The muscoskeletal system Flashcards
What is the axial skeleton?
The axial skeleton includes the bones of the skull, neck and the trunk
What is the appendicular skeleton?
The appendicular skeleton includes bones of the pectoral girdle, upper limbs, pelvic girdle and lower limbs
What two things make up the skeleton?
Bones and cartilage
Compare the bones in the upper and lower limbs
The upper limb has 1 long bone in the arm (humerous), 2 long bones in the forearm (radius and ulna), bones in the hand which is carpal bones in the wrist, metacarpals in the palm and phalanges in the fingers. Similarly, the lower limb has 1 long bond in the thigh (femur), 2 long bones in the leg (tibia and fibula), bones in the foot which is tarsals in the mid-foot, metatarsals in the forefoot and phalanges in the toes
When do bony features develop?
Bony features develop during bone growth
Explain the term functional in relation to bony features
Functional means the best shape for the job
Explain what is meant by an adjacent structure in relation to bony features
An adjacent structure is something like a tendon or another bone that applies force to a developing bone which helps to mould it’s shape. If an adjacent structure is developing at the same time as a bone, the bone has to grow around the other structure
What kind of tissue is bone made up of and what are some functions of bone?
Bone is made up of hard, connective tissue and some of it’s functions are:
- To provide support and protection
- Calcium metabolism
- Red blood cell formation
- Attachment for skeletal muscle
True or False - cartilage is more rigid than bone?
False - cartilage is less rigid than bone
Where is cartilage located in the body?
Cartilage is located in places where mobility is required such as at articulations (joints)
Name the 3 types of joints and rate them from most flexible to least flexible
- Synovial (most flexible)
- Cartilaginous
- Fibrous (least flexible) - e.g suture joints
True or false - If a joint has increased mobility, it will have increased stability
False - If a joint has increased mobility, it will have decreased stability and vice versa
Joints have excellent sensory nerve supply. Name the sensations which are detected by the sensory receptors of the joints
- Pain
- Touch
- Temperature
- Proprioception (body’s ability to perceive its own position in space)
True or False: Periarticular arterial anastomoses are uncommon
True
What can damage arteries supplying joints?
Dislocations can damage them which seriously compromises the blood flow distal to the joint
What are articular branches?
These are large named arteries near the joint which enable good arterial supply
Name 5 different skeletal muscle types and give an example of where to find each
- Circular (orbit of the eye)
- Fusiform (biceps brachii)
- Pennate (deltoid)
- Quadrate (rectus abdominus)
- Flat (external oblique)
Create a sentence describing the length of muscle fibres in relation to range of shortening and range of movement.
Longer muscle fibres have greater potential range of shortening and greater potential range of movement
What 5 things can you use in combination to help name skeletal muscles?
- Shape
- Location
- Size
- Main bony attachment
- Main movement
There are usually 2 points of attachment to bone, what are these called?
- Origin (on one side of joint)
2. Insertion (on other side of joint)
What is the only thing a skeletal muscle can do?
Contract (this moves the origin and insertion closer together and muscle fibres shorten along the long axis)
What usually attaches muscle to bone? Are these contractile or non-contractile?
Tendons - they are non-contractile
What is an aponeurosis?
An aponeurosis is a flattened tendon, it attaches muscle to soft tissue instead of bone
What does direction of movement depend on?
Direction of movement depends on which side of the joint the muscle spans. The shape of articular surface also determines possible movement (such as the ball and socket joint)
Reflexes can be…?
Reflexes can be automatic or protective
Name and explain the 2 main types of reflexes
- Flexions withdrawal reflex - This is a sudden reflex to withdraw from danger (e.g touching a hot iron, hand immediately pulls away). At spinal cord level but the brain is not involved in this reflex
- Stretch reflex - Normal response to being stretched is to contract (e.g knee jerk). At Spinal cord level but brain is involved
What does the stretch reflex test?
It tests:
- The muscle
- Sensory nerve fibres
- Motor nerve fibres
- Spinal cord connections
Explain the pathway of the deep tendon reflexes like the stretch reflex
The sensory nerve from the muscle detects a stretch and tells the spinal cord which goes to the synapse in the spinal cord between the sensory and motor nerves. The motor nerve from the spinal cord passes message to muscle to contract. The whole route taken by the action potentials is called the reflex arc. The brain is involved and prevents the reflex from being overly brisk
Explain paralysis
A muscle WITHOUT a functioning motor nerve supply is “paralysed”. A paralysed muscle CANNOT contract and on examination, the muscle would have REDUCED tone
Explain spasticity
This is when a muscle has an INTACT and FUNCTIONING motor nerve. The descending controls from the BRAIN are NOT working and on examination, the muscle would have INCREASED tone
What is the difference between reduced and increased muscle tone?
When someone has reduced muscle tone, they can have poor posture as their muscle are floppy. Whereas someone that has increased muscle tone means that their muscle are stiff and difficult to move
What is muscle atrophy?
This is the “wasting” of muscles as the muscle fibres become smaller reducing the muscle bulk. This develops as a result of inactivity such as:
- Immobilisation after a fracture
- Damage to motor nerve supply
- Being a “couch potato”
What is muscle hypertrophy and hyperplasia?
This is the opposite to muscle atrophy, so it is when the muscles enlarge but the number of cells don’t increase. Hyperplasia is an increase in the number of cells but each cell doesn’t actually get any bigger
