Body Systems PDF

**Respiratory System** - **Function**: Provides oxygen to the body and removes carbon dioxide. - **Main Organs**: - **Lungs** -- Main organ where gas exchange happens. - **Trachea** -- Air passes through here to reach the lungs. - **Bronchi & Bronchioles** -- Tubes tha...

**Respiratory System** - **Function**: Provides oxygen to the body and removes carbon dioxide. - **Main Organs**: - **Lungs** -- Main organ where gas exchange happens. - **Trachea** -- Air passes through here to reach the lungs. - **Bronchi & Bronchioles** -- Tubes that direct air into the lungs. - **Alveoli** -- Tiny air sacs where oxygen enters the blood and carbon dioxide leaves. - **Adaptations of alveoli**:One cell thick to allow easy gas exchange,blood capillaries to allow diffusion of gases in and out of blood,large surface area to allow fast exchange of gases - **Diaphragm** -- Muscle that helps in breathing. - **Process**: - Oxygen is inhaled into the lungs. - Oxygen diffuses into the blood at the alveoli. - Carbon dioxide is removed from the blood and exhaled. - **During Exercise**: - Breathing rate increases to supply more oxygen. - More carbon dioxide is removed. - Deep breathing helps improve oxygen intake. **Digestive System**  - **Function**: Breaks down food into nutrients the body can use. - **Main Organs**: - **Mouth** -- Breaks down food using teeth and saliva. - **Esophagus** -- Moves food to the stomach. - **Stomach** -- Uses acid and enzymes to digest food. - **Small Intestine** -- Absorbs nutrients into the blood - **Large Intestine** -- Absorbs water and forms waste. - **Liver & Pancreas** -- Help digest fats and regulate blood sugar. **Circulatory System** - **Function**: Transports oxygen, nutrients, and waste around the body. - **Main Organs**: - **Heart** -- Pumps blood around the body. - **Blood Vessels** -- - **Arteries** -- Thick walls(to withstand high pressure,small lumen,Carry oxygen-rich blood away from the heart - **Veins** -- Thin walls,large lumen,Carry oxygen-poor blood back to the heart. - **Capillaries** -- Tiny network of vessels where gas exchange happens ,connects veins to arteries - **Blood Components**: - **Red Blood Cells** -- Carry oxygen. - **White Blood Cells** -- Fight infection. - **Platelets** -- Help with blood clotting. - **Plasma** -- Carries nutrients and waste. - **During Exercise**: - Heart rate increases to pump more oxygen to muscles. - More carbon dioxide is removed through the lungs. **Endocrine System** - **Function**: Produces hormones to regulate body functions. - **Main Glands & Hormones**: - **Pancreas** -- Produces **insulin** to control blood sugar. - **Adrenal Glands** -- Produce **adrenaline** for the \"fight or flight\" response.(excited,scared) - **Thyroid** Produces thyroxin-- Regulates metabolism. - **Pituitary Gland** -- Controls other glands ,produces growth hormone and antidiuretic hormone - **Reproductive glands** **Nervous System**  - **Function**: Controls body movements and responses. - **Main Parts**: - **Brain** -- Processes information and controls actions. - **Spinal Cord** -- Sends signals between the brain and body. - **Nerves** -- Carry messages to and from the brain. - **(Neuron** :The nerve cell-made up of cell body, dendrites ,axon and myelin sheath - **Types of Responses**: - **Voluntary** -- Controlled movements (e.g., catching a ball). - **Reflexes** -- Automatic responses (e.g., pulling hand away from heat).