Presentation on theme: "Introduction to Body structure"— Presentation transcript:
1 Introduction to Body structure Chapter 37Introduction to Body structure
2 Levels/structure of organization Body OrganizationLevels/structure of organizationCells, tissues, Organs and Organ systemsWe did cells alreadyTissues:Epithelial: lines most body surfaces, also typically flat and thinNervous: makes up the nervous system, nerve cells and supporting tissueConnective: support, protect, and insulate the body. Example bone.Muscle: three types, enable movement.Skeletal: voluntary, moves bones in the trunk and limbsSmooth: involuntary, line walls of blood vessels, and organsCardiac: involuntary, found in the heart.
3 Stem Cells: embryonic stem cells are immortal, they divide indefinitely. They are not specialized, meaning they can become any cell. Stem cell research is very controversial.Organ systems: two or more types of tissues working together to perform a certain function.Page 848, major organ systems of the body. You should know the basics for this test, but we will be going into detail in all of them over the next couple of weeks.Human body cavities: consists of 4 fluid filled spaces where organs are found.Cranial cavitySpinal cavityThoracic cavityAbdominal cavity
4 Endothermy: We are endotherms, maintain a fairly constant internal temperature: approx. 37 degrees C.Maintained by the food we eat, large amount of energy consumed by our body is to regulate this temp.Maintained via the flow of blood through the body.Skeletal system (yes you will need to know the bones, and there is a bones test).keeps your body from being floppyProvides protection for internal organsHuman skeleton has 206 individual bones.80 form the axial skeleton (bones of the skull, spine, ribs, and sternum)126 form the appendicular skeleton (arms, legs, pelvis, and shoulder)
6 Axial SkeletonMost complex is the skull (29 bones in the skull, 8 form cranium, 14 facial, 6 middle ear, and a single bone that supports the base of the tongue).26 vertebrae12 pairs of ribs.Appendicular skeletonEverything else Bone structureHard outer covering of compact bone (dense connective tissue) surrounding a porous inner core of spongy bone.Bone marrow, Red: begins the production of all blood cells and platelets; yellow mostly fat, stores energy.periosteum: protective outer membrane that helps protect the bone, contains many blood vessels that supply nutrients to the bone.Bone GrowthHaversian canals: hollow narrow channels, where new bone growth occurs.Osteocytes: bone cells, supplied by nutrients via haversian canals.Osteoporosis: porous bone, bones become brittle and weak.
7 Joints: where two bones meet Ligaments: hold two bones togetherThree main types of joints immovable: little to no movement, base of craniumSlightly movable: limited amount of movement, vertebraeFreely movable: permit movement, several types. (you will need to know examples of each) See page 854Ball and socket: , all types, shoulders and hipsPivot: rotation, top of spineHinge: bending and straightening, elbows, knucklesGliding: sliding motion, wrists and anklesSaddle: rotation, base of thumb
8 Muscular SystemPrecisely timed and controlled contractions of many skeletal muscles.Muscles are attached to bones via tendons.Origin, part that remains stationary in movement. The muscle pulls against the origininsertion, the bone that moves when muscle contracts. The muscle pulls the insertion towards the origin.Have opposing pairs (usually), flexor (causes joint to bend) and extensor (causes joint to straighten).NOT DOING MUSCLE STRUCTURE, CONTRACTIONS, OR MYOSIN AND ACTIN INTERATION. (pages )
9 Actin and Myosin: Protein filaments, enable muscles to contract Myofibrils: small cylindrical structures in muscle fibers (alternate light and dark bands)Z line: (found in the light bands) anchors actin filamentsSarcomeres: area between the 2 z lines.
10 Skin, Hair, and Nails (integumentary system) Skin About 15 % of your total body weightLargest organ of the bodyA lot of specialized structuresTwo primary layers1. Epidermis: outermost layer, about as thick as a piece of paper, made up of epithelial cells.When you look in a mirror, you are looking at dead skin cells, made up of Keratin.Continuously shed and replacedMelanin: responsible for skin pigment.2. Dermis: functional layer of skin, just beneath the epidermis. Contains the nerve cells, blood vessels, hari follicles etc.No to pages 863 and 864 as well.