Anatomy: Nervous System

What kinds of Nervous System are there?

Central/Peripheral

What is Central Nervous System (CNS)

Brain/spinal cord

What is Peripheral Nervous System

Cranial/spinal nerves and branches.

What exits/enters the CNS?

Peripheral Nervous System

How many cranial nerve pairs?

12

Where do cranial nerves originate from

Brain Stem; Supply brain structures

Where do SPINAL nerves originate from

Spinal cord; supply body structures

What are subdivisions? (2 kinds)

Sensory/Motor

What does sensory subdivision do?

Bring info FROM body into CNS

Motor subdivision

Carries response OUT CNS into body

What kinds of sensory nerves are there?

Somatic/visceral sensory

What’s Somatic Sensory

Carry info from skeletal/skin/joints. (feel cramps)

What’s visceral sensory

Carry info from smooth/cardiac/gland

Kidney and spleen NOT hollow

TRUE

What does Viseral mean

Organs

Somatic motor causes

muscle contraction

Visceral motor causes

cramps

Viseral motor is also commonly called

Autonomic Nervous System (ANS)

Parasympathetic (PSNS)

Rest n’ Digest

Sympathetic

Fight or Flight

How many pairs mixed nerves

31 pairs!

Spinal nerves have BOTH

sensory/motor fibers

Neurons generate

Action Potential

Synaptic vesicles contain

neurotransmitters

Synaptic cleft

Space between neurons

What serves as middlemen between pre/post synaptic neurons? (Why are ___ important)

Neurotransmitters

Why do we need Action Potentials

Cause neurotransmitters release

All neurons generate action potentials

TRUE

Action Potential

Electrical signal

Characteristics of a neuron

1. Extreme longevity

2. Amitotic (no new ones can be made)

3. High metabolism → Need LOTS glucose/oxygen = ATP

Astrocyte

Holds neurons/blood vessels in place

What does astrocyte do?

1. Regulates extracellular environment

2. Forms blood-brain barrier

3. Repair damaged tissue → scar tissue

4. Feed neurons

5. Secretes NGF

NGF

Nerve Growth Factor

What’s a nerve

Axon bundles!

Why can’t a spinal cord injury be repaired

Scar tissue formed

What happens of nerves don’t have NGF

Nerve death

Astrocytoma

Astrocyte brain cancer

Myelin sheaths ARE completely formed when born

FALSE

What produces CNS

Oligodendrocytes

What produces PNS

Schwann Cells

What is myelin sheath

Wraps around cells

Ependymal Cell characteristics

1. Line cavities

2. Produce CSF (Cerebral Spinal Fluid)

Ion Channel types

Voltage gated

Ligand gated

How does neuron communicate?

With Action Potential and Neurotransmitters

Voltage gated ion channel

Opened by charge. Charge in membrane

Ligand gated ion channel

Opened by neurotransmitter