CH. 32 SKELETAL, MUSCULAR, AND

INTEGUMENTARY SYSTEMS

By: Melissa Montes, Annalise Castner, and Jessica Roesgen

32.1 Skeletal System

The skeleton supports the body, protects internal organs, assists movements, stores minerals, and is a site of blood cell formation.

The Skeleton

There are 206 bones in the adult body. The 2 types of skeleton systems areAxial skeleton: this supports the central axis

of the body. It consist of the skull the vertebral column and the rib cage.

Appendicular skeleton: The bones of the arms, legs, pelvis, and shoulder area.

BonesBones are a solid network of living cells and

protein fibers are surrounded by deposits of calcium salts.

Structure of bonesNerves and blood vessels run through out

compact bone in channels called Haversian canals.

Structure of Bones

Long bones are surrounded by a tough layer of connective tissue called periosteum.

Bones are cavities that contain a soft tissue called bone marrow.Yellow marrow: contains mostly fatRed marrow: produces blood cells

Development of bones Cartilage: type of connective tissue that is

soft, strong, and flexible that supports the body.Ossification: process were cartilage is replaced

by boneOsteoblasts: secrete mineral deposits that

replace cartilage in developing bonesOsteocytes: help maintain the minerals in bone

tissue and continue to strengthen the growing bone

Osteoclasts: cells that break down bone minerals

Joints Joints contain connective

tissue that holds bone together. Joints permit bones to move without damaging each other

Types of Joints: Immovable- cranium and

sacrumSemi-moveable- vertebrae Freely moveable- ball and

socket, pivot, hinge, and saddle.

Structure of Joints

Ligaments: hold bones together in a joint and are attached to the membrane that surround bones.Bones are held together by

ligaments

32.2 Muscular system

Muscle Tissue

There are three different types of muscle tissue:Skeletal- attaches to and moves bones;

voluntarySmooth- controls breathing, digestive

system; involuntaryCardiac- muscles only found in the heart;

voluntary

Muscles and Movement Muscles are joined to bones by connective

tissues called tendons Skeletal muscles generate force and

produce movement by pulling on body parts as they contract

Muscles work in pairs, one contracts and the other relaxesFlexor contracts when bone angle is decreasedExtensor contracts when angle between bones

increases

32. 3 Skin-The Integumentary System

The integumentary system serves as a barrier against infection and injury, helps to regulate body temperature, removes waste from the body, gathers information, and produces Vitamin D

Integumentary System Structures Skin and its related structures-the hair,

nails, and several types of glands-make up the integumentary system.

Epidermis: outer layer of the skin Outer layer is dead skin, inner layer are living

cells Keratin: tough fiber that causes

waterproofing Melanocytes: cells that produce brown

pigment called melanin

Dermis

The dermis lies beneath the epidermis and contains the protein collagen, blood vessels, nerve endings, glands, sensory receptors, and hair follicles.Forms finger prints

Sebaceous glands: secrete an oily substance called sebem that is released at the surface of the skin

Skin Problems

Acne: develops when sebem and dead skin cells form plugs in hair follicles

Hives: Allergic reactions to food or medicine often display themselves as red welts.

Skin Cancer: Excessive exposure to ultra violet radiation in sunlight and artificial radiation from tanning beds can produce an abnormal growth of cells in the skin