2Functions of the Skeletal System Movement: Muscles work on the foundation of the bones to allow for movement.Support: The backbone is the main support center for the upper body.Protection: The bones of your skull protect the brain.Storage: Bones store minerals, such as calcium, for use by the body.Blood Cell Formation: Red and white blood cells are formed by marrow.
3Two Major Parts of Skeletal System Axial: supports the central axis of the body; includes skull, vertebral column, ribcage.Appendicular: consists of the bones of the arms, legs, pelvis, shoulder area*THERE ARE 206 BONES IN AN ADULT SKELETON
6What are bones?Bones: solid network of living cells and protein fibers that are surrounded by deposits of calcium salts.
7Bone StructurePeriosteum: tough layer of connective tissue surrounding boneCompact bone: thick, dense layer of bone containing Haversian canals – containing blood vesselsSpongy bone: strong layer found inside compact boneBone Marrow: soft tissue located inside bone cavities
8Types of Bone Marrow Yellow Marrow – made up primarily of fat cells Red Marrow – produces red blood cells, some white blood cells, and platelets
9Development of BonesThe skeleton of an embryo is composed almost entirely of cartilageCartilage: connective tissues with cells that are scattered in a network of protein fibers including collagen and elastinOssification: process of cartilage being replaced by boneDuring adolescence/early adulthood, cartilage in growth plates are replaced by bone – stopping growth!
10Joints Joint: place where one bone attaches to another Depending on its type of movement, a joint is classified as immovable, slightly movable, or freely movable
11Types of Joints Immovable: allow for no movement Ex. SkullSlightly Movable: small amount of restricted movementEx. joint between adjacent vertebrae
12Types of JointsBall-and-Socket: Round end of one bone fits snuggly into anotherEx. Shoulder and Hip
13Types of JointsHinge Joint: movement at joint occurs in one direction, like a doorEx. Knee and Elbow
14Types of JointsPivot Joint: bone resting atop another bone permitting free movementEx. Neck, Wrist, Ankle
15Types of JointsSaddle Joints: permit one bone to slide in two directionsEx. knuckles
16Structure of JointsLigaments: tough connective tissue that connects bone to boneSynovial Fluid: a substance that enables joints to slide over each other smoothly
17Skeletal System Disorders Arthritis: Inflamed/stiff jointsOsteoporosis: weakening of bones, especially in women
19Muscular System More than 40% of the mass of a human is muscle Muscular system includes large muscles displayed by some athletesMuscular system also includes many tiny muscles used to help regulate blood pressure, move food, and power every movement of the body
20Types of Muscle Tissue: Skeletal Usually attached to bonesResponsible for voluntary movements: dancing, walking, typingReferred to as striated muscleControlled by the central nervous systemConsists of muscle fibers, connective tissue, blood vessels, and nerves
22Types of Muscle Tissue: Smooth Usually not under voluntary controlFound in walls of hallow structures: stomach, blood vessels, intestinesCan function without nervous system stimulation
23Types of Muscle Tissue: Cardiac Found in the heart ONLY!Cells may have up to two nucleiIs not under control of the central nervous system
24Muscle Tissue MakeupMyofibril: smaller structures that make up a muscle; composed of two filamentsMyosin: the name of the protein that composes the thick filamentActin: the name of the protein that composes the thin filament
25Muscle ContractionA muscle contracts when the thin filaments in the muscle fiber slide over the thick filamentsATP is used to power muscle contractionsLarge amounts of ATP are needed!
26Muscle and Bone Interactions Tendon: attaches bone to muscleOrigin: attachment of muscle to immovable boneInsertion: attachment to bone that moves when muscle contractionMuscles move from insertion point to origin
27Exercise and HealthMuscle tone: result of skeletal muscles remaining in a state of partial contractionRegular exercise is important in maintaining muscular strengthAerobic exercise causes the body systems to become more efficient
28Muscle PainSprain: wrenching, twisting, stretching injury to a ligamentStrain: injury to muscle or tendon – often caused by overuse
29Muscle Pain Shin splints Shin splints is pain resulting from damage to the muscles along the shin.Pain is felt in different areas, depending on which muscles are affected.Shin splints represent an "overuse injury" and occur most commonly in runners.
31Integumentary System Functions Barrier against infection and injuryRegulates body temperatureRemoves waste products from the bodyProvides protection against ultraviolet radiation from the sun
32SkinServes as a gateway through which sensations such as pressure, heat, cold, and pain are transmitted to the nervous systemTwo main layers: epidermis, dermisBelow the dermis is a layer of fat and connective tissue to insulate the body
34Skin: EpidermisEpidermis has two parts: outside portion is made of dead cells, inside portion is made of living cellsAs cells move from the inner layer towards the outer layer, they create keratin – a fibrous proteinEventually the cells die and form a waterproof coating – skinThe outer layer of cells is shed every 4-5 weeks
35Skin: EpidermisEpidermis contains melanocytes – cells that produce melaninMelanin protects skin from the damage of UV raysDifferences in skin color are due to the differences in the amount of melanin produced
36Skin: DermisDermis contains collagen, blood vessels, nerve endings, glands, smooth muscle, hair folliclesThe vessels in the dermis help control body temperature: contracting and widening as needed
37Skin: Dermis Dermis contains two types of glands: Sweat glands: produce perspiration; sweat contains salts, water, and other compounds; sweat helps get rid of wasteSebaceous glands: produce an oily secretion called sebum; sebum helps keep the epidermis flexible and waterproof
38Skin Cancer Skin cancer = abnormal growth of cells in the skin Excessive sun exposure can produce skin cancerSPF 15 should be the minimum!!!
39Hair and Nails Keratin forms the basic structure Hair Nails Functions: protect surface of the body from UV; prevent dirt/particles from entering bodyHair Follicles: tubelike pockets of epidermal cells that produce hairNailsNail root: area of rapidly dividing cells from which nails growGrow at a rate of 3mm per month