2 Ap exam

Functions of bone

Support, protection, movement, mineral storage, blood cell production

Bone classifications

Long, short, flat, irregular, sesamoid

Parts of a typical long bone

Diaphysis, epiphysis, metaphysis

Medullary cavity

Central cavity of bone shaft that contains marrow

Articular cartilage

Hyaline cartilage that reduces friction at joints

Periosteum

Outer fibrous membrane covering bone

Endosteum

Inner membrane lining the medullary cavity

Compact bone

Made of osteons with lamellae, lacunae, canaliculi

Spongy bone

Made of trabeculae, no osteons

Lacunae

Small spaces housing osteocytes

Bone cells

Osteoblasts (build), osteocytes (maintain), osteoclasts (break down)

Organic bone matrix

Made of collagen and proteoglycans

Inorganic bone matrix

Made of hydroxyapatite and minerals

PTH

Stimulates osteoclasts to increase blood calcium

Calcitonin

Stimulates osteoblasts to decrease blood calcium

Intramembranous ossification

Formation of bone from fibrous membrane (skull)

Endochondral ossification

Formation of bone from hyaline cartilage (long bones)

Ossification centers

Primary and secondary sites where bone forms

Fracture healing stages

Hematoma, soft callus, hard callus, remodeling

Stress fracture

Trauma-induced break from impact or overuse

Pathological fracture

Break due to disease like osteoporosis or cancer

Exercise effect on bone

Increases bone density and strength

Nutrients for bone health

Calcium and vitamin D

Hormones influencing bone growth

Growth hormone, thyroxine, estrogen, testosterone

Osteoporosis

Bone resorption outpaces deposit, leading to weak bones

Structural classifications of joints

Fibrous, cartilaginous, synovial

Functional classifications of joints

Synarthroses, amphiarthroses, diarthroses

Fibrous joint

Bones joined by dense connective tissue, no cavity

Cartilaginous joint

Bones joined by cartilage, no cavity

Synovial joint

Freely movable joint with cavity and fluid

Plane joint example

Intercarpal joints

Hinge joint example

Elbow or knee

Pivot joint example

Atlantoaxial or radioulnar joint

Condyloid joint example

Wrist (radiocarpal)

Saddle joint example

Thumb (trapeziometacarpal)

Ball-and-socket joint example

Shoulder or hip

Flexion

Movement that decreases joint angle

Extension

Movement that increases joint angle

Abduction

Movement away from the midline of the body

Adduction

Movement toward midline

Circumduction

Circular movement of limb

Supination

Rotation of forearm so palm faces up

Pronation

Rotation of forearm so palm faces down

Osteoarthritis

Wear-and-tear joint degeneration

Rheumatoid arthritis

Autoimmune inflammation of joints

Arthroplasty

Surgical joint replacement with prosthesis

Muscle tissue types

Skeletal, cardiac, smooth

Skeletal muscle

Voluntary and striated muscle type

Cardiac muscle

Involuntary and striated muscle type

Smooth muscle

Involuntary and non-striated muscle type

Muscle functions

Movement, posture, joint stability, heat generation

Sarcolemma

Muscle cell membrane

Sarcoplasm

Muscle cell cytoplasm

Myofibrils

Contractile units inside muscle cells

Sarcomere

Functional unit of contraction

T-tubules

Infoldings of sarcolemma that transmit signals

Sarcoplasmic reticulum

Stores and releases calcium

Sliding filament theory

Myosin pulls actin to shorten sarcomere

Neuromuscular junction

Synapse between motor neuron and muscle cell

Acetylcholine (ACh)

Neurotransmitter released at NMJ

Sarin poisoning

Blocks ACh breakdown, causing overstimulation

Excitation-contraction coupling

AP triggers calcium release for contraction

Muscle fiber types

Slow oxidative, fast oxidative, fast glycolytic

Slow oxidative fibers

Fatigue-resistant and aerobic fiber type

Fast glycolytic fibers

Fast and anaerobic fiber type

Fast oxidative fibers

Intermediate fiber type

Muscle hypertrophy

Increase in sarcomeres and myofibrils

Muscle atrophy

Loss of tension-producing structures

Fiber arrangements

Circular, parallel, convergent

Motor unit

Motor neuron and all muscle fibers it controls

Recruitment

Activating more motor units for stronger contraction

Muscle twitch

Single contraction response to one stimulus

Treppe

Gradual increase in tension with repeated stimuli

Tetanus

Sustained contraction with no relaxation

Isotonic contraction

Muscle changes length and moves load

Concentric contraction

Muscle shortens while contracting

Eccentric contraction

Muscle lengthens while contracting

Isometric contraction

Muscle generates tension without changing length

Muscle fatigue causes

CNS fatigue or ATP depletion

ATP sources for muscle

Creatine phosphate, anaerobic glycolysis, aerobic respiration

Creatine phosphate

Fastest but short-lived ATP source

Anaerobic glycolysis

Produces lactic acid

Aerobic respiration

Most efficient ATP source