Nervous Tissue/Brain; Blood supply to Brain (Ch. 14-15, 23.3) Flashcards Preview

Anatomy 2201 > Nervous Tissue/Brain; Blood supply to Brain (Ch. 14-15, 23.3) > Flashcards

Flashcards in Nervous Tissue/Brain; Blood supply to Brain (Ch. 14-15, 23.3) Deck (81)
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1

What does the nervous system (NS) include?

All neural tissue in the body (neurons and glial cells)

2

What is included in the central nervous system (CNS)?

Brain
Spinal Cord

3

What is included in the peripheral nervous system (PNS)?

Cranial nerves
Spinal nerves
Ganglia
All neural tissue outside the CNS

4

What are NS fxns?

Collect information
--monitor external and internal changes (sensory input from PNS)

Process and evaluate information
--process sensory input and determines response

Respond to information
--dictates response by activating effector organs

5

What are the 2 divisions of the NS?

CNS
PNS

6

What is the functional organization of the NS?

NS branches into: Sensory NS and Motor NS

Sensory NS branches into: Somatic Sensory and Visceral Sensory

Motor NS branches into: Somatic Motor and Autonomic Motor

7

What is Somatic Sensory?

Free nerve endings in almost all body tissues

Includes receptors for pain, touch, pressure, vibration, temperature...

Also proprioception (sense of body in space) in skin, body wall, and limbs

"Special" senses = vision, taste, hearing, balance, smell

8

What is Visceral Sensory?

Sensations from the organs (digestive and urinary tracts, reproductive organs, etc.)

Stretch, temperature

9

What is Somatic Motor?

aka Voluntary NS (b/c we can control it)
--motor nerves carry impulses from the brain to the skeletal muscles and somatic tissues, which creates voluntary movement

Contraction of skeletal muscles

10

What is Autonomic Motor?

aka Autonomic NS (ANS) or involuntary nervous system

Regulates contraction of smooth and cardiac muscle and gland secretion

We cannot control this

Subdivides into sympathetic and parasympathetic

11

What is Sympathetic (under ANS)?

"fight or flight"

12

What is Parasympathetic (under ANS)?

"resting and digesting"

13

What are the 2 types of cells in nervous tissue?

Neurons and Glia

14

What are neurons?

Neurons transmit electrical signals

"nerve cells"

15

What are glia?

"nerve glue"

Supporting cells

16

What is included in the structure of a neuron?

Soma (cell body)
Dendrites
Axons
Myelin

17

Structure of a Neuron: what are soma?

(cell body)

Contains nucleus, cytoplasm, organelles

18

Structure of a Neuron: what are dendrites?

receive signal, transmit to cell body

19

Structure of a Neuron: what are axons?

transmits signal to axon terminals (note direction of signal movement)

20

Structure of a Neuron: what is myelin?

Insulates neuron, helps propagate signal

21

Describe the signal pathway of dendrites and axons.

Dendrite --> cell body --> axon --> axon terminal (end of axon)

22

What is a synapse?

A synapse is a site where an axon connects with another cell (another neuron cell or muscle and gland cells)

23

What are the 4 types of Glia (of the CNS)?

1. ependymal cells
2. microglia
3. oligodendrocytes
4. astrocytes

In general, glia support and protect the neurons. Each type has slightly different functions though (*do NOT need to know functions for lecture exam)

24

What are Schwann cells? What are Satellite cells? Where are they found?

Found in Glia of the PNS

Schwann cells: myelinate axons of PNS

Satellite cells: found in ganglia, surround the neuron cell body

25

What are nerves?

A nerve is defined as a collection of axons in the PNS

The axons are arranged in parallel and wrapped in CT

A nerve can contain myelinated and/or non-myelinated, sensory and/or motor axons

26

What is included in the structure of a nerve?

Myelin sheath, Axon, Fascicle

Each axon is surrounded by myelin sheath (Schwann cells)

Groups of axons are nerve fascicles

Groups of fascicles = nerve

27

What are the 3 layers of nerve structure (from superficial to deep)?

1. Epineurium: surrounds entire nerve
2. Perineurium: surrounds fascicle
3. Endoneurium: surrounds axon and myelin sheaths

28

What 3 things protect the brain?

Meninges
Cerebrospinal fluid (CSF)
Blood brain barrier (BBB)

29

What are meninges?

They're membranes that surround and protect the brain

30

What is CSF?

It cushions the brain