8: Central Nervous System Flashcards
The Nervous System: Central Nervous System
1
Q
General anatomy of the central nervous system
A
- Consist of brain and spinal cord
- soft tissue = vulnerable to damage by physical traumas
- protected by glial cells, bone, connective tissue and CSF
2
Q
General anatomy of the central nervous system (2)
A
- Glial cells
- Physical support of the CNS
- Blood supply to the CNS
- The blood-brain barrier
- Gray matter and white matter
3
Q
- 90% of CNS
- release growth factors involved in the development of nervous system
- communicate with neurons
A
Glial cells
4
Q
Five types of glial cells
A
- Astrocytes
- Ependymal cells
- Microglia
- Oligodendrocytes
- Schwann cells
5
Q
Type of glial cells that has numerous functions
A
Astrocytes
6
Q
Type of glial cells that line cavities
A
Ependymal cells
7
Q
Type of glial cells that are phagocytes
A
Microglia
8
Q
Type of glial cells that form myelin
A
Oligodendrocytes
9
Q
Type of glial cells that is located in the PNS and responsible in forming myelin
A
Schwann cells
10
Q
Type of glial cells that is involved in:
- development of neural connections and blood-brain barrier
- modulate synaptic activity (wrapped around synapses)
- remove neurotransmitter from synaptic cleft (glutamate and biogenic amine)
- communicate to neurons through chemical messengers
- maintain normal electrolyte composition of ISF in CNS
- protect neurons against toxic substances
A
Astrocytes
11
Q
- protect CNS from foreign matter and oxidative stress
- phagocytosis and release of cytokines
- involved in immune response
A
Microglia
12
Q
(3) Physical support of the CNS
A
- Bone
- Meninges
- Cerebrospinal fluid
13
Q
- The outermost structure that protect the soft tissues of CNS (i.e cranium or skull)
- Vertebral column that surrounds the spinal cord
A
Bone
14
Q
- Connective tissue membranes that separate the soft tissue (brain) from the surrounding bones
- 3 layers (dura, arachnoid and pia mater)
A
Meninges
15
Q
(Meninges) outermost layer, very tough, fibrous tissue
A
Dura mater
16
Q
(Meninges) web-like structure, no space between this and dura mater
A
Arachnoid mater
17
Q
(Meninges) the innermost layer, immediately adjacent to the nervous tissue called subarachnoid space
A
Pia mater
18
Q
Serves as the cushion for the brain
A
Cerebrospinal Fluid
19
Q
The brain contains how many cavities
A
4 cavities (=ventricles filled with CSF)
20
Q
ventricles connected to a midline third ventricle by interventricular foramen
A
2 C-shaped lateral ventricles
21
Q
This connects the third ventricle to the fourth ventricle which is continuous with the central canal
A
Cerebral aqueduct
22
Q
The lining of the ventricles and central canal is composed of this type of glial cells
A
Ependymal cells
23
Q
The lining of the ventricles is vascularized (very small vessels) and forms a tissue called
A
choroid plexus
24
Q
- Extracellular fluid of the CNS
- recycled 3 times/day
- secreted by ependymal cells of the choroid plexus
- circulates to subarachnoid space and ventricles
- reabsorbed by arachnoid villi
A
Cerebrospinal Fluid (CSF)
25
What's causing the limited exchange between CSF and blood?
The blood-brain barrier
26
4 Functions of the Cerebrospinal Fluid (CSF)
1. Cushions brain (absorbs shock)
2. Maintains stable interstitial fluid environment
3. Exchange of material and fluids between cells (low K+, high Na+ outside the cells, few proteins)
4. Limited exchange between CSF and blood due to blood-brain barrier
27
CNS comprises how many % of body weight?
2%
28
CNS receives how many % of blood that the heart pumps?
15%
29
Brain uses __% of O2 consumed by body at rest.
20%
30
Brain uses __% of glucose consumed by body at rest.
50%
31
True or False. Cells in the CNS have very high glycogen.
False. CNS have very little glycogen.
32
A highly selective network of specialized capillaries that prevent many substances from entering the brain from the blood
Blood-Brain Barrier (BBB)
33
What is the BBB and its function?
A highly selective network of specialized capillaries that prevent many substances from entering the brain from the blood
34
Site of exchange between blood and interstitial fluid
Capillaries
35
Layers of capillaries surrounded by these two
1. Astrocytes
| 2. Ependymal cells
36
Protect the brain from blood borne pathogens, toxins and certain hormones
Ependymal cells
37
Name 5 materials that CAN cross the BBB
1. Lipid soluble
2. O2
3. CO2
4. Alcohol
5. Water
38
Name 4 materials that can only cross the BBB with a transporter
1. Glucose
2. Amino acids (facilitated diffusion)
3. Choline
4. Aspirin
39
Name 3 materials that CANNOT cross BBb
1. Catecolamines
2. Inorganic ions (H+)
3. Antibiotics
40
Which matter contains cell bodies, dendrites and axon terminal?
Gray matter
41
Which matter contains myelinated axons also called fibers?
White matter
42
T or F. White matter > Gray matter?
Yes.
White matter - approx. 60%
Gray matter -approx. 40%
43
External surface of the brain gray matter
Cerebral cortex
44
White matter is located _____________
beneath cerebral cortex
45
Embedded within the layer beneath the cerebral cortex are smaller areas of gray matter.
Nuclei or Subcortical nuclei
46
Axon (fibers) are organized in bundles called _________.
Tracts
47
Bundles of axons that connect one region of gray matter with another
Tracts
48
The 3 White Matter Fibers
1. Projection fibers
2. Association fibers
3. Commissural fibers
49
The white fiber that connect cerebral cortex with lower levels of the brain or spinal cord (i.e Corticospinal tract)
Projection Fibers
50
The white fibers that connect one area of the cerebral cortex to another area of the cortex on the same side of the brain
Association fibers
51
The white fibers that connect cortical regions on one side of the brain with corresponding cortical region on the other side (i.e Corpus callosum)
Commissural fibers
52
A cylinder of nervous tissue that is continuous with the lower end of the brain
Spinal cord
53
What is the spinal cord surrounded of?
Vertebral column
54
How many spinal nerves?
31
55
How many pairs of cervical nerves?
8. C1 to C8.
56
How many pairs of Thoracic nerves?
12. T1 to T12.
57
How many pairs of Lumbar nerves?
5. L1 to L5.
58
How many pairs of Sacral nerves?
5. S1 to S5.
59
How many pairs of Coccygeal nerve/s?
1. C0.
60
The bottom third of the column contains individual nerves but no spinal cord proper?
Cauda equina
61
This is the pathway between the body and the brain
Spinal cord
62
- Pathway between the body and the brain
- Contains ascending and descending nerve tracts of the CNS relaying information to and from the brain
- Initiates basic reflexes
Spinal cord
63
3 Functions of the Spinal Cord
1. Pathway between the body and the brain
2. Contains ascending and descending nerve tracts of the CNS relaying information to and from the brain
3. Initiates basic reflexes
64
Fills a butterfly-shaped region in the interior of the cord
Gray matter of the spinal cord
65
A cross-section area of the spinal cord contains many functional area including both _______ and ________ axons.
Afferent (ascending) and efferent (descending)
66
Horns of the gray matter in the spinal cord
1. Dorsal horn (back)
2. Ventral horn (front)
3. Lateral horn
67
White matter tracts that transmit sensory information from the periphery to the brain
Ascending tracts (dorsal columns)
68
White matter tracts that transmit motor commands to efferent neurons on both sides of the spinal cord.
Descending tracts (Pyramidal columns)
69
Function of ascending tracts
Transmit sensoryinformation from spinal cord to brain
70
Transmits the information to the brain
Interneuron
71
NEURONS that transmit information from the brain to spinal cord
Efferent neurons
72
The horn that controls the skeletal muscles once it receives the signal from the brain
ventral horn
73
When a pathway remains on the same side as its origin, it is called ________.
Ipsilateral
74
When a pathway crosses to the side opposite its origin, it is called _________.
Contralateral
75
3 Subdivisions of the brain (functional division)
1. Forebrain
2. Cerebellum
3. Brainstem
76
The forebrain contains these two parts:
1. Cerebrum
| 2. Diencephalon
77
The brainstem contains these three parts:
1. Midbrain
2. Pons
3. Medulla
78
This is also called the "small brain" located behind the brain close to midbrain
Cerebellum
79
Contains the Thalamus and Hypothalamus
Diencephalon
80
Part of the forebrain that includes the cerebral cortex and basal nuclei
Cerebrum
81
Part of the brain also known as "the gatekeeper"
Thalamus
82
Part of the brainstem that connects with spinal cord
Medulla oblongata
83
The largest C-shaped, containing both gray and white matter
Cerebrum
84
The outermost region of the cerebrum comprising a thin, highly convoluted layer of gray matter
Cerebral cortex
85
4 Lobes of the Brain
1. Frontal
2. Parietal
3. Temporal
4. Occipital
86
The RIDGES between two clefts on the cerebral surface
Gyri
87
The GROOVES on the surface of the brain
Sulci
88
Function of the gyrus and sulcus
Help increase the surface area of the cerebral cortex
89
Sulcus that divides the primary motor cortex and primary somatosensory cortex
Central sulcus
90
Give 6 functions of the cerebral cortex
1. Perceive
2. Formulate ideas
3. Experience emotions
4. Recall past events
5. Command our bodies to move
6. Acts as an integrating centre
91
Regions next to or near the primary cortical areas that integrate multiple sensory stimuli, motor stimuli/memory and emotional stimuli. Also requires input from primary cortical areas for integration
Cortical Association Areas
92
Side of the brain that is responsible for logic and analytical processing, strong language capabilities and math skills
Left brain
93
Side of the brain that is responsible for spatial orientation, creativity, face recognition, music, dream imagery, philosophy and intuition
Right brain
94
Among the more prominent subcortical nuclei are ________.
Basal ganglia
95
4 Structures of the Basal Nuclei
1. Globus pallidus
2. Caudate nucleus
3. Putamen
4. Claustrum
96
4 Functions of the Basal Nuclei
1. Modify movement
2. Inhibit unwanted movements
3. Selecting purposeful movements
4. Postural support
97
Also called the little brain
Cerebellum
98
2 Functions of the Cerebellum
1. Motor coordination and balance
| 2. Coordination of eye/body movements
99
Part of the diencephalon that filters, processes, and integrates sensory and motor info
Thalamus
100
Part of the diencephalon that produces many hormones. Also involved in food intake, water balance and thirst center. thermoregulation and links nervous and endocrine system.
Hypothalamus
101
A diverse collection of closely associated structures that affects motivations, basic emotions, social and sexual behaviours patterns and basic survival behaviours.
The Limbic system
102
6 Structures of the Limbic System
1. Amygdala
2. Hippocampus
3. Fornix
4. Cingulate gyrus
5. Mammillary bodies
6. Pre-frontal cortex
103
Part of the limbic system that regulates reward and fear
Amygdala
104
Part of the limbic system that's involved in long-term memory
Hippocampus
105
Part of the limbic system that carries signals from hippocampus to mammillary bodies
Fornix
106
Part of the limbic system that regulates heart rate, blood pressure and cognitive processing
Cingulate gyrus
107
Part of the limbic system that is important for formation of memory
Mammillary bodies
108
Part of the limbic system that is involved in decision-making and consciousness
Pre-frontal cortex
109
3 Functions of the Limbic System
1. Learning
2. Emotions
3. Behavior
110
This connects forebrain and cerebellum to spinal cord, involved in reticular formation and is the processing center for 10/12 cranial nerves
Brainstem
111
Superior portion of the brainstem that contains the superior and inferior colliculi
Midbrain
112
Involved in VISUAL REFLEXES
Superior colliculus
113
Involved in AUDITORY REFLEXES
Inferior colliculus
114
The bulging region between midbrain and medulla
Pons
115
This center works with medulla to maintain rhythmic breathing
Pneumotaxis respiratory centre
116
Base of the brainstem that connects with spinal cord. Also sends information to cerebrum and cerebellum.
Medulla oblongata
117
The medulla oblongata contains this nuclei.
Autonomic nuclei
118
The center that adjusts the heart rate and blood pressure
Cardiovascular center
119
The center that control rates and depth of breathing, work with pons for rhythm.
Respiratory center
