Intro to myology & Nervous system Flashcards
What are the three types of muscle tissue
striated muscle tissue
smooth muscle tissue
cardiac muscle tissue
Describe striated muscle tissue
Maintain bodys posture
attached to bone at both ends
dense packed groups of myofibers (myofibrils>myofilaments>myosin + actin)
innervated by peripheral or cranial nerves
contractions produce body movement
conscious control (usually)
Describe smooth muscle
found in organs of body (walls of tubes- gut blood vessl, resp tract) made up of single tapering cells controled by the autonomic motor nerves not consciously controlled
describe cardiac muscle
found in wall of heart
made of short interlinked fibers
rhythmic movement
controlled by autonomic nerves
What is happening when a muscle is relaxed
myosin and actin filaments are arranged in sarcomeres
Myosin heads are ‘energized’ but not ready for action
no interaction between actin and myosin
What happens when a muscle contraction signal is sent
Nerve impulses trigger the interaction of actin and myosin “to contract muscle”
What happens when a muscle is contracted
The ‘heads’ of each myosin filament interact with the actin filament which make the myofibril shorten and contract
What is skeletal muscle composed of
Skeletal muscle is composed of fibers
that combine into fascicles
Endomysium, Perimysium and
Epimysium are connective tissues
What is the ORIGIN
Attachment of a muscle to a stationary part of the body
What is INSERTION
Attachment of a muscle to a moving part of the body
What is a TENDON
Dense connective tissue that attaches muscle to bone
What is the MUSCLE BELLY
contractile part of a muscle
what is a unipennate muscle
diagonal insertion of fibers on tendon
Examples include the Lumbricals (deep hand muscles) and Extensor Digitorum Longus (wrist and finger extensor)
What is a bipennate muscle
Two rows of muscle fibers facing opposite and diagonal to a central tendon (feather)
Example: rectus femoris
What is a multipennate muscle
multiple rows of diagonal fibres, with a central tendon which branches into two or more tendons. Example Deltoid
What shape are fusiform muscle
spindle shaped (muscle belly wider that O and I) ex Biceps
What are circular muscles
spincter muscles
What is an agonist muscle
prime movers that produce specific movement
what is an antagonist muscle
muscles that oppose action of agonist muscles
what is a synergist muscle
muscles that complement action of prime movers
What are the three classes of levers
- first class
- second class
- third class
What is a first class lever
The fulcrum at the center
effort and resistance equally distributed on each end
(ex head/neck)
What is a second class lever
Fulcrum is at one end, effort at the other, and resistance in the middle (opposing eachother) (ankle)
What is a third class lever
Fulcrum at one end, resistance at the other end and effort in the middle (elbow)
What are the two STRUCTURAL divisions of the nervous system
Central nervous system (CNS)
Peipheral nervous system (PNS)
What does the CNS control
brain and spinal cord
What does the PNS control
cranial and spinal nerves
What are the two FUNCTIONAL divisions of the nervous system
Somatic nervous system
autonomic nervous system
What is the Somatic nervous system
sensory and motor innervation to the body-soma
What is the autonomic nervous system
sympathetic and parasympathetic
How can the nervous system be described (in simple terms)
INPUT (sensory)–> PROCESSING (interneurons)—> OUTPUT (motor)
What is the input (sensory) action carried by
afferent neurons (ascending)(sensory)
What is the output (motor) action ccarried by
efferent neurons (motor) (descending)
How many pairs of spinal nerves are there
31
How many CERVICAL nerves
8
How many THORACIC nerves
12
How many LUMBAR nerves
5
How many SACRAL nerves
5
How many coccygeal
1
What is the path that a trigger will take
Sensory receptor -> sensory neuron -> integrating center -> motor neuron -> effector
What is inside a spinal nerve
Fasicles and blood vessels
What is inside the fascicle
nerve fibers
What is surrounding the fascicle
perineurium
What is surrounding the nerve
epineurrium
What is surrounding the axon
endomeurium
What is a nerve made up of
- dendrite
- body
- axon
- myelin/ schwan cells
Where are the origins of spinal nerves seen
on the surface of the spinal cord
What at the origins of spinal nerves on the spinal cord called
rootlets
Where are the motor rootlets
on the anterior aspect of the spinal cord
where are the sensory rootlets
on the posterior aspect of the spinal cord
Rootlets merge to form what
single motor root, single sensory root
Motor and sensory nerves unite to form what
spinal nerve
Where does the spinal nerve emerge
from the spinal canal through the intervertebral or sacral formina
What are the exceptions to the emerging of spinal nerves
C1- passes between atlas and occipital bone
S5 and Co1- exit through the sacral hiatus
Why do we have 31 pair of spinal nerves
the spinal cord is divided into 31 segments that each are responsible for the production of a pair of spinal nerves
Can nerve cells multiply?
No.
What is the only reparative process in nerves
re-growth of axon
What is the rate of growth of an axon
1mm/day
What four rami (branches) will spinal nerves divide into once passed through the intervertebral foramen
- anterior primary ramus
- posterior primary ramus
- communicating ramus
- recurrent (minigeal) ramus
What does the anterior primary ramus continue to?
Trunk and limbs.
brachian + lumbosacral plexuses
What does the posterior primary ramus continue to?
Posteriorly.
Medial- skin and facet jointsL
Lateral - paravertebral muscles
Whats does the communicating ramus continue to?
carries autonomic nervous system fibers (sympathetic)
What do recurrent rami do?
re-enter the spinal canal
supplies meninges, posterior longitudinal ligament of spinal column and annulus fibrosus of IV discs
What would an average practitioner be able to do to obtain relevant and valuable clinical information on nervous system
- muscle strength
- cutaneous sensation (dematomes)
- reflexes
If incomplete paralysis occurs, what chart would be helpful
Chart 0-5 with muscle contractility
5 On the muscle contractility chart
(Normal) complete range of motion against resistance as well against gravity
4 on the muscle contractility chart
(Good) complete range of motion against the gravity with some resistance
3 on the muscle contractility chart
( fair) complete range of motion against the gravity
2 on the muscle contractility chart
(poor) complete range of motion with the gravity eliminated
1 on the muscle contractility chart
(trace) evidence of slight muscle contractility
0 on the muscle contractility chart
(zero) no evidence of muscle contractility
How must muscle testing be done
Comparatively (Left to Right)
Repeatedly (for follow-up on improvement)
Repetitively (for fatigue)
What is a dermatome?
a portion of the skin which is innervated by a single spinal nerve and its dorsal root.
What is the corss-reference for the C5 dermatome
anterolateral arm and forearm
What is the cross reference for the C6 dermatome?
lateral aspect of arm, forearm, and thumb
What is the cross-reference for the C7 dermatome
posterior arm, forearm, index and middle finger
what is the cross-reference for C8 dermatome
medial arm, forearm and medial two fingers (anularis and minimus)
What is the cross-reference for the T1 dermatome
anteromedial arm, forearm and armpit, upper surface of chest
What is the cross-reference for T4 dermatome
nipple line
What is the cross-reference for T10 dermatome
skin over umbilicus
What is the cross-reference for L4 dermatome
inferolateral thigh
top of patella
medial leg
great toe
What is the cross-reference for L5 dermatome
lateral thigh anterolateral leg lateral surface of the great toe, digits 2, 3, 4, dorsum and heel of the foot
What is the cross-reference for the S1 dermatome
posterolateral thigh and leg
lateral aspect of foot and toe #5
What is the cross-reference for the S2 dermatome
posteriomedial thigh and lef
heel
portion of buttocks
Define hyperaesthesia
increase preception of a particular stimulus
Define hypoaesthesia
decrease sensation of a particular stimulus
define anasthesia
absent sensation
Define dysaesthesia
altered sensation (general)
Define paraesthesia
altered sensation (pins and needles)
How are reflexes tested
bilaterally
What is a reflex arc composed of
- receptor
- sensory
- interneurons
- motor
- effector cells
What is a receptor cell
muscle spindle which is located in the middle of a muscles belly
whats is a sensory cell
(afferent fibers) that bring information from the receptor into the spinal cord
What is an interneuron
integration or processing reflex centers
whats is a motor neuron
(efferent fibers) bring info from the spinal cord to the muscle
what is an effector cell
muscle fiber
What is the nerve for the biceps brachii muscle reflex
C5
whats is the nerve for the brachioradioalis muscle reflex
C6
What is the nerve for the triceps brachii muscle reflex
C7
What is the nerve for the qudriceps femoris muscle relfex
L4
What is the nerve for the tibialis posterior muscle reflex
L5
What is the nerve for the achilles tendon reflex
S1