Bones & Muscles

How many bones does the human skeleton contain?

206

Functions of the skeletal system Gives shape & support Protects internal organs Moves muscles Produces blood cells Stores calcium and phosphorous

Bone Cross Section Marrow: manufactures red blood cells Periosteum: soft, thin layer- covers and protects the bone Compact Bone: Hard, outer surface. Can heal itself when broken Spongy Bone: Porous, contains blood vessels, nerves Marrow: manufactures red blood cells

http://www.bmb.psu.edu/courses/bisci004a/bone/fig81.jpg

http://www.bmb.psu.edu/courses/bisci004a/bone/bone.htm

Skeletal System is divided into two parts

Axial Skeleton Skull (protects the brain). Ribs ( protect lungs, and heart). Spinal column (houses and protects the spinal cord).

Appendicular Skeleton Legs Pelvis Arms Shoulders

Types of Joints Immovable Movable Skull Pelvis Pivot Ball & socket Hinge Gliding

http://www.nhfyouthworld.org/junior/mayjun/skeleton.jpg

Types of Joints Ball and Socket Joint Bone with a rounded end that fits into a cuplike cavity on another bone http://www.shockfamily.net/skeleton/JOINTS.HTML

Ball & Socket: Shoulders and Hips Allows arms and hips to move in any direction Can move in a full 360 degrees

Types of Joints Pivot Joint One bone rotates in a ring of another bone that does not move http://www.funhousefilms.com/b-pivot2.jpg

Pivot Joints: First two neck vertebrae & joint beneath elbow Moves in a semicircle motion by twisting against each other

Types of Joints Hinge Joint Back-and-forth movement like hinges on a door http://www.shockfamily.net/skeleton/JOINTS.HTML

Hinged: Elbows & Knees Move like hinges on a door Limited movement Can only swing back and forth

Type of Joints Gliding Joint One part of a bone slides over another bone http://www.shockfamily.net/skeleton/JOINTS.HTML

Gliding Joints: Spine, Wrists, Ankles Slide against each other in a gliding motion Gives your wrists and ankles lots of freedom

Immoveable joints are located in the skull and pelvis.

http://www.lifesci.utexas.edu/faculty/sjasper/images/john21.19.jpg

http://www.bio.psu.edu/

Skeletal muscle is the type of muscle that primarily responsible for movement.

http://www.bmb.psu.edu/courses/bisci004a/tissues/skeletal.jpg

http://www.bio.psu.edu/

Cardiac muscle is found only in the heart and it’s adapted function is to generate and conduct electrical impulses necessary for its rhythmic contraction (it keeps the heart beating)

http://www.sc.edu/union/Sears/AnimalTissue/im.tissueCardiac.jpg

http://www.bio.psu.edu/

The most common function of smooth muscle is to squeeze, exerting pressure on the space inside the tube or organ it surrounds in order to move material through it.

http://www.bmb.psu.edu

How do muscles work

http://www.sirinet.net/~jgjohnso/muscle.html

Inside a Muscle Muscle Fiber Muscle Myofibril

http://www.cytochemistry.net/microanatomy/muscle/smooth1.jpg