Anatomy and Physiology

• Anatomy studies form and structure of the body.
• Physiology studies how the body functions.

Microscopic Anatomy

• Examines structures not observable by the unaided eye.
• Structures are examined under a microscope.
• Cytology studies body cells and their internal structure.
• Histology is the study of tissues.

Gross Anatomy (Macroscopic Anatomy)

• Investigates structures visible to the unaided eye.
• Specimens are dissected for examination.
• Systematic Anatomy studies anatomy of each functional body system.
• Regional Anatomy examines structures in a particular body region.
• Surface Anatomy focuses on superficial anatomic markings and internal body structures.
• Comparative Anatomy examines similarities and differences in anatomy of different species.
• Embryology studies developmental changes from conception to birth.
• Pathologic Anatomy examines anatomic changes from disease.
• Radiographic Anatomy investigates internal structures visualized by scanning procedures.

Physiology: Details and Function

• Physiologists focus on the molecular and cellular level.
• Cardiovascular Physiology studies the functioning of the heart, blood, and blood vessels.
• Neurophysiology studies the functioning of nerves and nervous system organs.
• Respiratory Physiology studies the functioning of respiratory organs (lungs).
• Reproductive Physiology studies the functioning of reproductive hormones and the reproductive cycle.
• Pathophysiology studies the relationship between the function of an organ system and disease or injury to the system.

Characteristics that Describe Living Things

• Living things exhibit complex organization and order
• Living things engage in metabolism, the sum of all chemical reactions within the body.
• Anabolism (BUILDS) involves small molecules joining to form larger ones.
• Catabolism (BREAKS DOWN) involves large molecules breaking down into smaller ones.
• Responsiveness is the ability to sense and react to stimuli.
  • A hot stimulus to the hands causes a person to withdraw.
• Regulation indicates that the body adjusts internal bodily functions to environmental changes.
  • Homeostasis refers to the ability of an organism to maintain a consistent internal environment.
• Reproduction involves producing new cells for growth, maintenance, and repair.
  • Sex cells can develop into new organisms.

The View from Simplest to Most Complex

• The chemical level involves atoms and molecules
  • Atoms: smallest units of matter
  • Molecules: one or more combined atoms (sugar, vitamins)
• Macromolecules are more complex molecules, such as proteins and deoxyribonucleic acid (DNA).
• Organelles are microscopic subunits in cells composed of macromolecules.
• The cellular level consists of cells, which are the smallest living structures.
  • Basic units of structure and function in organisms.
  • Cells vary widely in structure, reflecting specializations.
    • Skeletal muscle is long.
    • Red blood cells are small and flattened.
  • Cells are formed from atoms and molecules from the chemical level.
• The tissue level consists of tissues, which are groups of similar cells performing common functions.

Four types of Tissues

• Epithelial Tissue covers exposed surfaces and lines body cavities.
• Connective Tissue protects, supports, and binds structures and organs.
• Muscle Tissue produces movement.
• Nervous Tissue conducts nerve impulses.
• The organ level consists of organs, two or more tissue types performing specific functions.
  • The small intestine is composed of all four tissue types and functions to process and absorb digested nutrients.
• The organ system level contains related organs that work together to achieve a common function.
  • Organs of the digestive system work together to digest food, absorb nutrients, and expel waste products.
• The organismal level is the highest level of structural organization.
  • All body functions work interdependently in an organism, a living being.

Anatomic Position

• Anatomists use a specific body position as a point of common reference
  • Upright stance.
  • Feet parallel and flat on the floor.
  • Upper limbs at the sides of the body.
  • Palms face anteriorly (toward the front).
  • Head is level.
  • Eyes look forward.

Section and Plane

• Sections and Planes are used to examine internal anatomy and describe the relative position of body parts.
  • Section: slice or cut to expose internal anatomy
  • Plane: Imaginary flat surface passing through the body
  • Coronal Plane (Frontal Plane): vertical plane dividing the body into anterior (front) and posterior (back) parts.
  • Transverse Plane (Cross-Sectional Plane): Horizontal plane dividing the body into superior (top) and inferior (bottom) parts.
  • Midsagittal Plane: vertical plane dividing the body into equal left and right halves.
  • Sagittal Plane: divides a structure into left and right structures at any number of sites; it's parallel to the midsagittal plane.
  • Oblique Plane: passes through structures at an angle.

Anatomic Directions

• Directional Terms: Help precisely describe the relative positions
  • Anterior - Front
  • Posterior - Back
  • Superior - Top
  • Inferior - Bottom
  • Dorsal - Toward the Back
  • Ventral – Toward the Belly
  • Proximal - Nearer to the Trunk
  • Distal - Farther from the Trunk

Regional Anatomy

• The human body is partitioned into two main regions
  • The axial region includes the head, neck, and trunk.
  • The appendicular region is composed of the upper and lower limbs.
  • All body processes depend upon cells for their activities.
  • Cells are "the functional units of the body".
• Knowledge of cell structure and function is crucial for understanding anatomy and physiology.
• Cells are studied through cytology.
• Cells were discovered after the invention of microscopes.
• Cells are measured in micrometers (1/10,000 cm).
• Microscopy involves using a microscope to view small-scale structures.
  • Microscopy is performed using staining techniques to provide contrast.

The Light Microscope (LM)

• Produces a two-dimensional image.
• Passes light through a specimen.
• Has glass lenses that focus and enlarge the image.
• Color-dye stains

The Electron Microscope (EM)

• Uses a beam of electrons to "illuminate" the specimen.
• Has greater magnification than a light microscope.
• Has greater ability to show details (resolution).

Transmission Electron Microscope (TEM)

• Directs an electron beam through thin cut sections.
• Produces two-dimensional images.

Scanning Electron Microscope (SEM)

• Directs an electron beam across the surface of a specimen.
• Generates a three-dimensional study.
• Cells vary greatly in size and shape.
  • An erythrocyte is between 7-8nm
  • An oocyte is 120nm.
• Most cells are microscopic.
• Cell shapes include spherical, cubelike, columnlike, cylindrical, disc-shaped, and irregular.

Overview of Cellular Components

• The plasma membrane forms the outer limiting barrier.
  • Separates internal contents of the cell from the external environment.
  • Includes cilia, flagellum, and microvilli - modified extensions of the plasma membrane.

Cytoplasm

• The cytoplasm is the cellular content between the plasma membrane and the nucleus.
  • Includes cytosol, organelles, and inclusions.
  • Cytosol (intracellular fluid) is the viscous fluid of the cytoplasm with high water content.

Nucleus

• Largest structure in the cell.
• Enclosed by a nuclear envelope.
• Contains the genetic material DNA.
• Inner fluid is called nucleoplasm.
• Organelles are organized structures within cells.
  • Inclusions are large diverse groups of molecules.
    • Not bound by a membrane and are not considered organelles (e.g., pigments, glycogen, triglycerides).
• General cell functions are performed by most cells to:
  • Maintain integrity and shape of the cell, dependent on the plasma membrane and internal contents.
  • Obtain nutrients and form chemical building blocks.
  • Harvest energy for survival.
  • Dispose of wastes.
  • Avoid accumulation disrupting cellular activities.
• Cell division involves making more cells of the same type, helping maintain the tissue with new cells.

Chemical Structure of Plasma Membrane

• The plasma membrane is a fluid mixture composed of equal parts lipid and protein. Regulates the movement of most substances in and out of the cell.
• It effectively allows nonpolar substances to penetrate without assistance
• Includes several different types of lipids
• Phospholipids
• Cholesteral
• Glycolipids
• Most membrane lipids are phospholipids.
  • They have a polar "head" and two hydrophobic "tails."
• Phospholipids form two parallel sheets (molecules lie tail to tail) forming an internal area within the membrane.
  • Heads are directed outward.
  • This structure is termed the phospholipid bilayer.
• Helps to ensure cytosol and fluid surrounding cells remain separate
  • Termed Interstitial Fluid
• Cholesterol is scattered within the phospholipid bilayer
  • strengthens the membrane and stabilizes it against temperature extremes.
• Glycolipids are lipids with attached carbohydrate groups.
  • They are located only in the outer phospholipid region.
  • Help form the glycocalyx (the "coating of sugar") on the cell surface.
• Proteins are embedded within and extend across the lipid layer.
• Hydrophobic regions interact with the hydrophobic interior.
• Hydrophilic regions interact with the surrounding hydrophilic regions.
• Peripheral proteins are not embedded in the lipid bilayer, but loosely attach to the membrane surface.

Tissue Organisation

• Cells organize into more complex units termed tissues.
  • Groups of similar cells and extracellular material.
  • Perform a common function such as providing protection.
• Histology is the study of tissues.

Four Types of Tissue

• Epithelial
• Connective
• Muscle
• Nervous

Epithelial Tissue

• Covers body surface
• Lines body cavities
• Majority of glands
• Composed of one or more layers of closely packed cells
• Contains little or no extracelluar matrix
• Contains no blood vessels
• Contains tightly packed cells
• Exhibit Polarity:
  • Contains a external envirnment or internal body space
  • lateral surface with intercellular junctions
  • Exhibits a Basal Surface: -Attached to connective tissue -Attachment to basement Membrane that is; complex structure produced by epithelium and connective tissue -Consists of 3 layers
• Lamina Lucida
• Lamina Densa
• Reticular Lamina
• Contains collagen fibers and specific proteins and carbohydrates
• Forms a selective barrier between epithelium and connectivity tissue Exihibit Avasculartity:
• Nutrients obtains across apical surface or from basal surface
• Exhibit Extensive of Innervation to detect changes in the envirnment
• Exhibits High capacity of retention for; exposed environments, frequency of damage or loss
• Cells adjacent to basement membrane will mitosis to replace the lost
• continual replacement

Epithelial Tissue Functions

• Contains physical protection for internal and external
• Selective permeability
• Secretions of some type
• Possess Sensations with nerve endings to supply information to the nervous system

Classification of Tissue

• Classification indicated by a two-part name

  • First part, number of epithelial cell layers
  • Second part, shape of the cells at apical surface

• Based on Top Layer

• One layer: Simple

• More than one layer: Stratified

• Squamous: Flat

• Cuboidal: Cube

• Columnar: Tall Column

• Simple Epithelium consist of one cell Layer Thick

• contains direct contact to basement membrane in areas where stress is minimal

• Stratified Epitheleium contains Two+ layers or more layers of cells

• Contains areas of wear tear for example in Skin, lining of pharynx esophagus, basal level

• Pseudo (false) Stratified Ephitelium resembles simple but all cells are attacted to basment memebrane even though layered to reach membrane

Tissue components

• Squamous Cells is flat, wide, irregular

• Cuboidal Cells are slender and shorter

• Columnar Cells are slender and tall like a column

• Transitional Cells change depending on surrounding enviorment and stretch

• The Integumentary system contains Derivitives such as sweat glands, hair, nails

• Is mainly the skins covering

  • contains membrane to protect the outside world
  • Is scientifically studied using dermatology
  • accounts for 7-8% of body weight

• layers of integument

• Epidermis mainly contains a a combination of specific dermis

• Subcutaneous/Hyperdermis

• contains alveolar deep within

• is not part of integument

• Compositon of inteument is mostly composed of cells

Layers with in Intugement

• includes dermis known as the epithelium which is usually composed of stratified keratinocytes
• stratum basal is the deepest epidermal layer known as stratum germinativum or basal level
• Contains types of cells such as keratinocytes, melanocytes, tactile cells
• Stratum corneum contains more polygonals keratinocytes

Overview of anatomy, the study of the body's form and structure, and physiology, the study of how the body functions. Includes microscopic and gross anatomy, cytology, histology and other anatomy specializations.