final test Flashcards
vertebral canal
all of the vertebral foramina
spinal cord
part of central nervous system (CNS) within the vertebral canal
spine
the bone part - chain of vertebrae
vertebral column
chain of vertebrae - same as spine
how many pairs of spinal nerves do we have?
31
How many vertebrae do we have?
26
where does the spinal cord start?
at the foramen magnum - in occipital bone
what is the subarachnoid space filled with?
CSF - cerebrospinal fluid
where does the first spinal nerve come from?
between atlas and occipital bone
where do the last 2 spinal nerves come from?
sacral hiatus
what is the conus medulary?
where the spinal cord ends
what is the C1 named after?
bone below it
starting from T1 how are spinal nerves named?
bone above the nerve
how many holes are in the sacrum?
4
where does the last sacral nerve come from?
sacral hiatus - end of the sacrum
what two spinal nerves come out of the sacral hiatus?
S5 and CO1
where do the nerves come from other than S5 and CO1?
intervertebral foramina
what are the spinal nerves names?
C 1-8 T 1-12 L 1-5 S 1-5 CO 1
How many C vertebrae?
7
How many C nerves?
8
What is the cervical part of the spinal cord continuous with?
medulla oblongata
where is the cervical part of the spinal cord located?
in the vertebral canal formed by the cervical vertebrae
what does the cervical part of the spinal cord contain?
neurons whose neurons contribute to spinal nerves C1-C8
how are cervical nerves named?
C1-C7 named for vertebrae below them, while C8 is below C7 vertebra
What does the thoracic part of the spinal cord contain?
neurons whose neurons contribute to thoracic spinal nerves T1-T12
where are the thoracic spinal nerves located?
in vertebral canal formed by thoracic vertebrae
how are thoracic nerves named?
named for vertebrae above them T1-T12
which part of the spinal cord is the shortest?
coccygeal part
Which part of the spinal cord is second shortest?
sacral part
where is the lumbar part of the spinal cord located?
within the vertebral canal formed by the lower thoracic vertebrae
what does the lumbar part of the spinal cord contain?
neurons whose neurons contribute to lumbar spinal nerves L1-L5
how are the lumbar spinal nerves named?
exist in vertebral canal below their corresponding vertebrae
where is the sacral part of the spinal cord located?
within the vertebral canal formed by lower thoracic and L1 vertebrae
what does the sacral part of the spinal cord contain?
neurons whose neurons contribute to sacral spinal nerves S1-S5
Where are the sacral nerves located?
S1-S4 exist through 4 pairs of sacral foramina, S5 exists through sacral hiatus
What is the third shortest part of the spinal cord?
lumbar part
where is the coccygeal part of the spinal cord located?
within the vertebral canal formed by the L1 vertebra
what does the coccygeal part of the spinal cord contain?
neurons whose neurons contribute to SN Co1
where does the Coccygeal spinal nerve exist?
through the sacra hiatus
what doe you find in the vertebral canal below the conus medullaris?
cauda equina
what is the conus medullaris?
the end of the spinal cord
Where is the conus medullaris?
at the level of the L1 vertebra
why are there places of enlargement in the spinal cord?
there are more soma more neurons there
where are the places of enlargement on the spinal cord?
the cervical enlargement and the lumbosacral enlargement
Which spinal cord enlargement is bigger?
the cervical enlargement
why do you need more neurons at the spinal enlargments?
because you have more nerves going to upper and lower limbs than elsewhere
what is the cauda equine?
a bundle of nerve roots (axons) derived from sacral and lumbar and coccygeal parts of the spinal cord
what is the filum terminale?
a thin strand of pia mater that anchors the conus medullaris to the coccyx
what kind of nerves are spinal nerves?
mixed
what does the cervical enlargement contain?
neurons that innervate the upper limbs
what does the lumbosacral enlargement contain?
neurons that innervate the lower limbs
what is the filum terminale made of?
pia mater - connective tissue - connects end of spinal cord to end of spine
what is another word for lumbar puncture?
spinal tap
what use is a lumbar puncture?
taking csf samples
where do you want to take csf from?
below L1 - safer below L2
what space does the needle go in for spinal tap?
subarachnoid space between arachnoid and pia mater
what is the difference between spinal tap and epidural?
epidural is for injecting anesthetics - goes in the epidural space between the dura mater and the vertebra - spinal tap goes farther in - epidural does not go through the dura mater into the spinal sac
how does the epidural work?
once injected, medication diffuses into meninges into subarachnoid space
what are the spinal cord meninges?
epidural space dura mater arachnoid mater subarachnoid space pia mater
where is the epidural space?
between dura mater and inner wall of vertebra
what is the epidural space filled with?
adipose CT
what is the difference between cranial and spinal cord dura mater?
spinal cord dura mater only has one layer, cranial has 2 layers because of sinus separation
where is the CSF in the spinal cord located?
in the subarachnoid space
what is the subarachnoid space filled with?
CSF
why is it better to get a spinal tap below L2?
spinal nerves are more flexible there- not pinned down by bone - less likely to get injured if touched by needle
where is the gray matter located in the spinal cord?
inside
what causes the white matter of the spinal cord?
myelinated axons
what are the parts of the white matter?
posterior funiculus
lateral funiculus
white commisure
anterior funiculus
what are the parts of the gray matter?
posterior horn
gray commissure
lateral horn
anterior horn
where is the central canal?
within the gray matter - in the middle of gray commissure
what is the central canal?
a hole containing CSF
what is another word for the posterior median sulcus?
dorsal median sulcus
what is another word for the anterior median fissure?
ventral median fissure
what are the two cracks called?
posterior median sulcus and anterior median fissure
where is the posterior funiculus?
surrounding the posterior median sulcus
where is the lateral funiculus?
on the two sides of the gray matter
where is the white commissure?
between the anterior median fissure and the gray commissure -right in the middle of the spinal cord
where is the anterior funiculus?
on the anterior side of the spinal cord - around the anterior median fissure
where is the posterior horn?
the bottom part of the gray bow - back side
where is the gray commissure
the thin band across the middle of the spinal cord - housing the central canal
where is the lateral horn?
the side parts of the bow
which sections of the spinal cord have the lateral horn?
T1-L2
where is the anterior horn?
the top parts of the bow
what does the posterior horn contain?
axons of somatic and visceral neurons, and somas and axons of interneurons
what does the lateral horn contain?
somas of visceral motor neurons
what does the anterior horn contain?
somas of somatic motor neurons
what does the gray commissure contain?
axons communicating between left and right sides of gray matter
what is the central canal continuous with?
4th ventricle in brain
what does the posterior root ganglion contain?
somas of somatic and visceral sensory neurons
what does the posterior root contain?
axons of somatic and visceral sensory neurons
what does the anterior root contain?
axons of somatic motor neurons and axons of visceral motor neurons
what does a spinal nerve contain?
axons of somatic and visceral sensory neurons, axons of somatic and visceral motor neurons
posterior horn is for
sensory axons and interneurons
anterior horn is for
somatic motor neurons
lateral horn is for
autonomic motor neurons
anterior root is
motor
posterior root is
sensory
which root has a ganglion?
posterior
how many cervical pairs of spinal nerves are there?
8
how many pairs of thoracic spinal nerves are there?
12
how many pairs of lumbar spinal nerves are there?
5
how many pairs of sacral spinal nerves are there?
5
how many pairs of coccygeal nerves are there
1
where does spinal nerve exit the vertebral canal?
intervertebral foramen
what are the 3 branches of a spinal nerve?
posterior ramus
anterior ramus
communicating ramus
what does the posterior ramus contain?
somatosensory and somatomotor nerves that innervate deep muscles of the back and skin of the back
which branch is the largest branch?
anterior ramus
what does the anterior ramus contain?
somatosensory and somatomotor nerves that innervate lateral and anterior of the trunk, upper and lower limbs
what does the communicating rami contain?
sympathetic nerve axons that control visceral organs - autonomic nervous system
where are the communicating rami located?
T1-L2 level
where do the intercostal nerves come from?
anterior rami of T1-T11
where do the subcostal nerves come from?
anterior rami of T12
what do the anterior rami of T1-T11 become?
intercostal nerves
what do the anterior rami of T12 become?
subcostal nerves
What do thoracic anterior rami nerves innervate?
intercostal muscles
abdominal muscles
skin of trunk
other branches also go to abdominal muscles and skin of trunk
does the thoracic region have plexus?
no
where are the nerves that control the bacon muscles derived?
thoracic spinal nerves
What do the anterior rami of C1-C4 form?
the cervical plexus
what forms the cervical plexus?
anterior rami of C1-C4
what do the anterior rami of C5-T1 form?
brachial plexus
what forms the brachial plexus?
anterior rami of C5-T1
what do anterior rami of L1-L4 form?
lumbar plexus
what forms the lumbar plexus?
anterior rami of L1-L4
What do L4-S4 form?
sacral plexus
what forms the sacral plexus?
anterior rami of L4-S4
what do S4-Co1 form?
coccygeal plexus
what forms the coccygeal plexus?
S4-Co1
what are terminal nerves?
nerves with specific names
what happens with the anterial ramus in thoracic region?
continues to become intercostal nerve (except last one - becomes subcostal nerve because not in between, just at bottom
what is a nerve plexus?
network of interweaving anterior rami of spinal nerves (except for ventral rami of T2-T11)
what happens after nerve plexuses?
split into multiple named nerves that innervate various body structures
what are benefits of nerve plexuses?
allow axons from each anterior ramus to extend to body structures through several different branches, so that each terminal branch of the plexus contains axons from several different spinal nerves
AND damage to a single segment of spinal cord or single spinal nerve does not result in complete loss of innervation of a particular structure
why no plexus in thoracic region?
less prone to injury because supported and protected by ribs
what does the cervical plexus do
terminal branches innervate head, neck and shoulders
what is one important terminal branch from cervical plexus
phrenic nerve
what does phrenic nerve do
innervates diaphragm
where is phrenic nerve derived?
anterior rami of spinal nerves C1-C4
where is the respiratory control center located?
pons
where are the somas for respiratory control located?
pons
what does brachial mean
arm
what forms the brachial plexus
anterior rami of C5-T1
what are the terminal branches of the brachial plexus?
musculocutaneous nerve axillary nerve radial nerve median nerve ulnar nerve
what kinds of nerves are the terminal branches of the brachial plexus?
somatosensory and somatomotor
what does the musculocutaneous nerve do?
innervates brachialis, biceps brachii
what does the brachialis do?
flexes elbow joint
what does the biceps brachii do?
flexes elbow, flexes shoulder, supination of forearm
what does the axillary nerve do?
innervates deltoid
what does the deltoid do?
abduction of shoulder, hyperextends and laterally rotates, flexes and medially rotates shoulder
what does the radial nerve do
innervates triceps brachii, extensor muscles of forearm
what does triceps brachii do?
extends elbow and shoulder, hyperextends shoulder
what does median nerve do?
innervates flexor muscles of the forearm
what do the flexor muscles of the forearm do?
flexion of hand and elbow
where are the flexor muscles of the forearm located?
anterior side of forearm
what does the ulnar nerve do?
innervates flexor muscles of the forearm
why do we need two terminal nerves to innervate flexor muscles of the forearm?
so many muscles there
if a person cannot flex his forearm, what nerves can be damaged?
median nerve and/or ulnar nerve
what does innervate mean?
send nerve to control something
where are extensors of the forearm located?
on postial side of forearm
where is the brachial plexus located?
in the armpit
where is the lumbar plexus located?
in groin area
what forms the lumbar plexus?
anterior rami of L1-L4
what do the L1-L4 form?
lumbar plexus
name the important terminal branches of the lumbar plexus
femoral nerve and obturator nerve
what does the femoral nerve do?
innervates iliacus, quads and sartorius
what does iliacus do?
flexes hip joint
what do quads do
extends knee joint and flexes hip
what does sartorius do?
flex knee, flex hip, abduct hip and lateral rotation of hip
what does obturator nerve do?
innervates gracilis, adductor longus, adductor magnus
what does gracilis do?
adducts hip
what does adductor longus do?
adducts and laterally rotates femur
what does the adductor magnus do?
adducts thigh
does the obturator nerve go through obturator foramen?
no
what forms the sacral plexus?
L4-S4
what do L4-S4 form?
sacral plexus
what are the important terminal branches of the sacral plexus?
sciatic nerve, pudendal nerve
what are the two branches of the sciatic nerve?
common fibular nerve and tibial nerve
what is the biggest nerve in the body
sciatic nerve
where is sciatic nerve located?
posterior side of body
what does the common fibular nerve branch do?
innervates biceps femoris, tibialis anterior, extensor digitorum longus, fibularis longus
all anterior thigh
what does the biceps femoris do?
flexes knee and hyperextends hip
what does tibialis anterior do?
dorsiflexion and inversion of ankle
what does extensor digitorum longus do?
dorsiflexion and extension of toes
what does fibularis longus do?
plantar flexion and eversion of ankle
what does the tibial nerve do?
innervates hamstrings and gastrocnemius and soleus medial thigh
what are the hamstring muscles
semitendinosus, semimembrabosus and biceps femoris
what do hamstrings do
extend hip and flex knee
what do gastrocnemius and soleus do?
plantar flex foot, flex knee (gastro)
what does the pudendal nerve do?
innervates clintoris, labia majora and minor, vagina and skin of penis
what causes sciatica
compression of lumbar nerves L4-L5 or sacral nerves S1-3
what do sensory nerves do
transmit signals from receptors (sensors) to CNS
what is another name for sensory nerves?
afferent nerves
what do somatic afferent nerves do?
transmit signals from receptors in skin, skeletal muscles, bones and joints
what do visceral afferent nerves do?
transmit signals from receptors in visceral organs in thoracic and abdominal cavities
what do motor nerves do?
transmit signals from CNS to effectors
what is another name for motor nerves?
efferent nerves
what do somatic motor nerves do?
transmit signals to skeletal muscles
what do visceral motor nerves do?
transmit signals to glands, cardiac muscles and smooth muscles
what do sympathetic nerves do?
arouse the body to action
what do parasympathetic nerves do?
have a calming effect
what are other names for somatic nervous system?
voluntary, somatic motor system
what is the function of the somatic nervous system?
transmit impulses from CNS to skeletal muscles
what is the pathway between CNS and skeletal muscles?
motor neurons via cranial nerves (except I,II & VII) and all spinal nerves (C1-S5), directly innervates effectors - no ganglia between CNS and effectors (skeletal muscles)
acetylcholine (ACh) is released at neuromuscular junctions
where is the anterior root located?
in vertebral canal
OUTSIDE of spinal cord
where is the spinal nerve located?
in intervertebral foramen
what is the name of the nerve that goes to bicep brachii?
musculocutaneous nerve
where is musculocutaneous nerve derived?
from brachial plexus derived from anterior rami of spinal nerves C5-T1
what are other names for autonomic nervous system?
involuntary nervous system
visceral motor system
what is the function of the autonomic nervous system?
transmit impulses from CNS to smooth muscle, cardiac muscle and glands
where are the somas of the autonomic nervous system located?
in the lateral horn of the T1-T12 section of the spinal cord
which somas are in the autonomic ganglia?
postganglianic nerve
where are somas of preganglionic nerve located?
lateral horn
where is the ganglionic neuron cell body located?
in the autonomic ganglion
where is the preganglionic neuron cell body located?
in the lateral horn
what are the two divisions of the autonomic nervous system?
sympathetic and parasympathetic
what does the sympathetic nerve division do?
fight or flight
what is another name for parasympathetic nerve division
resting and digesting system
where do the parasympathetic division nerves come from?
brainstem and S2-S4, CNIII, VII, IX and X
where do sympathetic division nerves come from?
T1-L2
which division has long preganglionic axon?
parasympathetic
which division has a long postganglionic axon?
sympathetic
which division has a branching preganglionic axon?
sympathetic
which division has the autonomic ganglion close to the vertebral column?
sympathetic
which division has the autonomic ganglion close to or within effector organ wall?
parasympathetic
what neurotransmitters are released in the autonomic ganglion
ACh in all of them
what neurotransmitters are released at junction with effector?
ACh or Norepinephrine
are neurotransmitter receptors different between sympathetic and parasympathetic divisions?
yes
do neurotransmitters get into the blood stream?
no
what is the function of the sympathetic division of the ANS
prepare body to cope with emergencies and to release energy
what and where do pre-ganglionic sympathetic neurons synapse
with post-ganglionic neurons in autonomic ganglia far from target organs
what are some other names for sympathetic trunk ganglia
sympathetic chain ganglia and paravertebral ganglia
what are some prevertebral ganglia
celiac ganglia, superior mesenteric ganglia, inferior mesenteric ganglia
what are the exceptions to sympathetic preganglionic nerves?
some of long axons, exit CNS through SN T1-L2 and synapse with adrenal medulla - releases catecholamines (epinephrine, norepinephrine and dopamine) into the blood stream.
what are catecholamines?
epinephrine, norepinephrine, and dopamine
what do postganglionic neurons release at neuron-target organ junctions?
norepinephrine (NE) or acetychoiline (ACh)
What cranial nerves go to the organs below your head?
Vagus X, and Accessory XI (controls muscles used in head movement)
which spinal nerves control things in your head?
sympathetic nerves - secreting saliva, controlling lens of eye, sweat glands and blood vessels
sympathetic trunk ganglia
autonomic ganglion chained together
what is different about the adrenal medulla?
no post ganglionic nerve goes here - from spinal cord to medulla with no ganglion involved at all - called a sympathetic nerve
what is the function of the parasympathetic division of the ANS
conserve energy, replenish energy stores
where are parasympathetic pre-ganglionic neuron somas located?
brainstem, gray matter of S2-S4 segments of spinal cord
where do pre-ganglionic parasympathetic axon neurons exit?
exit brain stem through CNIII, VII, IX, and X and through SN S2 - S4
what is CNIII
Oculomotor nerve - eye movement; pupil constriction
what is CN VII
Facial nerve - lacrimal gland to release tears and submandular salivary gland to release saliva
what is CN IX
glossopharyngeal nerve - stimulate parotid salivary glands to release saliva
what is CN X
vagus nerve - controls lungs, heart, digestive tract and glands, spleen, kidneys and testis or ovaries
what do parasympathetic postganglionic neurons release at neuron-target organ junctions?
ACh
which spinal nerves contain parasympathetic nerve fibers?
S2-S4 - to control large intestine, urinary bladder, reproductive organs
where do somas of parasympathetic nerves come from?
brain stem and gray matter of spinal nerves S2-S4
what kind of autonomic motor nerves are in head?
all parasympathetic - NO sympathetic in head
Sympathetic effect on heart
increases heart rate and contraction force
sympathetic effect on blood vessels
skeletal muscles vessels and brain vessels - vasodilation
vessels in other body parts - vasoconstriction
sympathetic effect on digestive system
reduce activity
salivary glands - produces viscous saliva
GI tract glands - inhibits (no digestive enzymes)
Motility of GI tract - inhibits (bowel movement)
GI tract blood vessels - vasoconstriction
Liver - stimulates glycogenolysis - releases sugar from liver because liver is storage site of sugar
sympathetic effect on respiratory system
increase activity
bronchi of lungs - bronchodilation - increase activity
sympathetic effect on urinary system
reduce activity - don’t want to worry about pee making
kidneys - renin secretion (reduces urine formation)
bladder - relaxation
internal urethral sphincter - contract
sympathetic effect on reproductive system
penile or clitoral erection - no effect penile ejaculation - stimulates uterine muscle - contraction gland secretion - inhibits vaginal muscular wall - contraction
sympathetic effect on integumentary system
arrector pili- contraction - raise hair and goose bumps
sweat glands - secretion
are there parasympathetic nerves to skin?
no
sympathetic effect on eye
pupil size - dilation - allows more light so you can see better
ciliary muscle - no effect - for moving/changing lens
lacrimal gland - no effect
sympathetic effect on adipose tissue
stimulates lipolysis - breaking down fat for providing more energy
sympathetic effect on adrenal medulla gland
secretion of catecholamines
parasympathetic effect on heart
decreases heart rate and contraction force
parasympathetic effect on blood vessels
skeletal muscle vessels - no effect
vessels in other body parts - no effect
parasympathetic effect on digestive system
salivary glands - produces watery saliva GI tract glands - stimulates Motility of GI tract - stimulates GI tract blood vessels - vasodilation Liver - stimulates glycogenesis???
parasympathetic effect on respiratory system
bronchi of lungs - bronchoconstriction
parasympathetic effect on urinary system
kidneys - no effect
urinary bladder - contraction
internal urethral sphincter - relax
parasympathetic effect on reproductive system
penile or clitoral erection - stimulates penile ejaculation - no effect uterine muscle - no effect gland secretion - stimulates vaginal muscular wall - no effect
parasympathetic effect on integumentary system
no effect because no parasympathetic nerves here
parasympathetic effect on eye
pupil size - constriction
ciliary muscle - contraction for near vision
lacrimal gland - stimulates secretion
parasympathetic effect on adipose tissue
no effect
parasympathetic effect on adrenal medulla gland
no effect because no sympathetic nerve
how can ANS neurons have different effects on the effectors?
they secret different neurotransmitters and effectors contain different receptors
what kind of neurons are preganglionic neurons
they are all cholinergic because they all release ACh at synaptic knobs
what do dendrites and somas of postganglionic neurons contain?
they all contain ACh receptors (cholinergic receptors
what are nicotinic receptors?
cholinergic receptors - they are sensitive to drug nicotine
target cells contain
either ACh receptors or NE receptors
what are muscarinic receptors?
ACh receptors - sensitive to mushroom toxins
what kind of target cells have NE receptors?
target cells from sympathetic pathways to body structures other than sweat glads and blood vessels in skeletal muscles
what is the difference between parasympathetic and sympathetic neurotransmitters?
parasympathetic neurotransmitters are only ACh, sympathetic release either ACh (to sweat glands, and blood vessels of skeletal muscles) or NE (to other body structures
definition of a reflex
a quick, involuntary reaction of glands, muscles or visceral organs to stimulation
what are the pieces of a reflex arc?
stimulus, receptor, afferent nerve fibers, integrating center, efferent nerve fibers, effectors, action or response
what are ways to categorize reflexes?
based on location or based on receptors and effectors
what are the ways to categorize reflexes based on location
cranial reflex (CNS involved is brain) and spinal reflex (CNS involved is spinal cord)
what kind of reflex are knee, ankle and bicep reflexes based on location?
spinal reflexes
what kind of reflex is pupil reflex based on location?
cranial
what is Jendrassik maneuver?
think of something else while reflex is being tested - reflex should be stronger - hampers brain’s inhibitory effect
what are the ways to categorize reflexes based on receptors and effectors?
somatic reflexes and visceral reflexes
what are the receptors and effectors for somatic reflexes?
receptors are in skin, skeletal muscle, or tendon, effectors are skeletal muscles
what are the receptors and effectors of visceral reflexes?
receptors are in visceral organs, effectors are in visceral organs
what are 2 kinds of somatic reflexes?
stretch reflexes and golgi reflexes
what are the receptors for stretch reflex?
receptors are in muscle spindle
what is another way to classify reflexes?
based on number of synapses of reflex arc
what are the two classifications of reflex arc synapses
monosynaptic reflex and polysynaptic reflex
monosynaptic reflex
faster because just one synapse
polysynaptic
2 or more synapses - diffusion takes time, so it takes more time to respond
stretch reflex
when muscle is stretched, it responds by contraction - prevents muscle from being stretched extensively
3 examples of stretch reflex
biceps reflex, knee jerk reflex, achilles tendon reflex
steps in knee jerk reflex
patellar reflex
- stimulus - tap on knee
- receptor - muscle spindle is stretch receptor in quads
- sensory nerve - femoral nerve sensory branch part
- integration center - spinal cord L2-L4
- motor nerve - femoral nerve motor branch
- effector - quads
- response/action - knee extension/knee jerk
what does the antagonist muscle do during patellar reflex?
hamstring relaxes
what is the golgi tendon reflex?
when a muscle over contracts, tendon starts to get stretched, so this reflex relaxes muscle - prevents muscle from contracting extensively and preventing injury of tendon
what are the receptors for golgi tendon reflex?
golgi tendon organ
steps of golgi tendon reflex arc
- stimulus muscle contraction increases tension on tendons
- receptor - golgi tendon organ
- stimulates sensory nerve (femoral) that travel to CNS spinal cord L1-L4
sensory neurons synapse with interneurons - motor nerve - femoral interneurons inhibit motor neurons to muscle
interneurons stimulate motor neurons to antagonistic muscles - muscle relaxes and there is relief of tension on tendon
antagonistic muscle contracts, more relief of tension on tendon
withdrawal reflex
quick contraction of flexor muscles resulting in withdrawal of a limb from an injurious stimulus
to prevent further harm to the limb
crossed extensor reflex
occurs in conjunction with withdrawal reflex
when withdrawal reflex is occurring in one limb, crossed extensor reflex occurs in the other limb
helps maintain body balance
visceral reflex
unconscious, automatic, stereotyped responses of visceral organs to stimulation of visceral receptors
examples of visceral reflexes
baroreflex
pupillary reflex
micturition reflex
baroreflex arc
- stimulus - high blood pressure
- receptor - barorectpros in blood vessels - also located in aortic body
- sensory nerve - CN IX or X - glssopharyngeal nerve sensory branch (because mixed)
- integration center - medulla oblongata
- motor nerve - visceral motor nerve (don’t need to say parasympathetic, because they are the only ones that come from head) CN X motor branch of vagus nerve
- effector - heart
- action - decreases heart rate and contraction force
baroreflex arc for low blood pressure
low blood pressure
baroreceptors in blood vessels or aortic body
sensory nerve IX
integration center medulla oblongata
sympathetic nerve from T1-L2
increase heart rate and increase contraction force
Micturation reflex arc
- stimulus - half full bladder
- receptor - stretch receptors in urinary bladder
- sensory nerve - visceral sensory nerve
- integration center - spinal cord S2-S4
- motor nerve - parasympathetic nerve
- effector - smooth muscle of urinary bladder
- response - contraction of smooth muscle - pee comes out
pupillary reflex arc
- stimulus - light
- receptor - retina - rods and cones
- sensory nerve - CN II optic nerve
- integration center - occipital lobe of brain
- motor nerve - CN III occulomotor nerve - parasympathetic branch of occulomotor nerve
- effector - pupilary contstrictor
- response - decrease size of pupil to prevent light from damaging retina
reflex arc of achilles tendon
- stimulus tap on achilles tendon
- receptor - muscle spindle of gastrocnemius and soles
- sensory nerve - tibial nerve
- integration center - spinal cord L1-S4
- motor nerve - tibial nerve
- effector - gastrocnemius and soleus
- response - plantar flexion
reflex arc of bicep
- stimulation - tap on biceps brachia
- receptor - muscle spindle in biceps brachii
- sensory nerve - musculocutanious nerve
- integration center - spinal cord C5-C11, primarily C5-C6
- Motor nerve - musculocutaneous nerve
- effector - biceps brachii
- response - elbow flex
