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Flashcards in Cells & Tissues Deck (25)
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1
Q

What are the main types of nervous tissue cells?

A
  • Neurons
  • Glial Cells

Glial cells are split into:

  • satellite Cells
  • Schwann Cells
  • Astrocytes
  • Oligodendrocytes
  • Microglia
  • Ependymal Cells
2
Q

Whats the difference between neurons and glial cells?

A

Neurons are excitable and carry action potentials.

Glial cells are supportive and non-excitable, they have other functions

3
Q

How do neurons divide?

A

By Amitosis

4
Q

Can neurons grow back?

A

If you cut the axon it can grow back

But if you crush the cell body in the spine or ganglia then its permanent

5
Q

Whats the function of myelin?

A

Reduces loss of electrical signals as they pass down the axon, so they can travel further faster. (Also known as saltatory conduction)

6
Q

What do we call the spaces between myelin sheaths?

A

Nodes of Ranvier

7
Q

What forms the myelin sheath?

A

Schwann cells in the PNS

Oligodendrocytes in the CNS

8
Q

How do schwann cells produce a myelin sheath?

A

They wrap around the axon and extrude their cytoplasm.

So the cell membrane becomes the myelin sheath

9
Q

What are the different types of neurons?

A

Multipolar

  • Motor neurons
  • Lots of dendrites

Bipolar:

  • Olfactory or retinal nerve fibres
  • One dendrite

Pseudounipolar

  • Sensory Neurons
  • Cell body sits off to the side of the axon
10
Q

Neurons are organised into different types/locations e.g. white vs gray matter or ganglia vs nuclei. What are they?

A

Myelinated axons are referred to as white matter when diffuse.
Or Tracts when bundled together by modality

Neuronal Cells bodies localised within the CNS are called nuclei, within the PNS they’re called Ganglia

Diffuse Cell bodies or non-myelinated axons are known as grey matter

11
Q

Divide Glial cells by PNS vs CNS:

A

PNS:

  • Satellite Cells
  • Schwann Cells

CNS:

  • Ependymal cells
  • Oligodendrocytes
  • Microglia
  • Astrocytes
12
Q

What do satellite cells do?

A

surround neuronal cell bodies in the PNS

13
Q

What do Ependymal cells do?

A

Type of Glial cell that line ventricles in the brain

14
Q

What do microglia do?

A

Type of glial cell in the CNS that phagocytose and form scar tissue

15
Q

What do astrocytes do?

A

Glial cells in the CNS that surround synapes and capillaries to buffer ions.
They contribute to the BBB

16
Q

How do the ventricles of the brain develop?

A
  • Neural tube above 4th somite develops into 3 primary vesicles
    Forebrain (prosencephalon)
    Midbrain (mesencephalon)
    Hindbrain (rhombencephalon)
  • From there into 5 secondary vesicles
    Telencephalon & Diencephalon
    Mesencephalon
    Myelencephalon & Metencephalon
  • These 5 vesicles form the ventricles
17
Q

Which cavity forms which ventricle?

A

Telencephalon (part of forebrain) –> Lateral ventricles in cerebral hemispheres

Diencephalon (part of forebrain) contains 3rd ventricle

Mesencephalon (Midbrain) –> Cerebral Aqueduct

The two division of the rhombencephalon form the 4th ventricle

18
Q

Whats contained in the ventricles?

A

Lined by ependymal cells

Filled with CSF

19
Q

List the folds of the dura mater?

A

Falx Cerebri
Attaches to Crista Galli & dips between cerebral hemispheres

Tentorium Cerebelli
Seperates cerebellum form occipital lobes

Falx Cerebelli

Diaphragma Sellae

20
Q

What layer of meninges contains CSF?

A

The subarachnoid space

21
Q

Where is CSF produced/absorped?

A

Produced in the choroid plexus of the ventricles

Its absorbed by arachnoid villa

22
Q

List the layers of the head

A
Scalp 
- Skin
- Connective Tissue
- Aponeurosis
- Loose Connective Tissue
- Pericranium
Cranium
Meninges
- Dura
- Arachnoid
- CSF
- Pia
23
Q

What does the blood brain barrier do?

A

Maintains a stable homeostatic environment for the brain, preventing harmful amino acids/ions/blood cells from reaching the brain

24
Q

What makes up the blood brain barrier?

A

Endothelium
Thick Basal Lamina
Foot Processes of the Astrocytes

25
Q

Where are the different fold of dura mater?

A

Falx Cerebri is a verticle fold between the cerebral hemispheres

Diaphragma Sellae lines the Sella Turcica, wrapping around the pituitary gland

Tentorium Cerebelli is a horizontal fold dividing the cerebellum and cerebrum

Falx Cerebelli between cerebellar hemispheres