Humans and Animals Chapter 1

Study Notes

Brain: Controls thinking, reasoning, and all body functions.
Lungs: Spongy organs in the chest for oxygen intake and carbon dioxide removal.
Stomach: Initiates protein digestion and combines food with digestive juices.
Liver: Stores energy, detoxifies substances, and produces bile for fat digestion.
Small Intestine: Completes digestion of proteins, fats, and carbohydrates; absorbs nutrients.
Large Intestine: Reabsorbs water from undigested food; expels waste.
Bladder: Stores urine.
Heart: Pumps blood to distribute food and oxygen throughout the body.
Kidneys: Maintain water and salt balance; filter blood to eliminate waste in urine.

Function: Acts as a pump for circulating blood throughout the body.
Size: Approximately the size of a human fist.
Major Features:
- Vena Cava: Carries deoxygenated blood to the heart.
- Left Atrium: Receives oxygenated blood from the lungs.
- Left Ventricle: Pumps oxygenated blood to the body.
- Right Atrium: Receives deoxygenated blood.
- Right Ventricle: Pumps deoxygenated blood to the lungs.
- Pulmonary Artery: Transports deoxygenated blood to the lungs.
- Pulmonary Vein: Carries oxygenated blood from lungs.
- Valves: Ensure one-way blood flow and prevent backflow.
- Aorta: Main artery distributing oxygenated blood.

Composed of the heart, blood vessels (arteries, veins, capillaries), and blood (red/white cells, plasma, platelets).
Primary Role: Distributes oxygen, nutrients, and hormones while removing waste.
Blood Vessel Types:
- Arteries: Carry blood away from the heart.
- Veins: Return blood to the heart.
- Capillaries: Smallest vessels connecting arteries and veins.
Double Circulatory System: Blood passes through the heart twice per circuit for oxygenation.
- Right pump sends blood to the lungs; left pump distributes it to the body.

Respiratory System: Involves organs responsible for exchanging oxygen and carbon dioxide.
Oxygen reaches cells for cellular respiration, producing carbon dioxide as a waste product.
Breathing Process:
- Inhalation:
  - Rib muscles contract, lifting ribs and lowering pressure, drawing air into the lungs.
- Exhalation:
  - Rib muscles relax, ribs lower, diaphragm rises, increasing pressure to expel air.

Functions to absorb nutrients from food for energy and raw materials for the body.
Involves breaking down food into small molecules for absorption into the bloodstream.
Digestive Organs:
- Salivary Glands: Produce saliva to moisten food and initiate starch digestion.
- Esophagus: Transports food to the stomach via peristalsis.
- Stomach: Churns food and releases enzymes/acids for digestion.
- Small Intestine: Absorbs nutrients from digested food.
- Pancreas: Produces digestive enzymes for the small intestine.
- Liver: Processes nutrients, produces bile, detoxifies blood.
- Gall Bladder: Stores and releases bile.
- Colon: Absorbs water from undigested food.
- Rectum: Eliminates waste material as feces.
Key Processes:
- Ingestion, digestion, absorption, and egestion.
Types of Digestion:
- Mechanical: Physical breakdown of food (teeth).
- Chemical: Breakdown of food molecules via enzymes.

Bean-shaped organs responsible for filtering blood and maintaining homeostasis.
Key functions include removing toxins, waste products, and regulating water and salt balance.
Kidneys filter approximately half a cup of blood per minute.
Components of the Urinary System:
- Kidneys, Ureters, Bladder, Urethra.
Primary roles: Waste excretion, regulating blood composition and volume, stimulating red blood cell production, and activating Vitamin D.

Located within the skull, roughly the size of two fists, weighing about 1.3 kg.
Covered in folds and protected by cerebrospinal fluid.
Often referred to as "grey matter" due to its color.
Central part of the nervous system responsible for processing information and coordination of body functions.