INTRODUCTION OF ANATOMY &
PHYSIOLOGY
Anatomy – is the scientific discipline that investigates the structure of the body.
Physiology – is the scientific discipline that deals with the processes or functions of living things.
TWO BASIC APPROACHES TO STUDY
Systemic Anatomy
- By system
- Used in introductory textbooks
Regional Anatomy
- By Areas
- Used in most medical and dental school
TWO GENERAL WAYS TO EXAMINE
Surface Anatomy
- External features which serves as landmarks
Anatomical Imaging
- Involves the use of x-rays, ultrasound, MRI
BRANCHES OF ANATOMY
Gross: Large structures
Surface: Landmarks
Histology: Cells and Tissues
Developmental: Structures change through life
Embryology: Structures form and develop before birth
DIVISONS OF ANATOMY
GROSS ANATOMY
- Structures that can be seen with the eye
- Muscles, bones, various organs
MICROSCOPIC ANATOMY
- Structures that cannot be seen with the eye
- Need to use a microscope
Cytology = study of cells
Histology = study of tissues
HIERARCHY OF FUNCTIONAL AND STRUCTURAL ORGANIZATION
Each of these build upon one another to make up the next level:
- Chemical level
- Organelle
- Cellular
- Tissue
- Organ
- Organ system
- Organism
1. Chemical level
- Atoms combine to make molecules
> 4 macromolecules in the body
Carbohydrates
Lipids
Proteins
Nucleic acids
2. Cellular
- Made up of cells and cellular organelles (molecules)
- Cells can be eukaryotic or prokaryotic
- Organelles are structures within cells that perform dedicated functions (“small organs”)
3. Tissue
- Collection of cells that work together to perform a specialized function
> 4 basic types of tissue in the human body:
Epithelium
Connective tissue
Muscle tissue
Nervous tissue
4. Organ
- Made up of tissue
> Heart
> Brain
> Liver
> Pancreas, etc…
5. Organ system (11)
- Made up of a group of related organs that work together
> Integumentary
> Skeletal
> Muscular
> Nervous
> Endocrine
> Cardiovascular
> Lymphatic
> Respiratory
> Digestive
> Urinary
> Reproductive
6. Organism
- An individual human, animal, plant, etc…
- Made up all of the organ systems
- Work together to sustain life
CHARACTERISTIC OF LIFE
1. Organization
- refers to specific interrelationships among the parts of an organism and how those parts interact to perform specific
functions.
2. Metabolism
- is the ability to use energy to perform vital functions. It includes an organism’s ability to break down food molecules,
which the organism uses as a source of energy and raw materials to synthesize its own molecules.
3. Responsiveness
- is the ability of an organism to sense changes in the environment and make adjustment.
4. Growth
- refers to an increase in size of all or part of the organism.
5. Development
- includes the changes an organism undergoes through time; it begins with fertilization and ends with death.
6. Reproduction
- is the formation of new cells or new organism.
ANATOMICAL DIRECTIONS
Anatomical position
Anatomical Directions - It’s all Relative!
Anterior (ventral) vs. Posterior (dorsal)
Medial vs. Lateral
Superior (cranial) vs. Inferior (caudal)
Superficial vs. Deep
Proximal vs. Distal
Anatomical Planes
Frontal = Coronal
Transverse = Horizontal = Cross Section
Sagittal
Regions
Axial vs. Appendicular
The normal anatomic position:
- Standing upright
- Head, eyes and toes directed anteriorly or forward
- Arms adjacent to the sides with palms facing anteriorly
- Lower limbs close together with the feet parallel
BODY PLANE
REFERENCE POINT
Anterior – (ventral) Posterior – (dorsal) Frontal Plane
Closer to the front Closer to the rear
surface of the body surface of the body
Medial – Lying closer Lateral – Lying Sagittal Plane
to the midline further away from
the midline
Superior – (cranial) Inferior – (caudal) Horizontal
Closer to the head in Away from the head Plane
relation to the entire or towards the lower
body (More General) part of the body
Superficial – Towards Deep – Away from Surface of
the surface the surface body or organ
Proximal – Closer to Distal – Further Origin of a
the origin of a body away from the origin structure
part (More Specific) of a body part
- Regional terms are used to describe certain body regions, many anatomical structures will have names relating to their body
region.
PLANES AND SECTION
Sagittal section – divides the body into right and left sides
Mid-sagittal section = straight down the center of the body
Frontal section – divides the body into front and back sides
Transverse (cross) section – cut straight across the body
C. Body planes and sections- a plane is a flat sectional cut along the body There are four planes:
Frontal (coronal)
Median (midline or sagittal)
Transverse (horizontal)
Oblique (diagonal)
ABDOMINAL QUADRANTS AND REGIONS
BODY QUADRANTS
Right Upper Quadrant (RUQ)
Left Upper Quadrant (LUQ)
Right Lower Quadrant (RLQ)
Left Lower Quadrant (LLQ)
BODY CAVITIES
Body cavities are internal chambers holding vital organs
o Cavities protect vital organs
o Cavities allow organs to change in shape and size
Two body cavities
o Dorsal body cavity includes the cranial cavity and the spinal cavity
o Ventral body cavity includes the thoracic cavity and the abdominopelvic cavity
HOMEOSTASIS
- Homeostasis is a stable internal environment
- Every organism must maintain homeostasis for survival
- Homeostatic regulation is responsible for keeping internal environment within certain limits.
Two General Points Within Homeostasis
- Autoregulation or intrinsic regulation – results when cell, organ or system adjusts its activity automatically.
- Extrinsic regulation - results from activity of nervous system or endocrine system.
Homeostasis Regulation Involves
A homeostatic regulatory mechanism consists of:
A receptor – senses an environmental change or stimuli.
A control center –processes information supplied by receptor and generates a response (command)
An effector – an organ or cell that responds to the command of control center.
A variation outside the desired range triggers an automatic response to correct the situation
Negative feedback
Negative Feedback: The Control of Body Temperature
Positive Feedback: Blood
In positive feedback an initial stimulus produces a response that enhances the change in the original condition. For
instance:
Damage to blood vessel wall will cause release of chemicals.
Chemicals will trigger blood clotting
Clotting process increases release of chemicals
More chemicals mean accelerated clotting
Accelerated clotting means more chemicals
