Skeleton, Muscular, Protection and Movement

Science

A protein filament that causes muscle contraction

Actin

A protein filament that causes muscle contraction. Actin. Actin is a protein that helps muscles move by working with another protein called myosin.

The part of the skeleton that allows movement, like bones of the arms, legs, and hips

Appendicular skeleton

The part of the skeleton that allows movement, like bones of the arms, legs, and hips appendicular skeleton. The appendicular skeleton includes the bones that help you move, like your arms and legs.

The part of the skeleton along its central axis, it includes the skull, spine, and ribs

Axial skeleton

The part of the skeleton along its central axis, it includes the skull, spine, and ribs. Axial skeleton. The axial skeleton is the central part of the skeleton that supports the head and trunk.

The soft tissue inside bone cavities

Bone marrow

The soft tissue inside bone cavities. Bone marrow. Bone marrow is a spongy tissue in bones that produces blood cells.

An involuntary muscle found only in the heart

Cardiac muscle

An involuntary muscle found only in the heart. Cardiac muscle is a type of muscle tissue that helps the heart pump blood throughout the body automatically.

A strong, flexible connective tissue found in skeletons

Cartilage

A strong, flexible connective tissue found in skeletons. Cartilage is a soft tissue that cushions joints and helps them move smoothly.

The tissue that connects and supports different parts of the body

Connective tissue

The tissue that connects and supports different parts of the body. Connective tissue. Connective tissue is the biological material that holds organs and tissues together, providing support and structure throughout the body.

The second layer of skin that contains blood vessels, nerves, sweat glands, and hair follicles

Dermis

The second layer of skin that contains blood vessels, nerves, sweat glands, and hair follicles. Dermis. The dermis is the thick layer of skin beneath the surface that helps regulate temperature and gives skin its strength and flexibility.

Tissue that lines the interior and exterior body surfaces

Epithelial tissue

Tissue that lines the interior and exterior body surfaces. Epithelial tissue. Epithelial tissue is a protective layer of cells that covers body surfaces and organs, acting as a barrier and involved in absorption and secretion.

A pit in the dermis from which hair grows

Hair follicle

A pit in the dermis from which hair grows. Hair follicle. A hair follicle is the skin structure that anchors and grows hair.

The system, including the skin, that separates the body from the outside environment

Integumentary system

The system, including the skin, that separates the body from the outside environment. Integumentary system. The integumentary system is the body's outer protective layer, including skin, hair, and nails.

A point where two or more bones meet

Joint

A point where two or more bones meet. Joint. In simple terms, a joint is the area where bones connect to allow movement and provide support.

A hard, waterproof protein that forms hair and nails, and is found in skin

Keratin

A hard, waterproof protein that forms hair and nails, and is found in skin. Keratin is a protein that helps build and protect our hair, nails, and skin.

A tough band of tissue that holds bones together at a joint

Ligament

A tough band of tissue that holds bones together at a joint. Ligament. Ligaments connect bones at joints, helping to stabilize and support movement.

The pigment that gives skin its color and protects it from UV damage

Melanin

The pigment that gives skin its color and protects it from UV damage. Melanin. Melanin is a natural pigment found in the skin, hair, and eyes that helps protect against sun damage by absorbing ultraviolet light.

A long, tubelike cell found in muscles and heart tissue

Muscle fiber

A long, tubelike cell found in muscles and heart tissue. Muscle fiber. Muscle fibers are the basic building blocks that make muscles work by contracting and relaxing to create movement.

The tissue that contracts and relaxes to produce body movement

Muscle tissue

The tissue that contracts and relaxes to produce body movement. Muscle tissue. Muscle tissue is a type of body tissue that enables movement by contracting and relaxing.

The organ system made up of muscles that help the body move

Muscular system

The organ system made up of muscles that help the body move is the muscular system. The muscular system consists of tissues that work together to create movement in the body.

A long strand of protein that makes up a muscle fiber

Myofibril

A long strand of protein that makes up a muscle fiber. Myofibril. Myofibrils are tiny threads in muscle cells that help them contract and produce movement.

The thick protein filament found in myofibrils of skeletal cells

Myosin

The thick protein filament found in myofibrils of skeletal cells. Myosin. Myosin is a protein that helps muscles contract by converting chemical energy into mechanical work.

The tissue, including neurons, that carries messages in the nervous system

Nervous tissue

The tissue, including neurons, that carries messages in the nervous system. Nervous tissue. Nervous tissue is the body's communication network that transmits signals between different parts of the body.

The bone formation process

Ossification

The bone formation process. Ossification. Ossification is the process by which new bone is formed in the body.

A cell that forms bones

Osteoblast

A cell that forms bones. Osteoblast. In simple terms, an osteoblast is a cell responsible for bone formation in the body.

A mature bone cell that maintains and strengthens bone tissue

Osteocyte

A mature bone cell that maintains and strengthens bone tissue. Osteocyte. An osteocyte is a type of cell that helps keep bones strong and healthy by maintaining the bone tissue.

The muscle fiber that causes muscle contraction, it is made of myofibrils

Sarcomere

The muscle fiber that causes muscle contraction is made of myofibrils. Sarcomere is the basic unit of a muscle that allows it to contract.

A muscle that is attached to the skeleton

Skeletal muscle

A muscle that is attached to the skeleton. Skeletal muscle. It is a type of muscle responsible for moving bones and body parts.

The outer, thinnest layer of skin that is made up of dead cells

Skin epidermis

The outer, thinnest layer of skin that is made up of dead cells. Skin epidermis. The skin epidermis is the top layer of your skin that protects your body from the environment.

An involuntary muscle that controls internal organs like the stomach and intestines

Smooth muscle

An involuntary muscle that controls internal organs like the stomach and intestines. Smooth muscle. Smooth muscle is a type of tissue that works automatically to help move substances through organs in your body.

A tough band of tissue that attaches bones to muscles

Tendon

A tough band of tissue that attaches bones to muscles. Tendon. In simple terms, a tendon is like a rope that connects muscles to bones, helping move parts of your body.