Anatomy Flashcards
(389 cards)
Upper limb overview as a result of evolution
- Has almost no locomotor function
- Has a great degree of freedom of movement
- Used as a locomotor prop
- Is an organ for grasping and manipulating
Overview of the lower limb
- Supports the body weight
- Involved mainly in locomotion
- The bones are more robust
- Joints are more stable
What happens during week 4 of development?
Specialised cells migrate from the somites and the lateral plate mesoderm. Limb buds form where the arms and legs will develop.
Name the 3 muscle types
Smooth, cardiac and skeletal
Define origin
The proximal end of the muscle, which remains fixed during muscular contraction
Define insertion
Distal end of the muscle, which is movable
Simple explanation of muscle contraction
When muscles contract and shorten, they usually shorten in the direction of insertion to origin however some muscles can shorten in both directions.
Isometric contraction
Muscle tone changes
Isotonic contraction
Muscle length changes
Concentric contraction
Muscle contracts according to the sliding filament mechanism and shortens
Eccentric contaction
the muscle elongates while under tension due to an opposing force greater than the muscle generates - protect from injury
Prime mover
Muscle(s) that play the primary role in movement
Agonist
Muscle(s) that acts directly to produce a desired movement
Synergist muscles
Muscle(s) which prevent unwanted movements associated with the action of the prime movers
Antagonistic muscles
Muscle(s) which directly oppose a movement
Fixating muscles
Muscle(s) that provide the necessary support to assist in holding the rest of the body in place while the movement occurs
What is fascia?
Connective tissue - two types: deep and superficial
Superficial fascia
- Just beneath the skin
- Contains adipose tissue
- 2 layers
Deep (investing) fascia
- Ensheath muscles but continuous
- Facilitate contraction
- Barrier between muscles
- Compartments of muscles
- Passages for nerves and vessels
- Attachment for muscles
- Hold tendons in place (by forming retinaculae)
Compartment syndrome
An injury to the muscle within a tough compartment may cause swelling and increased pressure that compresses the neurovascular bundles
Compartments of the arm
Anterior (flexor) and posterior (extensor)
Compartments of the forearm
Antebrachial fascia separates anterior (flexor) and posterior (extensor) compartments
Why is the deep fascia of the lower limb thicker
Because we need the muscles to compress the veins during contraction for the venous blood to return to the heart
Name for deep fascia of the thigh
Fascia lata