Muscular-Skeletal system

Question 1

Anatomy, Physiology

interelationship

Answer 1

Study of the structures of the body and their relationships.
Study of the proper functioning and relationships between body structures and systems.
Understanding how anatomy and physiology connect helps in maintaining health and maximizing movement capacity

Question 2

Skeletal system

Answer 2

The skeletal system consists of 206 bones and around 360 joints, along with connective tissues (ligaments and cartilage) that provide structural integrity.

Question 3

Functions of Skeletal System

Answer 3

o Support: Enables movement, standing, and sitting.
o Protection: Shields vital organs (e.g., skull protects the brain, ribs protect the heart and lungs).
o Movement: Bones acts as levers that transfer forces generated by contracting muscles.
o Blood Cell Production: Bone marrow generates blood cells.
o Storage: Bones stores minerals like calcium and phosphorus.

Question 4

Skeletal structure: axial and appendicular

Answer 4

• Axial Skeleton: 80 bones: Along the central ‘axis’ of the body. Part of the skeleton that comprises the head, vertebrae and rib cage and predominately protects vital organs
• Appendicular Skeleton: 126 bones: Part of the skeleton that comprises the shoulder, pelvic girdle, arms and legs and predominately designed for movement.

Question 5

Long bone

Answer 5

Longer than wide; has a shaft with 2 ends consisting of spongy bone.
Function: function as levers when muscles contract facilitating movement, support body weight
Examples: Femur, humerus or phalanges

Question 6

Short bone

Answer 6

Cube-shaped, as long as they are wide
Function: stability, little to no movement.
Example: carpals and tarsals

Question 7

Flat bone

Answer 7

Thin, slightly curved
Function: Protect vital organs, muscle attachment
Examples: Cranium, sternum and ribs

Question 8

Irregular bones

Answer 8

Varies in shape and includes sesamoid bones (round bone)
Function: protect organs, tendon attachment
Example: Patella

Question 9

Joint

Answer 9

A junction of 2 or more bones aka an articulation
3 types: Fibrous, cartilaginous, synovial

Question 10

Fibrous joint

Answer 10

Immovable connected by strong fibrous tissue e.g. skull sutures

Question 11

Cartilaginous

Answer 11

Slightly moveable, connected by cartilage
Examples of this joint exist in the vertebral column, where fibrous cartilage between discs allows a limited range of movement.

Question 12

Synovial joint

Answer 12

Highly moveable where 2 bones meet, tendons, ligaments articular cartilage and synovial fluid combine to provide support and reduce friction for movement efficiency
e.g. shoulder, knee

Question 13

Ligaments

+ impact if damaged

Answer 13

Well defined fibrous bands that connect bone to bone in the joint. Assist joint capsule to maintain stability by restricting excessive movement and prevent dislocation. Can control the degree and direction of movement that occurs. E.g. ACL (anterior cruciate ligament) stabilises the knee joint restricting knee rotation

Relatively inelastic structures: can become permanently lengthened/torn when stretched excessively - joint instability – more prone to disolocation

Question 14

Tendons

+ impact if damaged

Answer 14

Tough, inelastic cords of tissue that connect muscle to bone. Further strengthen joints that extend across it and help ligaments hold it closed. Protect joint by absorbing and transferring force, stabilise the joint, allow for full range of motion. E.g. Achilles tendon connects the gastrocnemius to the heel bone: the transfer of energy across this joint allows us to walk and run.

Weakness, restricted movement

Question 15

Synovial fluid

+ impact if damaged

Answer 15

Thick, slippery fluid that lubricates and forms a cushion between the joint surfaces reducing friction during movement. nourishes cartilage, carries away waste products and

stiffness, may lead to osteoarthritis

Question 16

Articular cartilage

+ impact if damaged

Answer 16

Firm slippery tissue that covers the end of bones acting as a shock absorber, reduces friction on bones during movement. E.g. articular cartilage in the knee joint allows for smooth and efficient joint movements like running.

Pain, decreased motion (can lead to osteoarthritis)

Question 17

Ball and socket

Answer 17

Freely moving joints that can rotate on any axis: wide range of movement e.g hip and shoulder

Question 18

Hinge joint

Answer 18

Move on just one axis: one-direction movement allowing for flexion and extension e.g. elbow, knee

Question 19

Gliding (plane) joint

Answer 19

Move against each other on a single plane: sliding movement e.g. wrist, ankle

Question 20

Condyloid (Ellipsoidal)

Answer 20

Two-direction movement: (backwards/forwards, sideways) circular motion, flexion and extension e.g. Wrist joint between the radius and the carpal bones.

Question 21

Saddle joint

Answer 21

Two-direction movement: (sideways, backwards/ forwards) allow for flexion, extension and other movements but not rotation. e.g. thumb

Question 22

Pivot joint

Answer 22

Allows one bone to rotate about another e.g. Top of the spine = pivot joint for rotation of the head.

Question 23

Flexion

Answer 23

Decreasing joint angle between 2 bones e.g. bicep curl

Question 24

Extension

Answer 24

Increasing joint angle e.g. kicking a ball

Question 25

Abduction

Answer 25

Body part moved away from the centreline (laterally) of the body e.g. breaststroke

Question 26

Adduction

Answer 26

body part is moved towards from the centreline (medially) of the body including movements that go past the centreline (only sideways) e.g. star jump

Question 27

Circumduction

Answer 27

the distal end of a limb has a circular movement moving 360 degrees while the proximal end remains fixed e.g. bowling in cricket

Question 28

Rotation

Answer 28

The motion of a bone moving around on a central stationary axis e.g. swinging a baseball bat

Question 29

Pronation

Answer 29

rotation of the hand and forearm so that the palm faces backwards or downwards. e.g. tennis serve

Question 30

Supination

Answer 30

rottion of the hand and forearm so that the palm faces upward e.g. basketball layup

Question 31

Eversion

Answer 31

movement of the sole of the foot outward, away from the midline of the body e.g. skiing

Question 32

Inversion

Answer 32

he action of turning the sole of the foot inward, towards the opposite foot or the midline of the body e.g. dodging

Question 33

Dorsi-flexion

Answer 33

the action of raising the foot upwards towards the shin decreasing the angle of the ankle e.g. pedalling on a bike

Question 34

Plantar flexion

Answer 34

the movement of the foot in a downward motion away from the body increasing joint angle e.g. kicking an AFL

Question 35

Protraction

Answer 35

Forward movement of the shoulder e.g. netball pass

Question 36

Retraction

Answer 36

Backward movement of the shoulder, the scapulae is pulled posteriorly and medially, toward the vertebral column. e.g. preparing to pass in netball

Question 37

Musclular system

Answer 37

A body system containing of over 700 muscles consisting of skeletal, smooth and cardiac muscle that produces movement of the body, maintains posture and helps circulate various fluids throughout the body.

Question 38

Skeletal Muscles

Answer 38

Voluntary (able to be consciously controlled).: made up of bundles of contractile muscle fibres surrounded by a layer of connective tissue fascia providing structure and support. Attach to bones via tendons and they primarily contract (shorten in length) to produce movement and maintain stability. controlled).

Question 39

Cardiac muscles

Answer 39

Involuntary: Found in the heart, responsible for making the heartbeat to delivering blood around the body.

Question 40

Smooth muscles

Answer 40

Involuntary: Found in the digestive system: line the walls of hollow internal organs such as the bladder.

Question 41

Muscle fibres

Answer 41

Skeletal muscle is made up of thousands of muscle fibres, which are bundled together and wrapped in connective tissue called fascia. Inside each muscle fibre are myofibrils, which contain repeating units called sarcomeres. Sarcomeres are the basic units of muscle contraction and contain two proteins: actin (thin) and myosin (thick). When a nerve signal triggers contraction, ATP provides energy for myosin to pull actin, causing the sarcomere to shorten and the muscle to contract, creating movement. Skeletal muscle is also called striated muscle due to its striped appearance, caused by the overlapping of actin and myosin filaments.

Question 42

Slow twitch fibres

Answer 42

**Energy release: **efficient, slow contraction releasing energy gradually as required by the body during sustained activity over longer periods of time: oxygen and stored carbs = help supply fuel for over long period of time (e.g., endurance type activities: marathons). **Oxygen supply: **Red in appearance (good blood supply)  because of this they are efficient in using oxygen to generate fuel (ATP) = resistant to fatigue. Unable to produce the power and force of fast twitch. Example: Endurance activities such as triathlon

Question 43

Fast-twitch fibres:

Answer 43

Energy release: contract quickly, reach peak tension quickly but fatigue rapidly (feature of anaerobic metabolism used to supply energy needs). Oxygen supply: White in appearance (less oxygen hence blood): less reliant on oxygen supplied via blood 4 energy  don’t need rich blood supply and can produce energy w/o oxygen. Example: recruited for power and explosive movements

Question 44

Fast twitch A

Answer 44

immediate fast twitch fibres that can produce a high output for longer periods that FTb -> ability to draw on aerobic and anerobic metabolism to support contraction. Moderate power, short bursts E.g. speed, strength and power activities lasting for up to 2 minutes (e.g., 400m run).

Question 45

Fast twitch B:

Answer 45

Possess high levels of glycolic enzymes  draw energy solely from anerobic sources. Contract extremely quickly, create forceful muscle contraction (but fatigue rapidly. E.g. speed, strength, power activities higher intensity and greater explosive power in very short bursts (approx. 10sec) (e.g., 100m sprint).

Question 46

Proportions of red and white muscle fibres

Answer 46

Most people have a similar mix of red (slow-twitch) and white (fast-twitch) muscle fibres, but genetics can lead to a higher proportion of one type. More slow-twitch fibres suit aerobic activities, while more fast-twitch fibres suit anaerobic activities. However, training can develop both fibre types to enhance performance.

Question 47

Muscle attachement: origin and insertion

Answer 47

* All skeletal muscles have 2 points of attachment: muscle origin, muscle insertion. * Muscles can only pull in one direction along the muscle fibres towards the muscle origin * The origin is the attachment site that doesn't move during contraction, while the insertion site does. it is pulled to where the muscle origin is. The insertion is usually distal, or further away, while the origin is proximal e.g. The origin of the biceps. brachii is the scapular and head of the humerus and the insertion in the radius in the forearm. As the biceps brachii contracts it creates elbow flexion bringing the forearm up to the shoulder.

Question 48

Isometric contraction

Answer 48

form of static contractions where muscle fibre are activated and develop force but muscle length doesn’t change and movement doesn’t occur e.g. plank: core muscles are engaged and tension applied by length of muscles in rectus abdominis and erector spinae aren’t changing length

Question 49

Isotonic contractions:

Answer 49

refer to a muscle to changing in length and include both concentric and eccentric contractions - Concentric isotonic: contractions involve the muscle shortening, decreasing the joint angle e.g. Bicep curl: bicep contracting to lift a weight (upward phase) - Eccentric isotonic: contractions involve the muscle lengthening increasing joint angle e.g. Bicep curl: biceps muscle fibres lengthening as weight is returned to its og position in bicep curl (lowering phase)

Question 50

Agonist and antagonist

Answer 50

Muscle causing the major action and doing the most work often contracting to create movement. Muscle that must relax and lengthen to allow movement helping control an action. These two roles are interchangeable depending on the directions of the movement. e.g. During elbow flexion, the biceps (agonist) contracts to pull the forearm towards the humerus, while the triceps (antagonist) relaxes. In extension, the triceps (agonist) contracts to move the forearm away from the humerus, while the biceps (antagonist) relaxes.

Question 51

Stabiliser

Answer 51

Contracts isometrically for stability giving muscles a fixed base. This permits the action to be carried out correctly allowing other joints to work more effectively e.g. When bending the elbow to do a dumbbell curl, the deltoid muscle in the shoulder acts as a stabiliser to allow the efficient working of the shoulder and elbow joint, biceps and triceps, and to reduce the possibility of damage to the joint.

Question 52

Interrelationship of skeletal and muscular systems

Answer 52

Vital for helping our bodies to respond and move efficiently, they work together to: Provide body with shape and stability, protect vital organs, produce all voluntary movement necessary for daily activities e.g. eating and exercise * Skeletal system: provides attachment points for muscles to connect to bones through tendons * Muscle’s ability to contract enables them to pull on the bones which act as levers: bring movement throughout body: The skeleton provides the framework, while muscles enable movement. * Joints allow different movements (e.g., flexion, extension). * Connective tissues (ligaments & tendons) ensure stability and coordination.

Question 53

Example of interrelationship of skeletal and muscular system

Answer 53

Kicking a soccer ball: To extend the knee, the quadriceps (agonist) contract while the hamstrings (antagonist) relax, pulling the tibia forward. The hip flexors contract to lift the leg, while the gluteus maximus stabilizes the pelvis. Tendons transfer force across the hip and knee joints, generating the kicking motion.