Structure and Function of the Skeletal System

• A&P
• Higher Education (non-degree)

ANATOMY AND PHYSIOLOGY FOR SPORTS MASSAGE 

THE STRUCTURE AND FUNCTION OF THE SKELETAL SYSTEM

ANATOMY AND PHYSIOLOGY 

THE STRUCTURE AND FUNCTION OF THE MUSCULO SKELETAL SYSTEM

What are you going to learn?

In this lesson you're going to learn to . . .

1

2

3

Describe the structure of the muscular system.

Describe the functions of the skeletal system.

Identify the muscles of the arm and leg

Identify the bones of the head, neck and shoulder

4

STRUCTURE OF THE SKELETON  

Cranium- This is the highest bone of the skeleton and is made up of 8 bones fused together to protect the brain.

Scapula- This bone is also named as the shoulder blade that connects the clavicle to the humerus. It forms the posterior of the shoulder girdle.

RIbs- Adults have 12 pairs of these flat bones which attach at the spine and the sternum to form a cage around heart and lungs to protect them.

Radius- This bone also forms part of the lower arm as it is positioned next to the Ulna and runs in line with the thumb side of the hand.

Clavicle- This bone forms part of the shoulder and attaches the upper arm to the body. It is sometimes called your collar bone.

Mandible- the lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton.

Femur- This is the longest bone in the body and attaches to the pelvis at the top and the knee at the bottom. It is commonly known as the thigh bone.

Fibula- This is the smaller bone of the lower leg, positioned behind the Tibia, it is mainly used for muscles of the lower leg to attach to

Tibia- This is the biggest bone in the lower leg, which joins with the Femur and Patella to form the knee joint, positioned at the front of the Fibula.

Pubis - This bone is one of three bones that fuse to form the hip bone. Together with the ilium and ischium.

Carpals- These bones are bones of the wrist that connect the end of the radius and ulnar bones of the forearm to the bases of the metacarpal bones of the hand.

Metacarpals- These bones are located in the wrist between the carpals and phalanges. 

Phalanges- These bones are found in both the hands and feet and form the bony core of the digits

Sternum- This is a flat bone in the middle of the chest that is shaped like a dagger. It is attached to the clavicle and protects the heart and joins the ribs together.

Patella- This is a small square bone that sits on top of the femur and the Tibia to form the knee joint.

Tarsals- These bones are situated between the lower end of the tibia and the fibula of the lower leg and the metatarsals. 

Metatarsals- These bones are located in the foot between the tarsals and phalanges.  

Phalanges - These bones are found in both the hands and feet and form the bony core of the digits.

Humerus- This is sometimes called your funny bone and it forms the upper arm connecting the shoulder at the top and the forearm at the bottom.

Ulna- This bone forms part of the lower arm and joins the Humerus with the elbow joint and runs in line with the little finger.

Illium- This bone is the uppermost and largest part of the hip bone.

Ishium- This bone is a paired bone of the pelvis that forms the lower and back part of the hip bone. 

Vertebral Coloumn- This is 33 separate bones all joined together and join your cranium to your hips. These bones also allow your to perform movements like bending and nodding.

 

Cranium

Mandible

Humerus

Clavicle

Scapula

Sternum

Ulna

Radius

Patella

Fibula

Tibia

Illium 

Ishium

Ribs

Pubis

Tarsals, metatarsals, phalanges

Carpals, metacarpals, phalanges

Match up the functions of the skeleton to the images

Storage

Production

Protection

Movement

Structure

What do you already know about the bones in the head, neck and shoulder?

BONES OF THE CRANIUM 

The  cranium (skull) is composed of 22 bones and protects the brain.  

Eight bones make up the cranium and 14 bones form the bones of the facial skeleton. 

EIGHT BONES OF THE CRANIUM 

Frontal x 1	Forms the front of the skull and forehead and the eye sockets.
Parietal x 2	Form the upper sides of the skull and the back of the roof of the skull.
Temporal x 2	Form the sides of the skull below the parietal bones and around the ears.
Sphenoid x 1	In front of the temporal bone. Serves as a bridge between the cranium and the facial bones.
Ethmoid x 1	Forms part of the orbit, nasal cavity and nasal septum.
Occipital x 1	Forms the back of the cranium.

FOURTEEN BONES OF THE CRANIUM 

Maxilla x 2	Largest bones of the face. Upper jaw, supports teeth.
Mandible x 1	Only moveable part of the skull. Forms the lower jaw.
Zygomatic x 2	Form the cheekbones.
Nasal x 2 Turbinate x 2	Bridge of the nose. Found inside the nasal cavities.
Lacrimal x 2	Smallest of the facial bones. Near the eye orbit.
Vomer x 1	Single bone which separates the nasal cavity.
Palatine x 2	Form the roof of the house.

Frontal

Parietal

Occipital

Temporal

Ethmoid

Sphenoid

Maxilla

Mandible

Vomer

Zygomatic

Nasal

suture

Which bone forms the upper arm?

1. Humerus
2. Fibula
3. Tibia
4. Femur

What is the largest bone in the human body?

1. Femur
2. Tibia
3. Ulna
4. Radius

Which bone protects the brain?

1. Skull
2. Sternum
3. Clavicle
4. Scapula

What are the small bones in the wrist called?

1. Carpals
2. Phalanges
3. Tarsals
4. Metacarpals

CHARACTERISTICS OF TYPES OF MUSCLE TISSUE  

In the muscular system, muscle tissue is categorised into three distinct types: 

1) Skeletal 2) Cardiac 3) Smooth. 

Each type of muscle tissue in the human body has a unique structure and a specific role. Skeletal muscle moves bones and other structures. Cardiac muscle contracts the heart to pump blood. The smooth muscle tissue that forms organs like the stomach and bladder changes shape to facilitate bodily functions. 

CHARACTERISTICS OF TYPES OF MUSCLE TISSUE  

Skeletal muscles attach to and move bones by contracting and relaxing in response to voluntary messages from the nervous system. Skeletal muscle tissue is composed of long cells called muscle fibers that have a striated appearance. 

Smooth muscle is found in the walls of hollow organs throughout the body. Smooth muscle contractions are involuntary movements triggered by impulses that travel through the autonomic nervous system. 

Cardiac muscle is found only in the myocardium of the heart, it contracts in response to signals from the cardiac conduction system to make the heart beat. 

Muscle fibers are organized into bundles supplied by blood vessels and innervated by motor neurons.

Smooth muscle tissue allows for contraction and relaxation with great elasticity. In the urinary bladder they allow those organs to expand and relax. In the digestive tract they facilitate swallowed food and nutrients. In artery walls they relax and contract to move blood through the body.

Cardiac muscle is made from cells called cardiocytes. Like skeletal muscle cells cardiocytes have a striated appearance, but their overall structure is shorter and thicker. 

MUSCLE ATTACHMENTS 

Learning the muscular system often involves memorising details about each muscle, like where a muscle attaches to bones and how a muscle helps move a joint. 

A skeletal muscle attaches to bone (or sometimes other muscles or tissues) at two or more places. 

Origin

If the place is a bone that remains immobile for an action, the attachment is called an origin. 

Insertion

If the place is on the bone that moves during the action, the attachment is called an insertion. 

UPPER LIMB SKELETAL MUSCLES   

Wrist Extensors

Origin- Lateral humerus

Insertion- Back of hand

Primary action/s- Extension of wrist.

Brachialis

Origin- Mid humerus 

Insertion- Superior ulna 

Primary action/s- Flexion of forearm. 

Brachioradialis

Origin- Distal humerus

Insertion- Distal radius

Primary action/s- Flexion and supination of forearm. 

Wrist Flexors

Origin- Medial humerus

Insertion- Palm of hand

Primary action/s- Flexion of wrist.

Triceps Brachii

Origin- Long head: superior scapula, Lateral head: lateral posterior humerus, Medial head: Posterior humerus

Insertion- Superior ulna (olecranion)

Primary action/s- Extension of shoulder and elbow joint. 

Bicep Brachii

Origin- Long head: superior scapula, Short head: anterior scapula

Insertion- Radius 

Primary action/s- Flexion of shoulder and elbow joint, supination of forearm. 

MUSCLES OF THE LOWER LEG

Plantaris

Origin- Lateral upper femur

Insertion- Calcaneus 

Primary action/s- Plantarflexion of ankle. 

Gastrocnemius

Origin- Posterior medial / Lateral upper femur

Insertion- Calcaneus

Primary action/s- Flexion of knee and Plantarflexion of ankle. 

Tibialis Anterior

Origin- Lateral tibia

Insertion- Plantar surface of foot

Primary action/s- Dorsiflexion and Inversion of ankle. 

Tibialis Posterior

Origin- Posterior surfaces of tibia and fibula

Insertion- Plantar surface of foot

Primary action/s- Plantarflexion and Inversion of ankle. 

Popliteus

Origin- Lateral upper femur 

Insertion- Posterior upper tibia

Primary action/s- Flexion and medial rotation of the knee

Soleus

Origin- Upper posterior tibia and fibula

Insertion- Calcaneus

Primary action/s- Plantarflexion of ankle. 

MUSCLES OF THE LOWER LEG  

Extensor Digitorum Longus

Origin- Lateral upper tibia and anterior fibula

Insertion- Dorsal surface of 4 outer toes

Primary action/s- Dorsiflexion and Eversion of ankle. Extension of the 4 outer toes. 

Extensor Hallucis Longus

Origin- Anterior surface of the fibula 

Insertion- Dorsal surface of 1st (big) toe

Primary action/s- Dorsiflexion and Inversion of ankle. Extension of the 1st (big) toe. 

Flexor Digitorum Longus

Origin- Posterior surface of the tibia

Insertion- Plantar surface of 4 outer toes

Primary action/s- Plantarflexion and Inversion of ankle. Flexion of the 4 outer toes. 

Flexor Hallucis Longus

Origin- Lower fibula

Insertion- Plantar surface of 1st (big) toe

Primary action/s- Plantarflexion and Inversion of ankle. Flexion of the 1st (big) toe. 

Which muscle in the lower leg is deep to the gastrocnemius?

1. Rectus femoris
2. Latissimus dorsi
3. Soleus
4. Trapezius

Which muscle is located in the upper arm?

1. Biceps brachii
2. Rectus abdominis
3. Gluteus maximus
4. Deltoid

What is the main muscle in the lower leg?

1. Gastrocnemius
2. Quadriceps
3. Soleus
4. Hamstrings