1. Muscles and Movement
IB Biology

2. 11.2.1
State the role of bones, ligaments, muscles, tendons and nerves in human movement.

4. Joints
Also called articulations or arthrosis
Two or more bones contact each other
Provide mobility
Determine the type or range of motion of a particular area of the body

5. Bones Are organs Provide a framework to support the body
Protection of soft tissue and organs
Act as levers for body movement
Form blood cells in the bone marrow
Allow storage of minerals – calcium and phosphorus
Bone to bone connection by ligaments
Strengthen joint
Provide stability

6. Muscles and Tendons Tendons – cords of dense connective tissue
Connect muscles to bone
Muscles – provide force for movement by shortening the length of their fibers (cells)
Muscles only move by contracting fibers
Most muscles occur as antagonistic pairs

7. Nerves Sensory nerve endings housed in ligaments
Allow for monitoring of the position of the joints
Help prevent over-extension of the joint and it parts

8. 11.2.2
Label a diagram of the human elbow joint, including cartilage, synovial fluid, joint capsule, named bones and antagonistic muscles (biceps and triceps).

9. Hinge joints
Works like a door

11. 11.2.3
Outline the functions of the structures in the human elbow joint named in

12. Joint Part
Function
Cartilage
Reduces friction & absorbs compression
Synovial fluid
Lubricates to reduce friction & provides nutrients to the cells of the cartilage
Joint capsule
Surrounds the joint, encloses the synovial cavity, & unites the connecting bones
Tendons
Attach muscle to bone
Ligaments
Connect bone to bone
Biceps muscle
Contracts to bring about flexions of the arm (reduce an angle)
Triceps muscle
Contracts to cause extension of the arm (increase an angle)
Humerus
Acts as a lever that allows anchorage of the muscles of the elbow
Radius
Acts as a lever for the biceps muscle
Ulna
Acts as a lever for the triceps muscle

13.
Compare the movements of the hip joint and the knee joint

14. Ball and Socket Joints The hip is ball and socket joint
Permits movement in several directions, including rotational movement
Head of femur (ball) fits into acetabulum (depression) of the hip

17. Hinge Joints
Provides an opening-and-closing type of movement like the action of a door

19. Comparing hip & knee joints
Hip Joint
Knee Joint
Freely moveable
Angular motions in many directions and rotational movements
Angular motion in one direction
Motions possible are flexion, extension, abduction, adduction, circumduction, and rotation
Motions possible are flexion and extension
Ball-like structure fits into a cup-like depression
Covex surfac fits into a concave surface

20. 11.2.5
Describe the structure of striated muscle fibres, including the myofibrils with light and dark bands, mitochondria, the sarcoplasmic reticulum, nuclei and the sarcolemma.

21. Muscle
3 types
Striated (skeletal)
Cardiac
Smooth (non-striated)

22. Striated (Skeletal Muscle)

23. Sarcomere

24. The Sarcomere

25. 11.2.6
Draw and label a diagram to show the structure of a sarcomere including Z lines, actin filaments, myosin filaments with heads, and the resultant light and dark bands.

27. 11.2.7
Explain how skeletal muscle contracts, including the release of a=calcium ions from the sarcoplasmic reticulum, the formation of cross-bridges, the sliding of actin and myosin filaments, and the use of ATP to break cross-bridges and re-set myosin heads.

29. 11.2.8
Analyse electron micrographs to find the state of contraction of muscle fibres.

30. Electron micrograph showing contraction of one sarcomere