1. Topic 11.2
Muscles and Movement

2. 11.2.1 Role of bones, ligaments, muscles, tendons and nerves in human movement
JOINT aka articulation or arthrosis
point where 2 or more bones contact one another
arthrology = study of joints
rheumatology = branch of medicine dealing with joint diseases and conditions
kinesiology = study of movement of the body
joints provide mobility
most joints include bones, ligaments, muscles, tendons and nerves

3. BONES Organs contain several different tissues Functions:
framework for support
protect soft tissues and organs
act as levers for movement
form blood cells in the marrow
storage of minerals, especially Ca and phosphorous
adults have 206 bones
Be able to identify: clavicle, ribs, humerus, ulna, radius, carpals, metacarpals, phalanges, femur, tibia, fibula, tarsals and metatarsals

4. Muscles and Tendons cords of dense connective tissue
attach muscles to bones
bones act like levers and magnify muscle contraction force
muscles provide force by shortening the length of their fibers or cells
antagonistic muscle pairs since only provide movement by shortening
biceps bends arm, triceps straightens it

5. Ligaments and Nerves
ligaments are tough band-like structures that strengthen joints
connect bone to bone
provide stability
proprioceptors = sensory nerve endings which monitor positions of joint parts
nerves help prevent overextension of the joint

6. Label a diagram of the human elbow including: cartilage, synovial fluid, joint capsule, bones and muscles
elbow is a hinge joint
joint capsule = connective tissue

7. 11.2.3 Outline the function of structures in elbow joint
Joint Part
Function
cartilage
reduces friction and absorbs compression (shock absorber)
synovial fluid
lubricates to reduce friction; provides nutrients to cells of cartilage
joint capsule
surround joint; encloses synovial cavity; unites connecting bones
tendons
attach muscle to bone
ligaments
attach bone to bone
biceps muscle
contract to cause flexion (bending) of the arm
triceps muscle
contracts to cause extension (straightening) of the arm
humerus
acts as a lever that allows anchorage of elbow muscles
radius
acts as lever for biceps muscle
ulna
acts as lever for triceps muscle

8. 11.2.4 Compare movement of hip joint and knee joint
flex, extend, abduction, adduction, rotation
hinge
socket and ball
synovial joints
hip
knee
move the leg
multiaxial
moves in one axis
required for walking
flex, extend, a little rotation
flex, extend, abduction, adduction, rotation

9. HIP MOVEMENTS:
flex and extend = < and > angle between connecting bones
abduction and adduction = move away and toward body midline
combination of these = windmill effect

10. Muscle Types skeletal or striated cardiac or heart muscle
smooth or non-striated

11. Describe structure of striated muscle fibers including: myofibrils with light and dark bands; mitochondria; sarcoplasmic reticulum; nuclei and sarcolemma

12. sarcoplasm = cytoplasm of a muscle cell
sacroplasmic reticulum = internal membrane which stores and releases calcium ions (Ca2+) to trigger a contraction
myofibrils = thin fibers that cause a striated (striped) pattern of light and dark bands; contain 2 types of myofilament, myosin and actin (protein-like substances)
many mitochondria = provide energy
sarcomere = the functional unit of the muscle
sarcolemma- plasma membrane of muscle cell

13. Draw and label a diagram of a sarcomere including: Z lines; actin filaments; myosin filaments with heads and light and dark bands

14. (cont.)
thin actin filaments attach to the Z line and form the light section, the I band
actin filaments overlap with thick myosin filaments to form the dark section, the A band
between the two Z lines, you find myosin only intermediate section, the H zone
sarcoplasmic reticulum regulates Ca ion movement
Ca2+ concentration determines ATPase activity; ATPase is an enzyme which hydrolyzes ATP to release its E

15. 11.2.7 Explain how skeletal muscle contracts
Sliding filament theory = actin myofilaments slide over myosin myofilaments
myofilaments do not shorten – when actin slides over myosin the sarcomere shortens
Sliding Filament Theory:
motor neuron carries impulse to neuromuscular junction
neurotransmitter (acetylcholine) released into synapse between axon terminal and sarcolemma of muscle fiber

16. acetylcholine binds to receptors on sarcolemma
ion channels open and Na ions move through the membrane
this generates a muscle action potential
causes release of Ca ions from sarcoplasmic reticulum
ATP is hydrolyzed releasing E
myosin heads bind to the actin
myosin slides along actin shortening the sarcomere

17. 11.2.8 Analyze electron micrographs to find the state of contraction of muscle fibers
Z line between Z lines = a sarcomere
I band H zone
A band