a tough layer of connective tissue that surrounds the bone
periosteum
a network of tubes running through compact bone that contain blood vessels and nerves
Haversian canal
soft tissue inside the cavities within the bone
bone marrow
strong connective tissue that supports the body and is softer and more flexible than bone
cartilage
when cartilage is replaced by bone.
ossification
a place where one bone attaches to another
joint
strip of tough connective tissue that holds bones together at a joint
ligament
protein that makes up the thick filaments in striations in skeletal muscle cells
myosin
protein that mainly makes up the thin filaments in striations in skeletal muscle cells
actin
point of contact between a motor neuron and a skeletal muscle cell
neuromuscular junction
neurotransmitter that diffuses across a synapse and produces an impulse in the cell membrane of a muscle cell
acetylcholine
tough connective tissue that joins skeletal muscles to bone
tendon
outer layer of skin
epidermis
tough, fibrous protein found in skin
keratin
dark-brown pigment found in skin
melanin
inner layer of skin
dermis
tubelike pocket of epidermal cells that extends into the dermis; cells that produce hair
hair follicle
What are the functions of the skeletal system?
The skeleton supports the body, protects internal organs, provides for movement, stores mineral reserves, and provides a site for blood cell formation.
What is the structure of a typical bone?
Bones are a solid network of living cells and protein fibers that are surrounded by deposits of calcium salts.
What are the three different kinds of joints?
Depending on its type of movement, a joint is classified as immovable, slightly movable, or freely movable.
What are the three types of muscle tissue?
Three types are skeletal, smooth and cardiac.
How do muscles contract?
A muscle contracts when the thin filaments in the muscle fiber slide over the thick filaments.
Why is exercise important?
It's important in maintaining muscular strength and flexibility.
What are the functions of the integumentary system?
It serves as a barrier against infection and injury, helps to regulate body temperature, removes waste products from the body, and provides protection against ultraviolet radiation from the sun.