What are the functions of the skeletal system?
Support and give shape to human body.
Protect internal organs like heart and lungs.
Provide levers on which muscles act to produce movement.
Mineral storage like calcium
Produce blood cells formation.
What is the structure of a typical human bone?
most of it is mineral salts--calcium and phosphorus. A solid network of living cells and protein fibers that are surrounded by deposits of calcium salts.
What is the role of joints?
contain connective tissues that hold the bones together and prevent bones from damaging each other.
How many bones are in adult body?
206
Axial skeleton
skull, spine, and ribcage
Appendicular Skeleton
arm, legs, pelvis and shoulder area
Haversian canal
one of a network of tubes running through compact bone that contains blood vessels and nerves.
Cartilage
type of connective tissue that supports the body and is softer and more flexible than bone.
Ossification
process of bone formation during which cartilage is replaced by bone.
Osteoblast
bone cell that secrets mineral deposits the replace the cartilage in developing bones.
Osteocyte
bone cell that helps maintain the minerals in bone tissue and continue to strengthen the growing bone.
Osteoclast
bone cell that breaks down bone minerals.
Ligament
tough connective tissue that holds bones together in a joint.
What are the principal types of muscle tissue?
skeletal, smooth and cardiac
Skeletal Muscles
are usually attached to bones also called muscle fibers.
Smooth Muscles
are involuntary muscle movement of stomach, blood vessels digestive tract.
Cardiac Muscles
is the heart muscle
How do muscles contract?
Muscle produce movement by shortening, or contracting from end to end.
Myofibril
tightly packed filament bundles found within skeletal muscle fibers.
Myosin
think filament of protein found in skeletal muscle cells.
actin
thin filament of protein found in muscles.
Sarcomere
unit of muscle contraction; composed of two Z lines and filament between them.
Neuromuscular junction
the point of contact between a motor neuron and a skeletal muscle cell.
Acetylcholine
neurotransmitter the produces an impulse in a muscle cell.
How do muscle contraction produce movement?
muscles provide the force to move the lever (bone) and pull in different directions surround each joint. It generates force and produce movement by pulling on body parts as they contract.
tendons
tough connective tissue that connects skeletal muscles to bone.
Two principal types of skeletal muscle fibers
Red and white.
Red muscles
slow-twitch muscle, contains many mitochondria using small blood vessels with myoglobin
Myoglobin
oxygen-storing protein
White muscles
fast-twitch muscle contracts more rapidly and more force, cell contain few mitochondria e.g. sprinting
Integumentary System functions
serves as a barrier against infection and injury, helps to regulate body temperature, removes wastes from body, gathers information, and produces vitamin D e.g. skin
Epidermis
in plants, single layer of cells that makes up dermal tissue; in humans, the outer layer of skin.
Melanocyte
cell in the skin that produces a dark brown pigment called melanin
Melanin
dark brown pigment in the skin that helps protect the skin by absorbing ultraviolet rays.
Hair follicle
tubelike pockets of epidermal cells that extend into the dermis
Where does hair produce at?
at the base of hair follicles.
What are some problems that affect the skin?
constant interaction with the environment like acne, hives and skin cancer.
Keratin
tough fibrous protein found in skin e.g. nails
Sebaceous gland
gland in the skin that secretes sebum (oily secretion) e.g. hair