Musculoskeletal System - Mr D'Antoni's Wonderful...

Musculoskeletal System

Musculoskeletal System

The musculoskeletal system is composed of three different parts:

Bones

Joints

Muscles

Bones

Our bones are hard solid organ that forms part of the skeleton.

Our bodies can be broken down into 3 sections

Head

Trunk

Limbs

Bones

Bones are mostly made up of bone cells that are continuously renewed.

There are two types of bone

Spongy bone contains many small cavities

Compact bone is much more dense

Bones

Bones come in a variety of shapes and sizes.

Bones can be divided into 4 categories.

Long bones

Short bones

Flat bones

Irregular bones

Long Bones

Longer than they are wide

They have a long thin body, called the diaphysis, and two rounded extremities, called epiphyses.

They are mainly compact bone.

The center contains bone marrow, a soft, fatty substance and blood vessels.

These bones are mainly found in the limbs.

Long Bones

Short Bones

Generally cubic.

Mainly composed of spongy bone

Generally found in the wrists and heels

Short Bones

Flat Bones

Thin, flat and generally curved.

They’re made up of two layers of compact bones separated by a small layer of spongy tissue.

These are found in the skull, ribs, sternum and scapula (Shoulder blade)

Flat Bones

Irregular Bones

These bones do not fit into any other category

They have irregular shapes.

They are found mainly in the spine

Irregular Bones

Bones

Bones

Function of Bones

Support Bones form a rigid structure that makes up the framework of

our bodies. They also provide an anchor for organs and muscles.

Protection Bones protect our internal organs. Rib cage protects the lungs

and heart. Skull protects the brain.

Movement Bones act as levers during muscle movement.

Function

Storage

Internal cavities of the bones store fat. Bony tissue stores minerals, such as calcium and phosphorus.

Production of blood cells

The bone marrow found in the bones produces the formed elements of the blood

Red blood cells, white blood cells and platelets.

Joint

A joint is the junction between two or more bones.

Joints are essential as they allow movement.

Almost all bones have at least one joint.

Joints are lined with cartilage to minimize wear on the bones.

Types of Joints

There are 3 types of joints in our bodies

Fixed

These joints do not move. They are the type of joints which are in our skull.

Semi-movable

These are joints with only a small range of motion. The spine is a series of these joints.

Fixed Joints

Semi-Movable

Types of Joints

Freely movable joint

Some joints can only move in one direction

Ex Elbow and Knees

Some joints have a complete range of motion

Hips and Shoulders

Movable Joints

Movable Joints

Types of Joints

Muscles

Muscles have the ability to contract causing our bodies or our internal organs to move.

Muscles have 4 functions Movement

Posture maintenance

Joint stabilization

Heat release

Movement

Muscle movement can either be voluntary or involuntary.

Voluntary movements are movements as raising your arm or moving your legs.

Examples of involuntary movements are peristalsis and your heart beating.

Posture, Joints and Heat

When we aren’t moving, our muscles are still contracting and releasing to maintain our posture.

Muscles are also used to stabilize your joints. Some joints need muscles to stay in place.

Most (75%) of the energy used by muscles are transformed into heat. The heat lost helps maintain our body’s temperature.

Types of Muscles

There are 3 different types of muscles

Skeletal Muscles

Also known as striated)

Smooth muscles

Cardiac Muscles

Skeletal Muscles

Skeletal muscles are the only voluntary muscles in our bodies.

They are attached to bones.

As they contract, they move the bones.

Skeletal muscles have relatively low endurance and must rest after being exerted.

Skeletal Muscles

Skeletal muscles are made up of several muscle fibers gathered into bundles.

Muscles are held together with connective tissue and is connected to the bone through tendons.

Skeletal muscles also have antagonistic muscles.

This means that they pull in opposite directions to move a joint in opposite directions Ex Bicep and Tricep

Skeletal Muscles

Antagonistic Muscles

Smooth Muscles

Smooth muscles make up the walls of certain internal organs.

Ex Uterus, stomach, uterus

They move involuntarily.

They move much slower but tirelessly.

Smooth Muscles

Cardiac Muscle

Cardiac muscle is the muscle that makes up the heart.

It is an involuntary muscle with a structure more similar to skeletal muscle.

It has great strength and endurance.

This type of muscle is branched.

Cardiac Muscle

Bones

The adult human body has 206 bones.

The femur, or thighbone, is the longest and strongest bone of the human skeleton.

There are 26 bones in the human foot.

The human hand, including the wrist, contains 54 bones.

Bones

We’re going to learning about the bones in the arms, legs, head and trunk.

We won’t be learning all of the bones.

You will be given a diagram on the test where you’ll have to identify them.

Bones of the Skull

Bones of the Skull

For the skull, all you are responsible to know is:

The skull

Mandible (jaw)

The skull is composed of 22 different bones, but most fuse together by the age of 2.

Bones in the Spine

Bones of the Spine

The spine is composed of 33 bones in 5 sections

From top to bottom, the sections are:

Cervical

Thoracic

Lumbar

Sacrum

Coccyx

Bones of the Arm and Hand

Bones of the Arm and Hand

There are 3 bones in the arm

Humerus – Upper arm

Ulna – Bone from the elbow to pinky

Radius – Bone from the elbow to thumb

The wrist and hand are in 3 sections

Carpals

Metacarpals

Phalanges

Bones of the Leg and Foot

Bones of the Leg and Foot

The legs have 4 bones

Femur – Thigh bone Tibia – Shin bone Fibula – A bone in the lower leg Patella – Kneecap

The foot is similar to the hand

Tarsals Metatarsals Phalanges

The link between the femur and spine is the pelvis.

Ribs

Scapula

Ribs and Scapula

You have 12 sets of ribs Some individuals can have 11 or 13 ribs.

Ribs are classified into 3 categories True ribs are connected directly to the sternum.

False ribs are connected to the sternum through another rib

Floating ribs do not connect to the sternum

The sternum is the bone where the ribs meet.

The scapula is the shoulder blade.

Muscles

You are born with every muscle fiber that you’ll ever have.

If all of your muscles could pull in one direction, they would be capable of pulling 25 tons.

There are around 650 muscles in the body.

Muscles

Muscles

The muscles you will be responsible for are:

Bicep

Triceps

Deltoid

Pectoral

Quadriceps

Glutes

Anterior tibialis

Calves

Hamstrings

Obliques

Abdominals

Erector Spinae

Latissimus Dorsi

Trapezius

Muscles in the Arm

Shoulder and Chest

Leg Muscles

Core Muscles

Back Muscles