Introduction to Neuroscience Flashcards

1
Q

Name the major divisions of the nervous system and what they include

A

Central nervous system:
- brain
- spinal cord
Peripheral nervous system:
- Autonomic nervous system - involuntary, internal organs, blood vessels, glands
- Somatic nervous system - voluntary, skin, joints, muscles

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

What is in the forebrain?

A
  • Cerebral hemispheres
  • cerebral cortex: controls voluntary movement and contains 4 lobes (frontal, temporal, occipital, parietal)
  • basal nuclei: fine tunes motor behaviour
  • Thalamus: relays motor and sensory input to cerebral cortex, regulates consciousness, sleep and alertness
  • hypothalamus: maintains homeostasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does the midbrain do?

A
  • controls basic movement

- contains the tectum, the cerebral aqueduct, tegmentum, and the cerebral peduncles.

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

what does the hindbrain do and contain?

A
  • pons: controls respiratory and breathing patetrn
  • medulla: controls respiration and heart beat
  • cerebellum: controls motor coordination and balance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the brainstem?

A
  • regulates the body’s autonomic functions

- connects the brain to the spinal cord

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

what is the association cortex?

A
  • integrates information from different sensory systems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the corpus callosum?

A
  • white matter area

- carries info between two hemispheres

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

what is diencephalon?

A
  • thalamus

- hypothalamus

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

Structure of the ventricular system

A

2 lateral ventricles
these form the 3rd ventricle at the hypothalamus
a cerebral aquiduct forms the 4th ventricle near pons and medulla
cavity filled with cerebrospinal fluid

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

what does cerebrospinal fluid do?

A
  • maintains ion levels
  • removes waste products
  • provide physical barrier by making brain more buoyant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the subdivisions of the spinal cord (rostral to caudal)?

A
  • Cervical,
  • cervical enlargement (control upper limbs),
  • thoracic,
  • lumbar,
  • lumbosacral enlargement (control lower limbs),
  • sacral
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what makes up the nervous tissue?

A

Grey matter:
- cell bodies of neurons and glia, neuronal cell bodies and dendrites, cerebral cortex, nuclei and spinal cord in centre

White matter:
- neuronal axons wrapped in myelin, outside of spinal cord via tracts which carry different info, forebrain

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

What are the functional divisions of the spinal cord?

A
Dorsal = where sensory info is processed
afferent = sensory neuron entering dorsally (peripheral to central)
Ventral = where motor info is sent out (anterior part)
Efferent = motor neuron leaving ventrally (central to peripheral)
Nucleus = cluser of cell bodies in CNS
Ganglion = cluster of cell bodies in PNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what cell types make up neural circuits?

A

Neurons:

  • excitable cells that conduct impulses
  • integrate and relay info within a neural circuit

Glia:

  • supporting cells which keep neurons healthy and influence neuronal output
  • maintain homeostasis, protection and assist neural function

there are 85 billion of each cell type

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

Structures of neurons

A

Soma/cell body:
- contains nucleus, nucleolus, ribosomes, RER, golgi apparatus, mitochondria (produce lots of ATP to maintain ion gradients for APs)

Axons:

  • axon hillock - attaches to soma
  • axon initial segment - where APs are first generated and have different no. ion channels depending on type of neuron
  • axon collaterals - branches diverging from axon to innervate other cells
  • axon terminal/bouton

Dendrites:

  • branches form dendritic trees (arbours) which can converge onto one neuron (lots of integration)
  • dendritic spines increase SA of dendrite and are plastic (inactive spines are taken up, active dendrites produce more spines)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is fast axoplasmic transport?

A

signals travel 1000mm per day
move along microtubules, with kinesin and dynein moving molecules using ATP
- anterograde transport by kinesin down the cell
- retrograde transport by dynein up the cell

17
Q

what is a pseudounipolar neuron?

A
  • example = dorsal root ganglion (afferent neuron)
  • one neurite coming off the cell body splits into 2
    • one end of the split will become presynaptic terminal
    • the other end will become a dendritic tree
  • there is a small area for receiving synaptic input, making it highly specific
  • peripheral process and central process are both axons
18
Q

what is a bipolar neuron?

A
  • example = retinal bipolar cells
  • has 2 neurites branching off from the soma
    • one arm is axonic, the other arm is dendritic
  • small area for receiving synaptic input = highly specific
19
Q

what is a multipolar neuron?

A
  • example = purkinje cells in the brain
  • receives around 150,000 contacts
    • large area for receiving synaptic
      input = integrates lots of info
  • high levels of convergence (lots of input into a single neuron)
20
Q

describe the two types of dendritic geometry:

A

Pyramidal:

  • distinct apical and basal dendritic trees
  • basal comes from cell bodies and processes info from multiple neurons to apical arms
  • pyramidal shaped soma
  • example = seen in layers of neocortex or hippocampus

stellate:

  • star shaped dendritic arbour
  • example = seen in neocortex
21
Q

name the 3 types of neuron:

A
  1. Sensory/afferent = project from PNS to CNS
  2. Motor/efferent = project from CNS to PNS
  3. interneuron = stays within CNS and connect brain regions, short axons and process info in local circuits
22
Q

What are the homeostatic, myelinating and phagocytic cells of the CNS, PNS and ENS?

A

CNS:

  • homeostatic = astrocytes
  • myelinating = oligodendrocytes
  • phagocytic = microglia

PNS:

  • homeostatic = satellite cells
  • myelinating = schwann cells
  • phagocytic = schwann cells + macrophages

ENS:
- homeostatic = enteric glia

23
Q

What are astrocytes and what are their functions?

A
  • control environment of surrounding neurons
  • glycogen stores of the brain
  • metabolise glycogen to supply lactate to neurons within 5 ins as a fuel to produce ATP
  • endfeet take up glucose to control separation of vasculature from ECF
    • forms the BBB
  • buffer extracellular calcium to control excitability
24
Q

what are microglia and what are their functions?

A
  • make up 15% of the glial cells of the CNS
  • phagocytic role = clear away cellular debris
  • release growth factors for neuron growth and myelination
  • involved in pruning = removes inactive parts of neuron
  • can have harmful roles in neurodegenerative diseases
25
Q

what are oligodendrocytes and what are their function?

A
  • myelinating cells of CNS = form myelin sheaths of CNS axons
  • can have 12-30 processes from cell body to myelin sheath
  • insulate axons
  • provide multiple segments to one axon
26
Q

what are schwann cells and what are their functions?

A
  • myelinating glial cell of the PNS = form myelin sheaths around PNS axons
  • one schwann cell provides one myelin segment to a single axon
27
Q

what is the formation and function of the myelin sheath?

A

formation:

  • oligo cytoplasm wraps many times around the axon
  • cytoplasm is squeezed out by compaction
  • myelin sheaths maintain contact with glial cells for nourishment
function:
- insulating role
- forms nodes of ranvier for saltatory conduction 
    - APs can jump along to increase 
      conduction speed
28
Q

What is the Nissl stain and what does it indicate?

A

Nissl stain:

  • Nucleus, nucleolus, RER and ribosomes are stained to distinguish between neurons and glia
  • Highlight rRNA as the basophilic dye binds to negatively charged molecules
  • cannot highlight axons as they do not have ribosomes or RER
  • allows observation of density and distribution of neurons - not in detail
29
Q

What is the Golgi stain and what does it indicate?

A

Golgi stain:

- silver chromate allows small % of neurons to be observed in depth

30
Q

what is immunohistochemistry and what does it indicate?

A

Immunohistochemistry:

  • primary antibodies specifically bind to target
  • secondary antibody is associated with fluorescent tag and binds to primary antibody
  • when bound, secondary antibody fluoresces to show location of target cells
31
Q

what is retrograde tracing and what does it indicate?

A

retrograde tracing:

  • spinal is injected with HRP to leave HRP deposit in brain cell bodies
  • 2 days later after retrograde transport, slice brain to see HRP labelled neurons
  • shows map of nervous system in brain
32
Q

what is GFP and what does it indicate?

A

GFP:

  • reporter gene GFP is tagged onto promoter of gene which expresses neurotransmitter
  • only neurons expressing that promoter will fluoresce