Musculoskeletal System

Question 1

What does red bone marrow form?

Answer 1

blood cells e.g. RBCs, platelets, WBCs

Question 2

What is yellow bone marrow?

Answer 2

stored energy in the form of fat

Question 3

What are the 2 canals in the bone matrix?

Answer 3

• vertical Haversian canals
• horizontal Volkmann’s canals

Question 4

What is seen in a cross-section of a bone?

Answer 4

concentric arrangements of osteocytes with Haversian canals in the centre to form osteons

Question 5

How are osteons produced?

Answer 5

through the continuous process of bone remodelling

Question 6

What are the 3 types of bone cell and what do they do?

Answer 6

• osteocytes - transfer calcium to the ECF without destroying the bone structure
• osteoclasts - secrete hydrochloric acid that dissolves calcium phosphate crystals and enzymes that break down the organic matrix
• osteoblasts - secrete organic matrix (osteoid) within which calcium phosphate crystals precipitate

Question 7

What does a typical joint have?

Answer 7

hyaline (glass-like) articular surfaces made of cartilage

Question 8

What is synovial fluid secreted by?

Answer 8

synovial membrane lining the joint cavity from inside

Question 9

What is the joint capsule?

Answer 9

the outer fibrous protective layer of a joint

Question 10

What are the 2 main joint types?

Answer 10

• ball and socket - can move around 3 axes e.g. shoulder and hip joint
• hinge - can only move in one axis e.g. elbow and knee joint

Question 11

What is a tendon?

Answer 11

a fibrous structure that connects a muscle to a bone

Question 12

What is the epimysium?

Answer 12

the outermost protective connective tissue layer within which there are multiple fascicles that contain muscle cells

Question 13

What is each fascicle in the epimysium lined by?

Answer 13

another connective layer called the perimysium

Question 14

What does each muscle fibre consist of?

Answer 14

multiple myofibrils

Question 15

What are muscle fibres?

Answer 15

striated, long, cylindrical multinucleated cells that undergo voluntary, rapid and powerful contractions

Question 16

What is the fundamental contractile unit of muscle?

Answer 16

a sarcomere

Question 17

What are the 2 major myofilaments in a sarcomere?

Answer 17

• myosin (thick)
• actin (thin)

Question 18

What is one sarcomere length made up of?

Answer 18

a set of overlapping myosin and actin myofilaments bound by two Z discs

Question 19

What is the sliding filament theory?

Answer 19

muscle contraction occurs when thick and thin filaments slide past each other which shortens the sarcomere

Question 20

What is the origin of the muscle?

Answer 20

the proximal attachment point that doesn’t move during contraction

Question 21

What is the insertion of the muscle?

Answer 21

the distal attachment point that moves when the muscle contracts

Question 22

What is the pectoralis and what is it involved in?

Answer 22

a thick, fan-shaped muscle present anteriorly in the chest area involved in flexion and adduction of the arm at the shoulder joint

Question 23

What are the biceps brachii and what are they involved in?

Answer 23

muscle present anteriorly in the upper arm involved in flexion of the forearm at the elbow joint

Question 24

What are the triceps and what are they involved in?

Answer 24

muscle present posteriorly in the upper arm involved in extension of the forearm at the elbow joint

Question 25

What is the deltoid muscle and what is it involved in?

Answer 25

muscle that covers the shoulder joint involved in flexion, extension and abduction of the arm at the shoulder joint

Question 26

What is the trapezius and what is it involved in?

Answer 26

a large triangular muscle present in the upper back region involved in stabilising posture

Question 27

What is the latissimus dorsi muscle and what is it involved in?

Answer 27

a muscle present in the middle and lower back region involved in the extension and adduction of the arm at the shoulder joint

Question 28

Where is the rectus abdominis?

Answer 28

anteriorly in the abdomen region

Question 29

What are the quadriceps femoris and what are they involved in?

Answer 29

a group of 4 muscles present anteriorly in the thigh involved in flexion of the thigh at the hip joint and extension of the leg at the knee joint

Question 30

Where does the common tendon of the quadriceps insert into?

Answer 30

patella bone (kneecap)

Question 31

What is the hamstring and what is it involved in?

Answer 31

a group of 3 muscles present posteriorly in the thigh involved in extension of the thigh at the hip joint and flexion of the leg at the knee joint

Question 32

What are the 3 muscles of the hamstring?

Answer 32

• semimembranosus – flat and broad, present most medially
• semitendinosus
• biceps femoris – present most laterally

Question 33

What is the gastrocnemius muscle and what is it involved in?

Answer 33

the bulk of most of the calf muscle present posteriorly in the lower leg essential for movement and stability involved in flexion of the leg at the knee joint

Question 34

What is the soleus muscle and what is it essential for?

Answer 34

part of the calf muscle group present posteriorly in the lower leg (deeper than gastrocnemius) essential for standing and walking

Question 35

What is the gluteus maximus and what is it involved in?

Answer 35

the largest muscle present posteriorly in the hip region involved in extension of the thigh at the hip joint

Question 36

Why do bones become weaker with age?

Answer 36

bone density decreases

Question 37

What are common causes of paralysis?

Answer 37

strokes, spinal cord injuries and nerve disorders