Bones & Joints
BONES & JOINTS11 JUNE 2014Lesson DescriptionIn this lesson we: Will look at the structure of long bonesJoints of the skeletonMuscles an locomotionSummaryThe Structure of a Long Bone Living bone consists of bone tissue (which you did in the mammalian tissue section) Bones are classified according to their shape and lengtho Flat bones e.g. ribs, scapula and cranial boneso Irregular bones e.g. hip bones, vertebrao Short bones e.g. carpals and tarsalso Long bones e.g. femur, tibia ulna humerous
Types of JointsA joint is formed when two or more bones meet and movement is possible. Ligaments and cartilageform part of the joint. Joints are classified according to the amount of movement they permitFibrous joints Immovable joints that are connected by dense connective tissue. E.g. sutures of the skullCartilaginous joints Limited movement.Connected by white fibrous tissue. E.g. pubic symphysis, intervertebral discsSynovial joints Are freely movableLocated at the end of bones that are not in direct contact with each other
The Structure of a Synovial JointTypes of Synovial JointSynovial joints are classified according to the type of movement that takes place at the joint.Ball and SocketJoint Head of one bone fitsinto the socket ofanother. Permitsmovement in anydirection Examples : shoulderand hip jointHinge Joint Permits movement inone plane Example – elbow andknee joint
Pivot JointGliding Joint One bone rotatesaround another. Example: atlas rotatesaround the axis of thecervical vertebra Flat articular surfaceof one bone slidesover that of another. Example: bones ofthe wrist and ankleTissues of the JointsBones Compact bone – hard dense bone. Provides strength and supportSpongy bone – softer lighter bone tissue. Consists of bone marrow (produces blood cells)CartilageSemi-transparent, tough, elastic connective tissue Hyaline cartilageWhite fibrous cartilageYellow elastic cartilageFunctions:o Prevents friction at jointso Attaches bone to boneo Shock absorbero Deepens sockets without hindering movementTendonsConsist of inelastic, white, fibrous connective tissue that connects muscle to bone.LigamentsConsist of tough, yellow elastic connective tissue that attaches muscle to bone. Stabilize jointsMuscles and Movement Skeletal muscles are attached to the skeleton and bring about movementAttached to the skeleton by inelastic tendonsHave dark and light bands- striatedAre voluntary.
Sliding Filament Theory – How a Muscle ContractsThe skeletal muscle fibers contract when the sarcomere in the myofibrils contract. The contraction ofthe sarcomeres is explained by the sliding filament theory.According to the sliding filament theory, the myosin heads become energized by using the energycontained in ATP. The energized myosin head then attaches to a binding site on the actinmyofilaments to form a cross bridge. The energy contained in the myosin head is then released asthe head swivels toward the middle of the sarcomere pulling the attached actin myofilaments with it.The cross bridge detaches only when another molecule of ATP attaches to the myosin head. Theenergy in the ATP is then used again to energize the myosin head.This cycle by which the myosin heads become energized, form an attachment, swivel and thendetach is repeated many times in all the sarcomeres of all the myofibrils within the cell. The net effectof all this molecular movement is muscle contraction!Antagonistic MusclesAntagonistic muscles are found in pairs called antagonistic pairs. As one muscles contracts, the otherrelaxes. For example the biceps contracts and the triceps relaxes.These consist of an extensor muscle, which "opens" the joint (i.e., increasing the angle between thetwo bones) and a flexor muscle, which does the opposite to an extensor muscle. They includemuscles such as triceps and hamstrings, quadriceps and biceps etc.Antagonistic pairs are needed in the body because muscles can only exert a pulling force, and cannotpush themselves back into their original positions. An example of this kind of muscle pairing isthe biceps brachii and triceps brachii.When the biceps are contracting, the triceps are relaxed, and stretches back to its original position.The opposite happens when the triceps contract. Another example on antagonistic pairs; abductorand adductor muscles.
Injuries of the Musculoskeletal System Sprains – stretching or tearing of ligaments. Swelling and painStrains – muscle or tendon over-stretched. Pain, weakness, spasmsCramps – sudden muscle contraction. Chemical or neurological imbalance.Dislocations - two bones forming a joint move away from each other.Fractures – bone is cracked or brokenDiseases of the Musculoskeletal SystemRicketsCondition that causes weak and soft bones inchildren. Result of the bodies inability absorbcalcium and phosphorus mainly due to a lackof Vitamin DArthritisCartilage wears away at the joints. Joints swell and are painful. OsteoarthritisWear and tear of old age.
Rheumatoid ArthritisAuto immune disease. The bones canactually merge and fuseOsteoporosisBones become porous and weak. Usuallyoccur in women over 50 when they stopproducing oestrogen. This causes calcium tobe removed from the bones and they becomeweaker.Test YourselfQuestion 1An example of a fixed joint is foundAin the neckBin the skullCin the handDbetween the vertebraeQuestion 2The joint of the elbowAis a ball and socket jointBallows movement in three planesCallows movement in one planeDis a swivel joint
Question 3In which way does the cartilage at the head of the human femur assist with body movement?Areducing frictionBholding bones in placeCattaching bone to boneDproviding rigidityQuestion 4The capsule of a joint is lined with theAlamellaBperiosteumCsynovial membraneDendosteumQuestion 5What is the difference between compact bone and spongy bone?AThey have different bone marrowBThey are made of different materialsCThey have different sized cellsDThey have a different arrangement of bone cellsQuestion 6Refer to the table below. Bone X refers to theType of boneExampleLongboneHumerusFlat boneXIrregular bonevertebraAfibulaBclavicleCsternumDpatella
Question 7The x – ray shows a condition called a “floating shoulder”.The correct medical treatment would beAa cast over the chestBstrapping with sticking plastersClet it heal by itselfDsurgery to screw the bones together.Improve your SkillsQuestion 1The diagram below shows the legs of an athlete while he is waiting for a race to start. The letters A toF show some muscles as well as joints that will be used during the race.1.1When the Starters gun is fired, the athlete’s right leg will straighten, pushing the athleteupwards and forwards. Which of the letters (A to F) indicate muscles that will:a.) Relaxb.) Contract(1)(3)
1.2The leg shown in the diagram has different types of joints. Which of the following letters (A toF) indicates:a.) A hinge jointb.) A ball and socket joint(1)(1)During the race the athlete suffered injury to his right knee resulting in torn ligaments. As a result, hewas not allowed to participate in competitions for six weeks. During this time he was only paid onethird of his monthly income.1.3What are ligaments?(2)1.4Do you think that athletes who are unable to take part in competitions due to injury should beentitled to their full income?(1)1.5Give a reason for your answer to QUESTION 1.41.6After six weeks the athlete found out that the knee injury was permanent.(2)He had surgery to fit in an artificial knee, which could perform better than his original knee.Suggest why he should NOT be allowed to participate in the competitions he took part inpreviously.(2)Question 2Study the diagram (A) and the X-ray (B) (of the leg) and answer the questions that follow.2.1Name the bones labeled 1, 2 and 3.2.2Name the bone that is broken in:a.) diagram A;b.) X-ray B.2.3(3)(2)Bones often break quite easily in older women due to softening of the bones.a.) Name the disease responsible for this.(1)b.) Name two precautions that women could take to reduce their chances of getting this disease.(2)
Question 3The x-ray below shows a human synovial joint.3.1Name the type of synovial joint shown in the diagram.(1)3.2State one location of this type of joint in the human body.(1)3.3Describe the range of movement permitted by this type of joint.(2)3.4On the copy of this X-ray on the answer sheet for section 1, label:a.) a named bone of the lower limbb.) the acetabulumc.) the iliumLinks Video: https://www.youtube.com/watch?v RW46rQKWa-g(3)
What is the difference between compact bone and spongy bone? A They have different bone marrow B They are made of different materials C They have different sized cells D They have a different arrangement of bone cells Question 6 Refer to the table below. Bone X refers to the Type of bone Example Longbone Humerus Flat bone X
There are other bone shapes besides long bones in the skeleton. Short bones, like the wrist and ankle bones, are cube shaped. Flat bones are flattened and usually curved. Cranial skull bones are examples of flat bones. Bones that are not shaped like any other bones are lumped together as irregular bones
Short bones. 3). Flat bone: 4). Irregular bones 5). Sesamoid bones are special short bones: Ex: patella Classification of Bones . Long Bones Long bones are characterized by having one shaft (the Diaphysis) that is much grea
hip bones (pelvic bones, coxal bones) are the bones of the pelvic girdle. In mature individuals, the pelvic girdle is formed by three bones: right and left hip bones and sacrum. Each hip bone develops from the fusion of three bones, the ilium, * Terminologia anatomica: international anatomical terminology.
The Skeletal System: Joints Joints Articulations of bones Functions of joints o Hold bones together securely o Gives the rigid skeleton mobility Ways joints are classified o Functionally o Structurally Functional Classification of Joints Focuses on the amount of movement allowed
Carpal, Metacarpal bones and Phalanges - articulations HAND BONES (see Metacarpals disarticulated) HAND JOINTS intercarpal joints IC joints Carpometacarpal, intercarpal joints C-MC, IC joints HANGING joint (see Atlanto-Axial median joint) also see the Back HEAD/SPINE JOINTS (see Craniovertebral
Explore the bones in the skeletal system Assemble a puzzle of the human skeleton. Materials: “Mr. Bones Puzzle” handout Scissors Glue. Class Time: 20 minutes. Activity: Poor Mr. Bones has lost some of his bones and needs your help to put all of his bones back in the right spots. Take .
Bones and Joints of Upper Limb Regions Bones Joints Shoulder Girdle Clavicle Scapula Sternoclavicular Joint Acromioclavicular Joint Bones of Arm Humerus Upper End: Glenohumeral Joint Lower End: See below Bones of Forearm Radius Ulna Humeroradial Joint Humeroulnar Joint Proximal Radioulnar Joint Distal Radioulnar Joint Bones of Wrist and Hand 8 .File Size: 2MBPage Count: 51
HUMAN ANATOMY AND PHYSIOLOGY JOINTS Joints or articulation is a site where two or more bones meet. Functions of joints: Serve as functional junctions between bones. Bind bones , strokes , and other related tissues together. Allow bone growth to occur .
