Muscle And Nerves Flashcards
What type of muscle is the rectus abominis
Strap muscle, separated by tendinitis intersections
What are the advantages of a bipenennate muscle as opposed to a strap or unipennate muscle
Increases in the number of muscle fibers that can be applied therefore increasing the power that can be generated
Deltoid is a good example of which type of muscle ? What actions does a deltoid have upon glenohumeral joint ?
Multipennate
Primary role is abduction but if the anterior fibers contract solely then flexion will occur and if only posterior fibers, extension will occur
What are the two functions of flat muscles, give an example
Produce movement of the skeleton and to enclose a cavity eg external oblique muscle
What is the main function of trapezius and what other actions does trapezius bring about if muscles fibers in certain area contracted alone
Retracts the scapula and upwardly rotates. If the upper fibers contract alone will elevate and upwardly rotate the scapula as well as extending the neck. Middle fibers retract the scapula, lower fibers will depress and upwardly roared the scapula
What type of muscle is often associated with walls of tubes such as blood vessels or part of the GI tract
Spincter
What is the function of the rotator cuff muscles
Stabilization of glenohumeral joint
What is the definition of an antagonist
A muscle which acts against the contraction of a prime mover
Muscles from which compartment brings about abduction of the wrist joint, what about abduction ?
For both abduction and addiction muscles in both extensor and flexor compartments contract.
Adduction: muscles on the ulnar side contract for abduction muscles on radial side contract
How many joints does biceps brachii cross, state it’s action over each joint
3
Shoulder - flexes
Elbow - flexes
Proximal radioulnar - supinates
What nerves has been damaged in the conditions “wrist drop” ? What muscle group has been affected
Radial nerve
Extensor group of muscles
What dermatome lies a lie the umbilicus
T9
What nerves form the brachial plexus and what does it supply
C5-T1
Muscles and skin of upper limbs
What nerves form the lumbar plexus and what does the lumbar plexus supply
L1-L4
Muscle and skin of lower limbs
How many cervical vertebrae are there and how many cervical nerves are there
7 vertebrae and 8 spinal nerves
How many thoracic vertebrae and thoracic nerves/lumbar vertebrae and lumbar nerves and sacral vertebrae and sacral nerves
12 thoracic v & 12 thoracic nerves
5 lumbar v & 5 lumbar nerves
5 sacral v & 5 sacral nerves
Do the spinal nerves exit above or below their associated vertebrae
For spinal nerves C1-C7 they exit above associated vertebrae eg spinal nerve C2 exits above vertebrae C2
C8 exits believe vertebrae C7
All other spinal nerves exit below their associated vertebrae eg spinal nerve T1 exits believe vertebrae T1
What dermatome supplies the tip of the thumb which peripheral nerve supplies the tip of the thumb? What is the root value of the peripheral nerve?
C6 dermatome
Median nerve
Median nerve root value is C6-T1
Explain why the dermatologist and root value of the peripheral nerve are not identical
While median nerves carries nerve fibers originating from C6 to T1, only C6 fibers (carried via the median nerve) supply sensory fibers to the tip of the thumb. The other fibers go elsewhere and do other things. Therefore traumatic damage to C6, will produce loss of sensation restricted to the C6 dermatome, while traumatic damage to median nerve distal to the brachial plexus will impact on some but not necessarily all the C6-T1 dermatomes, depending on the location of the injury.
What are the common examples of muscle shapes
Strap/parallel eg sartorius (anterior thigh)
Fusiform eg biceps brachii
Unioennate eg extensor digitorium longus
Bipennate eg rectus femoris
Multipennate eg deltoid
Flat eg external oblique
Circular eg orbicularis oris
Why do muscles have different shapes
Shape of muscle determines the degree of muscle contraction and the amount of force that can be generated within
An example where tendons go round a corner
Extensor hallucis longs - thin muscle extends from fibulae to big toe ( extends big toe)
Example of a flat tendon
Aponeurosis
Example of a muscle being away from point of function
Calf muscle responsible for plantar flex ion. Contraction of muscle results in translational force through the Achilles’ tendon