Skeletal System

The skeletal system is made up of 206 bones and related cartilage, tendons, ligaments and joints. The bones form a rigid framework that gives the body shape and form, and protect the vital internal organs. The skeleton features two parts: the axial skeleton, aligned along the front of the body and the appendicular skeleton, aligned along the back of the body
Main Function(s) of the Skeletal System

Support the overall body by providing a strong shape and form

Safeguard essential organs

Enable the body to move. 

Store fats and minerals

Produce blood cells

Components of the Skeletal System:

Bones: Mostly made from a protein called collagen and a mineral called calcium phosphate, together they give bones their framework and rigidness. Bones also provide the body with a shape and form, as well as structural support.

Cartilage: Flexible connective tissue made mostly up of collagen that align along the surface of bones at the joints to allow more fluid movement. It also serves to pad and protect the end of joints, and make up part of the ears and nose.

Ligaments: Elastic connective tissue made mostly up of collagen fibers that connect bone to bone. These fibers and tissue form muscular elastic bands of various shapes and sizes that help support the body’s framework and structure.

Tendons: Fibrous connective tissue made mostly up of collagen that connects muscles to bones. Ligaments prevent joints from

Joints: The point where bones come together to allow movement in various ways. Joints come in two types: immovable (skull) and movable (shoulders, elbows, knees)
 

The Nervous System

The nervous system is made up of the brain, spinal cord, sensory organs and associated nerves and neurons located throughout the body. It is split into two areas: the central nervous system (brain and spinal cord) and the peripheral (nerve and neuron) nervous system. It is responsible for collecting and processing information received from sensations from the body and sensory organs, and sending signals to the body with which to react with.

Main Function(s) of the Nervous System

Gather and interpret information

Respond to internal and external sensations and stimuli

Maintains homeostasis

Components of the Nervous System

Brain: Functions as the nervous system’s central control point. It gets signals from body and sensory organs and provides directions and instructions with which to react with.

Spinal cord: Relays brain signals to and from separate areas of the body, and co-ordinates reflexes managed alone through the spinal cord.

Sensory organs: Provides the five basic senses: sight, hearing, smell, taste and touch.

Nerves: Long, thin cables of fibers that send signals and information to various neurons, muscles and glands.

Hypothalamus: Manages homeostasis, the body’s need to maintain a stable inner condition that persists despite external stimuli. It also acts as a link between the endocrine and the nervous system.

The Respiratory System

The respiratory system is mostly made up of the lungs, nose, trachea, and all the parts of the bronchial tree. All body cells require oxygen to survive, and the respiratory system is responsible for oxygen intake and carbon dioxide expulsion.

Main Function(s) of the Respiratory System

Supplies the body with oxygen and disposes of carbon dioxide.

Gas exchange between the lungs and the bloodstream

Components of the Respiratory System

Nose: Provides an outside entry for air to flow into the body to the lungs by. Tiny hairs in the nose filter out dust and other particles that may be harmful to inhale.

Trachea: Serves as the main pathway from the nose to the lungs.

Bronchial tree: Performs the same role as the trachea: carries filtered air to the lungs from the nose. It includes the alveoli which is responsible for the lungs’ main function of exchanging oxygen and carbon dioxide in the bloodstream.

Lungs: Main function is to bring in oxygen from the outside to the body and bloodstream and exhale carbon dioxide waste back out of the mouth.

Maintenance of Body Temperature

A small but significant area of the brain, called the hypothalamus, manages body temperature that can activate sweat glands and muscles that control the hair of the body. Receptors in the skin cause the hypothalamus to trigger changes when the body begins to heat up to allow the sweat glands to produce an increase in sweat to cool down the body. It can also activate muscles in the skin that flatten body hair to increase heat loss. If the body temperature drops too much, the muscles can pull the body’s hair upright to reduce heat loss and send signals to cause the body to begin shivering, thereby expending energy to increase warmth.

Fluid Balance

Water is essential for life and general health, so maintaining the suitable fluid balance in the body is vital. Both liquids and food can provide water for the body. Water is lost primarily through urine and sweating. If the consumption of water is too high, the kidneys produce larger amounts of urine in an attempt to balance out fluids. If the body loses too much water, the kidneys try to maintain fluid balance by producing smaller but more concentrated amounts of urine.

Elimination of Waste

The body has a range of ways and organs to eliminate various wastes, including:
The liver – Breaks down and removes harmful substances from the body and filters out invasive bacteria, cells and viruses. Broken down wastes are then excreted out the body through the intestines and kidneys.

The kidneys – Uses water to dissolve and filter out toxic waste and excess water from the blood. Nephrons in the kidneys bring essential nutrients and water back into the blood, while keeping waste that is not needed by the body. The remaining liquid waste is then excreted out of the body in the form of urine through the bladder.

Intestines – As waste material and food from the stomach is carried through the intestines, it absorbs vital nutrients while avoiding any remaining harmful wastes or substances.
Colon – Remaining wastes are processed and excreted as part of the faeces.

Infection Prevention

Natural barriers such as skin and the immune system help protect the body from invasive organisms. White blood cells and antibodies are used by the immune system to identify and eliminate organisms that pass through these natural barriers of the body. Stomach acid is also an effective tool against infection as it is capable of dissolving and eliminating most harmful invading organisms.