Wk6- The Musculoskeletal System

There are 3 muscle types. What are they ?

Skeletal muscle Skeletal muscle is numerous in the human body and supports posture and positioning. Movement is via - and relaxation Movement is - Muscle fibres are - and cylindrical

Smooth muscle Smooth muscle is widely distributed in the body. Is found within - and vessels Smooth muscle fibres are s? shaped Movement is made by - contractions Smooth muscle is found within the circulatory, respiratory, digestive and reproductive systems

Cardiac muscle Cardiac muscle pumps blood around the body. Cardiac muscle is made of - branching fibres Contraction is -

Skeletal muscle organisation There are 3 layers of skeletal muscle 1.Epimysium: is the most - layer. It surrounds the muscle and consists of c? fibres 2.Perimysium: is the - layer. It surrounds each muscle fibre bundle -? It consists of c? fibres blood vessels and nerves 3.Endomysium: is the most - layer. It surrounds individual muscle fibres. It contains ca? satellite cells and nerve fibres.

Fascicle pattern and muscle shape: Muscle shapes are based on fascicle patterns A fascicle is a - of muscle fibres. There are 6 patterns 1.P- 4.C- 2.C- 5.S- 3.P- 6.F

Muscle shapes and fascicle patterns: Parallel: along the same - Convergent: broad to narrow p- Pennate: shape like - pasta. On a - axis for high tension areas Circular: sphincter c?/ p? and relax Spiral: suppernate/ - Fusiform: s? shaped and pinched at the ends

Structure of muscle fibres : Skeletal muscle consists of bundles of myo? consisting of repeated units called sarco? Myofibrils = Contain contractile protein fibres myo? Thin filament = A? Thick filament = M? Surrounded by sarcoplasmic reticulum and ? tubules Arranged into sections called s?

Levers class type: There are 3 classes 1. First- (basketball) f- between f- and r- 2. Second- (tip toes) r- between f- and f- 3. Third- (fishing) f- between f- and r-

The 4 Functional groups: • Agonist: - force • Antagonist: - force ,relaxation • Synergist: helps - add force • Fixator: - joint area

Joints / articulations There are 3 types of joints 1. F- Strongest 2. C- 3.S- Weakest

Fibrous Joints Bones are held by dense - tissue Im? strong joints Types of Fibrous joints: 1. S? = coronal suture (skull bones) dense regular collagen connective tissue 2. Gomphosis = osseous pocket and periodontal ligament 3. Syndesmosis = radius and ulna held by dense regular collagenous connective tissue

Cartilaginous joints Bones are held together by ? There is some degree of m? The s? is limited Types of cartilaginous joints: Synchondroses= epiphyseal plate between the diaphysis and epiphysis in bone. Sympheses= intervertebral joint = intervertebral disc and vertebrae *(further examples=pubic symphysis or joints between ribs and cartilage)

Synovial joints A w? range of movement - of all the 3 Synovial fluid - and protects Synovial cavity present Example of Synovial joint: Articular capsule bridging between femur and tibia/fibula. Articular capsule = fibrous outer layer, articular cartilage, synovial membrane and synovial fluid.

Major muscles Shoulder: D- Arm: B- brachii T- brachii B

Major muscles: Thorax and abdomen Pectoralis m- Inter- R- abdominus External O-

Major muscles Neck and back: T- Lat- dorsi Hip: Gluteus m G- maximus

Major muscles Thigh: Q- (Front) H- (Rear) Calf: Sol- Gastroc-

Activation of skeletal muscle: Action potential is generated in a m? neuron Signal is transferred across sy? to muscle at neuromuscular junction ACh (Acetyl?) causes de? of muscle fibre down the sar? and T ? De? occurs by ion channels opening and -a+ enters the muscle fibre. In turn this = causes release of -a++ within Myofibril. A? and m? fibres bind and ?