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Respiratory and Circulatory Systems

Respiratory System

Function: The respiratory system is responsible for the intake of oxygen and the expulsion of carbon dioxide.

Key Organs and Their Functions:

• Nose/Nasal Cavity: Filters, warms, and moistens air.
• Pharynx (Throat): Pathway for air to travel from the nose/mouth to the larynx.
• Larynx (Voice Box): Routes air and food into the proper channels and contains vocal cords.
• Trachea (Windpipe): Main passageway for air to enter the lungs.
• Bronchi: Two main branches from the trachea leading into each lung.
• Bronchioles: Smaller branches of the bronchi that spread throughout the lungs.
• Alveoli: Tiny air sacs where gas exchange occurs between the air and blood.

Cells Involved:

• Ciliated Epithelial Cells: Line the respiratory tract and move mucus and trapped particles.
• Type I Alveolar Cells: Facilitate gas exchange.
• Type II Alveolar Cells: Secrete surfactant to reduce surface tension in the alveoli.

Circulatory System

Function: The circulatory system transports blood, nutrients, gases, and wastes to and from cells in the body.

Key Organs and Their Functions:

• Heart: Pumps blood throughout the body.
  • Right Atrium: Receives deoxygenated blood from the body.
  • Right Ventricle: Pumps deoxygenated blood to the lungs.
  • Left Atrium: Receives oxygenated blood from the lungs.
  • Left Ventricle: Pumps oxygenated blood to the body.
• Blood Vessels:
  • Arteries: Carry blood away from the heart.
  • Veins: Carry blood to the heart.
  • Capillaries: Sites of exchange between blood and tissues.
• Blood:
  • Red Blood Cells (Erythrocytes): Carry oxygen.
  • White Blood Cells (Leukocytes): Fight infection.
  • Platelets (Thrombocytes): Aid in blood clotting.
  • Plasma: Liquid component that transports nutrients, hormones, and waste products.

Digestive System

Function: Breaks down food into nutrients that can be absorbed and used by the body, and eliminates waste products.

Key Organs and Their Functions:

• Mouth: Mechanical and chemical digestion begins here; saliva contains enzymes that start carbohydrate digestion.
• Esophagus: Transports food from the mouth to the stomach.
• Stomach: Secretes acid and enzymes for protein digestion; churns food into chyme.
• Small Intestine: Main site of nutrient absorption; divided into the duodenum, jejunum, and ileum.
• Liver: Produces bile to aid in fat digestion and detoxifies substances.
• Gallbladder: Stores and concentrates bile.
• Pancreas: Produces digestive enzymes and bicarbonate to neutralize stomach acid in the small intestine.
• Large Intestine (Colon): Absorbs water and electrolytes; forms and stores feces.
• Rectum and Anus: Control the expulsion of feces from the body.

Cells Involved:

• Epithelial Cells: Line the digestive tract and aid in absorption and secretion.
• Goblet Cells: Secrete mucus to protect the lining of the digestive tract.
• Enterocytes: Absorb nutrients in the small intestine.

Balanced Diet and Health Issues

Balanced Diet

Definition: A balanced diet contains the appropriate proportions of carbohydrates, proteins, fats, vitamins, minerals, and water necessary to maintain health and vitality.

Components:

• Carbohydrates: Provide energy. Found in fruits, vegetables, grains, and legumes.
• Proteins: Necessary for growth and repair. Found in meat, fish, dairy, beans, and nuts.
• Fats: Essential for energy storage, cell function, and protection of organs. Found in oils, butter, nuts, and fatty fish.
• Vitamins: Essential for various metabolic processes. Found in fruits, vegetables, and animal products.
• Minerals: Important for bone health, nerve function, and muscle contraction. Found in meat, dairy, vegetables, and nuts.
• Water: Vital for hydration, digestion, and nutrient transport.

Health Issues Related to Diet

• Obesity: Excessive fat accumulation due to an imbalance between calorie intake and expenditure.
• Diabetes: A condition where the body cannot properly regulate blood sugar levels.
• Cardiovascular Diseases: Conditions affecting the heart and blood vessels, often linked to diet high in saturated fats and cholesterol.
• Malnutrition: Results from a diet lacking in essential nutrients, can lead to conditions such as scurvy (vitamin C deficiency), rickets (vitamin D deficiency), and anemia (iron deficiency).

Plant and Animal Cells

Plant Cells

Unique Structures and Functions:

• Cell Wall: Provides rigidity and protection.
• Chloroplasts: Sites of photosynthesis, convert light energy into chemical energy.
• Vacuole: Large central vacuole stores nutrients and waste products, maintains turgor pressure.
• Plasmodesmata: Channels that allow communication and transport between plant cells.

Common Structures with Animal Cells:

• Nucleus: Contains genetic material (DNA).
• Mitochondria: Powerhouse of the cell, site of ATP production.
• Endoplasmic Reticulum (ER): Rough ER synthesizes proteins; Smooth ER synthesizes lipids and detoxifies chemicals.
• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for transport.
• Ribosomes: Synthesize proteins.

Animal Cells

Unique Structures and Functions:

• Lysosomes: Contain enzymes to break down waste materials and cellular debris.
• Centrioles: Involved in cell division and the formation of spindle fibers.

Common Structures with Plant Cells:

• Nucleus: Contains genetic material (DNA).
• Mitochondria: Powerhouse of the cell, site of ATP production.
• Endoplasmic Reticulum (ER): Rough ER synthesizes proteins; Smooth ER synthesizes lipids and detoxifies chemicals.
• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for transport.
• Ribosomes: Synthesize proteins.