GenBio Day 2 Review: Endocrine & Immune Systems PDF

Genbio [Day 2] Moving Exam Reviewer 1. Endocrine System – The endocrine system is a network of glands that produce and release hormones into the bloodstream. These hormones act as chemical messengers, regulating various bodily functions. Think of it as a sophisticated communication system...

Genbio [Day 2] Moving Exam Reviewer 1. Endocrine System – The endocrine system is a network of glands that produce and release hormones into the bloodstream. These hormones act as chemical messengers, regulating various bodily functions. Think of it as a sophisticated communication system using chemical signals instead of electrical ones like the nervous system. Glands & Hormones (Key Details): Pituitary (Master Gland): Anterior (GH, TSH, ACTH, FSH, LH, PRL); Posterior (ADH, oxytocin); Intermediate (MSH). Hypothalamus: Controls pituitary; produces ADH & oxytocin. Thyroid: T3, T4 (metabolism); Calcitonin (lowers blood calcium). Parathyroid: PTH (raises blood calcium). Adrenal Cortex: Corticosteroids (stress, metabolism, BP). Adrenal Medulla: Catecholamines (fight-or-flight). Pancreas: Insulin (lowers blood sugar); Glucagon (raises blood sugar). Pineal: Melatonin (sleep). Ovaries: Estrogen, progesterone (female reproduction). Testes: Testosterone (male reproduction). Key Concepts: Hormones need receptors to work. Feedback loops maintain balance. Hormones interact (work together or oppose each other). 2. Immune System – A complex network of cells, tissues, organs, and the substances they make that helps the body fight infections and other diseases. The immune system includes white blood cells and organs and tissues of the lymph system, such as the thymus, spleen, tonsils, lymph nodes, lymph vessels, and bone marrow. Parts [key details] : I. Lines of Defense: 1st Line (Innate): Physical barriers (skin, mucous membranes); chemical barriers (sweat, tears, stomach acid). Immediate, non-specific. 2nd Line (Innate): Inflammatory response (redness, swelling, heat, pain); phagocytes (macrophages, neutrophils); complement system (protein cascade). Fast, non-specific. 3rd Line (Adaptive): Specific immune response; lymphocytes (B cells, T cells). Slower, specific, creates memory. II. Key Players: Phagocytes: Engulf and destroy pathogens (macrophages, neutrophils). Lymphocytes: Specific immune cells. B cells: Produce antibodies (mark pathogens for destruction). T cells: Helper T cells: Activate B cells and other T cells. Cytotoxic T cells: Directly kill infected cells. Regulatory T cells: Suppress immune response. Antibodies: Proteins that bind to antigens (pathogen markers). Antigens: Molecules on pathogens that trigger an immune response. Memory Cells: Long-lived cells that provide immunity to future infections. III. Types of Immunity: Innate Immunity: Non-specific, present from birth. Adaptive Immunity: Specific, develops over time. Humoral Immunity: Antibody-mediated (B cells). Cell-mediated Immunity: T cell-mediated. Passive Immunity: Temporary immunity (e.g., antibodies from mother). Active Immunity: Long-lasting immunity (e.g., vaccination, infection). IV. Key Concepts: Antigen presentation: Macrophages display antigens to T cells. Clonal selection: Activated lymphocytes multiply to fight infection. Immunological memory: Basis for long-term immunity.  3. Lymphatic System – The lymphatic system is a network of delicate tubes throughout the body. It drains fluid (called lymph) that has leaked from the blood vessels into the tissues and empties it back into the bloodstream via the lymph nodes. Parts [key details] : I. Main Functions: Fluid Balance: Drains excess fluid (lymph) from tissues, returning it to the bloodstream. Immunity: Houses lymphocytes (white blood cells) that fight infection. Filters lymph and blood. Fat Absorption: Absorbs fats and fat-soluble vitamins from the digestive system. II. Key Components & Their Roles: Lymph: Fluid containing white blood cells, proteins, and fats. Lymphatic Vessels: Network of tubes carrying lymph throughout the body. One-way valves prevent backflow. Lymph Nodes: Bean-shaped structures filtering lymph, removing pathogens and debris. Swollen nodes indicate infection. Spleen: Largest lymphatic organ; filters blood, removes old red blood cells, and stores lymphocytes. Thymus: Where T lymphocytes mature; important in immune development (larger in children). Tonsils & Adenoids: Lymphatic tissue in the throat; trap pathogens entering through the mouth and nose. Bone Marrow: Produces lymphocytes (B cells and some T cells). Also crucial for red blood cell production. Appendix: Small pouch connected to the large intestine; its role in immunity is still being researched. May play a role in gut bacteria balance. III. Key Processes: Lymph Formation: Fluid leaks from capillaries into tissues; lymphatic vessels collect this excess fluid. Lymph Circulation: Lymph flows through lymphatic vessels, passing through lymph nodes for filtering. Immune Response: Lymphocytes in lymph nodes and other lymphatic organs attack pathogens. IV. Memorization Tip: – Think "FLIF": Fluid balance, Lymphocytes, Immunity, Fat absorption. This covers the main functions. Then, visualize the flow of lymph through the vessels and nodes.  4. Integumentary System – The integumentary system is your body's outer covering—skin, hair, and nails—protecting you from the environment. Parts [key details] : I. Skin (The Main Event): Epidermis (Outer Layer): Keratinocytes (produce keratin, waterproof), melanocytes (produce melanin, protects from UV), Langerhans cells (immune defense). Think: KML (Keratin, Melanin, Langerhans). Dermis (Middle Layer): Collagen & elastin (strength & elasticity), blood vessels (nourishment), nerve endings (sensation), hair follicles, sweat & oil glands. Think: C-B-N-H- S-O (Collagen, Blood, Nerves, Hair, Sweat, Oil). Hypodermis (Inner Layer): Fat (insulation, energy storage). II. Hair & Nails (The Accessories): Hair: Keratin protein, protects scalp, sensory function. Nails: Keratin protein, protects fingertips & toes. III. Glands (The Support Crew): Sweat Glands: Thermoregulation (cooling), waste excretion. Sebaceous (Oil) Glands: Lubricates skin & hair, prevents dryness. IV. Key Functions (The Big Picture): Protection: Barrier against infection, UV radiation, dehydration. Regulation: Body temperature, water balance. Sensation: Touch, pressure, temperature, pain. Excretion: Waste removal through sweat. Vitamin D Synthesis: UV exposure triggers vitamin D production. 5. Nervous System – The nervous system is your body's control center, using electrical and chemical signals for  – rapid communication. It's divided into two main parts: Parts [key details] : I. Central Nervous System (CNS): The "command center." Brain: Control center for thoughts, emotions, and actions. Major parts include: Cerebrum: Higher-level thinking, memory, voluntary movement. Cerebellum: Coordination, balance, posture. Brainstem: Basic life functions (breathing, heart rate). Diencephalon (Thalamus & Hypothalamus): Relay center (thalamus); hormone regulation (hypothalamus). Spinal Cord: Connects brain to the rest of the body; reflexes. II. Peripheral Nervous System (PNS): The "communication network." Connects CNS to the rest of the body. Divided into: Somatic Nervous System: Voluntary control of skeletal muscles. Autonomic Nervous System: Involuntary control of internal organs. Further divided into: Sympathetic Nervous System: "Fight-or-flight" response. Parasympathetic Nervous System: "Rest-and-digest" response. III. Key Concepts: Neurons: Nerve cells that transmit signals. Neurotransmitters: Chemical messengers that transmit signals between neurons. Reflex Arc: Rapid, involuntary response to a stimulus.  6. Plant Organ System I. The Plant Body: Basic Structure – Plants, unlike animals, have modular structures. They are composed of repeating units (modules) of leaves, stems, and roots. These are the main plant organs. II. Major Organ Systems & Their Functions: Root System: Anchors the plant, absorbs water and minerals from the soil. Key structures  include root hairs (increase surface area for absorption) and the taproot or fibrous root system. Shoot System: Everything above ground. Includes: Stems: Support the plant, transport water & nutrients (xylem & phloem). Key structures include nodes (where leaves attach) and internodes (spaces between nodes). Leaves: Main photosynthetic organs; capture sunlight to make food. Key structures include the blade, petiole (stalk), and veins (vascular tissue). Flowers (Reproductive): Produce seeds for reproduction. Key structures include sepals, petals, stamens (male), and carpels (female). III. Tissue Systems (Underlying Structure): Plant organs are made up of three tissue systems: Dermal Tissue: Outer protective layer (epidermis). In woody plants, this is replaced by bark. Vascular Tissue: Transports water, minerals, and sugars. Includes xylem (water & minerals up) and phloem (sugars down). Ground Tissue: Makes up the bulk of the plant; performs photosynthesis, storage, and support. IV. Key Concepts: Photosynthesis: Process where plants convert light energy into chemical energy (sugars). Transpiration: Loss of water vapor from leaves; helps pull water up from the roots. Tropisms: Plant growth responses to stimuli (e.g., phototropism – growth towards light).  7. Feedback Mechanism – Feedback mechanisms are control systems that maintain homeostasis (internal balance) in the body. They work by detecting changes and triggering responses to counteract those changes. Think of them as the body's built-in thermostat. – Feedback mechanisms are how your body keeps things balanced. Think of it like a self- adjusting system. Types of Feedback: Negative Feedback (Most Common): This is like a thermostat. It reverses a change to bring things back to normal. Example 1 (Body Temperature): Imagine you're too hot. Your body sweats to cool you down. Once you're at a normal temperature, the sweating stops. Example 2 (Hunger): You're hungry (low blood sugar). You eat (raising blood sugar). Once you're full, your hunger goes away. Positive Feedback (Less Common): This amplifies a change. It's like a snowball rolling downhill – it gets bigger and bigger. Usually used for quick processes. Example 1 (Fruit Ripening): One ripe fruit releases ethylene gas, which makes nearby fruits ripen faster. Example 2 (Blood Clotting): A cut triggers a chain reaction where more and more clotting factors are released until the bleeding stops. Parts of a Feedback Loop (Simplified): 1. Sensor: Something that detects a change (like your skin feeling hot). 2. Control Center: Your brain decides what to do (tells you to sweat). 3. Effector: Does the action (your sweat glands). Memorization Tip: Think "Super Control Effort" (Sensor, Control Center, Effector). Examples of Negative Feedback Loops (Beyond Blood Glucose): Body Temperature Regulation: Shivering when cold, sweating when hot. Blood Pressure Regulation: Baroreceptors detect changes in blood pressure and trigger  adjustments in heart rate and blood vessel diameter. Osmoregulation: ADH regulates water balance by affecting kidney function. Examples of Positive Feedback Loops (Beyond Childbirth): Blood Clotting: Platelet activation triggers more platelet activation to form a clot. Lactation: Suckling stimulates milk production, which stimulates more suckling.