidal tracts
56
What is somatotopy
entire body represented spatially in primary motor cortex of each hemisphere
57
Where is the premotor cortex
Anterior to precentral gyrus
58
What is the function of the premotor cortex
helps plan movements by selecting and sequencing basic motor movements into more complex tasks. Coordinates movement of several muscle groups simultaneously by activating motor cortex. Sometimes referred to muscle memory
59
Where is the Broca's area
overlaps brodmann areas 44 and 35, present in one hemisphere (usually left)
60
What is the function of Broca's area
motor speech area that directs muscles of speech production
61
Where is the frontal eye field
Brodmanns area 8.
62
What is the function of the frontal eye field
controls voluntary movements of the eyes
63
What is the function of the Sensory areas of the brain
conscious awareness of sensation
64
Which lobes of the cerebral hemispheres are involved in the sensory areas
parietal, insular, temporal, and occipital lobes
65
What are the 8 areas of the cerebral hemisphere that are involved in sensory
1. Primary somatosensory cortex
2. Somatosensory association cortex
3. Visual areas
4. Auditory areas
5. Vestibular cortex
6. Olfactory cortex
7. Gustatory cortex
8. Visceral sensory area
66
Where is the primary somatosensory cortex
in postcentral gyri of parietal lobe (Broddmann areas 1-3)
67
What is the function of the primary somatosensory cortex
Receives general sensory information from skin and proprioceptors of skeleton muscle, joints, and tendons.
Also capable of spatial discrimination
68
Where is the somatosensory association area
Posterior to primary somatosensory cortex. (BA 5-7)
69
Function of somatosensory association area
integrate/analyze somatic inputs (temps, pressure..) - interpret size, texture, relationships. ex// feeling in your pocket for keys
70
What are the two visual areas in the sensory areas of the cerebral hemispheres
1. Primary visual cortex
2. Visual association area
71
Where is the primary visual cortex
located on extreme posterior tip of occipital lobe
72
what is the function of the primary visual cortex
largest critical area; contains map of visual space on retina (opposite sides)
73
where is the visual association area
surrounds primary visual cortex
74
what is the function of the visual association area
uses past visual experiences to interpret visual stimuli (color, form, or movement)
75
What are the two auditory areas of the sensory area of the cerebral hemisphere
1. Primary auditory cortex
2. Auditory association area
76
what is the function of the primary auditory cortex
interprets information from inner ear as pitch, loudness, and rhythm
76
What is the function of the auditory association area
interpretation based on memory - speech, words, music, thunder
77
What and where is the vestibular cortex
responsible for conscious awareness of balance.
located in posterior part of insula and adjacent parietal cortex
78
What and where is the olfactory cortex
Involved in conscious awareness of odors
Medial aspect of temporal lobes (uncus?)
79
What and where is the gustatory cortex
Involved in the perception of taste
Located in the insula, just deep to the temporal lobe
80
What and where is the visceral sensory area
Conscious perception of visceral sensations (upset stomach, full bladder)
Located posterior to gustatory cortex
81
What is a multimodal association area
any cortical area that isnt primary.
Functions: Receive inputs from multiple sensory areas, send outputs to multiple areas.
82
What are the three parts of the multimodal association area
Anterior association area
Posterior association area
Limbic association area
83
What is the order of sensory information into cerebral hemispheres
Sensory receptors -> primary sensory cortex -> sensory association cortex -> multimodal association cortex
84
What is the anterior multimodal association area
the prefrontal cortex
85
What is the function of the prefrontal cortex
Most complicated cortical region- innvolved with intellect, cognition, recall, and personality
Closely involved in limbic system
86
What is the posterior association area
Large region in temporal, parietal, and occipital lobes.
Function: input from all sensory association areas, storage of complex memories, putting info to under what we see and feel.
Damage to this area can lead to contralateral neglect
87
What is the limbic association area
Part of the limbic system.
Function: provides emotional impact that makes the scene important and helps establish memories
88
What is lateralization
division of labor between hemispheres
89
______ fibers and their tracts responsible for communication between cerebral areas and between ____ and ____ CNS centers
myelinated fibers, cortex, and lower CNS
90
What are commissural fibers
cerebral white matter that connects corresponding areas between the 2 hemispheres- largest is corpus callosum
91
What are Association fibers
cerebral white matter that connects within a hemisphere (connect gyri, lobes)
92
What are projection fibers
cerebral white matter that connects cortex to rest of nervous system, run vertically
93
What are basal nuclei
subcortical structures found deep within the white matter of the brain
94
What does the basal nuclei consist of
Caudate nucleus + lentiform nucleus (putamen + globus pallidus)
95
What is the function of the basal nuclei
1. Receive input from entire cerebral cortex, other sub subcortical nuclei, and other basal nucleis
2. projects information to premotor and prefrontal corticles to influence muscle movements directed by primary motor cortex
96
What are the 3 parts that make up the diencephalon
Thalamus, Hypothalamus, Epithalamus
97
What is the thalamus
bilateral nuclei makes up 80%. Connected by Interthalamic adhesion
Function: consists of many different nuclei that are relay stations for incoming info then group to send to appropriate region of cortex
Known as "gateway to cerebral cortex"
98
What is the hypthalamus
a bunch of centers and nuclei responsible for regulating roles unconsciously. "background control"
Located below thalamus
Disorders cause problems w homeostatis
99
What is the epithalamus
Most dorsal portion of diencephalon
Consists of the Pineal gland (extends from posterior borders and secretes melatonin)
100
What is the choroid plexus
Part of the epithalamus that has special capillaries to filter blood to generate CSF
101
What is the brain step
structure that control automatic behaviours necessary to survive. Bridge between spinal cord and higher centers
102
What are the three regions to the brainstem
1. Midbrain
2. Pons
3. Medulla oblongata
103
What is the midbrain and what are the 5 things it consists of
involved in the processing of visual and auditory information.
1.Cerebral peduncles
2. Cerebral aqueduct
3. Periaqueductal gray matter
5. Superior colliculi (Corpora quadrigemina)
6. Inferior colliculi (Corpora quadrigemina)
104
What is the cerebral penduncles
two ventral bridges. control large pyramidal motor tracts
105
What is cerebral squeduct
channel running through midbrain that connects 3rd and 4th ventricles
106
What is Periaqueductal gray matter
nuclei that play a role in pain supressant and fight or flight response. Also include nuclei that control cranial nerve III (oculomotor) and IV (trochlear)
107
What is Superior colliculi (Corpora quadrigemina)
visual reflex centres when visually following a moving object
108
What is Inferior colliculi (Corpora quadrigemina)
part of auditory relay (startle reflex)
109
What are the two nuclei of the midbrain
1. Substantia nigra
2. Red nucleus
110
What is substantia nigra
band-like nucleus, high melanin content (precurder for dopamine), linked to a dampening effect on basal nuclei of cerebral hemisphere. Damage could lead to overexcited neurons
111
What is red nucleus
rich vascular supply, iron pigment in neuron cell bodies, relay neuclei for descending pathways influencing limb flexion
112
What is the Pons
composed of conduction tracts, mostly communication pathways (either up and down ex//Longitudinal fibers or transverse (between motor cortex and cerebellum)
113
What are the 3 parts of the medulla oblongata
1. Pyramids: two ventral longitudinal ridges formed by pyramidal tracts from motor cortex
2. Decussation: point where pyramidal tracts cross over to opposite side of body
3. Olives: swellings cause by underlying inferior olivary nuclei that relay stretch info from muscles to cerebellum
114
What is the function of the medulla oblongata
crucial role as autonomic reflex centre for homeostasis
115
What is the cerebellum
Processing input from cerebral cortex, brain stem, and sensory receptors to influence the timing and patterns of skeletal muscle contraction.
Not under conscious control
116
What does the cerebellum consist of
bilaterally symmetrical; connected by vermis. Fine folia to increase gray matter.
Each hemisphere divided into three lobes: anterior, posterior, and flocculonodular
117
Virtually all fibers in the cerebellum are _____
Ipsilateral (each side controls the same side of body)
118
What are the three pairs fiber tracts that connect cerebellum to brain stem
1. Superior (outgoing): connect cerebellum to midbrain
2. Middle (incoming)
connect pons to cerebellum
3. Inferior (incoming)
connect medulla to cerebellum
119
What are the steps to cerebellar processing
1. cortex frontal motor association area indicated intent to initiate action and sends collaterals to cerebellum to notify
2. Also receives proprioceptive info and info from visual and equilibrium pathways
3. cerebellar cortex receives this info and determines best way to coordinate direction extent of muscle contraction
4. Via superior peduncles, cerebellum dispatches blueprint to coordinate output also to brain stem nuclei (like red nucleus) which project to motor neurons of spinal cord
120
What are the two functional brain systems
1. Limbic system
2. Reticular formation
121
What is the limbic system
emotional-visceral brain consisting of amygdala, hippocampus and anterior cingulate gyrus.
Close association with hypothalamus provides a pathway for stress to affect bp, gi tract, hr, etc.
122
What is the reticular formation system
maintains arousal of brain and filters incoming signal (around 99 % of all sensory stimuli is filtered)
Severe injury results in permanent unconsciousness
