Presentation on theme: "Skeletal System What makes up the skeletal system?"— Presentation transcript:
1Skeletal System What makes up the skeletal system? Bones (& connective tissue) made up of living and nonliving materialCartilage-no blood vesselsTendons (attach muscle to bone)Ligaments (attach bone to bone)
2Functions Support and shape Protect organs Provide a system of levers (mov’t)Mineral reserve (Ca & P) store fatSite of blood cell formation (marrow)
3Bone Marrow Yellow Marrow Red Marrow Blood vessels Nerve cells Fat cellsRed MarrowProduces red blood cells(erythrocytes)Produces white blood cells(leukocytes-lymphocytes)Other elements(platlets-thrombocytes)
4Development of Bone Chondrocytes- cartilage cells Cartilage- connective tissue. Found where needed. (nose, ears, voice box, windpipe, ends of bones, ribs)3 Types of cartilage:Elastic-flexible(ears)Hyaline-loose collagen, not too strong(end of nose, ribs, bones, joints)Fibrocartilage- densely packed, tough(Intervertebral disks, pubis symphasis)
5Development continued Replacement bone- cartilage model of what bones will look likeNewborns are mostly cartilageCartilage is replaced by bones about two months in utero.Ossification is the process where cartilage is replaced by bone.Mineral deposits lay down near centerBone tissues form OSTEOCYTES (bone cells) that replace cartilage.
14Anatomical Planes Sagittal- separates Right and Left Frontal- separates Front and BackTransverse- separates Top and Bottom
15How do bones move?Bones move by using a system of levers called JOINTS.Joints-Where two bones meetPermit movementHold bones in place
16Joints Immoveable Joints- Slightly Moveable Joints- Fixed, allow no movementskullSlightly Moveable Joints-Small amount of mov’tTibia, fibula, and vertebral columnFreely Moveable Joints-Most joints, ends of bones covered with cartilageSynovial fluid-thin lubricant over jointSmall pockets of synovial fluid (BURSAE)
17Freely Moveable Joints Ball and socket- permits circular mov’t: widest range of motion.(shoulder and hip)Hinge-back and forth mov’t(Elbow and knee)Pivot- allow rotation around a fixed point(atlas and axis) and (radius and ulna)
18More Freely Moveable Joints Gliding-Sliding of one bone over another(Wrist, ankles, clavicles)Saddle-permit movement at 2 planes(Thumb)Ellipsoid- hinge type mov’t in 2 directionsFingers to palms and toes with soles.
19Muscles Muscles make up ½ of the body’s weight. Mrs. Hinzman in College
20Three types of Muscles Skeletal- voluntary Smooth- involuntary Attaches to boneSmooth- involuntaryAlimentary canal, keeps eyes focused, arteriesCardiac-involuntaryFound only in the heart
21Muscles Skeletal Smooth Cardiac Striated, multinucleated Spindle shaped, single nucleusCardiacStriated, single nucleus
22Muscle ToneMuscles are kept in partial contracted state by a steady flow of nerve impulses from the spinal cord.If muscles lose nerve supply, what happens?Shrinks, muscles lose about 2/3 bulk w/in monthsMuscles can repair themselves
23Origin Insertion Muscle attachment on stable bone Muscle attaches to one or more moveable bones.
24Muscle STRENGTH Depends on muscle shape: Most powerful muscle is where?Spine-maintain posture and liftingHand muscles-dexterityEye (sphinctor) muscles- dialate, open and close like a valve.
25How Do Muscles Contract? Myosin- thick filamentsActin- thin filamentsCross Bridges- knoblike projections that form in each myosin filament when actin and myosin come together.
26Sliding Filament Theory 1. When muscles contract, CROSS BRIDGES move pulling the ACTIN and MYOSIN passed each other.2. After CROSS BRIDGES move as far as it can, they release ACTIN to its natural position.Muscle work against each other (antagonist)Flexing-makes angle small (biceps)Extending-makes the angle bigger (triceps)
28The Return of ATPATPGives us energy (how do we get ATP in our bodies?)Aerobic process (required oxygen)-cellular respirationAnaerobic process (no oxygen needed)-fermentation (glycolysis)ATP makes and breaks contractions of actin and myosin. (enzyme, acetylcholinesterase, terminates a muscle contraction)
29Questions??? Do muscles push, pull, or do both? What would take longer to heal?Muscle, tendon, or ligament. Why?
32Integument (SKIN) System Skin is the largest organ in the bodySelf repairingHow does skin repair itself? What process occurs?What pigment determines the color of skin?
33Functions Protect body from injury or infection Helps regulate body temperatureHow?Removes wasteProtects from UV rays
34EPIDERMIS Outer most layer of skin, NO BLOOD VESSELS, but has NERVES Cells undergo rapid division (MITOSIS)As new cells are produced, old cell are pushed to surface become KeratinKeratin is tough fibrous protein that forms hair, nails, and callusesKeratin waterproofs our skinNew outer layer of skin is renewed every days
35DERMIS Inner most layer under the epidermis Contains blood vessels and nerves, sense organs, smooth muscle, and hair follicles
36Hot or Cold? What does our body do to conserve heat? Blood vessels constrict to limit the heat lost…keeps us warmerWhat does our body do to cool down?Blood vessels open up, increases heat loss
37Glands in Dermis 1. Sweat gland- 2. Sebaceous gland- Produces sweat (salt and water)Nerve impulses stimulate when body temp. rises2. Sebaceous gland-Produces oily secretion called SEBUMKeeps skin flexible and waterproof
38Hypodermis Layer beneath the dermis Composed mostly of fat Insulates the bodyProtectsEnergy storage