Body Systems

• Skeletal Reproductive

• Integumentary Muscular

• Respiratory Endocrine

• Circulatory

• Digestive

• Nervous

• Excretory

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• Skeletal System is made up of bones and ligaments.

• 5 Functions of the skeletal system• provides shape and support

• allows movement

• protects organs

• produces blood vessels in the marrow

• stores certain materials like calcium and phosphorous

Skeleton

• Bone-protect organs, stores materials and produces blood cells.

• 2 parts of the skeletal system• axial-top of the head down to the hips (skull and

vertebral column)

• appendicular-branches out from axial skelston (pelvis, hips, arms,legs,clavical,scapula)

Formation of Bone

• Bone is living tissue

• Cartilage is a flexible connective tissue and most bone is made up of this.

• Ossification- when the cartilage disappears leaving a hard bone

Structure of Bone

• Periosteum-a tough membrane covering – contains small blood vessels that carry

nutrients into the bone.– Contains cells involved in the growth and

repair of bone.

• Compact Bone- hard outer layer under the periosteum– gives bone strength– has a framework containing deposits of calcium

phosphate.

• Spongy bone- found toward the ends of long bones– has many small open spaces that make bones

lightweight– filled with marrow, which produces blood cells.

• Cartilage- a rubbery layer of tissue found on the ends of bones where they form joints.– Acts as shock absorbers and reduces friction

between bones when they rub together– painful if damaged.

• Haversian canals-running through the middle of bone. It is a system of passageways. These canals also contain nerves.

• Marrow• Red marrow produces blood cells

• Yellow marrow produces blood cells and fat

• Your skeleton begins as cartilage which is broken down and replaced by bone.– Healthy bone tissue is always being formed and

re-formed– OSTEOBLASTS- build up bone by depositing

calcium and phosphorous which makes the tissue hard.

– OSTEOCLASTS-break down bone tissue

JOINTS

• Any place where 2 or more bones meet

• Bones must be kept just far enough apart so they don’t rub on each other

• Ligament- attaches bone to bone

• Tendon-attaches bone to muscle

TYPES OF JOINTS• Immovable-allows little or NO movement

– ex) joints in your skull

• Pivot-one bone rotates in a ring of stationary bone– ex) turning you head is pivot movement

• Ball-and-Socket- rounded end of one bone fits into a cup-like cavity of another bone– ex) should,hips

• Hinge Joint-Back and for the movement– ex) elbow

• Gliding- one part of a bone slides over another bone– ex) wrists– ** used the most in the body.

Bone Injuries and Diseases

• Broken bone is called a fracture

• Diseases:• Arthritis- inflammation or irritation of joints

• Osteoporosis- causes bones o become weak or brittle

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• Muscles are made up of thin fibers. These fibers run beside or parallel to one another and are held together by connective tissue. These fibers give muscle ability to shorten or contract. In order for a muscle fiber to contract, these fibers need oxygen and energy

• Action of muscles-they always work in pairs.( ex. When biceps contract, the tricep lengthen)

Functions of Muscular System

• Movement

• Stability

• Protection

• Temp. Regulation

3 Types of Muscle Tissue• Skeletal- attached to bone

– tendon-attaches muscle to bone

– these have bands and are called striated

– under voluntary control

– most common in the body

• Smooth– involuntary control

– flat, thin sheets found in internal organs

– react and tire slowly

– involved in breathing and digestion

• Cardiac– found only in the heart and do get tired

– Involuntary

– striated like skeletal muscle

14-3 SKIN• Skin is the largest external organ of the

body

• 5 main functions:– Protection-prevents injury, helps fight off

disease causing organisms so they can’t pass through. Prevents water loss

– Sensory Response- nerve cells in the skin detect and relay information to the brain.

– Makes Vitamin D- helps body to absorb calcium

• Regulates body temperature– blood vessels in skin help release or hold heat– Perspiration from the sweat glands eliminates

body heat by evaporation– Elimination of waste through sweat glands

3 Layers of the Skin• Epidermis- the outermost and thinnest layer

– these are dead and rub off easily– new cells are made at the base of the epidermis– porduces melanin-a pigment that protects your

skin and gives it color

• Dermis- middle layer– thick, contains blood vessels, nerves, oils,

sweat glands

• Fatty Layer- insulates the body

Injury• When the skin is injured it produces new

cells and repairs tears.

• BRIUSE- when tiny blood vessels beneath the skin burst and leak into surrounding tissue

• CUTS- a scab will form to prevent bacteria from entering your body– cells in the surrounding blood vessels fight

infection– skin cells beneath the scab grow to fill the gap

of torn skin

Burns

• First Degree- damages top layer

• Second Degree- damages top two layers

• Third Degree- damages all three layers

Most serious

May require surgery

Skin Damage• Skin Grafts- when pieces of skin that are

cut from one part of a person’s own body and moved to the injured area.

• Doctors are able to use patches of skin from cadavers to prevent infection until the victims skin heals

• Grow large sheets of epidermis from small pieces of the victim’s own body