The PNS Flashcards
Where does the PNS emerge from?
the CNS
Where do cranial nerves emerge from?
the brainstem
Where do spinal nerves emerge from?
the spinal cord
What nerves use Roman numerals?
cranial nerves
What nerves use Arabic numerals?
spinal nerves
What nerves take messages from the brain?
Efferent
What nerves take messages to the brain?
Afferent
What 3 structures of the brain are cranial nerves found in?
- Midbrain
- Pons
- Medulla
Cranial nerve I
Olfactory
Cranial nerve II
Optic
Cranial nerve III
Oculomotor
Cranial nerve IV
Trochlear
Cranial nerve V
Trigeminal
Cranial nerve VI
Abducens
Cranial nerve VII
Facial
Cranial nerve VIII
Vestibulocochlear
Cranial nerve IX
Glossopharyngeal
Cranial nerve X
Vagus
Cranial nerve XI
(Spinal) Accessory
Cranial nerve XII
Hypoglossal
What is the function of the olfactory nerve?
smell
What is the function of the optic nerve?
vision
What is the function of the oculomotor nerve?
- eye movement
- pupil dilation
What is the function of the trochlear nerve?
eye movement (oblique)
What is the function of the trigeminal nerve?
- face/head (somatosensory)
- chewing
What is the function of the abducens nerve?
eye movement (lateral)
What is the function of the facial nerve?
- taste/ear (somatosensory)
- facial expressions
What is the function of the vestibulocochlear nerve?
- hearing
- balance
What is the function of the glossopharyngeal nerve?
- taste
- tongue (somatosensory)
- swallowing
What is the function of the vagus nerve?
- larynx
- velum
- viscera
What is the function of the accessory nerve?
head movement
What is the function of the hypoglossal nerve?
tongue movement
What cranial nerves are not for speech?
- Olfactory
- Optic
- Oculomotor
- Trochlear
- Abducens
- Vestibulocochlear
What cranial nerves are for speech?
- Trigeminal
- Facial
- Glossopharyngeal
- Vagus
- Accessory
- Hypoglossal
What does the trigeminal nerve control anatomically?
jaw
What does the facial nerve control anatomically?
- Face
- lips
What does the glossopharyngeal nerve control anatomically?
- pharynx muscles
- tongue muscles
What does the vagus nerve control anatomically?
- Velar muscle
- pharyngeal muscle
- Larynx
What does the accessory nerve control anatomically?
Sternocleidomastoid muscle
What does the hypoglossal nerve control anatomically?
Tongue
Where does the trigeminal nerve emerge from?
Pons (middle of brainstem)
How many branches does the trigeminal nerve divide into?
3
What are the sensory branchs called?
- Ophthalmic nerve branch
- Maxillary nerve branch
What is the sensory/motor branch called?
Mandibular nerve branch
What nerve branch is responsible for the jaw?
Mandibular nerve branch
Where does the facial nerve emerge from?
Between pons and medulla oblongata
Is the facial nerve motor or sensory?
Both (more motor)
What does the facial nerve control?
- facial expressions
- lips (opening, closing, rounding)
- tastebuds
Where does the glossopharyngeal nerve emerge from?
Medulla oblongata (anterior to vagus nerve)
Where does the glossopharyngeal nerve innervate?
pharyngeal muscles
What does the glossopharyngeal muscle control?
- pharynx
- tongue
Which 2 nerves do the heavy lifting when it comes to speech?
- Vagus nerve
- Hypoglossal nerve
Where does the vagus nerve emerge from?
Medulla oblongata (posterior to glossopharyngeal nerve)
What are the 3 major branches of the vagus nerve?
- Recurrent laryngeal nerve
- Superior laryngeal nerve
- Pharyngeal branch
Where does the superior laryngeal nerve branch out to?
- larynx
What does the superior laryngeal nerve control?
- pitch
What does the pharyngeal branch control?
- pharynx
- velum
What takes much shorter to heal than a cut nerve?
broken bone
What struggles to get through the nerve if it is damaged?
signal
What is the pathway of the recurrent laryngeal nerve?
- drops into the chest cavity
- loops around major blood vessels
- rises to larynx
What is a plexus?
network of nerves that physically communicate with other nerves
What is the pharyngeal plexus formed by?
- Pharyngeal and external laryngeal branches of the vagus nerve
- Pharyngeal branches from the glossopharyngeal nerve
What does the pharyngeal plexus innervate?
- palate
- pharynx
What muscle makes a triangle from sternum to collar bone, to mastoid process?
Accessory nerve
What nerve is used for head-turning & respiration?
Accessory nerve
Where does the accessory nerve originate?
neurons in upper spinal cord
What is the only CN that begins outside the skull?
Accessory nerve
What nerve innervates the sternocleidomastoid muscle?
Accessory nerve
Where does the hypoglossal nerve emerge from?
- medulla oblongata
- spinal nerves C1-C3
What does the hypoglossal nerve innervate?
most of the tongue
Where do spinal nerves emerge from?
Between vertebrae
What vertebrae are spinal nerves named according to?
ertebra BELOW
How many cervical nerves are there?
C1-C8
How many thoracic nerves are there?
T1-T12
How many lumbar nerves are there?
L1-L5
Where does the C1 nerve emerge?
below skull
Where do C2-C8 nerves emerge?
below cervical vertebrae C1-C7
What nerves join to form 1 nerve?
C3-C5
What nerves are muscles for respiration innervated by?
Cervical nerves
What thoracic nerves insert into the intercostal muscles?
T1-T11
What thoracic nerves insert into the abdominal muscles?
T7-T12
What muscles do the thoracic nerves control?
Breathing muscles
What nerve do C3-C5 nerves form?
phrenic nerve
What muscle does the phrenic nerve innervate?
the diaphragm
What are the 2 types of roots that emerge from the spinal cord?
- dorsal
- ventral
Dorsal roots are ___.
afferent (sensory)
Ventral roots are ___.
efferent (motor)
What does the muscle tissue cause?
movement
What is muscle tissue designed to do?
shorten
What does the matrix do for the muscle?
makes the muscle more flexible, but with degree of stiffness
What does the matrix consist of?
- collagen (stiffness)
- elastin (elasticity)
What are the 3 types of muscle tissue?
- Cardiac
- Skeletal
- Smooth
What is the cardiac tissue attached to?
the heart
What is the skeletal tissue attached to?
the skeleton
What is the smooth tissue attached to?
the hollow viscera
What muscle tissue types are involuntary?
- Cardiac
- Smooth
What muscle tissue types are voluntary?
Skeletal
What muscle tissue type is related to speech?
Skeletal (striated)
Skeletal (striated) muscles have the configuration of ___ within ___.
bundles within bundles
What are muscles made up of?
Muscle bundles (muscle fascicles)
What are muscle bundles made up of?
Muscle Fibres
What level of the muscle attaches to the nerves?
Muscle Fibres
A single nerve will attach to ___ muscle fibres.
Multiple
What is a motor unit?
A nerve and all the muscle fibres it attaches to
What is the size of the muscle with many muscle fibres (100 +) attached to a single neuron?
Big
What muscles have few muscle fibres ( < 10) attached to a single neuron?
Fine motor muscles
What are muscle fibres made up of?
Myofibrils
What are myofibrils made up of?
Sarcomeres (chuncks) of myofilaments
What type of muscles is responsible for speech?
Fine control muscles
Why are skeletal muscles called striated muscles?
Because they have light and dark stripes
What does the nerve affect when it attaches to the muscle fibres?
Myofibrils
What are the 2 types of myofilaments (proteins)?
- Actin filaments (thin/strong)
- Myosin filaments (thick/flexible)
What are the 2 types of lines in a sacromere?
- Z lines
- M lines
Where are the Z lines located?
at either end of the sarcomere
What do Z lines exert during
contraction?
tension
What attaches to Z lines?
Actin
What do Z lines link?
Sacromeres
Where is M line located?
In the middle of the sarcomere
What attaches to Z lines?
Myosin
At what level of the muscle does the contraction occur?
Myofibrils
Do all muscle fibres contract?
No
What does the number of muscle fibres involved in a contraction depend on?
- needed force
- needed period of time
The more muscle fibres recruited by the CNS, the ___ the force generated by the muscular contraction.
Stronger
What synapses with muscle fibres?
Nerve bouton
What is the function of nerve boutons?
- Releases neurotransmitter
- Triggers release of calcium ion
- Affects myofilaments
How do the release of calcium ions affect myofilaments?
Trigger a chemical reaction by inhibiting the proteins that stop actin and myosin from interacting
What makes the bridging arms of myosin filaments get sticky, stick onto actin & pull?
A chemical reaction
What is a muscle contraction?
Muscles sliding into each other down the length of the fibre
What filament has bridging arms?
myosin
Are myosin & actin in contact when muscles are not contracting? Why?
No, because of proteins in sarcomere
What do muscles use for muscle contraction?
adenosine triphosphate (ATP)
Where does adenosine triphosphate (ATP) live?
inside cells
Where does adenosine triphosphate (ATP) carry/store energy?
in phosphate bonds
When is the energy released from phosphate bonds?
When bonds are broken
How fast does the cell need to make new ATP?
As soon as the old stuff is used
What is muscle fatigue?
ATP is depleted & contraction can’t occur
What are the 2 ways bodies make ATP?
- anaerobic (no oxygen needed)
- aerobic (oxygen needed)
Training muscles ___ the sources of ATP.
increases
What gets pulled out to maximum resting length when you stretch?
sarcomere
What places additional force on connective tissue?
additional stretching
Why is connective tissue not as stretchy?
higher collagen content
As the tension increases, what fibres align along the same force line as the tension?
Collagen fibres
What does the length of the entire muscle depend upon?
The number of stretched fibres
What does the strength of a contracting muscle depends on?
Number of recruited fibres contracting
More muscle fibres stretched = ___ ___ of the stretched muscle.
greater length
What is the reflex arc?
A bodily system in place to protect muscles from lengthening or contracting too much
What allows for a faster, “automatic” response (reflex)?
Sensory neurons that synapse in the spinal cord (not on the brain)
What allows for a faster, “automatic” response (reflex)?
Sensory neurons that synapse in the spinal cord (not pass on the brain, but)
What are 2 things that trigger reflexes?
- muscle spindles (stretch receptors)
- Golgi tendon organs
What are the primary proprioceptors in the muscle?
Muscle spindles
What do muscle spindles send info about?
- muscle length
- motion
- position
What are muscle spindles sensitive to?
- length
- rate of change
When the muscle is being stretched, why is there an automatic response (reflex) to contract the muscle?
to protect it from being overstretched and torn
What does the automatic response (reflex) to contract the muscle involve?
- triggering contraction (stretch reflex)
- inhibition of antagonist muscle
What are proprioceptors?
sensory receptors that receives stimuli from within the body and send messages back to the brain about where the body is and what it’s doing
Where are muscle spindles located?
in muscle belly
Where can muscle spindles run a reflex arch?
Into CNS (spine);
What will a reflex arch into CNS (spine) cause?
Even more contraction
What are Golgi tendon organs?
proprioceptors
Where are Golgi tendon organs located?
in tendon near end of muscle fiber
What do Golgi* tendon organs respond to?
tension in the muscle/tendon unit
What do Golgi* tendon organs do if there is too much tension? Why?
Send a signal to your body telling it to inhibit the muscle to not damage it
What does the location of put them at risk of
