Muscles and Nerves Flashcards
What are muscles that attach both to the axial and appendicular skeleton?
Appendicular muscles
How does muscle attach to bone?
Muscle attaches to bone by a tendon
What is the origin of a muscle?
The origin of a muscle is the proximal/supperior/medial attachment
What is the insertion of a muscle?
The insertion of a muscle is the distal/inferior/lateral attachment
At the bone, where are the fibres of a tendon embedded?
The fibres of a tendon at a bone are embedded within the periosteum
What is an aponeurosis?
An aponeurosis is the flat, thin and broad tendons of the abdominal oblique muscles
What happens when triceps contract?
When triceps contract they pull the elbow back (extends the joint)
What are diaphagm skeletal muscles?
Diaphagm skeletal muscles are ones which attach bones from either side of the midline of the sagittal plane
What is the purpose of the diaphragm?
The purpose of the diaphragm is to increase volume of the tharacic cavity during inspiration, descending on contraction and ascending on relaxation
What happens when the muscle fibres of the central tendon contract?
When the muscle fibres of the central tendon contracts the dome descends
What direction does the dome move on contraction?
The dome moves inferior on contraction
Why can muscles such as the deltoid perform many movements on the joint?
They have many fibres (anterior, middle and posterior) that can pull the shoulder joint in different directions
What is an antagonistic pair?
Antagonistic pairs are muscles that combine in an antagonistic way to carry out a particular action on a joint
What muscles are responsible for the arm flexing?
Anterior arm and forearm muscles are responsible for the arm flexing
What groups of muscles relax as you flex your elbow?
Posterior muscles relax as you flex your elbow
What is the agonist muscle?
The agonist muscle is the one that produces the motion
What is the antagonist muscle?
The antagonist muscle is the one that opposes the action
What is a synergist?
A synergist assists the agonist by helping to perform the same set of joint movement
What is an example of stabalising muscles?
An example of stabalising muscles are the rotaror cuff muscles around the shoulder, they reduce the risk of dislocation
What does muscle testing allow?
Muscle testing allows the diagnosis of both muscle and nerve injuries by assesing the power of movement
What is muscle atrophy?
Muscle atrophy is the wasting of muscle tissue
What is an example of a muscle that crosses two joints and performs a different movement on each?
The hamstring is an example of a muscle that crosses two joints and performs a different movement on each
What can muscles be compartmentalised by?
Muscles can be compartmentalised by:
- Deep fiscial intermuscular septa which seperates them into compartments
- Common nerves supplying all the muscles in a compartment
- Common actions of the muscles in a compartment
What is A?
Intermuscular septum
What is B?
Skin
What is C?
Deep fascia
What is D?
Superficial fascia
What is E?
Intermuscular septum
What is F?
Posterior compartment
What is G?
Humerus
What is H?
Anterior compartment
What is a ligament?
A ligament joins a bone to an adjacent bone
Which of A and B is a ligament and tendon?
A is a ligament
B is a tendon
What is a plexus?
A plexus is a nerve network
What plexus are all arm and forearm compartments supplied by?
The brachial plexus supplies all arm and forearm comparments
What plexus are all thigh and leg muscles supplied by?
The lumbosacral plexus supplies all thigh and leg muscle compartments
What spinal roots supply the brachial plexus?
C5 - T1 supplies the brachial plexus
What spinal roots supply the lumbosacral plexus?
L1 - S4 supplys the lumbosacral plexus
What are muscles named according to?
Muscles are named according to:
- Direction of muscle fibres
- Location
- Size
- Number of origins
- Shape
- Action
- Attachments
What effect does muscles being at 90o to each other, such as the oblique muscles, have?
Being 90o to each other increases both strength and integrity
What is the name given to tendons that are flat and thin?
Aponeurosis tendons are ones which are flat and thin
What does ‘rectus’ mean?
Rectus means straight
What does ‘teres’ mean?
Teres means round
How are muscles arranged in a sphincter?
Muscles are arranged circularly and thickened around the wall of a structure in a sphincter
What are axial muscles innervated by?
Axial muscles are innervated by non-limb nerve plexus or segmentally (individual spinal cord nerves that do not network with others)
What imaging technique is the best for showing muscle?
MRI is the best for showing muscle
What is A?
Air filled space
What is B?
Bone
What is C?
Blood vessel
What is D?
Muscle
What kind of muscle is this?
Cardiac muscle
What kind of muscle is this?
Skeletal muscle
What kind of muscle is this?
Smooth muscle
What are properties of skeletal muscle
Skeletal muscle is:
Striated
Straight muscle fibres
Multinucleate
What are properties of cardiac muscle?
Cardiac muscle is:
Striated
Branched
Mononucleate
Intercalated disks
What are properties of smooth muscles?
Smooth muscles are:
Monomucleate
Not striated
What is the motor unit composed of?
The motor unit is composed of neurons and muscle fibres integrated together
What is the end of the nerves in a motor unit called?
The end of the nerves in a motor unit is called the motor end plate
Where do somatic sensory nerves emerge from the spinal cord from?
Somatic nerves emerge from the dorsal (posterior) nerve root
Where do somatic motor nerves emerge from the spinal cord from?
Somatic motor nerves emerge from ventral (anterior) nerve root
Where do motor and sensory nerves join after travelling through the dorsal and ventral nerve roots?
They join in the intervertebral foramen to form a mixed spinal nerve
How does the mixed spinal nerve branch after leaving the intervertebral foramen?
Branches into the dorsal and ventral ramus
What does the ventral ramus supply?
The ventral ramus supplies:
Skin
Muscles and bones of the anterolateral sides of the trunk
Upper and lower limbs
What does the dorsal ramus supply?
The dorsal ramus supplies the posterior side of the trunk
What kinds of nerves are in the ventral and dorsal ramus?
Both sensory and motor nerves are in the ventral and dorsal ramus
Which horn, of the dorsal and ventral, is wider?
The dorsal horn is wider
What is A?
Dorsal horns
What is B?
Dorsal root ganglion
What is C?
Sensory neuron
What is D?
Dorsal root
What is E?
Spinal nerve (mixed)
What is F?
Sensory receptors at back
What is G?
Skeletal muscles at back
What is H?
Dorsal ramus (mixed)
What is I?
Ventral ramus (mixed)
What is J?
Sensory receptors of limbs and trunk
What is K?
Skeletal muscles of limbs and trunk
That is L?
Ventral root
What is M?
Ventral horn motor neurons
What is N?
Ventral horns
What does the dorsal ramus do at each spinal (segmental) level?
At each spinal level the dorsal ramus segmentally innvervates the main muscle of the back (erector spinae muscle) and the skin overlaying it with sensory and motor fibres
How does the ventral ramus innvervate muscles?
The ventral ramus passes laterally and then anteriorly to segmentally innervate the muscles of the anterolateral tharacic and abdominal walls, and the skin overlaying the muscles
What are the ventral rami that supply the muscles between the ribs known as?
The ventral rami supplys muscles that supplys the muscles between the ribs (intercostal muscles) are known as intercostal nerves
Where does each intercostal rami lie?
Each intercostal nerve lies below the rib of the same number, ie, intercostal nerve 7 lies below rib 7 (intercostal space 7)
How many intercostal nerves are there?
There are 12 ribs so there are 12 intercostal nerves
What do the lower intercostal nerves also supply (T7 - T12)?
The lower intercostal nerves also supply the muscles of the anterior abdominal wall
What is a cutaneous nerve?
A cutaneous nerve is a branch of the brachial plexus that supplies the skin overplaying the muscle, containing fibres from various spinal levels
What are dermatones?
Dermatones are innervated by nerves from a single spinal level
The joined up strip of skin supplied by fibres coming from only one single spinal nerve
What joint occurs in the midline of the trunk at dermatome T2?
The sterno is at T2
What surface feature of the body is found at dermatome T4?
The nipples are found at dermatome T4
What surface feature of the body is found at dermatome T10?
The belly button is found at dermatome T10
In what region of the body is dermatome L1 found?
Dermatome L1 is found in the inguinal region
What do dermatomes C5 - T1 supply?
Dermatomes C5 - T1 supplies the upper limbs
What are the layers surrounding the myeline sheath?
Myeline sheath is surrounded by endoneurium, forming fascicles (bundles of fibres) surrounded by perineurium, forming fascicles surrounded by epineurium
What is A?
Spinal nerve
What is B?
Epineurium
What is C?
Axon
What is D?
Fasciculus
What is E?
Perineurium
What is F?
Endoneurium
What is G?
Blood vessels
What surrounds individual axons?
Endoneurium and a dissolved myelin sheath surrounds individual axons
What surrounds nerve fascicles?
Blood vessels and perineurium surrounds nerve fascicles
What surrounds a nerve?
Epineurium surrounds a nerve
What is the function of the aponeurosis?
Join muscles and the body parts that they act on
Transfer force and absorb energy
