What is A&P?
Anatomy is the exploration of the Structures of the Human Body: it is the body parts and how they relate to each other
Physiology is the function of these structures.
Anatomy can be divided into 3 parts:
- Gross (Macro) - which are the large visible structures of the body. This can be further broken down into another 3 subdivisions:
Systemic: looking at systems of the body
Surface: structures below the epithelium, which can be palpated
- Micro: smaller structures within the body. e.g. Cytology (study of cellular anatomy) or Hystology (study of tissue.
- Specialised: radiographic; pathological, molecular
Observation
Manipulation
Anatomical Terminology
Physiology on the other hand, concerns the operation of specific organ structures i.e. neurological, renal and cardiovascular
The body's ability depends on the operation of its individual cells and cells abilities ultimately depend on the chemical reactions that go with them (p2, Marieb, Anatomy & Physiology)
The integration of these two exploratory ways of looking at the human body results in a complementarity of structure and function - basically, what a structure can do depends on its specific form.
The levels of structural complexity within the body can be shown as being:
- Chemical: atoms leading to molecules
- Cellular: molecules leading to cells
- Tissues: cells leading to tissue
- Organ: many tissue layer type
- Organ system: Organ functionality derived from similar organ groupings
- Organismal: the entirity of the human body
Integumentary System: This forms the outer surface of the body, consisting of hair, nails and skin. The purpose is to protect deeper tissues; synthesise vitamin D; and is the site of cutaneous receptors, sweat and oil glands.
Skeletal System: Forms the 'bony' framework the muscles use to cause movement. Consisting of bones and joints the purpsoe of which is to protect and support body organs; blood cell formation within the bone marrow and mineral storage.
Muscular System: This provides heat. maintains posture and provides the environmental impetus for locomotion. Consisting of skeletal muscles attached to the bones by ligments, tendons etc.
Nervous System: Consists of the autonomic and central nervous systems which provides the responses to internal and external homeosatic changes via sensory receptors within the neural cortex. It is the 'control' centre of the body.
Endocrine System: The hormonal regulation of the body. Consisting of glands, thyroid, thymus and reproductive organs.
Cardiovascular (Circulatory) System: Almost like the central heating system of house. It is the transportation via blood vessels, arteries and capillarires which carry nutrients, oxygen and nitrate waste throughout the body. The heart provides the pumping mechanism for this.
Lymphatic (Immune) System: Production of immune response via white blood cells; the reabsorption of fluid back into the bloodstream. Consisting of the spleen, lymph nodes, thymus, bone marrow and lymphatic vessels.
Respiratory System: Gas exchange from the lungs to the blood stream. Consists of the larynx, trachea, pharynx and nasal cavity.
Digestive System: Distribution of nutrients via the breakdown of food into body cells for energy production. Consists of the oral cavity, oesphagus, stomach, large and small intestine, rectum and anus.
Urinary System: Elmination of blood waste products through urine production. Regulation of fluid electrolyte balance and acid-base balance. Consists of the kidneys, ureter, urinary bladder and urethra.
Reproductive System: Production of offspring; consisting of male and female reproductive organs.
Before moving onto exploring the function necessary for life, it is worthwile stopping and examining the beginnings biomedicine. Why is it important? And how has it evolved?
Health Science has progressed far more in the last 25yrs than in the 2500 yrs before that, but the field did not spring up overnight. It is built upon centuries of thought...We cannot fully understand its present state without understanding its past - Saladin (2001, Anatomy & Physiology: The Unity of Form and Function, 2nd Edition, McGraw Hill)
Illness has existed as long as man has; coupled with this is search for knowledge of how to combat this - to prolong life; relieve pain and maintain control. Herbal remedies, shamanism, astrology - examples of early ways thought to eliminate illness. However, the 'father' of medicine, of the biomedical sciences as we choose to explore them now, is regarded as being the Greek physician Hippocrates (460-375BCE). The hippocratic oath taken by physicians was originally established by him and his followers. He inspired others to step back from regarding illness as having a 'divine' origin and to search for rational, biologically rooted explanation.
Aristotle (384-322BCE) the philosopher held that disease had a unity with nature. That the structure of nature could be broken into smaller components. This is an important step, the leap from this supposition to that conclusive identification of cellular and molecular material made within modern times.
If Hipprocates is the theorist of medicine, it is to the roman Galen (129-199BCE) we owe the practical basis of pathology. His dissection of animals, as cadaver examinations were illegal due to earlier cadaver 'demonstrations' including 'living' dissections on slaves and criminals, provided a first cohesive look at anatomy of creatures. He openly reasoned that his findings could be wrong, and he urged others to question and trust their observations.
Yet, during the middle ages, when many prestigous medical schools and universities were established, the method of teaching was entrenched and limited; the idea of medicine as research was ignored, instead the earlier teachings of Hippocrates and Galen were continued with little addition. However, this stasis within the field of physiology was European; within the Muslim world Ibn Sina (Avicenna) (980-1037CE) was reviewing Galen and Aristotle and adding his own original findings to this. He questioned the established authority and published his own treatise which was utilised within Europe until the 16th c.
With the Renaissance a renewed vigour of inquiry occurred. The flemish anatomist Andreas Vesalius (1514-64CE) broke with convention, where physicians refused to dissect, and openly undertook dissections which resulted in the first authoritative exploration of human anatomy. It is the English William Harvey (1578-1657CE) who first proposed a physiological mechanism. Prior to his work into cardiovascular function, it was widely accepted that blood was the product of digested food made in the liver and travelled to organs via veins. Through study of reptiles and mammals, Harvey concluded that the amount of food digested couldn't possible amount to the blood produced and that the leading hypothesis was therefore flawed. He suggested that blood must be recycled via the heart.
Biomedical science owes much to the invention of the microscope by Anthony van Leeuwenhoek a textile merchant who wished to examine the quality of his fabric more fully but instead discovered little animalcules very prettily a-swimming this revolution was widely applauded but soon fell out of favour - until Robert Hooke produced the compound microscope.
It was not, however, physicians who propelled medical science forward but biologists, such as Carl Zeiss, and zoologists, Theodor Schwann, for instance, who had decreed by as early as 1839, that all organisms were composed of cells. The birth of Cell Theory began at this time.
