Download - Unit 33 Musculoskeletal System
33.1 Skeletal System
KEY CONCEPT The skeletal system includes bones and tissues that are important for supporting, protecting, and moving your body.
33.1 Skeletal System
Your skeletal system is made up of the appendicular and axial skeletons.
• The skeletal system protects, supports, and moves the body.
33.1 Skeletal System
• The appendicular skeleton includes legs, arms, feet and hands. – allows for movement– includes bones called girdles that connect limbs to
body
33.1 Skeletal System
• The axial skeleton includes the skull, rib cage, and spinal column.
skull
rib
breastbone
vertebra
– supports body and protects tissues
– allows for limited movement
33.1 Skeletal System
– cushions bones – allows for smooth movement– connect two bones
• Cartilage is connective tissue between bones.
cartilage
33.1 Skeletal System
Bones connect to form joints.
• Joints are places were two bones meet.• There are three types of joints.
– fibrous, which does notallow for movement
fibrous joint
33.1 Skeletal System
Bones connect to form joints.
• Joints are places were two bones meet.• There are three types of joints.
cartillage
– cartilaginous, which allows partial movement
33.1 Skeletal System
Bones connect to form joints.
– synovial, which allows for greater movement
• Joints are places were two bones meet.• There are three types of joints.
33.1 Skeletal System
• Ligaments are long bands of tissue that connect bones across a joint.
ligament
33.1 Skeletal System
• There are several types of synovial joints.– gliding– pivot– ball-and-socket– saddle– hinge
GLIDING JOINT
PIVOT JOINT
BALL-AND-SOCKET JOINT
SADDLE JOINT
HINGE JOINT
33.1 Skeletal System
Bones are living tissue.
• Bone is made of compact bone tissue and spongy bone tissue.
Compact bone
Spongy bone
33.1 Skeletal System
• Compact bone is hard and dense.– Osteocytes (bone cells) maintain compact bone rings.– Haversian canals allow blood vessels in the bone.
osteocytes blood vessel
Haversian canals
33.1 Skeletal System
• Spongy bone protects red or yellow bone marrow.– Red bone marrow produces blood cells.– Yellow bone marrow is mostly fat.
PeriosteumA layer of connectivetissue that covers bone
Red bone marrow
33.1 Skeletal System
• Calcification is the process of building hard bone.– combines collagen and calcium phosphate– transforms cartilage into hard bone during childhood
osteocyte
compact bone
33.1 Skeletal System
KEY CONCEPT Muscles are tissues that can contract, enabling movement.
33.1 Skeletal System
Humans have three types of muscle.
• The muscular system moves substances throughout the body.– bones of the skeletal system– food through digestive system– blood through circulatory system– fluids through excretory system
33.1 Skeletal System
– skeletal muscle
• There are three types of muscle tissue.
SKELETAL MUSCLE CARDIAC MUSCLESMOOTH MUSCLE
– smooth muscle– cardiac muscle
33.1 Skeletal System
• Skeletal muscle attaches to the skeleton by tendons.– Tendons connect muscle to bone.– Skeletal muscles are mostly voluntary.
SKELETAL MUSCLE
33.1 Skeletal System
– move food through digestive organs– empty liquid from the bladder– control width of blood vessels
• Smooth muscle lines organs and is involuntary.
Smooth musclearound this artery allows theartery to regulate blood flowby shrinking and expanding.
SMOOTH MUSCLE
33.1 Skeletal System
– pumps blood throughout body– controlled by pacemaker– contains more mitochondria than skeletal muscle cells
• Cardiac muscle is found only in the heart.
CARDIAC MUSCLE
33.1 Skeletal System
muscle fiber
Muscles contract when the nervous systems causes muscle filaments to move.
• Muscle fibers are cells of the muscular system.
muscle
33.1 Skeletal System
• Myofibrils are long strands of protein in the muscle fiber.
muscle fibermuscle
myofibril
33.1 Skeletal System
• Each myofibril is divided into sarcomeres.• Sarcomeres contain filaments that cause contraction.
myofibril
muscle fiber
muscle
sarcomere
33.1 Skeletal System
• Each myofibril is divided into sarcomeres.• Sarcomeres contain filaments that cause contraction.
– Actin filaments are pulled during contraction.– Myosin filaments pull actin during contraction.
CONTRACTION
RELAXATION
M linemyosin
Z line
33.1 Skeletal System
• Neuron stimulates muscle at the neuromuscular junction.
neuromuscular junction
neuron
MUSCLE
33.1 Skeletal System
• Neuron stimulates muscle at the neuromuscular junction. – Neurotransmitters
cause calcium channels in the sarcomere to open.
regulatory protein
– Calcium exposes binding sites.
– Myosin binds to actin and pulls it.
– As the sarcomere shortens, the muscle contracts. myosin
actin
Z line
33.1 Skeletal System
KEY CONCEPT The integumentary system has many tissues that protect the body.
33.1 Skeletal System
The integumentary system helps maintain homeostasis.
• The integument is the body system that surrounds all your other organ systems.
33.1 Skeletal System
The integumentary system helps maintain homeostasis.
• The integumentary system consists of many parts.– skin– hair– nails– oil glands– sweat glands– proteins,
such as keratin
33.1 Skeletal System
• Integumentary system removes substances from the body.– water– salts– urea
pore
sweatglands
33.1 Skeletal System
• The outermost layer of the skin is the epidermis.– dead skin cells– oils– pores
The integumentary system consists of many different tissues.
epidermis
pore
33.1 Skeletal System
– Keratin makes cells waterproof and tough feeling.
• Cells in the epidermis produce keratin and melanin.
– Melanin is a dark pigment that absorbs UV rays.
33.1 Skeletal System
– sweat glands– oil glands– pressure receptors– blood vessels– hair follicles
• The dermis contains most of the tissues in the skin.
dermis
hair follicle
oil gland
pressurereceptors
sweat gland
33.1 Skeletal System
• The dermis also produces elastin and collagen.
• A hair follicle is pit of cells that produces hair.
– Elastin makes skin flexible.– Collagen gives skin its shape.
33.1 Skeletal System
• Beneath the dermis is a layer of fat.
fat layer