A&P - Chapter 18 (Part 2) Flashcards
What are 2 types of cells found in the nervous system?
- Glial/neuroglial cells
2. Neurons
What kind of cells are glial cells?
Supporting cells
What kind of cells are neurons?
Nerve cells
What do glial cells do?
Provide support and protection for the nervous system
What do glial cells play a role in?
In regulating function and structure of neurons
- act like glue
- binds cells of the nervous tissue together
What do glial cells not do?
Transmit nerve impulses
How many times more abundant are glial cells compared to neurons?
5x
What are 5 major types of glial cells?
- Astrocytes
- Microglia
- Ependymal cells
- Oligodendrocytes
- Schwann cells
What major types of glial cells are considered part of the CNS? (4)
- Astrocytes
- Microglia
- Ependymal cells
- Oligodendrocytes
What major types of glial cells are considered part of the PNS?
Schwann cells
Astro
Star
Cyte
Cell
What is the relative size of astrocytes compared to glia?
Larger
Astrocytes
Cell extensions that wrap around and secure small blood vessels to neurons
Are astrocytes part of the blood brain barrier?
Yes
Blood brain barrier
Separates blood from brain tissue and protects the brain from harmful substances that may be in the blood
Micro
Small
What is the relative size of microglia cells compared to glia?
Smaller
What do microglia cells act as?
The first and main form of active immune defence for CNS tissue
- macrophages
What do macrophages do?
Decrease inflammation and/or destroy any harmful substance to prevent potentially fatal damage to the sensitive CNS tissue
What is the motility of microglia?
Usually stationary
When will microglia move?
When they sense any trouble (eg. tissue of the CNS is damaged or inflamed) they will quickly response by enlarging and moving around
What do ependymal cells resemble?
Epithelial cells
What do ependymal cells form?
Thin sheets that line fluid-filled cavities in the CNS
What do some ependymal cells produce?
Fluid
What do some ependymal cells aid in?
Circulation of fluid
Oligo
Few or scanty
Dendro
Branches
What do oligodendrocytes help with?
Holding neurons together by extending its branches to the axon of neurons
How many branches can oligodendrocytes wrap around?
Up to 50 axons
What do oligodendrocytes form?
A myelin sheath of axons in the CNS
Myelin
Is a fatty substance that electrically insulates axons
What is myelin essential for?
Proper function of the nervous system and nerve impulse conduction
