Related Anatomy

UNIT 7 Peripheral NERVOUS SYSTEM

1. Name the 2 DIVISIONS of the Peripheral Nervous System

• CENTRAL brain and spinal cord

• PERIPHERAL all nerves outside

brain and spinal cord 2 branchesSomatic- nerves that

serve skeletal system and sense organs

Autonomic- serve smooth muscles and heart

The 3 parts of a neuron

• Dendrite- conduct impulse toward cell body

• Axon- conduct impulse away from cell body

• Cell body

motor sensory

More on Nerve cells

• PNS axons and dendrites may be coated with a MYELIN Sheath(this speeds conduction)(White matter)

• Gaps between axons and dendrites are called Synapses

NERVE IMPULSE

• Sodium and Potassium Pump

• POLARIZE DEPOLARIZE REPOLARIZE

• Note where charges are and where Sodium and Potassium are in relation to nerve cell

1

2

3

4

Nerve Impulse

1

2 3

REFLEX

• An automatic, involuntary response

• Examples, heartbeat, breath, swallow, sneeze, vomit

2. 12 Pair of Cranial Nerves

V Trigeminal- teeth

V!! Facial- face

IX Glossopharyngeal- swallow

XII Hypoglossal- tongue

3. 31 Pr of Spinal Nerves

• Cervical Plexus- head, neck, shoulders, upper chest

• Brachial- shoulder, arm, hand

• Lumbar- lower abdominal, thigh, buttock, genitals

• Sacral- thigh, leg, foot

4. 2 Divisions of the ANS

• SOMATIC

Voluntary nerves that serve muscle and bone

• AUTONOMIC

Involuntary nerves that serve internal organs

2 branches

• Sympathetic-emergency fight or flight

• Parasympathetic- normal at rest

Vocab

• Efferent- motor• Afferent- sensory• Myelin sheath- coating on PNS nerves,born with

none, form as we develop, must have to toilet train. Common disorder- MS

• Synapse- gap where axons and dendrites meet but do not touch. Impulse may need neurotransmitter to cross this space. Common diseases- Parkinsons, Huntington, Alzheimers

• Ganglia- mass of nerve cells outside CNS

Vocab Continued

• White Matter- covered in Myelin• Grey Matter- no Myelin• Meninges- protective covering of brain and

spinal cord. Disease- Meningitis• CSF- cerebrospinal fluid, clear• CNS- central nervous system• PNS- peripheral nervous system• ANS- autonomic nervous system

The End