Introduction to the nervous system Flashcards
1
Q
What are the divisions of the central nervous system?
A
Brain and spinal cord
2
Q
What does the brain do?
A
- Receives and processes info
- Initiates responses, stores memories, generates thoughts and emotions
3
Q
What does the spinal cord do?
A
- conducts signals to and from brain
- controls reflex actions
4
Q
What is the peripheral nervous system physically made up of?
A
12 pairs of cranial nerves, and 31 pairs of spinal nerves
5
Q
What are the cranial nerves?
A
- arise directly from brain
- 2 nerves from cerebrum
- 10 nerves from brainstem
6
Q
What are the spinal nerves?
A
- each pair comes from spinal cord at one vertebral segment
- function as intermediaries between CNS and a certain region of the periphery
7
Q
What are the main regions of the brain?
A
- cerebrum
- brainstem
- cerebellum
8
Q
What are the regions of the brainstem?
A
Midbrain, pons, medulla oblongata
9
Q
What makes up the forebrain?
A
Cerebrum
10
Q
What makes up the midbrain?
A
Midbrain region (superior brainstem)
11
Q
What makes up the hindbrain?
A
Pons, medulla, cerebellum
12
Q
What are the lobes of the cerebrum?
A
- frontal
- parietal
- temporal
- occipital
- insula - under fissure between frontal and temporal
13
Q
What is a sulcus?
A
a groove in the brain
14
Q
What is a fissure?
A
A deep groove in the brain
15
Q
What is a gyrus?
A
A raised area in the brain
16
Q
What are the notable fissures in the brain?
A
Longitudinal fissure - divides brain into right and left hemispheres
17
Q
What are notable sulci in the brain?
A
- central sulcus - between frontal and parietla
- lateral sulcus - between frontal and temporal
- parieto-occipital sulcus
18
Q
What are notable gyri in the brain?
A
- precentral gyrus - primary motor cortex for voluntary movements
- postcentral gyrus - primary sensory cortex
19
Q
What is the corpus callosum?
A
Thick bundle of neurons connecting right and left hemispheres which allow transfer of info between them
20
Q
What is the cerebral cortex?
A
The outermost layer of the brain made of grey matter which processes and respons to info
21
Q
What are the notable regions of the cortex?
A
- primary motor cortex - frontal lobe
2, primary sensory cortex - parietal - Visual cortex - occipital
- auditory cortex - temporal
- brocas area - left frontal
- wernickes area - left temporal
- prefrontal cortex - frontal
22
Q
What is the midbrain of the brainstem?
A
- imp for relaying info between cerebral cortex and spinal cord
- contains red nuculei, superior and inferior colliculus, substantia niagra
23
Q
What do the superior and inferior colliculi do?
A
aspects of vision and hearing
24
Q
What does substantia niagra do?
A
aspects of motor control
25
What does the pons do?
contains respiratory centres and reticular system (arousal, postural control)
26
What does the medulla oblongata do?
Contains ventral and dorsal respiratory groups and cardiovascular centre
27
What does the cerebellum do?
1. receive and process sensory info about joint info and muscle tension
2. receives info about planned movement
3. instruct primary motor cortex in terms of direction, timing and force when the movement is executed
28
How is the cerebellum imp for speech?
1. motor control of muscles
2. timing - for intelligible speech
3. monitoring speech production and adjusting if needed
29
What is the diencephalon?
the 'through' brain between cerebral hemispheres and brainstem
30
What are the parts of the diencephalon?
1. hypothalamus
2. thalamus
3. pituitary gland
31
What does the hypothalamus control?
homeostasis and endocrine
32
What does the thalamus do?
It is the main relay centre for sensory impulses from the body to the cerebral cortex
33
What is the limbic system?
A system in the brain for regulating and processing emotions, and some memory, behaviour, and motivation
34
What are the parts of the limbic system?
1. amygdala
2. hippocampus
3. cingulate cortex
4. thalamus
5. hypothalamus
35
What is the hippocampus responsible for?
Formation of long term memories , spatial navigation, learning, and memory processes
35
What is the amygdala responsible for?
Processing emotions and forming emotional memories
36
What is the cingulate cortex?
A region in the cortex with a role in emotional and cognitive processing, decision making, social behaviour, and pain perception
37
What can come from limbic system dysfunction?
Can contribute to mood disorders, anxiety disorders, and other emotional and behavioural issues
38
What are the regions of the spinal cord?
1. cervical (neck area) - C1-8
2. thoracic (chest area) - T1-12
3. lumbar (lower back) - L1-4
4. Sacral (lowest region) - S1-5
39
Define quadraplegia
A cervical injury resulting in paralysis from the neck down
40
Define paraplegia
A thoracic injury resulting in paralysis from the trunk down
40
How is the spinal cord protected?
By the vertebrae bones of t he spine and vertebral discs
41
What type of nerves do spinal nerves have?
1. sensory nerve - from body to spinal cord
2. motor nerve - from spinal cord to muscle, organ, or gland
42
What doe the spinal nerves join up to?
The four main plexus - gives rise to other peripheral nerves in this region
43
What are the functions of a neuron cell?
Transmit impulses to allow communication between CNS and PNS within the CNS
44
What are the main parts of a neuron cell?
1. cell body
2. dendrite
3. axon
4. myelin sheath
5. nodes of ranvier
6. synapse
45
What makes up the glia in the CNS?
1. oligodendrocytes
2. astrocyte
3. ependymal cells
4. microglial cells
46
What do oligodendrocytes do?
Produce the myelin sheath in the CNS
47
What do astrocytes do?
Support, repair, and allow homeostasis in the CNS
48
What are ependymal cells responsible for?
Production and flow of cerebrospinal fluid, brain metabolism and waste clearance
49
What are microglial cells responsible for?
Immune function in the CNS
50
What makes up the glia in the PNS
1. satellite cells
2. schwann cells
51
What are satellite cells responsible for in the CNS?
Support, repair, and homeostasis in the PNS
52
What do Schwann cells do?
Form the myelin sheath in the CNS
53
What is saltatory conduction?
When Schwann cells become wrapped around the axon of a neuron. The lipid in the cells acts as an insulator and increases the speed of electrical impulses
54
What is muscular sclerosis (MS)?
A condition where the immune system attacks the myelin sheath
55
What neurons are white matter made up of?
Myelinated neurons
55
What neurons are grey matter made up of?
Unmyelinated neurons
55
What is a nerve made of?
Bundles of individual neuron cells, blood vessels, connective tissue
56
What are the layers of a nerve?
1. endoneurium
2. perineurium
3. epineurium
57
What are the stages of an action potential?
1. polarised
2. depolarised
3. repolarised
4. hyperpolarised
58
What happens in a neuron at rest?
1. sodium potassium pumps move sodium ions outside the cell
2. makes inside negative and outside positive
3. sodium channels are closed so cannot reenter
59
What happens in a neuron when an stimulus occurs?
1. when passes threshold sodium channels open
2. sodium floods in
3. creates positive charge inside cell
4. results in depolarisation
60
What is the threshold for an action potential?
55mV
61
What happens in the neuron during the refractory period (hyperpolarisation)?
1. Sodium potassium pump returns ion concentrations on either side to resting potential
2. new action potential cannot be fired in this time
62
What are the factors affecting the speed of an impulse?
1. Axon diameter
2. Temperature
3. (myelination)
63
How does axon diameter affect speed of impulse?
Greater diameter = faster speed
64
How does temperature affect speed of impulse?
Increased temp = faster speed
Due to increased enzyme activity, but will only increase to a point
65
What is a synapse?
The point where one neuron communicates with another neuron/muscle cell
66
How is the impulse propagated along the axon?
1. Voltage gated sodium ion channels sense a change in voltage
2. causes nearby channels to open
3. allows another rush of sodium into the cell
