Cardiovascular system overview Components: Heart: A muscular organ that pumps blood. Blood Vessels: Arteries: Carry oxygenated blood away from the heart. Veins: Return deoxygenated blood to the heart. Capillaries: Tiny vessels connecting arteries and veins, facilitating nutrient exchange. Blood: The mobile component containing red blood cells, white blood cells, and plasma. Function: Oxygen Delivery: The heart pumps oxygen-rich blood to body tissues. Waste Removal: Blood transports waste (like carbon dioxide) back to the lungs. Nutrient Transport: Blood delivers nutrients (glucose, amino acids, etc.) to cells. Pathway: Blood enters the right atrium, flows through the right ventricle, and goes to the lungs. In the lungs, oxygen enters the blood, and carbon dioxide is removed. Oxygenated blood returns to the left atrium, then flows through the left ventricle. The left ventricle pumps blood into the aorta, distributing it throughout the body.

Nervous System overview Nervous System us subdivided into: Central Nervous System (CNS): Consists of the brain and spinal cord. Acts as the supreme command center, regulating vital functions. Protected by meninges and encased within the skull and vertebral column Peripheral Nervous System (PNS): Compresses spinal nerves and cranial nerves. Connects the CNS to the rest of the body. Divided into: Somatic Nervous System (SNS): Controls voluntary movements. Automatic Nervous System (ANS): Regulates involuntary functions (eg, heartbeat, digestion). Sympathetic Division: Prepares the body for stress (fight or flight). Parasympathetic Division: Promotes relaxation and homeostasis (rest and digest). Enteric Section: Manages gut function.

Overview: The immune system detects and responds to various pathogens, including viruses, bacteria, parasites, and even cancer cells. It distinguishes these invaders from our healthy tissues. Components: Innate Immune System:Provides a preconfigured response to broad situations.Includes natural barriers (skin, mucous membranes) and innate immune cells (neutrophils, macrophages). Adaptive Immune System:Tailored response to specific stimuli. Utilizes lymphocytes (B cells, T cells) and immunoglobulins (antibodies). Creates immunological memory for faster and stronger responses. Functions: Innate Immunity: Acts as the first line of defense. Destroys pathogens using inflammation, complement system, and phagocytosis. Adaptive Immunity: Recognizes specific pathogens. Generates antibodies and memory cells for future encounters.

Respiratory system overview: Respiratory system is subdivided into Upper Respiratory Tract: Nasal Cavity: The external opening where air enters. It’s lined with ciliated columnar epithelium and contains sebaceous glands and hair follicles. Paranasal Sinuses: Air-filled spaces connected to the nasal cavity.Pharynx: The throat region. Larynx (Voice Box): Contains vocal cords. Lower Respiratory Tract: Trachea (Windpipe): Connects the larynx to the bronchi. Bronchi and Bronchioles: Branches of the trachea that lead to the lungs. Lungs: Contain alveoli for gas exchange. Muscles of Respiration: Diaphragm and intercostal muscles aid breathing. Functions: Conduction: Air moves through the respiratory tract. Filtration: Sebaceous glands and cilia prevent harmful particles from entering. Humidification and Warming: Nasal mucosa warms and moistens inhaled air. Gas Exchange: Lungs exchange oxygen for carbon dioxide in alveoli.