ch. 1-3 Flashcards
What is anatomy?
the study of structures
what is physiology?
study of their functions
What is Radiograpghy?
-X-rays
A technique of medical imaging, photographing internal structures
common uses of x-ray
dentistry, mammography, diagnosis of fractures
disadvantages of x-ray
organs overlap, can cause cancer
Computed Tomography (CT scan)
-A slice of body with little organ overlap
- much sharper image than x-ray
what is CT used for?
identifying tumors, cerebral hemorrhages, kidney stones
Magnetic resonance imaging (MRI)
-better than CT for visualizing soft tissue
-Patient surrounded by large electromagnet, tissue responds to magnetic field and radio waves
Functional MRI (fMRI)
visualizes changes in physiology
Positron emission tomography (PET scan)
-injection of radioactively labeled glucose, highlights most active ares of body
- can diagnose cancer
-example of nuclear medicine
Sonography
-safer, uses handheld device against skin
-emits ultrasound, recurves signals reflected back from internal organs
- cons: does not provide very sharp image
metabolism
sum of all chemical changes in an organism
Homeostasis
Internal stability despite a changing external environment
EX: stable temperature, blood pressure, and body
why is homeostasis important?
loss of homeostatic control tends to cause illness or death
Negative feedback
-maintains homeostasis
-IS A KEY MECHANISM FOR MAINTAINING HEALTH
-ex: shivering, sweating
Does negative feedback produce absolute constancy?
NO, it’s it maintains physiological values within narrow range, fluctuate slightly around a SET POINT
Negative feedback examples
when you stand up gravity pulls blood back down; blood pressure falls
-this makes the heart beat faster, raising blood pressure and returning the body to homeostasis
Receptor
a structure that senses change in body
Integrating (control) center
processes information, makes response decision
Effectors
carry out response to restore homeostasis
- end of loop. response is then sensed by receptor, this completes the feedback loop
positive feedback
self-amplifying cycle where change in the jody leads to a greater change in the same direction
organism
an individual
organ system
-group of organs that carry out basic function
-there are 11 organ systems (ex circulation, respiratory, digestion)
organ
composed of two or more tissue types that work together to carry out a particular function
ex: heart, skin, bones
Tissue
a mass of similar cells and cell products that perform a specific function
Cells
smallest units that carry out the functions of life
Organelles
- microscopic structures that carry out cell’s functions
composed of MOLECULES, molecules are made of ATOMS
sagittal plane
extends vertically, dividing the body into right and left portions
Frontal (coronal) plane
extends vertically, divides body into front and back
transverse (horizontal) plane
divided body into upper and lower portions
axial
-everything but the limbs(head, neck, trunk)
trunk is further divided into thoracic region above diaphragm, abdominal and pelvic regions below the diaphragm
body cavities that are open to the environment are lined by
mucous membranes
