Breakdown for Function PDF

1. Integumentary and Sensation Skin Structure and Function: The skin is made up of three layers: Epidermis: Protective barrier. Dermis: Contains blood vessels, nerves, and glands. Hypodermis: Stores fat, provides insulation. Role of Melanin: Pr...

1. Integumentary and Sensation Skin Structure and Function: The skin is made up of three layers: Epidermis: Protective barrier. Dermis: Contains blood vessels, nerves, and glands. Hypodermis: Stores fat, provides insulation. Role of Melanin: Protects against UV radiation by absorbing harmful light. Skin Glands: Sebaceous glands: Secrete sebum for moisturizing. Sweat glands: Aid in thermoregulation. Eye Structures and Functions: Cornea: Refracts light to help focus. Retina: Converts light into neural signals. Iris: Regulates the amount of light entering the eye. Optic Nerve: Transmits visual information to the brain. Hearing Process: Outer Ear: Captures sound. Middle Ear: Ampli es sound via ossicles. Inner Ear: Converts sound to neural signals; cochlea is key for this. Hair and Nail Structure: Hair: Composed of keratin; grows from follicles in the dermis. Nails: Made of keratin; protect the tips of ngers and toes. 2. GI System Digestion Types: Mechanical: Physical breakdown (e.g., chewing). Chemical: Enzymatic breakdown (e.g., amylase breaking down carbohydrates). Alimentary Canal Functions: Mouth: Starts digestion. Esophagus: Transports food. Stomach: Acidic breakdown. Small Intestine: Absorbs nutrients. Large Intestine: Absorbs water, forms stool. Liver Functions: Produces bile for fat digestion. Regulates glucose via glycogen storage. Pancreas (Exocrine Function):  Produces digestive enzymes (e.g., lipase, amylase). Fat-Soluble Vitamins: A, D, E, and K require fats for absorption. Peritoneal Cavity Importance: Reduces friction during organ movement. 3. Endocrine System Hormonal Regulation: Negative Feedback: Regulates hormones to maintain balance (e.g., insulin). Positive Feedback: Ampli es changes (e.g., oxytocin in childbirth). Endocrine Glands: Hypothalamus: Controls pituitary gland. Pituitary: Secretes hormones (e.g., growth hormone). Thyroid: Regulates metabolism. Adrenal Glands: Produce epinephrine, cortisol. ADH & Oxytocin: ADH (antidiuretic hormone): Water retention (secreted by posterior pituitary). Oxytocin: Stimulates uterine contractions and milk ejection. Thyroid and Parathyroid Hormones: Thyroid: Produces T3, T4 (metabolism regulation). Parathyroid: Regulates calcium via parathyroid hormone (PTH). Pancreatic Hormones: Insulin: Lowers blood sugar. Glucagon: Raises blood sugar. E ects of Epinephrine: Increases heart rate, blood pressure, and energy. Circadian Rhythm Hormones: Regulated by melatonin (pineal gland). Aldosterone Function: Maintains blood pressure by regulating sodium and potassium levels (secreted by adrenal cortex). 4. Lymphatic and Immune System Immune Cells and Functions: Neutrophils: First responders, ght infections. Lymphocytes: T-cells (kill infected cells) and B-cells (produce antibodies). Antigens: Foreign molecules triggering an immune response. Lymphatic System Structures: Lymph Nodes: Filter pathogens. Lymphatic Fluid: Transports immune cells. In ammatory Process: Steps: Redness, heat, swelling, pain. Bene ts: Protects and begins healing. Factors Promoting Lymph Flow: Skeletal muscle contraction, breathing. Immunity: Passive: Antibodies from another source (e.g., breastfeeding). Active: Antibodies from infection or vaccination. 5. Renal System Kidney Structure and Function: Nephron: Filters blood, regulates electrolytes. Renal Cortex/Medulla: Site of ltration and urine concentration. Blood Filtration Process: Blood ltered in the glomerulus, urine forms through reabsorption and secretion. Micturition Re ex: Coordination of bladder contraction and urethral sphincter relaxation. ADH and Aldosterone in Blood Pressure: ADH: Retains water, increases blood volume. Aldosterone: Promotes sodium reabsorption, raises blood pressure. 6. Nervous System Somatic vs. Autonomic: Somatic: Voluntary control (e.g., skeletal muscles). Autonomic: Involuntary control (e.g., heart rate). Central vs. Peripheral: Central (CNS): Brain and spinal cord. Peripheral (PNS): Nerves outside CNS. A erent/E erent: A erent: Sensory input to CNS. E erent: Motor output from CNS. Neuron Components: Dendrites, cell body, axon. Cranial vs. Spinal Nerves: Cranial: 12 pairs; emerge from brain. Spinal: 31 pairs; emerge from spinal cord. Types of Neurons: Chemoreceptors: Detect chemicals. Osmoreceptors: Monitor osmotic pressure. Nociceptors: Detect pain. Thermoreceptors: Detect temperature. Brain Lobes: Frontal: Decision-making. Parietal: Sensory input. Temporal: Hearing, memory. Occipital: Vision. Autonomic Nervous System: Sympathetic (“ ght or ight”) and Parasympathetic (“rest and digest”). Cerebrospinal Fluid Functions: Protects, nourishes brain/spinal cord. Role of Myelin: Insulates axons, speeds up nerve impulses. 7. Reproductive Systems  Uterus Functions: Supports fetal development. Uterine Tubes: Transport ova, site of fertilization. Hormones of Mammary Glands: Prolactin (milk production), oxytocin (milk ejection). Male Reproductive System: Components: Testes, vas deferens, prostate, penis. Hormones: Testosterone regulates spermatogenesis. Relation to Urinary System: Shared urethra for semen and urine passage.