Principles - Anatomy 07 - Muscle Movement Flashcards
Name the 3 different types of muscle.
Skeletal, Smooth, Cardiac
Fibres commonly found within skeletal muscles are…
myofibrils
Why do striations appear when skeletal muscle is viewed through a microscope?
Due to the overlapping of actin and myosin
State the 5 types of skeletal muscle.
Flat with aponeurosis, fusiform, circular, pennate, quadrate
What is meant by a muscle strain?
Fibres become torn
Explain what a fusiform muscle looks like.
Thinner at each end and fatter in the middle
State an example of fusiform muscle.
Biceps brachii
State an example of a circular muscle.
orbicularis oculi (eye socket)
Explain the shape of a pennate muscle
Feather-like
Give an example of a pennate muscle
deltoid
Explain the shape of a quadrate muscle.
Square
Give an example of a quadrate muscle.
rectus abdominus
What does a flat muscle with aponeurosis look like?
Fibrous sheet in place of tendons/ligaments
Give an example of a flat muscle with aponeurosis
External oblique
What is meant by the origin of a muscle?
The most proximal point at which it attaches to bone
What is meant by the insertion of a muscle?
The most distal point at which it attaches to bone.
Tendons are found…
at the end of muscles
Aponeuroses attach via…
soft tissue
The direction in which a joint can move depends on…
The position of attachment of the muscle to the bone
When the muscle spans the joint anteriorly, this results in…
Flexion
When the muscle spans the joint posteriorly, this results in…
Extension
Where is the proximal radioulnar joint located?
Just below the elbow
From where to where does the deltoid muscle span?
Scapula to humerous
The posterior fibres of the deltoid allow for…
extension
The anterior fibres of the deltoid allow for…
flexion
The middle fibres of the deltoid allow for…
abduction
Why can the shoulder circumduct?
Due to the shallow socket of the glenoid fossa of the scapula
What is the difference between a stretch reflex and a flexion withdrawal reflex?
Flexion withdrawal relfex occurs when we touch something potentially damaging but stretch reflex occurs when a muscle is stretched in order to protect it
Name the 4 different stretch reflexes.
Biceps, triceps, knee and ankle jerks
What is the difference between a tendon and aponeurosis?
Aponeurosis is a flattened tendon and attaches to soft tissue whereas tendons attach muscle to bone.
Explain the route taken by deep tendon and stretch reflex pathways.
Sensory neuron, motor neuron in spinal cord, motor neuron
A muscle could be termed paralysed if…
motor neuron supply not working, muscle cannot contract, reduced muscle tone
Spasticity of a muscle involves…
Constant contraction of the muscle, increased muscle tone - motor neuron still in tact but descending signals from the brain not working
Explain what happens during atrophy.
Muscles waste due to inactivity - myocytes reduce in size
Explain what happens during hypertrophy.
Myocytes enlarge to develop larger skeletal muscles
Where are skeletal muscles found?
Deep fascia
What separates skeletal muscles into different compartments?
Intermuscular septum
Give an advantage of muscle compartments.
Means that inflammation is contained within that area
What is meant by compartment syndrome and how may it be resolved in severe cases?
Pressure build up in muscle compartments due to swelling or bleeding. Relived by fasciotomy
Where roughly in the body is skeletal muscle found?
Above top 1/3 of trachea and below pelvis & perineum
How many muscle compartments are found in the thigh?
3
How many muscle compartments are found in the leg?
3
How many muscle compartments are found in the arm?
2
How many muscle compartments are found in the forearm?
2
