Unit 3 - The PNS Flashcards
Sensory neurons
Carries info to CNS
Motor neurons
Carries info from the CNS, to muscles
Mixed neuron
Carrying both sensory and motor information
How many nerves make up the cranial nerves
12 nerves
Cranial nerve I
Olfactory nerve is a sensory nerve involved in smell
Cranial nerve II
Optic nerve, sensory involved in vision
Cranial nerve III
Oculomotor nerve is a motor nerve involved in movement of eye and constriction of pupil
Cranial nerve IV
Trochlear nerve that moves eye (controls extra-ocular muscles around eye)
Cranial nerve V
Trigeminal nerve is a mixed nerve (sensory and motor)
- controls jaw
- sends sensory info from eye and forehead
- controls chewing
Cranial nerve VI
Abducens nerve is a motor nerve that moves the eyes (around eye muscles)
Cranial nerve VII
Facial nerve, mixed
Muscle of facial expression and glands for tears and salivation, and 2/3 of tongue
Cranial nerve VII
Vestibulocochlear nerve is a sensory nerve involved in hearing and equilibrium
Cranial nerve IX
Glossooharyngeal nerve, mixed. Swallowing and salivary glands and other 1/3 of tongue
Cranial nerve X
Vagus, mixed, functions of thoracic and abdominal organs. Some sensory stimuli for eardrum and internal organs
Cranial nerve XI
Spinal accessory nerve , motor, trapezius muscles of back and neck
Cranial nerve XII
Hypoglossal nerve motor, controls tongue muscles
Spinal nerves
There are 31 and they are all mixed (sensory and motor nerves)
Five main categories of spinal nerves
- Cervical nerves (8 pairs)
- Thoracic nerves (12 pairs)
- Lumbar nerves (5 pairs)
- sacral nerves (5 pairs)
- Coccygeal nerves (1 pair)
Cervical plexus
C1-C5
Contains phrenic nerve and supplies diaphragm muscle for breathing
Brachial nerve
C5-T1
- axillary (shoulder)
- Musculocutaneous (anterior arm)
- Radial (posterior arm)
- median (forearm flexor)
- Ulnar (forearm and most of hand)
Lumbar plexus
L1-L4
Femoral- anterior leg muscle
Obturator- medial thigh muscle
Sacral plexus
L4-S4
- sciatic nerve, sacrial plexus and muscles and skin on posterior of leg (end of lumbar)
Acetylcholine
Neurotransmitter:
- excitatory and depolarizing neurotransmitter
- resting and digesting
- Parasympathetic
Norepinephrine
Neurotransmitter
- excitatory or inhibitory
- flight or fight
- heart rate, pupil dilation and blood pressure
- sympathetic
Epinephrine
Neurotransmitter
- adrenaline (from adrenal gland)
- strong emotions like fear or anger
- reaction is also fight or flight
Prefrontal cortex
Cognitive decision to move
Premotor cortex
Organizes the movement
Primary motor cortex
Directs the muscle to movements
Basal nuclei
Fine tune movements and posture
Cerebellum
Learning specialized movements that become automatic
Lateral corticospinal tract
Muscle tone and skilled hand movements
Anterior corticospinal tract
Muscle tone and trunk movements
Vestibulospinal tracts
Balance and posture
Tectospinal tracts
Reflexive head turning in response to visual and auditory stimuli
Receptor
Detects the stimuli
Sensory neuron
Sends information to the CNS
Integration center
Within the CNS
Motor neuron
Carries info to the effector
Effector
Muscle or gland
