Unit 18 (Ch. 14) Support & Movement

Which two systems work together to allow support & movement?

What’s another word for movement?

The Role of the Skeleton• What are the functions

of the skeletal system?– support the body– protect organs– aid in movement

• provides attachment site for muscles

• Is bone living?– Yes, even though it’s hard & made of minerals,

bone IS a LIVING tissue that grows.• Think about it… are you the same height as you were

when you were… a baby? …a young child? …last year?

Bone Structure

Bone Structure• What types of tissue make up

the skeletal system?– cartilage– bone

• compact (solid) bone• spongy bone• membrane (periosteum)• marrow

– ligaments

• What is cartilage?– A tough, flexible tissue that doesn’t store calcium,

so it is less dense than bone.

• Where is cartilage found?– mostly at the ends of bone

• Why?– acts as a cushion for joints

Bone Structure

Bone Structure• What types of tissues are

found in bone?– compact (solid) bone

• hard part of bone– very strong b/c stores calcium

• usually found along outer edges

– spongy bone• has many empty spaces• usually found near end of bones

– membrane (periosteum)• covers bone• contains nerves & blood vessels

– marrow• soft center in bone• makes blood cells

Interactive Bone Diagram

Bone Structure• What are ligaments?

– connective tissue that holds bones to other bones

Joints• What is a joint?

– where bones come together

• What allows joints to move smoothly?– cartilage

covering the end of the bones

– fluid-filled bags between cartilage & bone

• types– fixed– movable

1. ball & socket

2. hinge

3. pivot

4. gliding

Jointsfixedjoint

Classification of Joints Animation

gliding joint

Fixed Joints• Are not connected by ligaments.

– Do they move?• no

– What is an example?• skull

• 1. ball & socket– In which direction(s) does it move?

• rotate, front-back, side-side– most mobility of all joints

– What are examples?• hip, shoulder

Movable Joints

• 2. hinge– In which direction(s) does it move?

• open-closed (only in 1 direction) – like a door

– What are examples?• elbow, knee

Movable Joints

• 3. pivot– In which direction(s)

does it move?• twists/rotates

– like a door knob

– What are examples?• skull w/ vertebrae,

lower arm

Movable Joints

• 4. gliding– In which direction(s) does it move?

• slides back-forth, side-side

– What are examples?• vertebrae (back), wrist, ankle

Movable Joints

The Role of Muscles• What is the

muscular system?– all muscles in

the body

• What is the function of the muscular system?– movement

• What is a muscle?– tissue that can

change shape & length

• What are the 3 different muscle types in humans?– skeletal (a.k.a.

striated)

– smooth

– cardiac

• Each has a different structure, pattern, job, & location in the body.

Human Muscles Types

• 1. skeletal (striated)– What do the cells look like?

• long fibers• dark & light stripes (striations)

– Where are they typically found?• most of the body• attached to skeleton

– What is their function?• move bones of the skeleton

– Are their movements voluntary or involuntary?

• voluntary

Human Muscles Types

• 2. smooth– What do the cells look like?

• tapered (thin ends, thick center)• no stripes (no striations)

– Where are they typically found?• digestive tract, respiratory tract,

blood vessels, other organs

– What is their function?• regulate activity of organs or vessels

– Are their movements voluntary or involuntary?

• voluntary

Human Muscles Types

• 3. cardiac– What do the cells look like?

• long fibers that branch & weave together

• dark & light stripes (striations)

– Where are they typically found?• ONLY in heart

– What is their function?• contracts rhythmically pump blood

out of heart

– Are their movements voluntary or involuntary?

• involuntary

Human Muscles Types

Striated (skeletal)

Cardiac Smooth

Appearance of cells?

Striped (striated)

Striped (striated) & branched

Tapered(thin ends, thick center);no stripes (not striated)

Where typically found?

Attached to skeleton (ex. legs/

arms)

heartdigestive system, respiratory

system, blood vessels

Function? movementpump blood from heart to arteries

peristalsis, regulate activity of organs or diameter or

vessels

Voluntary or

involuntary?voluntary involuntary involuntary

Muscle Types in the Body

• What are tendons?– connective tissue that holds muscles to bones

• must be attached to bones at 2 points– at opposite ends of the muscle

How Muscles Work

• How do muscles work?– by changing their length

• How does it do this?– muscle fibers contract (or relax)

» cannot lengthen– So, skeletal muscles must work

in opposing pairs.» flexors» extensors

How Muscles Work

• What does a flexor do when it contracts?– bends the joint– Examples of flexors?

• biceps, hamstring (back of thigh)

Muscles Work in Pairs

•Animation of Muscles Working in Pairs•Muscles Contracting in Pairs

flexor

extensor

• What does an extensor do when it contracts?– straightens the joint– Examples of extensors?

• triceps, quadriceps (front of thigh)

Muscles Work in Pairs

•Animation of Muscles Working in Pairs•Muscles Contracting in Pairs

flexor

extensor