bodily systems

Skeletal system

• The skeleton is the internal framework of the human body

• Is composed of 270 bones at birth and decreases to approximately 206 bones by adulthood after some fuse together

Bones to know

• Cranium

• Mandible

• Clavicle

• Pelvis

• Fibula

• Ulna

• Calcaneus

• Cervical

• Sternum

• Phalanges (of the feet)

• scapula

• Humerus

• Femur

• Tarsals

• Sacrum

• Coccyx

• Ribs

• Thoracic

• Radius

• Carpals

• Metacarpals

• patella

• metatarsals

• lumbar

• phalanges (of the hands)

• tibia

Vertebrae

• Small bones making up the spine

• Each vertebrae increases in size as you move down from the head to the waist

• Each vertebrae has a hollow centre through which is the spinal cord passes

• The spinal cord relies on the vertebrae for protection

Skeletal system functions

1. Allows movement

   • The skeleton allows movement of the body

   • Bones provide surfaces for the attachment of muscles

   • Bones allow muscles to pull on them to produce movement

2. Shape and protection

   • The skeleton gives the correct shape to our body

   • Bones protect internal organs and reduce the risk of injury on impact

     • rib cage protect the heart and lungs

     • Cranium protects the brain

     • Vertebra protects the spinal cord

3. Mineral storage

   • Bones store minerals such as calcium, iron, potassium and phosphorus

   • minerals will be released into the blood when the body needs them

4. Production of blood cells

• Red and white blood cells are produced in the bone marrow (centre of most bones)

Red blood cells

• Carry oxygen to muscles

• Are red in colour due to haemoglobin

  • haemoglobin is a protein containing iron

• Production is very high during growth years and decreases with age

White blood cells

• Fight infection in the body

Muscular System

• The muscular system is an organ system consisting of approximately 600 muscles

Muscles to know

• Trapezius

• Wrist flexors

• Soleus

• Biceps

• Gluteus Maximus

• Rectus abddonminus

• deltoid

• hamstrings

• tibialis anterior

• triceps

• obliques

• erector spinae

• pectoralis major

• gastrocnemius

• quadriceps

• latissimus dorsi

• adductors

• abductors

Muscular system functions

• Create movement

  • muscles are responsible for the movements we make

  • muscles pull on bones to produce movement

• Posture

  • Flexibility and strength are ket to maintaining proper posture

  • Poor posture can lead to joint pain and weaker muscles

• Heat production

  • when muscles contract, they generate heat

  • the heat produced is vital for maintaining body temperature

Musculoskeletal system

• Refers to the bones, ligaments, tendons and muscles

• The collaboration between the skeletal and muscular systems gives the body it’s ability to move

Ligaments

• Are a fibrous tissue that connect bone to bone

Tendons

• Tendons are tough bands that connect muscles to bones

• To create movement, muscles pull on tendons which pull on bones

Flexion

• A movement that decreases the angle between the bones at a joint

Extension

• A movement that increases the angle between two body parts

Reciprocal Inhibition

• Skeletal muscles work in pairs to enable movement

• When one muscle contracts, it’s pair relaxes

• Agonist describes the muscle that contracts (shorten)

• Antagonist describes the muscle that relaxes (lengthens)

Cardiovascular System

• Also known as the circulatory system

• Consists of the heart and blood vessels working together to transport gases and nutrients around the body

Functions of the cardiovascular system

1. circulates blood around the body

2. transports oxygen and nutrients to the cell

3. transports wastes (carbon dioxide) away from the cells

4. Maintains stable body temperatures

Blood vessels

• Types of blood vessels include:

1. Arteries

   • Generally carry oxygen rich (oxygenated) blood

   • Always transport blood away from the heart to the body

   • Have elastic walls so they can expand to accommodate more volume

   • An artery has a thick, elastic, muscular walls

   • The Aorta is the largest artery in the body

     • the left ventricle pushes blood into the aorta and on to the rest of the body

2. Capillaries

   • The smallest type of blood vessel

   • The site where nutrients and waste are exchanged between the blood and the body cells

     • the exchange is extremely fast because of the thin capillary walls

   • A capillary has very thin walls that allows oxygen, carbon dioxide and nutrients to pass into the cells

3. Veins

   • Generally carry blood with lower oxygen content and higher carbon dioxide content (deoxygenated)

   • Always transports blood from the body back to the heart (towards the heart)

   • Have thin walls and not as elastic as the walls of the arteries

   • Rely on skeletal muscles contracting to transport blood back to the heart

   • One-way valves prevent blood flowing in the wrong direction