Science

• Science — a broad field of inquiry that attempts to understand nature in rational logical manner.

  • Its process is active and changing as new experiments add new knowledge.

  • It is affected by culture and culture is affected by society.

• Hypothesis — an idea formed from observations and experiments.

  • Experiment — series of tests of a hypothesis.

  • Controlled experiments — eliminated any influences or biases not being directly tested.

• Theory — a hypothesis that has been supported by experiments and thus shown to have a high degree of confidence

• Laws — a theory that has an unusually high level of confidence, or an observable occurrence appears to be always true.

Anatomy and Physiology

Anatomy

• Anatomy — study of the structure of an organism and the relationship of its part.

  • (Greek) — to cut apart.

• Gross Anatomy — study of body parts visible to naked eye.

• Microscopic Anatomy — study of body parts with a microscope

  • Cytology — study of cells.

  • Histology — study of tissues.

• Developmental Anatomy — study of human growth and development.

• Pathological Anatomy — study of diseased body structures.

• Systemic Anatomy — study of body by systems.

  • Systems —groups of organs that have common function.

Physiology

• Physiology — science that deals with the function of the living organism; how the body works.

  • (Greek): physis [nature] ; logos [study, words]

• It is subdivided according to:

  • type of organism involved (human, plants, animals)

  • organisational level studied (molecular, cellular)

  • a specific or systemic function studied (neuro, respiratory, cardiovascular)

Language of Science and Medicine

• Scientific terms are often based on Latin or Greek word parts.

• International Federation of Associations of Anatomists (IFAA) — They formed a worldwide committee to publish a list of universal standard anatomical terminology.

  • Terminologia Anatomica (TA) — published 1998; list of gross anatomy.

  • Terminologia Histologica (TH) — published 2008, list of microscopic anatomy.

• Avoidance of Eponyms

  • Eponyms — terms that are based on a person’s name.

    • Eustachian Tube = Auditory tube

      • tube connected to the middle ear.

    • Islets of Langerhans = Pancreatic islets

      • endocrine component of the pancreas.

    • Bowman’s capsule = Glomerular capsule

      • a part of the nephron that forms a cup-like sack surrounding the glomerulus.

Characteristics of Life

• Criterion that might be used to define life:

  • Autopoiesis — a concept where living organisms self-organise or self-maintain.

  • Cell theory — any independent structure made up of one or more microscopic units are called cells in a living organism.

• Metabolism — the whole sum of reactions that occur throughout the body within each cell and that provide the body with energy.

Levels of Organisation

Chemical Level

• Atoms — smallest unit of matter, so small they are invisible.

• Molecules — combination of atoms to form larger chemical groups.

• Macromolecules — combination or larger and more complex molecules.

  • Cytoplasm — a gel-like material made of fluids, particles, and membranes; this fills the inside of the cells.

Cellular Level

• Cells — smallest and structural units that possess and exhibit the basic characteristics of a living matter.

• Each cell is surrounded by membrane and characterised with single nucleus surrounded by the cytoplasm—that includes numerous organelles.

• Cells specialise of differentiate to perform unique functions.

  • Fat cells — structurally modified to permit the storage of fats.

  • Cardiac muscle cells — able to contract with great force.

Organelle Level

• Organelles — subunit of cells which performs specific functions within it.

  • Tiny organs that allow cells to live.

  • They cannot live outside the cell, the cell can’t survive without the organelles.

• Some examples:

  • Mitochondria — powerhouse of the cell—which provides energy that needed by the cell.

  • Golgi apparatus — set of sacs that provides packaging services to the cll by storing material for future use.

  • Endoplasmic reticulum (ER) — network of channels within the cell that act as highways for movement of chemicals, and acts as sites for chemical processes.

Tissue Level

• Tissue — a group of cells that all developed together from the same part of the embryo and perform a certain function.

  • The fabric of the body.

• Four major tissues:

  • Epithelial Tissues — tissues that forms the covering of internal and external surfaces of the body.

  • Connective Tissues — tissues that supports, protects, and gives structure to other tissues and organs in the body.

  • Muscle Tissues — tissues that have the special ability to shorten or contract in order to produce movement of the body parts.

  • Nervous Tissues — tissues that are the main component of the nervous system.

Organ Level

• Organ — a structure made up of different kinds of tissues arranged together to perform specific functions.

• Heart as an example of organ level:

  • Muscle and connective tissues give it shape and helps pumps blood.

  • Epithelial tissues lines that cavities/chambers.

  • Nervous tissues controls the pumping contractions.

• Each organ has unique shape, size, appearance, and placement in the body—and each can be identified by the pattern of tissues that forms it.

System Level

• Systems — the most complex of the organisational units; it involves varying numbers and kinds of organs and together, they perform complex functions in the body.

• Major Body Systems:

  • Integumentary

  • Skeletal

  • Muscular

  • Nervous

  • Endocrine

  • Cardiovascular

  • Lymphatic/Immune

  • Respiratory

  • Digestive

  • Urinary

  • Reproductive

• System groupings:

  • Musculoskeletal system

  • Neuromusculoskeletal system

• Microbiome — a set of interacting communities of bacteria and other microorganisms that inhabit the human body; microbial systems influence normal body functions

• Human microbiome — the microorganisms that live in or on a particular part of the body.

Organism Level

• Organism — a living thing that can function on its own.

  • a living thing that has an organized structure, can react to stimuli, reproduce, grow, adapt, and maintain homeostasis.

• Human Body — the physical substance of the human organism, composed of living cells and extracellular materials and organized into tissues, organs, and systems.

Anatomical Position

• Anatomical position — the body is in an erect, or standing, posture with the arms at the side and palms forward.

  • It is the reference position that gives meaning to the directional terms used to describe body parts and regions.

• Bilateral symmetry — the right and left sides of the body mirror images of each other.

  • Only one plane can divide the body into right and left halves.

  • Its important feature is the balanced proportions.

• Body Placement

  • Ipsilateral — placement of a body part meaning same side.

  • Contralateral — placement of a body part meaning opposite side.

• Body Position

  • Supine — position where the body is lying face upward.

  • Prone — position where the body is lying face downward.

Body Cavities

• Cavity — any hollow within the body or its organs.

Membranes that line cavities

• Parietal Pericardium — the outer layer that's firmly attached to your fibrous pericardium.

• Visceral Pericardium — the innermost layer of pericardium; it covers heart and the roots of your great vessels.

• Parietal Peritoneum — the membrane lining the inside of the abdominal cavity.

• Visceral Peritoneum — the membrane that covers the organs within the abdominal cavity.

• Peritoneal Cavity — the space between the two membranes in the abdomen.

Body Regions

• Major Subdivision of Body as a Whole

  • Axial Portion — portion of the body consists of the head, neck, and torso, or trunk.

    • Dorsal Cavities

    • Ventral Cavities

  • Appendicular Portion — portion of the body consists of the upper and lower extremities and their connections to the axial portion.

    • Upper extremity (limb) — shoulder, arm, forearm, wrist, and hand components

    • Lower extremity (limb) — hip, thigh, leg, ankle, and foot.

Latin-Based Descriptive Terms for Body Regions

Abdominopelvic regions

• Hypochondriac — “under cartilage“ ; the rib cartilage.

• Epigastric — “upon the stomach“.

• Iliac — hip region.

• Hypogastric — “below the stomach.“

Abdominopelvic quadrants

Terms used in describing body structure

Directional terms

Terms related to organs

• Lumen — the hollow area of organs.

  • Luminal — of or near the lumen.

  • Luminal Obstruction — blockage of the respiratory airway.

• Central — near the centre.

  • the central nervous system

• Peripheral — around the boundary.

  • the peripheral nervous system

• Medullary — an inner region or core of an organ.

  • medulla is the inner region of the kidney.

• Cortical — an outer region or layer of an organ.

  • cortex is the other part of the kidney

• Basal — the base or widest part of an organ.

  • the basal surface of the cell faces away from the lumen.

• Apical — the narrow tip of an organ.

  • the apical surface faces the lumen of a hollow organ.

Anatomical Compass Rosette

Body planes and sections

Interaction of structure and function

• Complementarity of structure and function

  • Structure determines function, and function influences the actual anatomy of an organism over time.

  • Anatomical structures are adapted to perform specific functions because of their unique size, shape, form, or body location.

  • Understanding the interaction of structure and function assists in the integration of otherwise isolated factual information.

• Atrophy — the wasting away of a part of the body as we age.

  • reduce our ability to repair or replace worn tissues.

  • Developmental Processes — the changes in functions that occur during the early years.

  • Ageing processes — the changes the occur during the late years of life.

    • Gerontology — the study of ageing processes and other changes that occur in our lives as we get older.