Lecture 7 (2/10) Flashcards Preview

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Flashcards in Lecture 7 (2/10) Deck (34):
1

Glial Cells

Main function is to protect and support neurons/nerve cells

Typically small in size

Do NOT transfer information, do NOT generate active electrical signals

2 Types:
Astrocytes
Oligodendrocytes

2

Astrocytes

One of 2 main types of Macroglia cells

Star-shaped cells with irregulars shaped cell bodies and numerous extensions

2 Main Classes:
Fibrous
Protoplasmic

3

Fibrous Astrocytes

A type of astrocyte; type of glial cell

Found in white matter

4

Protoplasmic Astrocyte

A type of astrocyte; type of glial cell

Found mostly in grey matter

Have shorter extensions

Associated with nerve cell bodies, dendrites, and synapses - they envelop synapses

5

Oligodendrocytes

One of 2 main types of Macroglia cells

Small, with few processes

Found in myelinated fiber tracts in the CNS
They wrap around axons and contribute to the formation of myelin sheaths

Multiple sclerosis involves the gradual death of these cells

6

Schwan

Macroglia cells/glial cells

Found in the PNS

Form myelin sheath around the axons of peripheral neurons

7

Ependymal

Macroglia cells/glial cells

Line the ventricles (cavities) which are filled with CSF

They produce/secrete CSF

8

Microglia

A class of glial cells

Found scattered through the brain

Look like a small, hair spider

Type:
Phagocyte

9

Macroglia

A class of glial cells

Includes:
Astrocytes (fibrous & Protoplasmic)
Oligodendrocytes
Schwan
Ependymal

10

Phagocyte

A type of microglia/glial cell

Cells that dispose of cellular debris; garbage collectors

Help seal off damaged brain tissue: rush to site of injury and clean up dead cells

11

Brain Stem

3 Main Parts:
Midbrain
Pons
Medulla Oblongata

12

Midbrain (General)

Part of the brain stem

Connects the brain stem to the diencephalon above and the pons below

13

Midbrain (Structures)


Cerebral Peduncle
Interpedunclur Fossa

Cranial Nerve IV

2 Important Nuclei:
Inferior Colliculus
Superior Colliculus

14

Cerebral Peduncles

Large swellings on the anterior, lateral surface of the midbrain

15

Interpedunculur Fossa

Deep grooves or sulci between the cerebral peduncles

Cranial Nerve III emerges from them

16

Inferior Colliculus

Important nucleus in the midbrain

Concerned with auditory info
The Lateral lemniscus is a tract that runs into the inferior colliculus and provides it with auditory information

17

Superior Colliculus

Important nucleus in the midbrain

Carries visual information to the midbrain

18

Pons

A portion of the brainstem

Cerebellar Peduncles connect the brainstem and cerebellum
There are 3;
Inferior Cerebellar Peduncle
Middle Cerebellar Peduncle
Superior Cerebellar Peduncle

Lesions on the anterior portion of the pons can cause Locked-in Syndrome.

19

Locked-in Syndrome

Caused by a lesion to the anterior portion of the pons

Patients with this condition are unable to talk even though they are conscious

20

Medulla Oblongata

Lies between the pons and the spinal cord

Main Structures:
Pyramid
Pyramidal Tract
Nucleus Cuneatus
Nucleus Gracilis
Fasciculus Cuneatus
Fasciculus Gracilis
5 Cranial Nerves (8-12)

21

Pyramid

A nucleus on the anterior surface of the Medulla

Axons of cells in the pre central gyrus travel through the pyramid on their way to the spinal cord

These axons form the Pyramidal Tract

22

Pyramidal Tract

A dense band of fibers made of axons that travel from the pre central gyrus on their way to the spinal cord

23

Pyramidal Decussation

Occurs when the axons traveling on the pyramidal tract reach the pyramid and switch sides

24

Nucleus Cuneatus & Nucleus Gracilis

Nuclei where cells traveling from the spinal cord pass through when traveling up to the cortex.

They form tracts called Fasciculus Cuneatus and Fasciculus Gracilis

25

Fasciculus Cuneatus & Fasciculus Gracilis

Bands created by cells from the spinal cord

These cells synapse with the Nucleus Cuneatus and the Nucleus Gracilis

26

Cranial Nerves in the Medulla

There are 5

Numbers 8-12

27

Damage to the Medulla

Causes Vertigo/dizziness, paralysis of the muscles in the throat/larynx, and combinations of sensory loss in limbs and face

28

Ventricles

Cavities

4 Main
2 Lateral Ventricles (one in each hemisphere)
1 Third Ventricle
1 Fourth Ventricle

29

Lateral Venticles

There are 2, 1 in each hemisphere

They are connected to the third ventricle by the Foramen of Monro

30

Foramen of Monro

Connects the lateral ventricle to the third ventricle

31

Third Ventricle

Located in the diencephalon

Connected to the fourth ventricle by the Cerebral Aqueduct

32

Cerebral Aqueduct

Connects the third and fourth ventricles

33

Fourth Ventricle

Located in the pons and the upper part of the medulla

Smallest ventricle

Ends in subarachnoid space

34

Choroid Plexus

Contained in ventricles

A spongey mass of tissue which is the primary producer of CSF