Skeletal and Muscular System

Cartilage

A connective tissue that is more flexible than bone and that protects the ends of bones and keeps them from rubbing together.

involuntary muscle

A muscle that is not under conscious control.

voluntary muscle

A muscle that is under conscious control like skeletal

bone marrow

A soft tissue inside the bone; red or yellow

pivot joint

Allows for rotation around the length of a bone, and only allows for rotation; top of spine allows head to turn

Attachment of skeletal muscle

Attached to one end of bone, stretch across joint, and are fastened to end of another bone

Tendon

Connects muscle to bone; tough and fibrous

Muscular System

Consists of skeletal muscles, tendons that connect muscles to bones; makes up 1/3 of weight; necessary for every other system

appendicular skeleton

Consists of the bones in the arms and legs along with the scapula, clavicle, and pelvis

axial skeleton

Consists of the skull, ribs, spine and sternum

Sarcomere

Contractile unit of muscle; region from one z-line to the next

yellow bone marrow

Found in shafts of long bone; Stores fat as energy reserve; can become red if severe blood loss occurs

epiphyseal plate

Growth plate in ends of long bones, made of cartilage, gradually ossifies; cartilage divides and pushes to middle; as it dies, cells are replaced with bone cells; growth continues until no more cartilage in plate

rheumatoid arthritis

Immune system attacks tissues; characterized by inflammation of the joints, stiffness, pain, and swelling that results in crippling deformities

spongy bone

Inside of compact bone; hard and strong; arranged in lattice pattern; bony spikes; makes bone light and strong

muscle contraction

Interactions between actin and myosin filaments of the sarcomere are responsible for; myosin heads (extensions) attach to points between "beads" and bend inward. Then they let go, bend back, reattach, and do it again; this pulls in and overlaps actin, shortening/contracting muscle; REQUIRES ATP; more fibers that are stimulated, the more force of contraction; Muscles are in opposing pairs

smooth muscle

Involuntary muscle found inside many internal organs of the body; no striations but they have tissue and no tendons; one cell one nucleus

cardiac muscle

Involuntary muscle tissue found only in the walls of the heart; striated; one cell one nucleus; bundle of specialized muscle cells in upper heart send signals through cardiac muscle tissue causing heart to pump

hinge joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane

muscle fiber

Made of threadlike structures called myofibrils

Myofibrils

Made of two types of protein filaments that give muscle striated appearance

Smooth movement

One muscle relaxes, one gets tense

Long bone

Porous (having spaces or holes which liquid or air can pass through) central canal surrounded by ring of dense material

Skeletal system

Protects and supports body organs and provides a framework the muscles use to support movement. Made up of bones and joints; endoskeleton; variation represents different roles

Myosin

Protein making up thick filament; has heads or extensions

Actin

Protein that makes thin filament anchored at midpoints to structure called Z-line; look like twisted strand of beads

skeletal muscle

Responsible for moving parts a of body like limbs; made of elongated cells called muscle fibers (contains many nuclei) that are crossed by striations (light and dark stripes)

Some muscles always contracted

This causes cramps and overtired muscles; to prevent, body activates some muscles at one time and others later, allowing all fibers to rest at some point

Oxygen Debt

When the amount of oxygen required after physical exercise to convert accumulated lactic acid to glucose isn't present and waste builds up causing soreness; respiratory and circulatory system doesn't work as fast as muscles

fracture

a crack or break in a bone; if periosteum survives and circulation continues, bone will heal

semimovable joint

a joint at which limited movement occurs; examples include the joints between the bones of the vertebral column (spine); bend and twist; vertebrae separated by disks of cartilage

fixed joint

a joint that does not move, found in skull; small amount of connection tissue to absorb impacts

Achilles tendon

a large tendon that runs from the heel to the calf

gliding joint

allows one bone to slide over another; found in small bones of food (allow flexing when walking)

Orgin

attachment to immovable bone

Insertion

attachment to movable bone

Osteocytes

bone cells between protein cylinders

moveable joints

bones that move relative to each other

Fasticle

bundle of muscle fibers grouped into bundles which are joined by tissue to form muscle

Osteoarthritis

cartilage shock absorbers between bones wears away. bones rub together causing severe discomfort

compact bone

dense, hard layers of bone tissue that lie underneath the periosteum; endures stress

Attachment methods

directly- muscle is fused to the periosteum of a bone and indirectly- connective tissue tendon separates two

Red bone marrow

found in spongy bone, ends of long bones, ribs, sternum, vertebrae, and pelvis; produces red blood cells and certain white blood cells

muscle fatigue

inability of muscle to maintain force of contraction after prolonged activity due to a lack of energy and thus a lack of ATP; causes cramps

arthritis

inflammation of a joint

endoskeleton

internal skeleton or supporting framework in an animal

multinucleate

many nuclei (skeletal muscles)

Flexor

muscle that serves to bend a limb; bicep

Extensor

muscle that straightens a joint; tricep

Joints

place where two bones meet; three kinds (movable, semi movable, fixed)

Ossification

process of bone formation from cartilage hardening into osteocytes (hard bones no cartilage; softer bones some cartilage)

Bones

provide a resting ground for muscles and protection of vital organs; bones store minerals for metabolic processes; interior can create red and white blood cells; 20 percent of body mass

ball and socket joint

shoulder and hip: allows circle of motion

Periosteum

thin membrane that covers a bone; contains blood vessels and nerves

Muscle

tissue composed of fibers that can contract, causing movement of an organ or part of the body; smooth, skeletal, and cardiac

Ligaments

tough bands of connective tissue that attach one bone to another at a joint; sinovial fluid reduces friction;

saddle joint

type of joint found at the base of each thumb; allows grasping and rotation