Peripheral nervous system

parts of the PNS

• stomatic (voluntary) nervous: sensory and motor

• automatic (involuntary) nervous: sympathetic and parasympathetic 

What does the somatic nervous system do?

• Contains sensory/afferent neurons: detect stimuli

• contains motor/efferent neurons: signal from cns to muscles for movement

• controls bones, muscles, skin

• movement that a person can control

How many nerves in the somatic nervous system

• 12 pairs of cranial nerves (brain)

• 31 pairs of spinal nerves

• Pairs because two sides of body, hemispheres of brain, spinal cord

Cranial nerves and nerve damage

• cannot be repaired

• Causes loss of certain functions

Somatic nervous system is also known as

voluntary nervous system

How come cranial nerves attach to brain stem?

Many cranial nerves have nuclei in the Brain stem allowing them to attach to the brain stem

Sensitivity and nerves

• how sensitive an area of your body is reflects how many nerves present

• place that are more sensitive have more nerves

• Back has less nerves than palm

• Palm has 3 nerves: ulnar, median and radial nerve

Autonomic nervous system

• regulates glands, blood vessels, internal organs

• Process that occur without conscious control; unaware

• Divided into sympathetic and parasympathetic

Skeletal muscles are in

Somatic nervous system

Smooth muscle and glands

Autonomic nervous system: sympathetic division

Cardiac muscle

Autonomic nervous system: parasympathetic division

What is autonomic nervous system also called?

Involuntary nervous system

Anatomy of autonomic nervous system

• parasympathetic nervous farther off spinal cord

• allow for impulses to certain organs for rest and digest

• Sympathetic nervous closest to spinal cord

• allow for quick impulses to multiple organs, needed for fight or flight

Sympathetic nervous system

• fight or flight

• Stress response

• Response to unusual stimuli by increase overall activities

• activated during e division: exercise, excitement, emergency, and embarrassment

• Works against parasympathetic nervous system

Parasympathetic nervous system

• Rest and digest: Body rests and recovers

• conserves energy

• Maintains daily necessary body function

• Acetylcholine is released: regulates bp, heart rate, digestion, etc.

• Opposes sympathetic

Sympathetic and adrenaline release

• hypothalamus signals adrenal glands via sympathetic nervous system

• Produces adrenaline

• Adrenaline (epinephrine) and norepinephrine are released into bloodstream

• Causes fight or flight response

Sympathetic vs parasympathetic: pupil, saliva, bop, breathing, digestion, glucose, adrenaline, excretory

• sympathetic: dilates pupil to let more light in, inhibits saliva (dry mouth), increases heartbeat, increases breathing, liver releases glucose for more energy production, adrenaline produced, relaxes excretory system

• Parasympathetic: pupils become smaller, saliva flows, slows heartbeat, breathing is slowed, digestion is stimulated, bile is released, contracts bladder

sensory, motor and interneurons, pns or cns?

• sensory: pns, carry impulse from stimuli to cns

• motor: pns, carry impulse from cns to muscles

• interneurons: pns