Themes_of_A_P_and_Chemistry_of_Life

Major Themes of A&P

Disciplines of Anatomy and Physiology

  • Anatomy: the study of the structure of the body

  • Physiology: the study of dynamic processes in the living body

    • Both fields are interrelated, focusing on the relationship between structure and function.

Criteria That Define Life

  • Organization

  • Cells

  • Metabolism

  • Development

  • Excitability

  • Reproduction

  • Evolution

  • Homeostasis

Levels of Organization

  • Organism

  • Organ system

  • Organ

  • Tissue

  • Cells

  • Organelles

  • Molecules

  • Atoms

Study of Anatomy

Approaches

  • Gross Anatomy: study of structures visible to the naked eye

  • Histology: microscopic study of individual cells

  • Surface Anatomy: external structures of the body and visible features.

  • Regional Anatomy: examination of multiple organ systems in a specific area

  • Systemic Anatomy: focused study of one organ system at a time

Learning Anatomy

  • Dissection: exposure to real structures but limited for future applications

  • Palpation: feeling with hands to locate structures

  • Auscultation: using a stethoscope to listen for bodily sounds

  • Percussion: tapping and listening for sounds produced by organs

  • Medical Imaging: utilizing technologies to visualize inside the body.

Medical Imaging Techniques

  • Radiography (X-rays)

    • High-energy radiation that creates images of internal structures

    • Best for dense structures but has disadvantages like overlapping images

    • Computed Tomography (CT scans): Thin-section imaging using low-intensity X-rays

    • Magnetic Resonance Imaging (MRI): employs magnets to visualize soft tissues

    • Positron Emission Tomography (PET): assesses metabolic states

    • Sonography: uses ultrasound waves to create images of motion

Anatomical Variation

  • Focus on common structural patterns, e.g., the palmaris longus muscle can be absent in ~26% of individuals

Study of Physiology

  • Involves the study of the body's life processes with various subdisciplines like neurophysiology.

  • Emphasizes the body's interconnected processes rather than just structures.

Maintaining Homeostasis

Negative Feedback Loop

  • Mechanisms activated to reverse changes and maintain physiological values within a narrow range

  • Examples include blood pressure and glucose regulation

  • Components of Negative Feedback

    • Receptor: senses the change

    • Integrating (control) center: processes information and decides on a response

    • Effector: implements corrective actions to restore homeostasis

    • Response: results in return to normal conditions

Positive Feedback Loop

  • Produces greater changes in the same direction (e.g., childbirth)

  • Self-amplifying cycle leading to rapid effects.

Chemistry of Life

Acids, Bases, and pH

  • Acid: proton donor (releases H+)

  • Base: proton acceptor (accepts H+)

  • pH Scale: ranges from 0 (acidic) to 14 (basic), with 7 being neutral

  • Even slight pH changes can disrupt physiological processes (e.g., Blood pH 7.35 – 7.45)

Carbohydrates

  • Composed of carbon, hydrogen, and oxygen (2:1 ratio)

  • Examples: glucose (C6H12O6), starch, glycogen

Forms of Carbohydrates

  • Monosaccharides: simplest forms (e.g., glucose, fructose)

  • Disaccharides: two monosaccharides bonded (e.g., sucrose)

  • Polysaccharides: polymers of glucose (e.g., glycogen)

Lipids

  • Composed mainly of carbon, hydrogen, and oxygen with a higher ratio of H to O

  • Triglycerides: fats (solid) or oils (liquid) used for energy storage

  • Phospholipids: form cell membranes, amphipathic in nature

  • Steroids: lipids structured in four rings (e.g., cholesterol, hormones)

Proteins

  • Made of amino acid polymers with diverse functions

  • Shape dictates function; importance of conformation

  • Enzymes: biological catalysts that speed up reactions; specificity to substrates defined by shape.

Nucleic Acids

  • Polymers vital for genetic functions (DNA and RNA)

  • DNA: stores genetic information, composed of A, T, G, C, forming a double helix

  • RNA: active in protein synthesis, single-stranded and contains uracil instead of thymine

  • ATP: energy currency of the cell; powers various physiological processes.