Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Body Logs > L21- Nervous Tissue Structure And Function > Flashcards

L21- Nervous Tissue Structure And Function Flashcards

1
Q

What are the two divisions of the nervous system?

A
  1. Central nervous system (CNS): brain and spinal cord

2. Peripheral nervous system (PNS): cranial nerves and spinal nerves

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

Difference between grey and white matter?

A

Grey matter:

  • peripheral in brain but central in spinal cord (butterfly shaped)
  • consists of: nerve cell bodies, dendrites, axon terminals, non-myelinated axons and neuroglia (support cells)

White matter:

  • central in brain, peripheral in spinal cord
  • consists of: myelinated material (axons), no cell bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Outline the structure of the white and grey matter in the spinal cord

A

Grey matter is in the form of a butterfly:

  • found in the centre
  • anterior prongs: ventral horns (VH)
  • posterior prongs: dorsal horns (DH)
  • connected by the grey commissure (GC)

White matter on the periphery:

  • contains nerve fibres that form ascending and descending tracts
  • blood vessels from the outer connective tissue layer (pia mater), the ventral fissure (VF) and some dorsal roots of the spinal nerves are visible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the basic structure of a neuron?

A
  • Dendrite/s: elongated processes specialised for receiving stimuli and conducting towards cell body
  • cell body (perikaryon): contains nucleus and cytoplasm—> maintenance of cell (cytoplasm contains nissl bodies)
  • axon: single process—> generates or conducts nerve impulses away from cell body to other cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In the a) CNS and b) PNS which cells produce myelin?

A

A) Oligodendrocyte

B) Schwann cell

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

What are the 4 types of neurons?

- Location and function

A
  1. Motor
    - Location: CNS —> Periphery
    - Function: to send signals to effector tissues
    - tyPES: presynaptic and postsynaptic autonomic neuron
  2. Sensory:
    - Location: Periphery —> CNS
    - Function: to send environmental signals to integrative centre
    - Types: pseudounipolar and bipolar neuron
  3. Integrative
    - Location: CNS
    - Function: collate all information
    - 3 TYPES: Pyramidal cell, interneurons (most common) and purkinje cell
  4. Anaxonic
    - Location; retina (some parts of CNS)
    - Function: act as relays
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A) Where are the following neuron cells found?

B) What type of neurons are they?

I) Pseudounipolar 
II) purkinje cells
IIi) pyramidal cells
Iv) Interneurons
V) postsynaptic autonomic neurons
Vi) presynaptic autonomic neurons
Vii) Bipolar
A

I)
A) outside CNS
B) Sensory

II)
A) CNS
B) Integrative

Iii)
A) CNS
B) Integrative

Iv)
A) CNS
B) Integrative

V)
A) Outside CNS
B) Motor

Vii)
A) CNS
B) Motor

Vii)
A) Outside CNS
B) Sensory

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

What type of neurons are the majority of neurons in the CNS?

A

Interneurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q 
Outline the structure of the following:
A) multipolar neurons
B) bipolar neurons
C) unipolar neurons
D) anaxonic neurons
A

A) - one axon and multiple dendrites

  • mot common
  • most neurons in brain and spinal cord

B) - one axon and one dendrite
- olfactory cells, retina, inner ear

C) - single process leading away from soma
- sensory from skin and organs to spinal cord

D) - many dendrites but no axon
- help in visual processes

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

What would you see in a histology slide of a CNS Neuron?

A
  • Nucleus
  • Lots of rough endoplasmic reticulum (high protein synthesis)
  • lots of Golgi apparatus
  • many free ribosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A) What is axonal transport?

B) Structure of the axon related to this?

A

A) cellular process responsible for the movement of mitochondria, lipids, synaptic vesicles, proteins and other organelles through the cytoplasm of its axon

B) - microtubules made of tubular run along length of axon: provide cytoskeleton tracts

  • Kinesin motor protein: moves cargoes in anterograde
  • Dynactin motor protein: moves cargoes in retrograde
  • these motor proteins bind and transport different cargoes including mitochondria and neutrotrnasmitter vesicles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A) What are the two types of axonal transport directions?

A

A)

  1. Anterograde (away from cell body to synapse): kinesin
    - cargo tents to be Golgi derived vesicles (vesicles with neutrotrnsmitter )
  2. retrograde (conveys materials from axon to cell body): dynactin
    - cargo tends to be molecules being returned for degeeneration (vesicles that are empty)

B)

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

Outline the synthesis and transport of neurotransmitters

A
  1. Synthesis of neurotransmitter in ER and Golgi with only enzyme
  2. Transport of neurotransmitter down axon (anterograde) using microtubules- as it travels it synthesises neutrotransmitter
  3. AP down axon, AP causes calcium to enter, release of NT in synaptic cleft
  4. NT binds to post synaptic receptor, response in post synaptic neuron
  5. Reuptake of NT to be recycled
  6. Vesicles without neurotransmitter travel back down cell body (retrograde)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the fate of an empty neurotransmitter vesicles?

A
  1. Recycled through clathrin-coated endocytosis

2. Lost to neurolemma

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

Different types of synapses?

A
  1. Axosomatic: directly to plasma membrane or nerve of cell
  2. Axodendritic: axon terminal synapses with dendritic spine
  3. Axoaxonic: synapse at axonic button
  4. Dendro-dendritic
  5. Axo-axonal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Structure of peripheral nerves

A

Nerve fibres separated by connective tissue layers

Out to inner:

  1. Paraneurium: fascia that seperates nerves from surrounding structures
  2. Epineurium:
    - dense irregular CT
    - seperates diff types of nerves and fills spaces between fascicles
  3. Perineurium:
    - specialised CT: transport proteins
    - maintains ionic composition
    - surrounds clusters of axons (fasicle)
  4. Endoneurium:
    - loose CT
    - surrounds single nerve cells
17
Q

What types of nerves to peripheral nerves contain?

A
  • all 3 types: sensory, motor and integrative

- but each fasicle tends to only contain 1 type

18
Q 
There are A, B and C fibres. 
Compare them with the following headings:
A) Size
B) Speed
C) Location
D) Function
E) Myelination
F) Internodal distance
A

A FIBRES:

  • Size: thickest
  • Speed: fastest
  • Location; CNS
  • Function: motor
  • Myelination: myelinated
  • Internodal distance: largest

B FIBRES:

  • Size: medium
  • Speed: intermediate
  • Location: viscera
  • Function: sensory
  • Myelination: myelinated
  • Internodal distance: smallest

C FIBRES:

  • Size: thinnest
  • Speed: slowest
  • location: periphery
  • Function: sensory
  • Myelination: unmyelinated
  • Internodal distance: none
19
Q

Steps of how myelination occurs

A
  1. The axon sitting in a groove is surrounded by a Schwann cell
  2. The mesaxon membrane initiates myelination by the surrounding embedded axon
  3. A sheet-like extension of the mesaxon membrane then wraps successively around the axon, forming multiple membrane layers
  4. Cytoplasm is extruded from between the two apposing plasma membranes of the Schwann cell, which then become compacted to form myelin (19-20 rounds)
20
Q

What is an oligodendrocyte?

A
  • it does the same thing as a Schwann cell except in the CNS

- Cytoplasmic processes from the cell body form flattened cytoplasmic sheaths that wrap around each of the axons

21
Q

What is the difference in function between a Schwann cell and oligodendrocyte?

A

Pretty much the same except the oligodendrocyte wraps around more than one axon simultaneously—> 5 or 6

  • oligodendrocyte in the CNS
  • SChwann cell in the PNS
22
Q

What are the other support cells in the CNS?

A
  • astrocytes
  • microglial cells
  • ependymal cells
23
Q

Astrocyte:
A) Structure
B) Location
C) Function

A

A) - star-like structure
- have perineural feet that contain gap junctions
B) CNS
C) - biochemical support for endothelial cells
- transport of nutrients (lactate and glucose) from blood to nerve cells
- regulate nerve impulses by releasing glutamate (near to node of ranvier)
- contribute to BBB

24
Q

Microglial cell:
A) Structure
B) location
C) function

A

A) large cells with elongated nucleus and few processes from cell body
B) CNS
C) - Resident macrophage: immune function, remove damaged nerve cells, Sense increased K+ ions
- phagocytose dead cells or pathogens, process the proteins and then act as antigen presenting cells and blood brain barrier

25
Q

Ependymal cell
A) structure
B) location
C) function

A

A) - ciliated simple columnar shape cells lining spinal canal and brain ventricles
- joined by a junction all complex that seperates lumen of canal from lateral intercellular space
- not epithelial cells as they have no basal lamina
- apical surface has cilia and microvilli
B) CNS
C) - synthesise and secretes CSF in ventricles (choroid plexus)
- cilia move CSF through ventricles to spinal cord
- microvilli absorb CSF for removal of pathogens—present pathogens to microglial cells and astrocytes
-modified tight junctions between epithelial cells control fluid release into brain

26
Q

What cells do we lose as we age?

A

Microglial cells

27
Q

What do clinicians do to monitor contents of brain

A

Spinal tap

28
Q

What is multiple sclerosis?

A

Cause: autoimmune degradation of myelin leading to loss of conduction velocity

Characteristics:

  • remitting and relapsing
  • degenerative (gets worse)

Symptoms:

  • fatigue
  • vision problems: Diplopia
  • slurred speech: dysarthria
  • numbness and tingling sensations: paraesthesia
  • mobility issues: muscle spasms
  • urinary retention
  • constipation
29
Q

Functions of nerves

A
  • electrical conduction

- neurotransmitter production and release

30
Q

How are Neurons classified structurally?

A

Based on number of processes found on celll body

  1. MULTIPOLAR NEURON
  2. BIPOLAR NEURON
  3. UNIPOLAR NEURON
  4. ANAXONIC NEURON
31
Q

What are nissl bodies?

  • how does it stain
A
  • aggregations of rough ER

- stains with basic dyes because of rRNA

32
Q

Peripheral nerves are made up of different neuron types. Outline what you would see in a histology of a peripheral nerve.

A
  1. Histology stained toluidine blue
    - stains fat —> myelinated neurons will stain blue
    - Myelinated neurons: stain dark blue on the outside, the nucleus on the Schwann cell will be found on the inside with the axon found on the periphery
    - Non-myelinated neurons: found through Schmidt- lander man clefts- there will be 2 distinct membrane layers: inner membrane of Schwann cell and outer membrane of basal lamina
33
Q

What are schmidt lanterman clefts?

A
  • small pockets of cytoplasm left behind during the Schwann cell myelination

Body Logs (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions