Cardiovascular System

The cardiovascular system's primary function is to circulate blood throughout the body, delivering essential substances to cells and removing waste products. This complex system includes various chambers and vessels that work in harmony.

Definition: The cardiovascular system pumps blood around the body to deliver required substances and remove waste products.

Highlight: The system includes specialized valves that prevent backward blood flow, ensuring efficient circulation.

Vocabulary:

• Atrioventricular valve: Prevents blood flow from ventricles back to atria
• Semilunar valve: Prevents blood flow from arteries back to ventricles

Digestive System

The digestive system processes food through both mechanical and chemical means, utilizing various organs and enzymes to break down nutrients for absorption.

Definition: Digestion is the process of breaking down food both chemically and mechanically using specialized enzymes.

Highlight: The liver performs over 7,200 different functions, including bile production and blood filtration.

Example: In the stomach, pepsin breaks down proteins into amino acids while hydrochloric acid kills harmful bacteria.

Vocabulary:

• Enzymes: Biological catalysts that speed up chemical reactions in the body
• Peristalsis: Muscle contractions that push food through the digestive tract

Respiratory System

The respiratory system facilitates gas exchange through a complex network of organs and structures. The process begins at the nose for air filtration and continues through the trachea, bronchi, and bronchioles, ultimately reaching the alveoli where gas exchange occurs.

Definition: Respiration is the process where oxygen and carbon dioxide are exchanged in the alveoli during inhalation and exhalation.

Highlight: The alveoli walls are only one cell thick to enable efficient gas exchange through diffusion.

Example: Oxygen moves from high concentration in the alveoli to low concentration in the blood, while carbon dioxide moves from high concentration in the blood to low concentration in the alveoli.

Vocabulary: Alveoli are tiny bubble-like structures where gas exchange occurs between deoxygenated blood and air.