Presentation on theme: "Annie Lee, Sarah Bartley, Lauren Thames"— Presentation transcript:
1Annie Lee, Sarah Bartley, Lauren Thames IB Standards / ReviewAnnie Lee, Sarah Bartley, Lauren Thames
2SkeletonsThe three main functions of a skeleton: support, protection, and movement (11.2.1)A hard skeleton provides protection for soft tissues and provides a framework for our bodies.Name some examples?Three types of skeletonsHydrostatic skeletons, Exoskeletons, and Endoskeletons
3Hydrostatic Skeletons Consists of fluid held under pressure in a closed body compartmentCnidarians, flatworms, nematods, and annelidsThese animals are able to change shape because of the fluid-filled compartmentsFlexibilityEx. Worms.
4ExoskeletonsThis type of skeleton is a hard encasement deposited on the surface of the animal.Ex. MolluscsArthropods have cuticle exoskeletons, a non-living coat. The cuticle contains chitin (polysaccharide similar to cellulose).
5Endoskeleton Consists of hard supporting elements, like bones. Buried within the soft tissues of an animal.Echinoderms have endoskeletons of hard plates called ossicles beneath their skin.Sea urchins vs. Sea Stars
6JointsIB specifically wants you to know the human elbow joint. (11.2.2)Specifically the cartilage, synovial fluid, joint capsule, named bones, and antagonistic muscles.Make sure you can label these things !!
7Elbow Joint ContinuedIB also wants you to know the functions of the structures in the human elbow joint (11.2.3)CartilageA type of connective tissue with an abundance of collagenous fibers embedded in chondroitin sulfate.Cartilage is retained in certain locationsDisks that acts of cushions between vertebrae and the caps on the ends of some bonesAbsorbs physical impactSynovial FluidThick stringy fluid found in the cavities of Synovial joints.Reduces friction between the cartilage and other tissues in jointsJoint Capsule (Articular Capsule)Envelope surrounding the Synovial jointCovers the end surfaces of bones
8Joints Continued Three types of joints: Ball-and-socket joint Where the Humerus contacts the shoulder girdle, and our femur contacts the pelvic girdleHinge JointBetween the Humerus and the head of the UlnaPivot JointSame place above
9The Hip Joint and Knee Joint IB wants you to know the comparison between the knee joint and the hip joint (11.2.4)Knee JointHinge joint, and is the biggest joint in our bodyHip JointBall-and-socket type of joint, specifically called a synovial joint.
10MusclesThe purpose of muscles is to provide movement to the body by the providing ability to move bones. ( IB wants you to know the purpose of muscles)The action of a muscle is to contractMuscles only extend passivelyAntagonistic pairs, each member of the pair working against each other.Ex. Flexing an arm
11Vertebrate Skeletal Muscle The skeletal muscleStructure ( IB wants you to know the skeletal muscle structure and its components)Hierarchy of smaller and smaller unitsA muscle fiber = bundle of smaller myofibrilsMyofibrils = two types of myofilaments (thin filaments and thick filaments)
12Structure Continued Thin filaments Two strands of actin and one strand of regulatory proteinThick filamentsStaggered arrays of myosin moleculesThe arrangement of myofilaments make a pattern of light and dark bands. Each repeating unit is called a sarcomere.There are two bandsI Band: area near the edge of sarcomere where there are only thin filamentsA Band: broad region that corresponds to the length of the thick filamentsThere is an H zone, which is in the center of the sarcomere
13The Structure of the Sarcomere Things to note (11.2.6)Z linesLight bandDark bandH zone
14Sliding-Filament Model When the muscle contracts, thin and thick filaments do not change in length when the sarcomere shortensThere is an overlap between both filaments instead.Results in the I band and the H zone shrinking
15Sliding-Filament Model Continued The sliding/overlap of the filaments result from Myosin-Actin interactionsTake a look at the diagram
16Myosin-Act Interaction (11. 2. 7 Myosin-Act Interaction ( IB wants you to know how this works…so pay attention)
17Role of Calcium and Regulatory Proteins Skeletal fiber only contracts when activated by a motor neuron.This is where the Calcium and Regulatory Proteins come into work
18Role of Calcium and Regulatory Proteins (11.2.7)
19The StimulusThe stimulation provided by the motor neuron is an action potential that makes a synapse with the muscle fiber.The synaptic terminal releases neurotransmitters, called acetylcholineDepolarization, causes it to produce action potentialThe action potential spreads into …A plasma membrane called transverse (T) tubulesAnd then the sarcoplasmic reticulum (SR) which the tubes make close contact withThe action potential opens Calcium ion channels in the SR(look at diagram on pg. 1070)
20A quick look at the standards.. 11.2.1: State the roles of bones, muscles, etc in human movement11.2.2: Label a diagram of the human elbow joint, including cartilage, synovial fluid, joint capsule…etc.11.2.3: Outline the functions of the structures in the human elbow joint named in11.2.4: Compare the movements of the hip joint and knee joint11.2.5: Describe the structure of striated muscle fibers, including myofibrils with light and dark bands… etc11.2.6: Draw and label a diagram to show the sarcomere, including Z lines, actin filaments, myosin..etc11.2.7: Explain how skeletal muscle contracts, including the release of calcium ions from the SR, formation of cross bridges…etc.