physiology: chapter 1 review

physiology

study of biological function; how the body works

pathophysiology

study of how disease or injury affects body processes

steps of scientific method

1. observations

2. hypothesis: testable

3. experiment, observations

4. analyze

5. replicate results and draw conclusions

control group

A baseline group in an experiment that does not receive the treatment being tested, used for comparison to assess the effects of the treatment.

scientific theory

a well-substantiated explanation of phenomena based on several verified hypotheses

blind experiment

A study where participants are unaware of which group they belong to, preventing bias in the results.

double blind experiment

an experimental procedure where neither the participants nor the experimenters know who is receiving a particular treatment,

placebo

a substance with no therapeutic effect used as a control in testing new drugs.

phase 1 in clinical trials

test the drug on healthy human volunteers; test for side effects, rates of passage and dosage

phase 2 of clinical trials

tests drug effectiveness on people with the particular disease

phase 3 of clinical trials

tests the drug on a larger population to include both sexes, many age groups and ethnicities and people with more than the one health condition

phase 4 of trials

tests other applications for the drug

homeostasis and examples

constancy of the internal enviroment. Ex: body temp, body ph and blood glucose

pathway and mechanism of feedback loops

sensors: detect changes and send information to;

integrating center: assseses information and sends instructions to;

effector: make appropriate adjustments to counter the change from the set point

negative feedback

moves in the opposite direction to reverse the change in the set point.

A continuous process, always making fine adjustments to maintain homeostasis

examples: body temp, glucose, calcium, blood PH

positive feedback

the end product stimulates the process and moves in the same direction. Amplifing changes stimukated to the effectors.

example: uterine contractions, blood clots

negative feedback inhibition

usually involves an antagonist to maintain homeostasis by inhibiting the initial stimulus in a system, thus preventing excessive responses and restoring balance.

antagonistic effectors

Two opposing mechanisms that regulate a physiological variable, working to maintain homeostasis by balancing each other.

ex: glucagon secretion rising blood sugar when blood sugar is too low

intrinsic regulation

cells within an organ sense a change and signal to neighboring cells

extrinsic regulation

the brain or other organs regulate an organ using the endocrine or nervous system

feedback inhibition

hormones are secreted in response to specific stimuli. Secretion can be inhibited by its own effects

levels of orginization

cell- basic unit of structure and function

tissue- group of similar cells performing a similar function

organ- group of two or more tissues into structual and functional units

system- group of organs working together to perform related functions

organism- systems working together in coordination

muscle tissue

contraction, voluntary control; skeletal, cardiac, smooth

striations: skeletal, cardiac- intercalated discs

nervous tissue

neurons and gilia: found in brain, spinal cord and nerves

conduct impluses

epithelial tissue

form membranes that cover body surfaces, line organs and glands

simple epithelium

a single layer of cells that transports substances

stratified epithelium

multi layers of cells that protect

squamous

flat epithelial cells that facilitate diffusion and filtration.

cuboidal

cube-shaped epithelial cells that assist in secretion and absorption.

columnar

tall, column-like epithelial cells that aid in absorption and secretion.

endocrine gland

secrete hormones directly into the bloodstream. derived from epithelial tissue.

exocrine gland

secretes hormones into ducts. Derived from epithelial tissue

stem cells

connective tissue

matrix made of protein fibers, extracellular material and specialized cells that supports, binds, and protects other tissues and organs in the body.

connective tissue proper

contains protein fibers and gel. like ground substance

loose: collagen fibers scarted loosely containing

loose connective tissue

collagen fibers loosely room for vessels and nerves

ex: upper dermis

dense regular connective tissue

densely packed collagen fibers with no room for ground substance

ex: tendons and ligaments

dense irregular connective tissue

densely packed collagen fibers arranged in various ways

ex: adipose tissue- which stores fat

cartilage connective tissue

composed of chondrocytes surronded by semi solid ground substance

ex: joints

bone connective tissue

osteoblasts and osteocytes embedded in a mineralized matrix around a canal filled with vessels and nerves

stem cells

highly specialized cells used for tissue development

totipotent

stem cells that can differentiate into any cell type,

ex: zygote

pluripotent

stem cells that can differentiate into nearly all cell types.

Ex: embryonic stem cells

multipotent

adult stem cells are limited to a narrow range of possibilities but can become several related cells

ex: bone marrow can become any type of blood cell

intracellular

area inside cells seperated by membranes; contains 65% total body water

extracellular

area outside of cells seperated by membranes; blood plaasma and intersitial fluidthat contains the remaining 35% of total body water.