Ch36 Bones Part Flashcards
Cartilage
-contains fibrous protein - collagen
-lacks blood vessels or nerves
-slower to heal than bone, which has a rich blood supply
Acts as a shock absorber and prevents friction
Found in ears nose trachea between vertebrae and ends of bones
Bone structure : external
Ling bones are covered by a tough, fibrous membrane - the periosteum
Diagram outer
Cartilage, periosteum, epiphysis, diaphysis
Diagram inner
Compact bone, springy bone, medullary cavity
Compact bone
Consists of living cells embedded in a matrix of calcium salts and collagen
-salts give strength to the bone
-collagen gives flexibility
Has blood vessels and nerves
Found in the shaft (diaphysis) and as a layer around the end (epiphysis)
Spongy bone
Contains numerous hollows - spaces are filled with red bone marrow
-Mostly found at the end of bones
-makes blood cells and gives strength to the skeleton
MEDULLARY CAVITY
-contains bone marrow
-in young people, contains red marrow which makes blood components
-in adults, contains inactive, yellow, fat-rich marrow (yellow marrow stores fat)
Osteoblasts
Bone forming cells
Growth plate
Area between epiphysis and diaphysis in a long bone in which growth occurs
Bone growth
- bone development begins in 8th week of embryonic growth
- osteoblasts produce a protein called collagen
- hard compound (mostly calcium phosphate) forms around collagen
- osteoblasts are trapped in this and are dormant bone cells
Growth plate poi
-made of cartilage
-cartilage is continually made and turned into bone (ossified)
-growth plate ceases to function at adulthood
Osteoclasts
Bone digesting cells
Catabolic
Osteoclasts function
-bone is dissolved and replaced throughout life,
-osteoclasts move into medullary cavity, digest bone lining the cavity and deposit it in the blood
Osteoblasts function
Form new bone to replace the bone that is destroyed
Why do we need to remove bone
Removal of bone from medullary cavity prevents bones from becoming too heavy as they become larger
Osteoclasts and osteoblasts
Work together to en,argue the medullary cavity and thicken the compact bone
Bone renewal depends on
Hormones, physical activity, diet
How does physical activity affect bone renwal
Bones become thicker when stressed by physical activity - osteoblasts are stimulated
How do hormones affect bone renewal
Growth and sex hormones increase the size of bones eg puberty
Why does diet affect bone renewal
Parathormone Removes calcium from bones
Happens as a certain level of calcium is need in blood for muscles and nerves to work properly
-calcium in diet is need to replace the calcium
Diagram of joints
Osteoporosis
The loss of protein (collagen) material from bone
-causes brittle bones that are easily broken
Osteomalacia
Loss of mineral (calcium) from bone due to lack of vitamin d
Joints
Where two or more bones meet
Synovial fluid
Produced in movable joints to lubricate and reduce friction
Immovable joints
The bones are fused ( skull, pelvic girdle)
Partially movable joints
Bones slide over each other and are connected by ligaments (spine,wrist,ankle)
Movable/synovial joints
-ball and socket joint
Allows movement in all directions eg shoulder and hip
-hinge joint
Allows movement in one direction eg elbow and knee
Ligaments
Strong fibrous Slightly elastic tissues that connects bone to bone
Tendons
Strong flexible Inelastic fibres that connect muscle to bone
Muscles
Consists of elongated cells arranged in bundles and enclosed in connective tissue
Muscle contraction
Energy ATP is required for muscles contraction, not relaxation
-muscles can only pull on bones (contract), they cannot push (expand）
Extensor
Opens a joint eg triceps
Flexor
Closes a joint eg biceps
Skeletal muscle
Striped appearance
Under voluntary control
Smooth muscle
Found in internal structures eg blood vessels, digestive system, bladder etc
- under involuntary control
Cardiac muscle
has many mitochondria
Does not tire
Involuntary
Antagonistic pair
Two muscles that have opposite effects to each other
Arthritis
Musculoskeletal disease
Arthritis cause
-arthritis is a disorder that results from inflammation of a joint
Over 100 types
Osteoarthritis
Caused by the cartilage in joints wearing down, which causes the bones to enlarge and more synovial fluid to form
Rheumatoid arthritis
An autoimmune disease where the body’s immune system attacks the synovial membrane
Arthritis t prevention
Avoiding running on hard surfaces
Swim or walk instead
Wear proper runners when excercising
Arthritis treatment
- anti-inflammatories and steroids help reduce inflammation
-rest, physiotherapy and weight loss may ease symptoms
-surgery may be needed to replace joint
