Science Starter How many bones are there in the human body? Be sure your “Mystery of the Bones” skeleton is turned in & completed Science Starter How many bones are there in the human body? What is a “soft spot” in a baby? Why are our joints important? How many different joints do you think you have in your body?
Today’s Agenda Science Starter What does it mean to be double-jointed? Types of Joints Joints Worksheet Whack-a-Bone Exit Quiz
What does it mean to be Double-Jointed? Some genetic basis Medical term is “hypermobility” (no double/extra joint) http://abcnews.go.com/Health/rare-medical-condition-secret-contortionists-ability/story?id=29054612
Ehlers Danlos Syndrome http://abcnews.go.com/Health/rare-medical-condition-secret-contortionists-ability/story?id=29054612
Unit 4: Skeletal & Muscular System 4.2 Joints
Places where 2 (or more) bones meet I. What are Joints? Places where 2 (or more) bones meet Bones are joined by more flexible connective tissue Main connection types Ligaments: “strings” that connect bone to bone Cartilage: Provides cushioned, smooth surface for bones to contact each other
II. Types of Joints Fibrous: Joined by tough connective tissue, not moveable E.G: Skull fissures Cartilaginous: Joined directly by cartilage, slightly moveable E.G: Vertebral disks Synovial (contains fluid-filled space, moveable) E.G: Knees, shoulders, and more
III. Basic Motions at joints Flexion: Decreasing angle of joint Extension: Increasing angle at joint Rotation: Movement of bone around longitudinal axis Abduction: Moving bone laterally (away from body midline) Adduction: Moving bone medially (toward midline) Circumduction: Moving distal end of bone in a circle while proximal end stays in place (combination)
IV. Synovial Joints Synovial Fluid- fluid within the joints that helps to lubricate
A. Ball and Socket Structure: A ball (round) fits into a concave socket Movements allowed: Circumduction Examples: Shoulders, hips
B. Hinge Structure: A cylinder fits into a notch Movements: Flexion and extension only Examples: Fingers, toes, elbows, knees
C. Pivot Structure: A cylindrical post fits into a cylindrical space Movements: Rotation Examples: Radioulnar joints (allow lower arm to rotate)
D. Saddle Structure: A C-shaped bone fits over a saddle- shaped bone Movements: Flexion, extension, abduction, adduction Examples: Base of thumb
E. Condyloid (ellipsoidal) Structure: Ellipsoid, bone rests in concave cavity Movements: Circumduction, but limited Examples: Attachment of wrist to arm
F. Gliding Structure: Flat bones sit atop one another Movements: Bones slide past one another (flexion and extension) Examples: Joints between carpals
Joint Worksheet Use your notes and the book to complete the worksheet Anything you don’t complete will be homework This will be checked tomorrow at the beginning of class If you finish early, grab a laptop and go to my website to check out “Whack-a-bone”. See who is the fastest in your group!
/ Ligament Synovial Fluid
Exit Quiz What are the 2 connection types for joints? What are the 6 types of synovial joints? What joint type is in the top picture? What movement type is in the bottom picture?