Flashcards in CNS Ch 12 Deck (56):
Specialized to respond to changes in environment called stimuli
Classification by stimulus type
Respond to mechanical force such as touch, pressure, vibration, and stretch
Respond to light, such as those in the retina.
Respond to chemicals in solution ( molecules smelled or tasted, or changes in blood or interstitial fluid chemistry)
Respond to potentially damaging stimuli that result in pain (extremes of cold and heat, excessive pressure and inflammatory chemicles
Classification by location
Exteroceptors: Outside the body
Internoceptors: Within the body
Occure in skeletal muscles, tendons, joints, ligaments and connective tissues or bones and muscles
Simple receptors of general sences
Non-encapsulated (free) nerve endings
Encapsulated nerve endings
Non-encapsulated nerve endings
Non-mylinated, small diameter and have knob like distal ends
Nearly everywhere, abundant in epithelial and connective tissue.
Examples: Tactile (merkel) disk in skin and Hair follicle receptors
Encapsulated nerve endings
ONe or more fiber terminal enclosed in connective tissue capsule
Joint kinethetic receptors
Part of the sensory system serving the ody wall and limbs. Receives input from exteroceptors, interoceptors and proprioceptors
3 levels of neural integration
Receptor level: sensory receptors
Circuit level: processing in ascending pathways
Perceptual level: processing in cortical sensory areas
Ability to detect that stimulus has occured
Ability to detect how intense the stimuli is
Ability to identify the site and pattern of stimuli
The ability to identify multiple features of an object
Ability to identify submodalities of a sensation, eg. sweet or bitter.
Ability to recognize a familiar or unfamiliar pattern, or a special significance.
Results from noxious stimulation of receptors in thorax or abdomen.
Vague, dull, aching or burning
Arises from one part of the body but is perceived in another part.
Cord like organ, consists of multiple fascicles full of axons and a blood supply
Endoneurium: encloses each axon
Perineurium: surrounds each fascicle
Epineurium: encloses all fascicles, outer sheath of nerve.
Regeneration of PNS nerves
1. Axon fragments at injury site
2. Macrophages clean out the dead axon
3. Schwann cells form regeneration tube and axon sprouts grow through tube.
4. Axon regenerates and new myelin sheath forms
Tiny nerve filaments of sense of smell
SENSORY ONLY, nerve of vision, outgrowth of the brain so it is actually a tract.
MOTOR ONLY, "eye mover", supplies the 4 extrinsic muscles that move the eyeball up down and inward.
MOTOR ONLY, "pulley" innervaed the extrinsic eye muscle that rotate eye inferolaterally
SENSORY & MOTOR to the face and chewing muscles
MOTOR. Controls eye abduction
MOTOR & SENSORY, controls muscles of facial expression
SENSORY, for balance and hearing.
SENSORY & MOTOR for tongue and pharynx
How many spinal nerve pairs are there
8 cervical (C1-C8)
12 thoracic (T1-T12)
5 lumbar (L1-L5)
5 sacral (S1-S5)
1 coccygeal (C0)
Dorsal root = Afferent, Ventral root = Efferent
Ventral rami branch and join one another laterally forming complicated interlacing nerve networks
mostly supply cutaneous nerves
and muscles of anterior neck
Fibers from C3, C4 & C5
motor and sensory for the diaphragm
Nerves that innervate upper limb
C5-C8 and T1
Really Tired Drink Coffee
Brachial plexus branches from medial to lateral:
Nerves of brachial plexus
innervated deltoid, teres minor, shoulder skin and joint
Biceps brachii, brachialis and coracobrachialis
5 muscles of lateral palm, pronates foreare, flex wrist and thumb and index finger
Medial part of forearm and the last 3 fingers, flexors not supplied by median nerve
Extend the elbow, supinate forearm, extend wrist and fingers, and abduct the thumb.
Within Psoas major muscle
Innervates abdominal wall and psoas muscle, anterior and medial thigh
Largest terminal nerve in lumbar plexus
Innervates quadriceps and knee extensors.
innervates adductor muscles through obturator foramen
Innervates butt ox lower limb pelvic structures and perineum
Largest nerve in sacral plexus
thickest and longest in the body
supplies entire lower limb except anteromedial thigh.
Any nerve serving a muscle that produces movement also innervates the joint and skin over the joint.
Hierarchy of motor control
Highest level, cerebellum and basal nuclei, programs and instructions.
Middle level, motor cortex and brain stem nuclei (vestibular and reticular formation ect)