KEY CONCEPT Muscles are tissues that can contract, enabling movement'

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KEY CONCEPT Muscles are tissues that can
contract, enabling movement.
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Functions of Muscles

• The muscular system moves substances throughout
  the body. It moves
• bones of the skeletal system
• food through digestive system
• blood through circulatory system
• fluids through excretory system

• Muscles protect the body and give it shape.
• Muscle contractions help regulate body
  temperature

Watch Muscle Function Clip
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• There are 600 muscles in the human body
• 40-50 of total body weight
• There are three types of muscle tissue.

• skeletal muscle

• smooth muscle

• cardiac muscle

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• Skeletal muscles are mostly voluntary.

• Striated light and dark bands when viewed under
  a microscope.

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• Antagonistic Muscle Pairs One muscle is
  flexed while the other is relaxed

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Skeletal muscle attaches to the skeleton by
tendons.

• Tendons connect muscle to bone.
• Works like a lever to move bones

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• Smooth muscle lines organs and is involuntary.

• move food through digestive organs
• empty liquid from the bladder
• control width of blood vessels

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• Cardiac muscle is found only in the heart.

• pumps blood throughout body
• controlled by pacemaker
• contains more mitochondria than skeletal muscle
  cells

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Muscles contract when the nervous systems causes
muscle filaments to move.

• Muscle fibers are cells of the muscular system.

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• Myofibrils are long strands of protein in the
  muscle fiber.

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• Each myofibril is divided into sarcomeres.

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• Sarcomeres contain the filaments actin and myosin.

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• Myosin filaments pull actin during contraction.

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Muscle Contraction visual

• Watch Bioflix

The Universe Within - Muscles and Bones
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KEY CONCEPT The skeleton - supports the body. -
protects internal organs. - provides for
movement. - stores mineral reserves. - provides a
site for blood cell formation.
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Your skeletal system is made up of the
appendicular and axial skeletons.
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• The appendicular skeleton includes legs, arms,
  feet and hands.

• allows for movement
• includes bones called girdles that connect limbs
  to body

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• The axial skeleton includes the skull, rib cage,
  and spinal column.

• supports body and protects tissues
• allows for limited movement

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• Cartilage is connective tissue between bones.

• cushions bones
• allows for smooth movement
• connect two bones

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Bones connect to form joints.

• Joints are places were two bones meet.
• There are three types of joints.
• Fibrous or immovable joint, which does not allow
  for movement
• These bones are held together
• by connective tissue or they are
• fused together

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Bones connect to form joints.
2. Cartilaginous or slightly movable, which
allows partial movement
Vertebrae
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Bones connect to form joints.
3. Synovial or freely movable, which allows for
greater movement
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• There are several types of synovial joints.

• Gliding
• Pivot
• Ball-and-socket
• Hinge
• Saddle

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Ball and Socket Joint
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Hinge Joint
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Pivot Joint
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Gliding Joint
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Saddle Joint
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• Go to What Kind of Joint Is It? To test
  knowledge!!

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• Ligaments are long bands of tissue that connect
  bones across a joint.

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• Cartilage covers the end of bones at the joint to
  provide cushioning and reduce friction.
• Synovial fluid is a lubricant that allows for
  bones to slide smoothly along one another
• Sacs of synovial fluid form bursa which serve as
  shock absorbers in joints

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STRUCTURE Bones are living tissue.

• Bone is made of compact bone tissue and spongy
  bone tissue.

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• Compact bone is hard and dense.

• Osteocytes (mature bone cells) maintain compact
  bone rings.
• Haversian canals allow blood vessels in the bone.

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• Spongy bone protects red or yellow bone marrow.

• Red bone marrow produces blood cells and
  platelets.
• Yellow bone marrow is mostly fat.

Yellow Bone Marrow
Red Bone Marrow
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• The bone is surrounded by a tough layer of
  connective tissue called the periosteum.
• Blood vessels in the periosteum carry oxygen and
  nutrients to the bone.

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• Calcification is the process of building hard
  bone.

• combines collagen and calcium phosphate
• transforms cartilage into hard bone during
  childhood

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• Skeletal System Disorders
• Excessive strain on a joint may produce
  inflammation, in which excess fluid causes
  swelling, pain, heat, and redness.
• Inflammation of a bursa is called bursitis.
• Inflammation of the joint itself is called
  arthritis.

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• Another skeletal system disorder is osteoporosis.
  Osteoporosis is caused by a loss of calcium in
  the bone causing a loss in bone mass.

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• Traditionally found in menopausal women (lack of
  estrogen)
• Now emerging as a concern for young people.
• Lack of exercise
• Lack of calcium (soda instead of milk)
• Smoking
• Diabetes

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Sprains Strains
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Sprains

• Ligaments connect one bone to another.
• A stretched or torn ligament is a sprain.
• Common locations are ankles, wrists knees.

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Strains

• A strain is a stretching or tearing of muscle.
• Strained muscles are also called pulled
  muscles.
• Hamstring and back injuries are among the most
  common strains.

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• Sprains
• Involve ligaments
• Occur across joints
• Can cause rapid swelling
• May cause bruising and discoloration

• Strains
• Involve muscles
• Partial or complete tears of muscle can occur
• Chronic strain results from prolonged, repetitive
  movement
• Acute strain when muscles suddenly and powerfully
  contract, like during a slip, jump, or heavy
  lifting.
• May cause bruising and discoloration.

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Risk Factors

• Lack of conditioning
• Poor technique
• Fatigue
• Inadequate stretching and warm-up