04/12/231

The Skeletal and

MuscularSystems

Today’s Warm-Up

Skeletal facts…

1. How many bones are in the average adult human body?

2. How many bones does a baby have?

3. What/where is the longest bone on the body?

4. What/where is the smallest bone in the body?

206

Over 300!

The “femur” or thighbone

3 bones in the middle ear- stirrup, anvil & hammer

Function The skeletal system includes bones and tissues that are important for supporting, protecting, and moving your body.

Parts of the skeletal system

• Bones (skeleton)

• Cartilage

• Joints: hold bone together & mobility

• Ligaments & Tendons

Your skeletal system is made up of the appendicular and axial

skeletons.

• The skeletal system protects, supports, and moves the body.

• The appendicular skeleton includes legs, arms, feet and hands.

– allows for movement– includes bones called girdles that connect

limbs to body

• The axial skeleton includes the skull, rib cage, and spinal column.

skull

rib

breastbone

vertebra

– supports body and protects tissues

– allows for limited movement

– cushions bones– allows for smooth movement

(damaged cartilage leads to joint pain)

– connects two bones

– As you age much of your cartilage is gradually broken down & replaced by bone

• Cartilage is connective tissue between bones.

Bones connect to form joints.

• Joints are places were two bones meet.

• There are three types of joints.– Immoveable or

fibrous, which does notallow for movement

fibrous joint

Bones connect to form joints.

• Joints are places were two bones meet.

• There are three types of joints.

cartillage

– Semi-moveable or cartilaginous, which allows partial movement

Bones connect to form joints.

– Moveable or synovial, which allows for greater movement

• Joints are places where two bones meet.

• There are three types of joints.

• Ligaments are long bands of tissue that connect bones across a joint.

ligament

Bones are living tissue. • Bone is made of compact bone tissue and

spongy bone tissue.Compact bone

Spongy bone

• Compact bone is hard and dense.

– Osteocytes (bone cells) maintain compact bone rings.

– Haversian canals allow blood vessels in the bone.

osteocytes blood vessel

Haversian canals

• Spongy bone protects red or yellow bone marrow.

– Red bone marrow produces blood cells.– Yellow bone marrow is mostly fat.

PeriosteumA layer of connectivetissue that covers bone

Red bone marrow

The Muscular System

Function Muscles are tissues that can contract, enabling movement.

• They provide movement and force.

• There are 3 types of muscle tissue: - skeletal,- smooth, - cardiac

• Muscle tissue is made up of muscle fibers

• Most muscles work in pairs

Muscles make up the bulk of the body and account for 1/3 of its weight.

What are muscles made of?

• Thousands, or even tens of thousands, of small fibers make up each muscle.

Humans have three types of muscle.

• The muscular system moves substances throughout the body.– bones of the skeletal system– food through digestive system– blood through circulatory system– fluids through excretory system

– skeletal muscle• There are three types of muscle tissue.

SKELETAL MUSCLE CARDIAC MUSCLESMOOTH MUSCLE

– smooth muscle– cardiac muscle

Skeletal Muscles• Skeletal muscles attach to bones by tendons

(connective tissue) and enable movement.

• Skeletal muscles are mostly voluntary

Feel the back of your ankle to feel your Achilles tendon - the largest tendon in your body.

– move food through digestive organs– empty liquid from the bladder– control width of blood vessels

• Smooth muscle lines organs and is involuntary.

Smooth muscle around this artery allows the artery to regulate blood flowby shrinking and expanding.

SMOOTH MUSCLE

– pumps blood throughout body– contains more mitochondria than skeletal

muscle cells

• Cardiac muscle is found only in the heart.

CARDIAC MUSCLE

How the Heart is Different

• How is the heart different from other muscles?

– It is part of both the Muscular System and the Circulatory System.

– It is responsible for circulating blood throughout the body.

– It has its own pacemaker for rhythmic beating.

muscle fiber

Muscles contract when the nervous systems causes muscle filaments to

move. • Muscle fibers are cells of the muscular

system.

muscle

Muscle pairs: Muscles are grouped together in pairs on your skeleton

Relaxed or contracted: When one muscle of a pair contracts, the other relaxes

Pulling muscles:Skeletal muscles only pull in one direction. For this reason they always come in pairs. When one muscle in a pair contracts, to bend a joint for example, its partner then contracts and pulls in the opposite direction to straighten the joint out again.

Today’s Warm-up• Muscle Trivia…

• How many muscles are in the average adult human body?

• What is the strongest muscle in the body?

• What is the largest muscle in the body?

Approximately 650

Debatable, but many say the masseter (jaw).

The gluteus maximus in your rear end (buttocks).

Today’s Close

• Here’s one flexible guy and strong dude…

• In control of both his skeletal and muscular systems…

Robot Dancing

Amazing Strength Break-Dancing

http://www.youtube.com/watch?v=B9JZbqoR0Kg