Muscles & Movements Flashcards
What are the 3 types of muscle found in the body?
- Cardiac 2. Smooth 3. Skeletal
Out of the 3 types of muscle stated, which one is voluntary? Which type is non- striated, while the others are striated?
Skeletal
Smooth muscle
Skeletal msucles contain many muscle _, which are further divided into _ , which contain _ and _
Fibres
Myofibrils
Actin & Myosin
What happens to the muscle fibres when a seletal muscle is strained?
They are torn.
The more fibres torn, the worse the strain
What are the types of skeletal muscle? (5) Give an example of each type.
- Circular- orbicularis oculi
- Pennate- deltoid
- Quadrate- rectus abdominus (abs)
- Flat with aponeurosis- external oblique
- Fusiform- biceps brachii
Skeletal muscles have to cross the joint and attach to bones on the other side in order to move it. T/F?
True
Muscles extend during contraction. T/F?
False- shorten
Muscles attach to bone via _ .
Tendons
Tendons have contractile properties. T/F?
False- non contractile
Define an aponeurosis.
Flattened tendon- commonly associated with flat muscles.
They attach muscle to soft tissue rather than bone.
What are the two attachments of a skeletal muscle called?
- Origin
- Insertion
Only thing skeletal muscle can do is shorten during contraction, shortening the long axis between the origina and the insertion
Direction of movement of a muscle depends on what?
Side of the joint the muscle spans.
Eg bicep brachii- spans over anterior surface of shoulder joint- flexes shoulder joint
Also spans anterior elbow joint- flexes elbow joint.
Where are the 3 origins of the deltoid found?
- Spine of scapula
- Acromion process of scapula
- Lateral 1/3rd of clavicle
At which point is the insertion of the deltoid found?
Deltoid tuberosity of humerus
What are the movements produced by the posterior, middle and anterior fibres of the deltoid?
Posterior- Extension of shoulder
Middle- Abduction of shoulder
Anterior- Flexion of shoulder
The deltoid muscle only crosses one joint – the shoulder joint, however it can cause different movements at that joint as it has muscle fibres in different orientations.
The _ of the articular surface determines the extent of possible movement.
Shape
Eg Shallow socket- cicrumduction movement
Trochlea of the distal humerus- only flexion/extension
Reflexes are rapid, involuntary responses that serve a _ function
Protective
What are the two main reflexes involving skeletal muscles?
- Stretch reflex
- Flexion withdrawal reflex- when we touch something potentially dangerous, a sudden Flexion to withdraw from the danger (eg hot plate)
The brain is involved in reflexes. T/F?
False- Nerve connections at spinal cord level
Stretch reflex is also known as deep _ reflex. Describe this reflex.
Tendon- eg Patellar tendon
A brief sudden stretch is applied to the muscle via its tendon. This causes a contraction of the muscle- resulting in a brief twitch of the muscle belly or a movement in the normal direciton.
Reflexes are protective against over-stretching
Describe the communications between the spinal cord and the deep tendon during reflex action.
•Sensory nerve from muscle detects the stretch & tells the spinal cord
•
•Synapse (communication) in the spinal cord between the sensory & motor nerves
•
•Motor nerve from spinal cord passes message to muscle to contract
Whole route taken by the AP’s is called the reflec arc
Define muscle paralysis.
Muscle wihtout a functioning motor nerve supply
Define muscle spasticity.
Muscle has functioning motor nerve, but descending controls from the brain are not working
What are the examinational differences in muscle tone between muscle paralysis and spasticity?
Paralysis- reduced tone
Spasticity- increased tone
Define atrophy.
Wasting of muscle- develops as a result of inactivity
Myocytes become smaller
The opposite to muscle atrophy is _
Hypertrophy - each individual myocyte enlarges
Skeletal muscle are usally found in deep fascia, which have a tough fibrous _ _ covering
Connective tissue
Lower limb muscle have _ muscle compartments.
3- Anterior, middle, posterior
The thigh and the leg are _ and _ compartments of the lower limb
Middle and lateral
The arm and forearm both have_ number of muscle compartments.
2- Anterior & posterior
What is compartment syndrome?
Fascia creates enclosed space. Increased pressure due to swelling of tissue or increased fluid- Affects the muscle and nerves of that compartment.
Fasciotomy is needed in an acute presentation to relieve pressure
