Chapter 13 181

How are receptors classified based on stimulus type and location

Receptors can be classified based on stimulus type into mechanoreceptors, thermoreceptors, photoreceptors, chemoreceptors, and nociceptors, while their classification by location includes external receptors (exteroceptors), internal receptors (interoceptors), and proprioceptors.

Mechanoreceptors

Respond the mechanical force

Thermoreceptors

Respond to temperature changes

Photoreceptors

Respond to light

Chemoreceptors

Respond to chemicals

Nociceptors

Respond to pain-causing stimuli

Exteroceptors

Located near body surface, respond to stimuli outside the body

Interoceptors

Respond to stimuli within the body

Proprioceptors

Respond to stretch in muscles, tendon, joint, ligaments

Provide information about body position and movement

Location and functions of tactile receptors

In skin

Detect touch, pressure, vibration

Location and functions of muscle spindles

In Skeletal muscles

Detect muscle stretch and initiate reflexes

Location and functions of tendon organ

In tendons

Monitor tension and prevent muscle damage from excessive force

Location and functions of joint kinesthesia receptors

In synovial joints

Monitor joint position and movement

What is somatosensory system and its functions

Serves body wall and limbs

Processes sensory input from skin, muscles, and joints allowing perception of touch, pressure, pain, temp, and proprioception

What are the three main levels of the somatosensory system

Receptor

Circuit

Perceptual

How does each system work

Sensory receptors detect stimuli and convert to electric signals

Ascending pathways transmit signals to higher brain levels

Processing in the cerebral cortex results in perception of stimulus

What is encoding/transduction

Transduction is the conversion of stimulus energy into a graded potential in a sensory receptor

What is neuronal adaptation

A decrease in receptor sensitivity with constant stimulation

what is perceptual detection

Ability to detect stimuli

What is magnitude estimation

Ability to detect intensity of a stimulus

What is spatial discrimination

Ability to identify the site or pattern of stimulation

What is feature abstraction

Identifying more complex aspects

What is quality discrimination

Ability to differentiate submodalities

What is pattern recognition

Recognizing familiar or significant patters

What role does substance p have in pain sensation

Pain transmitter

What role does histamine have in pain sensation

Promotes inflammation and pain

What role does glutamate have in pain sensation

Excitatory neurotransmitter involved in pain transmission

What role does endorphins have in pain sensations

Natural pain killers that inhibit pain perception

What role does enkephalin have in pain sensations

Function as neurotransmitters that inhibit pain perception and provide analgesic effects.

What is the first cranial nerve and its function

Olfactory, sense of smell

What is the second cranial nerve and its function

Optic, vision

What is the third cranial nerve and its function

Oculomotor, motor to eye muscles

What is the fourth cranial nerve and its function

Trochlear, eye movement

What is the fifth cranial nerve and its function

Trigeminal, face and motor functions of chewing

What is the sixth cranial nerve and its function

Abducens, lateral eye movement

What is the seventh cranial nerve and its function

Facial, controls muscles of facial expression and provides taste sensations from the anterior two-thirds of the tongue.

What is the eighth cranial nerve and its function

Vestibulocochlear, hearing and balance

What is the ninth cranial nerve and its function

Glossopharyngeal, provides sensory information from the posterior one-third of the tongue and contributes to swallowing.

What is the tenth cranial nerve and its function

Vagus, controls autonomic functions and provides sensory information from internal organs.

What is the eleventh cranial nerve and its function

Accessory, controls shoulder and neck movements.

What is the twelfth cranial nerve and its function

Hypoglossal, controls tongue movements for speech and swallowing.

What is the role of nerve plexus in the body

A network of intersecting spinal nerves that innervate limbs and anterior body

Allows for redundancy and reorganization after injury

What are dermatomes

Skin regions innervate by specific spinal nerves

What are components of a reflex arc and what does it do

Receptor, Sensory neuron, Integration center, Motor neuron, Effector

Allows for the body to respond automatically to stimuli.

Function of the stretch reflex

Maintain muscle tone and posture

Function of the tendon reflex

Prevent muscle and tendon damage from excessive force

Function of the crossed extensor reflex

Maintains balance during withdrawal reflex by extending opposite limb

There are 41 pairs of spinal nerves

False

The only cranial nerves to extend beyond the head and neck region are the vagus nerves

True

Dermatomes are skin segments that relate to sensory innervation regions of the spinal nerves

True

Reciprocal inhibition means that while one sensory nerve is stimulated, another sensory neuron for synergistic muscles in the same area is inhibited and cannot respond

True

The patellar knee jerk reflex is an example of a

Stretch reflex

What is not an example of an exteroceptor

Baroreceptor

The abducens nerve

Supplies innervation to the lateral rectus muscle of the eye

Striking the funny bone is actually stimulation of the

Ulnar nerve

A reflex that causes muscle relaxation and lengthening in response to muscle tension is called a

Golgi tendon reflex

Pressure, pain, and temperature receptors in the skin are

Exteroceptors

Potentially damaging stimuli that result in pain are selectively detected by

Nociceptors

Nerves that carry impulses toward the CNS only are

Afferent nerves

In a crossed-extensor reflex, if the right arm was grabbed it would flex and the left arm would

Extend

What is the simple spinal reflex arc

Receptor, afferent neuron, integration center, efferent neuron, effector

The flexor muscles in the anterior arm are innervated by what nerve

Musculocutaneous

The cranial nerve that has major neural connections with the tongue is the

Glossopharyngeal

Problems in balance may follow trauma to which nerve

Vestibulocochlear

The motor bran of the median nerve serve the

Flexor group of the anterior forearm

What are the two subdivisions of the motor efferent division of PNS

Somatic and autonomic nervous system

Muscle spindles detect muscle — and initiate a reflex that cause — of that same muscle

stretch,contraction

The three main levels of neural integration are

receptor level, circuit level, perceptual level

Loss of a spinal dorsal nerve root would result in loss of

Afferent signals to skin

Cranial nerves I, II, and III are what nerves

Olfactory, optic, occulomotor

The — plexus gives rise to nerves that innervate the upper limb; and its spinal root originate and span — and —

Brachial, C5 and T1

The area of skin innervated by cutaneous branches of a spinal nerve is called a

Dermatome

The Babinski sign is apparent when the nervous system is

Immature and unmyelinated

The head bobbing that often occurs when falling asleep is an example of what spinal reflex

Stretch

Golgi tendon reflexes serve to — muscular contraction

Suppress

Ventral spinal cord roots contain what fibers

Efferent

What fibers do dorsal roots contain

Afferent

The facial nerve is what cranial nerve number

VII

What is a protective reflex that also overrides the spinal pathways and prevents any other reflexes from using them at the same time

Golgi tendon reflex

Information regarding skeletal muscle tension is provided by — and muscle length by —

Golgi tendon organs, muscle spindles