🫁Honors Anatomy and Physiology Unit 1 – Intro to Anatomy & Physiology

Key Concepts and Terminology

• Anatomy studies the structure of living organisms including their systems, organs, and tissues
• Physiology focuses on the functions and processes carried out by anatomical structures to maintain life
• Homeostasis maintains stable internal conditions necessary for survival and proper functioning
• Negative feedback loops help maintain homeostasis by counteracting changes in the body's internal environment
• Positive feedback loops amplify changes and push systems away from equilibrium
• Anatomical position is the standard reference position used to describe the location of structures in the body
• Directional terms (superior, inferior, anterior, posterior, medial, lateral) describe the position of one structure relative to another

Body Organization and Homeostasis

• Levels of organization in the human body from simplest to most complex: chemical, cellular, tissue, organ, system, organism
• Cells are the basic structural and functional units of life
• Tissues consist of specialized cells that work together to perform a common function
  • Four main tissue types: epithelial, connective, muscular, nervous
• Organs are composed of multiple tissue types that work together to carry out specific functions
• Systems are groups of organs that work together to perform related functions and maintain homeostasis
• Homeostatic mechanisms regulate internal conditions such as body temperature, blood glucose levels, and pH
• Disruption of homeostasis can lead to disease or dysfunction

Anatomical Structures and Their Functions

• Skeletal system provides support, protection, movement, mineral storage, and blood cell production
  • Consists of bones, cartilage, ligaments, and tendons
• Muscular system enables movement, maintains posture, and generates heat
  • Includes skeletal, smooth, and cardiac muscle tissues
• Cardiovascular system transports oxygen, nutrients, hormones, and waste products throughout the body
  • Composed of the heart, blood vessels (arteries, veins, capillaries), and blood
• Respiratory system facilitates gas exchange between the air and blood
  • Includes the nose, pharynx, larynx, trachea, bronchi, and lungs
• Digestive system breaks down food, absorbs nutrients, and eliminates waste
  • Consists of the mouth, esophagus, stomach, small intestine, large intestine, and accessory organs (liver, pancreas, gallbladder)
• Nervous system receives, processes, and responds to internal and external stimuli
  • Divided into the central nervous system (brain and spinal cord) and peripheral nervous system (nerves)
• Endocrine system secretes hormones that regulate growth, development, metabolism, and reproduction
  • Includes glands such as the pituitary, thyroid, adrenal, and reproductive glands

Major Organ Systems Overview

• Integumentary system (skin, hair, nails) provides protection, temperature regulation, and sensory reception
• Lymphatic system defends against infection, maintains fluid balance, and absorbs fats
  • Includes lymph vessels, lymph nodes, spleen, and thymus
• Urinary system filters blood, removes waste, and regulates fluid and electrolyte balance
  • Consists of the kidneys, ureters, bladder, and urethra
• Reproductive system produces gametes and enables sexual reproduction
  • Male reproductive system includes testes, epididymis, vas deferens, prostate, and penis
  • Female reproductive system includes ovaries, fallopian tubes, uterus, and vagina
• Immune system defends against pathogens and abnormal cells
  • Involves white blood cells, antibodies, and lymphoid organs (lymph nodes, spleen, thymus)
• Sensory organs (eyes, ears, nose, tongue, skin) detect and respond to stimuli from the environment
• Endocrine and nervous systems work together to coordinate and regulate the functions of all organ systems

Cellular and Tissue Basics

• Cells are composed of organelles that carry out specific functions
  • Nucleus contains DNA and controls cellular activities
  • Mitochondria generate ATP for energy
  • Endoplasmic reticulum synthesizes and transports proteins and lipids
  • Golgi apparatus modifies, packages, and distributes proteins and lipids
  • Lysosomes break down cellular waste and foreign materials
• Cell membrane is a selectively permeable barrier that regulates the movement of substances in and out of the cell
• Tissues are classified based on their structure and function
  • Epithelial tissue covers surfaces, lines cavities, and forms glands
  • Connective tissue provides support, protection, and connects other tissues
    • Includes loose connective tissue, dense connective tissue, cartilage, bone, and blood
  • Muscular tissue enables movement and generates force
    • Includes skeletal, smooth, and cardiac muscle
  • Nervous tissue transmits electrical signals and processes information
    • Consists of neurons and glial cells
• Tissue repair involves inflammation, proliferation, and remodeling phases

Common Anatomical and Physiological Processes

• Cell division (mitosis) enables growth, repair, and replacement of cells
• Metabolism encompasses all chemical reactions in the body, including catabolism and anabolism
• Diffusion is the passive movement of substances from high to low concentration
• Osmosis is the diffusion of water across a selectively permeable membrane
• Active transport moves substances against their concentration gradient using energy (ATP)
• Secretion is the release of substances (hormones, enzymes, mucus) from cells or glands
• Excretion is the removal of metabolic waste products from the body
• Thermoregulation maintains a stable body temperature through mechanisms like sweating and shivering
• Neuronal signaling involves the generation and transmission of electrical impulses (action potentials) along neurons
• Muscle contraction occurs when myosin filaments slide past actin filaments, shortening the muscle fiber

Lab Techniques and Practical Applications

• Microscopy allows the visualization of cells, tissues, and microorganisms
  • Light microscopy uses visible light and lenses to magnify specimens
  • Electron microscopy uses a beam of electrons to create high-resolution images
• Histology is the study of tissues using microscopic examination of thin, stained sections
• Dissection involves the careful cutting and separation of anatomical structures to study their relationships and internal features
• Electrophysiology techniques (EEG, ECG, EMG) measure the electrical activity of neurons, the heart, and muscles
• Medical imaging techniques (X-ray, CT, MRI, ultrasound) provide non-invasive visualization of internal structures
• Physiological measurements (blood pressure, heart rate, respiratory rate, body temperature) assess the functioning of organ systems
• Biochemical assays analyze the presence, concentration, or activity of specific molecules (enzymes, hormones, neurotransmitters) in body fluids or tissues
• Anatomical knowledge is essential for medical procedures, surgery, and the development of prosthetics and medical devices

Connections to Other Biological Sciences

• Biochemistry studies the chemical processes and molecules that underlie anatomical structures and physiological functions
• Genetics examines how genes influence the development, structure, and function of organisms
  • Mutations in genes can lead to anatomical and physiological abnormalities
• Developmental biology investigates the processes by which a single fertilized egg develops into a complex, multicellular organism
• Evolutionary biology explores how anatomical structures and physiological processes have evolved over time in response to environmental pressures
• Ecology studies the interactions between organisms and their environment, including how anatomical and physiological adaptations enable survival
• Pathology examines the structural and functional changes associated with disease
  • Understanding normal anatomy and physiology is crucial for identifying and treating pathological conditions
• Pharmacology investigates how drugs interact with the body's tissues and organs to produce therapeutic or adverse effects
• Biomedical engineering applies engineering principles to the design and development of medical devices, prosthetics, and diagnostic tools based on anatomical and physiological knowledge