Summary Introduction to peripheral nervous system

PERIPHERAL NERVOUS SYSTEM
Subdivided into the 
SOMATIC (Movement and sensation)
AUTONOMIC
- Sympathetic (flight and fight)
- Parasympathetic (rest and digest)

THE SOMATIC nervous system:
It involves the CNS and PNS both.

Functions 
- Receive sensory signal
- Integrating and processing sensory information
- Processing motor responses involving skeletal muscles


SENSORY RECEPTORS ARE CLASSIFIED BY:
POSITION:
- Exteroceptor: external environment
- Interoceptor: internal environment
- Proprioceptor: position of body in relation to the rest of the body

FUNCTION:
- Chemoreceptor: chemicals
- Osmoreceptor
- Nociceptor: pain
- Mechanoceptor: mechanic like pressure
- Thermoceptor: temperature

CELL TYPE
- Free nerve ending
- Encapsulated ending (encapsulated in
connective tissue which increase sensitivity)
- Specialised receptor cells




SOMATIC NERVOUS SYSTEM: Sensory perception
An individual or organism capable of processing the stimuli in their environment is
called to have a sensory perception. This processing is done through the
coordination between sense organs and the brain. Hearing, vision, taste, smell, and
touch are the five senses we possess.

, GUSTATION: TASTE
We have 5 distinct tastes:
1. Sweet (glucose)
2. Salty (Na+)
3. Sour (H+)
4. Bitter (Alkaloids)
5. Umami (L-glutamate)

Gustatory receptor cells in taste buds are found in raised
bumps called papillae on the tongue.

4 types of PAPILLAE:
- Circumvallate
- Foliate
- Filiform
- Fungiform

OLFACTION: SMELL
Olfactory sensory neurones detect Airborne molecules in the nasal cavity.
Signals travel along the olfactory nerve.

AUDITION: HEARING

Bones inside the ear
Vibrations are picked up by the small
structures in the cochlear




BALANCE:




SOMATOSENSATION:
Exteroception
Interoception
Proprioception