Lecture 1 Overview Of Nervous System Flashcards
1
Q
Name the 3 planes the brain (and body) can be viewed in
A
- Sagittal
- Coronal
- Transverse
2
Q
What is the anatomical terminology for above and below?
A
Above = superior
Below = inferior
3
Q
What is the anatomical terminology for front and back ?
A
Front = anterior or ventral
Back = posterior or dorsal
4
Q
What does medial mean?
A
Close to (midline)
5
Q
What does lateral mean?
A
Away from/next to (midline)
6
Q
What are the 2 components of the nervous system?
A
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
7
Q
What are the components of the CNS? (2)
A
Brain and spinal chord
8
Q
What are the components of the PNS? (2)
A
Cranial and peripheral nerves
9
Q
What are the 3 functions of the nervous system ?
A
- Sensory function- detect external and internal changes
- Integrative function - analyses & makes decisions based on voluntary and involuntary responses
- Motor function - initiates motor movement and glandular secretions
10
Q
Name the 3 features of the gross anatomy of the brain
A
- Cerebrum
- Cerebellum
- Brain stem
11
Q
What is the cerebrum and what (regions) does it contain?
A
- Largest part of the brain
- It contains the cerebral cortex and subcortical regions
12
Q
What is the cerebellum? Where is it located and what is it responsible for ?
A
- Located in the posterior region of the brain
- Mainly responsible for balance and coordination
13
Q
What 3 things does the Brainstem contain?
A
Contains the:
- midbrain
- pons
- medulla oblongata
14
Q
What does the brainstem do ?
A
It communicates with the PNS to control involuntary processes such as breathing and heart rate
15
Q
The cerebrum is separated into 2 hemispheres that are connected by a large fibre bundle, what is this called?
A
Corpus callosum
16
Q
What is the outer layer of the cerebrum composed of ?
A
Cerebral cortex
17
Q
What are the 4 cortical lobes ?
A
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
18
Q
What is the frontal lobe responsible for? (3)
A
- Higher cognitive functions e.g. decision-making and problem solving
- Responsible for some features of language and voluntary movement
19
Q
What is the parietal lobe responsible for? (2)
A
- Integrates information from visual pathway
- Coordinates motor movement and interpretation of sensory information
20
Q
What is the temporal lobe responsible for? (3)
A
Interpreting speech and hearing, object recognition and emotion
21
Q
What is the occipital lobe responsible for?
A
Processing primary visual information
22
Q
What are the subcortical regions?
A
Brain regions that lie underneath the (cerebral) cortex
23
Q
Give some examples of what the subcortical regions are responsible for? (4)
A
- memory
- emotions
- motor movement
- processing sensory information
24
Q
Name 5 particular important subcortical structures?
A
- Hypothalamus
- Amygdala
- Hippocampus
- Thalamus
- Basal ganglia
25
What does the midbrain do ?
Serves as a connection between the brainstem and subcortical regions
26
What 3 structures does the midbrain consist of ?
1. Colliculi
2. Tegmentum
3. Cerebral peduncle
27
What does the colliculi do ?
Directs eye movement towards objects of interest
28
What does the tegmentum responsible for?
Coordination of movement, alertness/spleep
29
What is the cerebral peduncle responsible for ?
Control of ocular muscles
30
What is the spinal cord/why important?
Critical link between the CNS and PNS
31
What do nerves that branch off from the spinal cord form and do?
Form the PNS and innervate the rest of the body
32
The spinal cord is divided into 5 main sections based on the corresponding body area that is innervated. Name these 5 sections and the area they innervate
1. Cervical (neck)
2. Thoracic (chest)
3. Lumbar (lower back)
4. Sacral (hip)
5. Coccygeal (tail)
33
What 2 systems is the PNS split into?
- Somatic (voluntary)
- Autonomic (involuntary)
34
What is the somatic nervous system responsible for?
Voluntary
Controls the skeletal muscles and provides sensory information from the body and from the outside world
35
What 3 things is the autonomic (nervous system) split into?
- Enteric
- Sympathetic
- Parasympathetic
36
What does the enteric nervous system do?
Regulates movement of water and solutes between gut and tissues
37
Brief overview of What do the sympathetic and parasympathetic nervous systems do?
Modulate and balance involuntary functions
e.g. heartbeat, breathing
38
What is the sympathetic nervous system responsible for?
Responsible for ‘fight or flight’ reaction that occurs in response to a stressful stimulus
39
What does the parasympathetic nervous system do?
Balances the sympathetic response by stimulating ‘rest and digest’ pathways
40
What is the interaction between sympathetic and parasympathetic nervous system crucial for?
Maintaining homeostasis
41
What do afferent pathways do?
Carry sensory information from periphery up to the brain via ascending nerve tracts
A for ARRIVING input to brain
42
What does the efferent pathway do ?
The brain sends signals down to the peripheral nerves along efferent descending nerve tracts A to control motor output
E for EXITING out from brain
43
Reflex arc - leg jerk response
44
What are the 2 main cell groups in the CNS?
1. Neurons (nerve cells)
2. Glia (support cells)
45
Glial cells are further subdivided into 4 groups.
Name the 4 subdivisions
1. Microglia
2. Astrocytes
3. Oligodendrocytes
4. Ependymal cells
46
How many neurons does the brain contain
10^11
47
How many glial cells does the brain contain ?
10^12
48
What are the 5 main features of a neuron?
1. Dendrite
2. Nucleus
3. Soma (cell body)
4. Axon
5. Synaptic connection
49
What are dendrites ? (3)
- short, bristle-like, highly branched processes
- receive nerve input (at synapse)
- not myelinated
50
What is the soma (cell body) ? (3)
- contains the normal cell organelles
- main site of protein synthesis and degradation
- has pronounced rough ER = ‘Nissl’ substance
51
What is the axon? (4)
- long, thin process
- propagates nerve impulses to another neuron, muscle fibre or gland
- often myelinated
- terminates at axon terminals or synapses
52
What are the synaptic connections?
Release of neurotransmitters to communicate with other cells (post synaptic)
53
What are bipolar neurons? Where would you find them (3)
1 main dendrite and 1 axon
- retina of the eye
- inner ear
- olfactory area of brain
54
What are unipolar neurons? What/where would you find them?
Just 1 cell process from the body, part way down axon
- always sensory neurons (pain, temperature, touch, pressure)
55
What are multipolar neurons and where are they found?
Many dendrites and 1 axon
Most neurons in the CNS
56
What are microglia ?
Immune cells that survey the CNS and respond to signs of infection or damage
57
Micorglia exist in a wide-range of morphologies depending on activation state. What are 2 states called?
1. Surveillant
2. Activated
58
What are surveillant microglia ?
Smaller with multiple processes
59
What are activated microglia ?
Larger, with rounded cell body and shorter processes
60
What are astrocytes ?
Small, star-shaped cells that provide support for the development and homeostatic maintenance of the nervous system and cerebral blood vessels
61
What can astrocytes form after severe injury?
Glial scar
62
Heterogeneity across different brain regions ?
63
What are oligodendrocytes?
Cells that form lipid-rich sheath of myelin that wraps around some neurons to increase the speed at which information is transmitted by the neuron
64
What are oligodendrocytes called in the PNS?
Schwann cells
65
What is white matter in the brain ?
Area of the brain that contain myelin (bundles of axons)
66
What is grey matter?
Regions of unmyelinated cell bodies
67
What does myelin do?
Increase the speed of axon potentials
68
What is the velocitie range for unmyelinated axon conduction?
From about 0.5 to 10 m/s
69
What velocities can myelinated axons conduct at?
Up to 150 m/s
70
What are blood vessels made up of in the brain ? (5)
1. Endothelial cells
2. Astrocytes
3. Pericytes (capillaries)
4. Smooth muscle cells (arteries)
5. Neurons
71
Together What are the components that make up the blood vessels in the brain referred to as?
The Neurovascular unit
72
How is blood-brain barrier (BBB) made?
Endothelial cells of the brain express form tight junction proteins
These junctions allow the brain to create a physical barrier between the blood and the brain
73
What does the (BBB)blood-brain barrier give the brain ?
Gives brain high degree of selectivity
Thereby protecting it against entry of potentially harmful substances in the blood
74
Where is the Cerebrospinal fluid (CSF) found?
Contained within the **ventricles**and in the **subarachnoid spaces of the brain and spinal cord**
75
What does CSF do? (3)
Provides buoyancy for the brain
Cushions the brain against injury
Waste removal
76
How is CSF produced from?
Produced from filtered blood by the **choroid plexus** in the ventricles
77
Why can samples of CSF collected from the spinal cord be used to provide a Snapshot of the brain environment?
Because CSF is shared between the brain and spinal cord
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