The Human Body

Cells The basic unit of life Humans are multicellular organisms We are made of more than one cell Cells work together to perform certain functions All cells work together in multicelluar organisms to carry out lives processes Red blood cells in the human body.

Human Body Organization

Human Body Organization Tissues- A large group of similar specialized cells. Organs: A group of related tissues that perform a specific function. Organ Systems: A group of related organs that work together to perform a specific function.

Respiratory System

Respiratory System Function: Brings oxygen to the blood, and removes carbon dioxide from it. Main Organ: Lungs

Lungs Diseased Lungs- Smoker’s Lungs Healthy Lungs

Respiratory System When you inhale, air is brought in through two tubes – the bronchi Each bronchus branches into smaller tubes. The smallest tubes are alveoli

Respiratory System The alveoli are surrounded by capillaries. Oxygen passes from the alveoli into the blood, while carbon dioxide passes from the blood into the alveoli. Muscles attached to your ribs help pull the lungs up when you breathe The diaphragm at the bottom of the lungs help Pull the lungs down.

Common Questions Related to Respiratory System…. Why Do I Yawn?      When you are sleepy or drowsy the lungs do not take enough oxygen from the air. This causes a shortage of oxygen in our bodies. The brain senses this shortage of oxygen and sends a message that causes you to take a deep long breath---a YAWN. Why Do I Sneeze?      Sneezing is like a cough in the upper breathing passages. It is the body's way of removing an irritant from the sensitive mucous membranes of the nose. Many things can irritate the mucous membranes. Dust, pollen, pepper or even a cold blast of air are just some of the many things that may cause you to sneeze. What Causes Hiccups?     Hiccups are the sudden movements of the diaphragm. It is involuntary --- you have no control over hiccups, as you well know. There are many causes of hiccups. The diaphragm may get irritated, you may have eaten to fast, or maybe some substance in the blood could even have brought on the hiccups.  

The Circulatory System

The Circulatory System Function: Responsible for bringing oxygen and nutrients to all the cells of an animal’s body. It also takes carbon dioxide and waste away from the cells.

The Circulatory System Main Organ: Heart The Heart is about the size of your fist. Made of muscle tissue that pumps blood The human heart beats roughly 35 million times a year. It weighs less than a pound.

The Circulatory System Blood from the heart travels to the rest of the body through a network of arteries, capillaries, and veins.

Capillaries: microscopic blood vessels which connect arteries and veins Veins- Carry blood to the heart Arteries carry Blood Away

Heart Divided into four sections or chambers

Flow of Blood Blood from the body travels into the right atrium, moves into the right ventricle, and is finally pushed into lungs in the pulmonary arteries The blood then picks up oxygen and travels back to the heart into the left atrium through the pulmonary veins The blood then travels through the to the Left Ventricle and exits to the body through the Aorta…

Blood Flow Oxygen rich blood leaves the heart and travels through arteries In the capillaries the oxygen and food is given to the body’s cells The blood finally travels back through veins to the heart to pick up oxygen

Now… In summary who can tell how the blood flows in the human body?

The respiratory and circulatory systems work together by circulating carbon dioxide and oxygen throughout the body.