anat and phys exam 1

anatomy

study of structure

physiology

study of function

anatomy and physiology are…

complementary to one another

inspection

look at appearance

palpation

feeling a structure with the hands

auscultation

listening to sounds produced by the body

percussion

tap on the body, feel for resistance, and listen to the emitted sound for abnormalities

dissection

cutting and separating human body tissues to reveal tissue relationships; use a cadaver, a dead human body

comparative anatomy

study (for example, dissection) of multiple species to learn about form, function, and evolution

exploratory surgery

opening the living body to see what is wrong; now replaced by medical imaging to view inside without surgery

radiology

branch of medicine specializing in imaging

gross anatomy

structures visible with the naked eye

subdivisions of gross anatomy include

surface anatomy, regional anatomy, systemic anatomy, clinical anatomy, developmental anatomy

surface anatomy

exterior features

regional anatomy

body areas

systemic anatomy

organ systems

clinical anatomy

medical specialties (pathological anatomy – changes that occur during illness, radiographic anatomy – structures seen using specialized imaging techniques)

developmental anatomy

from conception to death, includes embryology

Microscopic anatomy

requires the aid of a microscope

Cytology

study of structure and function of cells; fine detail (ultrastructure) may be resolved using an electron microscope

subdivision of microscopic anatomy

Histology

examination of tissues with microscope

Histopathology

microscopic examination of tissues for signs of disease

Neurophysiology

physiology of nervous system

Endocrinology

physiology of hormones

Systemic physiology

functions of an organ system

Pathophysiology

mechanisms of disease

Comparative physiology

Study of different species to learn about body functions

Basis for much of our understanding of human physiology and the development of new drugs and medical procedures

organism composed of (highest hierarchy)

organ systems

organ systems composed of

organs

organs composed of

tissues

tissues composed of

cells

cells composed partly of

organelles

organelles composed of

molecules

molecules composed of (lowest hierarchy)

atoms

organism

a single, complete individual

organ system

group of organs with a unique collective function; for example: circulation, respiration, digestion

Organ

structure composed of two or more tissue types that work together to carry out a function

An organ has defined anatomical boundaries; can have organs within organs (i.e. skin is the body’s largest organ, contains hairs, nails, glands, etc., which are each considered organs

Note: organs can belong to more than one organ system – the pancreas belongs to both system

Tissue

similar cells and cell products forming a discrete region of an organ and performs a specific function

Cell

smallest unit to carry out all basic functions of life

Organelle

structure within a cell that carry out a function

Molecule

particle composed of two or more atoms

Largest molecules (proteins, fats, DNA) are called macromolecules

Atom

smallest particle with unique chemical identity

no human exactly alike

• diff fingerprints

• some lack certain muscles

• diff number of vertebra

• situs inversus (left-right reversal)

images are in the patient’s pov, flip right and left sides.

ex) patient’s right kidney is on the left to my pov

Reference male

22 years old, 154 lb, light physical activity, consumes 2,800 kcal/day

1kcal = 1 cal

Reference female

22 years old, 128 lb, light physical activity, consumes 2,000 kcal/day

physiology is more variable than anatomy

Variations in sex, age, diet, weight, physical activity, genetics and environment

Failure to consider variation can lead to overmedication of the elderly or medicating females on the basis of research done on males

Homeostasis

ability to detect change, activate mechanisms that oppose it, and thereby maintain relatively stable internal conditions

Claude Bernard

noted fairly constant internal conditions despite changing external conditions (for example, internal temperature stays fairly constant at 97-99°F or 36 37°C - internal conditions fluctuate within a limited range)

Walter Cannon

coined the term homeostasis

Negative feedback

allows for dynamic equilibrium within a limited range around a set point

The body senses a change and “negates” or reverses it

Loss of homeostatic control causes

illness or death

feedback loops

feedback mechanisms alter the original changes that triggered them

homeostasis in body temperature (97-99°F)

If too warm (> 97-99°F), skin blood vessels dilate (vasodilation) and sweating begins (heat-losing mechanism)

If too cold (< 97-99°F), skin blood vessels constrict (vasoconstriction) and shivering begins (heat-gaining mechanism)

homeostasis of blood pressure (baroreflex)

1. Rise from bed, blood drains from head and blood pressure falls in this region

2. Blood pressure drop detected by baroreceptors that transmit signals to cardiac center of brainstem

3. Cardiac center transmits signals to heart to increase heart rate, raising blood pressure and restoring homeostasis

4. The raise in blood pressure is detected by the baroreceptors which then stops sending signals to the cardiac center to increase heart rate

baroreflex components of a feedback loop

receptor, integrating (control) center, effector

Receptor

structure that senses change in the body (for example, the baroreceptors above heart that monitor blood pressure)

thermometer

Integrating (control) center

control center that processes the sensory information, “makes a decision,” and directs the response (for example, cardiac center of the brainstem)

Effector

cell or organ that carries out the final corrective action to restore homeostasis (for example, the heart)

Positive feedback is a self-amplifying cycle

Leads to a greater change in the same direction, as opposed to the corrective action of negative feedback

Normal way of producing rapid changes

Examples: childbirth, blood clotting, protein digestion, and generation of nerve signals

Dangerous positive feedback system

vicious circle of runaway fever. Infection causes fever to raise body temperature. This can increase metabolism in cells, which then generate even more heat and raise the temperature even more, which then increases the metabolic rate in cells even more which then generates even more heat… causing a positive feedback loop

positive feedback in childbirth

1. head of fetus pushes against cervix

2. nerve impulses from cervix transmitted to brain

3. brain stimulates pituitary gland to secrete oxytocin

4. oxytocin stimulates uterine contractions and pushes fetus toward cervix

Gradient

difference in chemical concentration, charge, temperature, or pressure between two points

Matter and energy tend to flow down gradients

Blood flows down a

pressure gradient, from a place of higher pressure to a place of lower pressure

Chemicals flow down a

concentration gradient

Charged particles flow down an

electrical gradient

Electrochemical gradient

combination of concentration, electrical gradients

Heat flows down a

thermal gradient

Movement in the opposite direction is

up the gradient and requires spending metabolic energy