Name the loose connective tissue covering that encloses nerve fibers?
endoneurium
Name the connective tissue layer that surrounds nerve fascicles or bundles?
perineurium
Name the connective tissue that covers group of fascicles?
epineurium
What are the categories of nerves based on function?
somatic efferent (motor), somatic afferent (sensory), visceral efferent, visceral afferent
What is a mixed nerve?
contains both sensory and motor nerves
What is the sensory root ganglia?
dorsal root ganglia
What is the motor root ganglia?
ventral root ganglia
What are the pain receptors called?
nociceptors
What type of receptors detect stretch of muscles, tendons, joints, and ligaments?
proprioceptors
What type of receptor generates a nerve impulse at a constant rate unless inhibited?
tonic receptor
What type of receptor is only activated by a change in the environment?
phasic receptors
What is the difference between sensation to perception?
- sensation - awareness in a change in environment
- perception - the conscious interpretation of stimuli
What are the 3 requirements of receptor processing?
specificity for the stimulus, receptive field applied to, generation of a graded potential
What is the relationship between the complexity of a nerve and the sensitivity?
the more complex the nerve the more sensitive
The area monitored by a specific receptor is known as the?
receptive field
What is the implication of the size of a receptive field?
the smaller the receptive field the better the sensation can be localized
What do transducers do in response to stimuli?
graded potential (generator potential)
What are the 12 cranial nerves?
- I - olfactory
- II - optic
- III - oculomotor
- IV - trochlear
- V - trigeminal
- VI - abducens
- VII - facial
- VIII - vestibulocochlear
- IX - glossopharyngeal
- X - vagus
- XI - accessory
- XII - hypoglossal
What is the function of the olfactory nerve?
sense of smell (pure sensory)
What is the function of the optic nerve?
carries vision impulses (pure sensory)
What does the oculomotor nerve control?
controls extrinsic muscle of the eye, provides parasympathetic innervation to the pupil, proprioception
What does the trochlear nerve do?
innervates extrinsic eye muscles
Name the 3 divisions of the trigeminal nerve and collectively what they do?
- ophthalmic, maxillary, and mandibular division
- sensory from the face
- motor to the muscles of mastication
What does the abducens nerve do?
- motor to extrinsic eye muscles
- proprioceptors
Name the 5 branches of the facial nerve and collectively what they do.
- sensory - proprioceptors of the face, taste buds
- motor - muscles of facial expression, parasympathetic innervation of the salivary glands
What is the function of vestibulocochlear nerve?
hearing and equilibrium
List the functions of the glossopharyngeal nerve?
- motor - somatic to the tongue and pharynx, parasympathetic to the parotid gland
- sensory - taste and carotid body
What is the function of the vagus nerve?
- motor - parasympathetic to the heart, lung, and abdominal viscera, somatic to the pharynx and larynx
- sensory - thorax, abdominal viscera, proprioceptors, carotid receptors
What makes the vagus nerve different from the other cranial nerves?
only cranial nerve to go below the neck
What are the functions of the accessory nerve?
- motor to the larynx, pharynx, and soft palate and the sternocleidomastoid
- proprioception from the sternocleidomastoid
What does the hypoglossal nerve do?
motor and proprioception to the tongue
What are the 31 pairs of the spinal nerves?
- cervical 1-8
- thoracic 1-12
- lumbar - 1-5
- sacral - 1-5
- coccygeal - 1
Which spinal nerve root is motor and which is sensory?
- motor - ventral
- sensory - dorsal
What happens to the length of the spinal roots?
length progressively increases passing distally
What are the only nerves that are not involved in a plexus?
T2 - T12
What spinal nerves make up the cervical plexus?
C1-C5
What is the major nerve coming from the cervical plexus that innervates the diaphragm?
phrenic nerve (C3,C4)
What nerves make up the brachial plexus?
C4-T2
List the terminal nerves of the brachial plexus?
axillary, musculocutaneous, median, ulnar, radius
What nerves make up the lumbar plexus?
L1-L4
What major nerve comes from the lumbar plexus?
femoral
What is the composition of the sacral plexus?
L4-S4 (part of the lumbar plexus)
Name the 2 major nerves from the sacral plexus?
sciatic, pudendal
The area of skin innervated by the cutaneous branch of a single spinal nerve is a?
dermatome
What is Hilton's Law?
any nerve serving a muscle that produces movement also innervated the joint and the skin overlying the joint
What are stereotyped sequential motor actions that are triggered internally or by appropriate environmental stimuli?
fixed-action pattern
What are the 2 types of reflexes?
intrinsic and acquired
What is an intrinsic reflex?
rapid predictable motor response to a stimuli
What is an acquired reflex?
results from practice or repetition
What are the components of the a reflex arc?
receptor, sensory neuron, integration center, motor neuron, effector
What type of reflex involves multiple synapses with chains of interneurons?
polysynaptic reflex
What are the components of a monosynaptic reflex?
single synapse between and efferent and afferent neuron
Reflexes that occur without involvement of the brain are known as?
spinal reflex
What is required for normal spinal reflex activity?
continuous facilitation from the brain
What types of sings can be expected in abnormal spinal reflexed?
exaggerated, distorted, or absent
What 2 reflexes are seen with painful stimuli?
- flexor/withdrawal reflex in which the threatened body part withdrawals from pain by flexion
- crossed extensor reflex in which the contralateral body part extends in response to the flexor reflex
What is the normal response to stimulation of the sole of the foot?
plantar reflex in which the toes curl
What is an abnormal plantar reflex called?
Babinski's sign
What is the function of the autonomic nervous system?
routine homeostatic adjustments, coordinates organ activity, protection
What are the 2 divisions of the autonomic nervous system?
sympathetic and parasympathetic
Sympathetic and parasympathetic innervates the same organs with opposite effects. What is this principle known as?
dual innervation
What are the effects of activation of the sympathetic nervous system?
- increases alertness
- feelings of energy
- increase in general muscle tone
- mobilization of energy reserves
- increased activity in the cardiovascular and respiratory centers (BP, HR, breathing rate, depth of respiration)
Where does the sympathetic nervous system originate?
thoracolumbar spinal cord
What is the relative length of the fibers of the sympathetic nervous system?
- short preganglionic
- long post ganglionic
What are the components of the sympathetic nervous system?
- collateral (prevertebral) ganglia
- splanchnic nerves
- adrenal medulla
What are the 3 fates of sympathetic preganglionic fibers?
- synapse in - chain ganglia, collateral ganglia, adrenal medulla
Where do preganglionic and postganglionic synapse in chain ganglia?
- preganglionic enter ganglia via the white ramus
- postganglionic exit the ganglia and enter the ventra l(dorsal ramus) via the gray rami
Where do the sympathetic nerves that synapse in the chain ganglia originate from?
T1-T6
Where do sympathetic nerves that synapse in the collateral ganglia originate from?
T2-L2
What is the name of the nerves that are formed by those sympathetic nerves that synapse in the collateral ganglia?
splanchnic nerves
what do the splanchnic nerves form?
abdominal aortic plexus
What are the names and the order of the ganglia in the abdominal aortic plexus?
- celiac
- superior mesenteric
- inferior mesenteric
- hypogastric
Where do the fibers that innervate the adrenal medulla come from?
thoracic splanchnic nerves that pass through the celiac ganglia without synapsing
where do the sympathetic nerves that innervate the adrenal medulla synapse?
medullary cells of the adrenal gland
What are the neurotransmitter of the autonomic system?
acetylcholine, norepinephrine
Which neurotransmitter is found in all preganglionic synapses in the autonomic nervous system?
acetylcholine
Postganglionic axons that release norepinephrine are classified as?
adrenergic
What are the adrenergic receptors of the sympathetic nervous system classifies as?
beta one, beta two, beta three, alpha one, alpha two
What are the organs that have beta one receptors what effects does the sympathetic nervous system have on them?
- heart - increases rate and force of contraction
- coronary arteries - dilates
- kidneys - renin release
- adipose tissue - actives fuel supplies
What are the organs that have beta two receptors and what effect does the sympathetic nervous system have on them?
- lungs - dilates bronchioles
- coronary arteries - dilates arteries
- most other sympathetic target organs - stimulates secretion of insulin, relaxes smooth muscles walls of the digestive, urinary tract, and pregnant uterus
What are the organs that have alpha one receptors and what effect foes the sympathetic neurons have on them?
- skin, mucosa, abdominal viscera, kidneys, salivary glands, all sympathetic targets except the heart
- constricts blood vessels, visceral organ sphincters, and dilates pupils of the eye
In the absence of stimuli, autonomic motor neurons show a resting level of spontaneous activity. This is known as?
autonomic tone
What are the effects of sympathetic tone?
blood vessels keep a continual state of partial contraction
What organs are subject to autonomic control?
heart, smooth muscle of the digestive and urinary tract
Which organs have sympathetic innervation only?
adrenal medulla, sweat glands, arrestor pili, kidneys, most blood vessels
What are the effects that are unique to the sympathetic nervous system?
- heat regulation - arrector pili innervation, controls arteries of the skin
- release of renin
- metabolic effects - increase metabolic effect, raise glucose and mobilize fat, and increase mental alert ness
What effects are seen with activation of the parasympathetic portion of the autonomic nervous system?
�Stimulate and coordinate defecation
�Contraction of the urinary bladder
�Constriction of respiratory passages
�Reduce heart rate and force of contraction
�Constrict pupil and focus on nearby objects
�Secretion by the digestive glands
�Promote absorption
Where does the parasympathetic nervous system originate?
brain and spinal cord
What is the relative length of the fibers in the parasympathetic nervous system?
long preganglionic, short post ganglionic
Where are the ganglia of the parasympathetic nervous system located?
in the visceral effector organs
Which cranial nerves are subjected to the parasympathetic nervous system?
oculomotor nerve, facial nerve, glossopharyngeal nerve, vagus
Where does the sacral outflow of the parasympathetic nervous system originate?
S2-S4
What is the neurotransmitter of the preganglionic and postganglionic nerves of the parasympathetic nervous system?
acetylcholine
What determines the action of acetylcholine in the parasympathetic nervous system?
the receptors
The types of receptors that are found on postganglionic fibers in parasympathetic system are?
nicotinic, muscarinic
Where are nicotinic receptor found and what are their effects?
all postganglionic neurons, excitatory
Where are the muscarinic receptors and what is their effect?
all target organs, mostly excitatory except it inhibits cardiac muscle
what is the relative length of time parasympathetic reactions take place?
short lived because acetylcholine is quickly destroyed by acetylcholinesterase
Which portion of the autonomic nervous system is more localized and why?
parasympathetic is more localized because in addition to synapses the sympathetic system also releases norepinephrine in the blood
Why do sympathetic reactions last longer that parasympathetic reactions?
norepinephrine is inactivated more slowly than acetylcholine plus norepinephrine works through a second messenger
In addition to motor nerves, there are visceral sensory nerves, what does this allow for?
visceral reflex arc
Because autonomic sensory neurons travel the same pathways as somatic sensory neurons, pain in the viscera are perceived as being of somatic origin. What is this phenomenon known as?
referred pain
What portion of the brain stem controls HR, respiratory rate, and blood vessel diameter?
medulla
Where is the respiratory center?
pons
What controls the autonomic system?
hypothalamus