4.1 Muscles and Bones Lesson

Bones

P5

Learning Objectives:

● What is the role of skeleton?

● Why joints are needed?

● Cartilage and bones are hard

tissue

Support

Protection
Movement

Skeleton

https://study.com/academy/lesson/axial-skeleton-functions-and-anatomy.html

Skull

Backbone

Ribs

Femur
-thighbone

Vertebrae

Spinal cord

Skeleton -
your bones
are rigid
and are
moved by
muscles.

https://study.com/academy/lesson/axial-skeleton-functions-and-anatomy.html

Limbs

shoulder

joint

How can the
skeleton move?

joints 关节

Ball-and-socket joint

● let the bone move in

every direction

● shoulder, hip

Hinge joint

● let the bone move in

only one direction

● elbow, knee

Ligaments
韧带

Cartilage
软骨

Synovial fluid
滑液

Do long bones break more
easily than short bones?

Apparatus:
Straw 吸管
Forcemeter 测力器
Stand

Length of straw (cm)

Force to bend the straw (N)

Muscles and movement

Learning Objectives:

How do muscles work?

P4

● Your body moves

when muscle pull
on your bones.

● Your brain tells

your muscles to
contract.

Muscles are attached to bones by tendons.

https://study.com/academy/lesson/what-is-a-tendon-anatomy-definition-quiz.html

Muscles get shorter
when they contract.

Muscles work in

pairs called
antagonistic

muscles.

▪One pulls a bone one way and the
other pulls it back the other way.

A robotic exoskeleton could give you extra strength.

The muscles in your intestines
are involuntary and push food
from your mouth and through
your body.

The heart is made of Involuntary muscle. When it beats,
the muscle contracts.

Circulatory system circulates
blood through the body.

The blood leaves
the heart through

arteries.

The blood returns
to the heart
through veins.

skeletal system muscular system