Chapter 1
The Scope of Anatomy and Physiology
Anatomy and Physiology Defined
Anatomy – the study of the structure of an organism
Physiology – the study of the function of those structures
Four Ways to Study Anatomy
- Dissection – observing structures of the body by cutting apart
-uses a cadaver (dead body)
- Palpation – touch or feel structures of the body to determine presence
of disease or disorder.
e.g. taking pulse or feeling for swollen glands
3. Auscultation – listening to the sounds of the body.
e.g. lungs or heart
4. Percussion – tapping on body structures to determine if air or fluids are
present in structures.
Other Disciplines of Anatomy and Physiology
Histology – the study of tissue
Gross Anatomy – observation of body structures through dissection.
Neurophysiology – workings of the Nervous System
Endocrinology – study of hormone production and delivery
The Origins of Biomedical Research
-medicine may have begun 3000 years ago in Egypt and Mesopotamia
-Hippocrates – a Greek physician who was considered the father of medicine.
- today, physicians are administered the Hippocratic Oath whose
basic tenet is “do no harm”.
-Claudius Galen – father of experimental physiology
- wrote first anatomy book
- studied living patients and observed animals such as monkeys.
- wrote book that was used by many doctors.
-Andreas Vesalius – father of anatomy
- wrote book based on cadaver studies (executed criminals)
- corrected many of Galen’s studies.
Robert Hook – made many improvements of the microscope
- was first to coin the term “cell” by observing the holes in cork.
Antony Leeuwenhoek –improved microscope by increasing magnification
- made it easier to observe cellular contents.
e.g. blood, sperm, drops of water
Schleiden and Schwann – concluded that all organisms are made of cells.
- their research led to the “Cell Theory”.
- theory states that living things arise from living things
- and that all living things are made up of cells.
The Scientific Method – a process by which scientists formulate a hypothesis, gather data
by observation and experimentation, and come to a conclusion.
Two methods: Inductive Method – makes generalizations
through repeated observations.
Hypthetico-deductive Method – uses hypothesis
(educated guess)
-must be consistent with known data.
-must be able to be tested and repeatable.
Steps for Scientific Method - Observation
Previous data
Formulation of hypothesis
Observation or experimentation
New data
Conclusion
Theory
Experimental Design – consists of: sample of specific size
controls
control group
experimental group
-both groups are the same in every way except the experimental group is the group that is tested
e.g. the control get the placebo (fake pill) while the experimental receives the drug that is being tested.
Human Origins and Adaptations
Two important concepts that are essential to the understanding of the human body are:
The Cell Theory
Natural Selection – the evolutionary mechanisms by which individuals with characteristics best suited to a particular environment, survive and reproduce with greater frequency than do those without them.
Charles Darwin - English biologist who wrote “The Origins of Species”
- responsible for the theory of evolution
Evolution – theory that various plant and animals are descended from other kinds that lived in earlier times and that differences are due to inherited changes that occurred over many generations.
Adaptation and mutation are the basis for evolution
Adaptation – evolutionary modifications that improve the chances of an organism’s survival and reproductive success.
- a response to selection pressures.
Selection Pressures – natural forces such as competition, food availability, and climate.
Mutation – a change or alteration in genetic material.
A sign of adaptation or mutation are found in vestigial structures.
Vestigial Structures – anatomical features that are present in a species, that are functional in one group but not another.
e.g. man has approximately 100
- coccyx (tail bone)
- appendix
- third molar
- muscles that move the ear and scalp
- erector pili muscles (hair muscles)
Primate Adaptation
-Chimpanzees are closely related to humans with a 1.6% difference in DNA
- there is a 2.6 % difference between chimps and gorillas.
- features that are similar in humans and other primates are opposable thumb (important for grasping items)
- stereoscopicvision - possessing depth perception (necessary for hand eye coordination)
-bipedal – can walk upright
Levels of Structural Organization:
There are several levels that make up the human body.
1. Molecular – Atoms = the smallest unit of matter
(matter is anything that occupies space and has weight or
mass.
- Molecules = atoms which have bonded together to form a
chemical unit e.g. proteins, carbohydrates, lipids, nucleic
acids, etc. (2 or more atoms)
- Macromolecules – large molecules such as DNA.
2. Organelles – small structures that are found within the cell
3. Cellular - basic structural and functional unit
- the smallest living unit of life or the human body
- the body consists of a variety of cells
4. Tissue – groups of similar cells with common precursor
- cells work together to perform a particular function.
5. Organs – structures composed of 2 or more tissues
- organs have a specific function
- have recognizable shape
6. System – several related organs
-common function
e.g. digestive system
7. Organism – a living individual comprised of the above mentioned
organ systems.
Anatomical Variations – differences in 30% of the population.
- 70% similarities are considered normal
e.g. Palmaris longus (missing in forearm)
Metatarsal bones (missing foot bones)
Vertebra (4 or 6 lumbar or lower back bones)
Ribs (less than 12 pairs)
Appendix and large intestine reversed (situs inversus)
Characteristics of The Living Human Organism:
- distinguishes living from non-living.
1. Metabolism - how well cells work
- includes catabolism (breakdown) and anabolism (buildup) of
molecules
2. Responsiveness – the ability to react to internal and external stimuli or change.
e.g. body temperature
3. Movement – motion of the whole body or individual components from single
cells to organisms.
4. Growth – increase in size or number of cells
- increase in area surrounding cells
can also include development: all the changes that take place
life of organism (conception to death).
5. Differentiation – the change of a cell from precursor cell (stem) to a
specialized cell.
e.g. blood cells
6. Reproduction – the formation of new cells or the process in which individuals
are developed.