Respiratory System

This system involves taking in and exchanging oxygen and carbon dioxide between organs. All this takes place in the lungs. We inhale air into our lungs and then exhale air out of the lungs. Let me explain the physiology in this:

• Ventilation: This pretty much mean how fast gas is going in and out of our lungs
• Control: Ventilation occurs with the help of our nervous system. Part of the brain is in charge of coordinating the movement of our breathing.
• Inhalation: This process involves the muscles in our chest and rib cages. When we inhale, our chest becomes larger because the volume inside our chest has increased. This mean our chest contracts.
• Exhalation: This is when we exhale the air out.
• Gas Exchange: During this process, carbon dioxide is removed as well as other gasses not needed in our body. This process is very important in keeping homeostasis balanced.
• Immune functions: Many molecules are secreted to help defend the lungs. They can also help with infection.
• Vocalization: The movement of gas is what help a person speak. Gas exchange is very important for communication.
• Coughing and sneezing: This happens because of an irritation of a nerve. When we sneeze or cough, air is being forced out. But coughing can be a good thing. Coughing helps remove dust, mucus and other things from the lungs.

The respiratory can also come across some disorders. Some of those disorders are asthma and pneumonia.

Cardiovascular System

This system involves the circulation of blood and transporting nutrients. All these nutrients help fight diseases and it maintains homeostasis. The structure consist of:

1. Closed cardiovascular system
2. The heart is where oxygenated blood is being pumped to the body. The heart consist of a right and left atrium and a right and a left ventricle.
3. The coronary system brings blood to the heart muscles.
4. Oxygen-depleted blood is pumped from the heart into the lungs. Then it is returned back to the heart.
5. Systemic circulation circulates blood everywhere.

Skeletal System

The skeletal system is the internal framework of the body. It consist of bones supporting the body and all its organs. We have about 270 bones when we are born but then that decreases to 206 bones by adulthood. The skeleton has six function:

1. Support: It provides support and structure to the body. If a certain bone is not functioning right or giving support, then it can ruin everything around it. An example can be seen in the chest. Without the rib cages and all the bones around it, it would lead to failure of the lungs.
2. Movement: Movement in the bones is done by the joints. We humans have a thing called a ball and socket joint that allows greater range movement like our arms. Other bones in our body use a pivot joint that does not allow so much movement like our necks.
3. Protection: The bones in our body protects important organs from being damages. The skull protects the brain and the rib cage protects our lungs.
4. Blood cell production: Blood cell developed in the bone marrow.
5. Storage: The bone stores calcium and iron involved in iron metabolism.
6. Endocrine regulation: This regulates the blood sugar and it is involved in secreting insulin.

The skeletal system can also produce many disorders.

1. Arthritis: This is an inflammation of the joints. As you can see from above, joints are used for movement. This disorder makes it very hard and painful to move.
2. Osteoporosis: Bone mineral is reduced and there is a big chance of fractures.