Chapter 1- Introduction Flashcards
What are the levels of organization and the related fields of study?
1) . Chemistry (atoms & molecules)
2) . Molecular Biology (cells & molecules)
3) . Cell Biology (molecules, cells, tissues)
4) . Physiology (molecules, cells, tissues, organs, organ systems, organisms, populations)
5) . Ecology (everything & ecosystems of different species &a biosphere)
Consists of heart, blood vessels, & blood
Functions to transport materials between all cells of the body
Circulatory system
Stomach, intestine, liver, pancreas
Functions to convert food into particles that can be transported into the body; elimination of some wastes
Digestive system
Thyroid gland, adrenal gland
Function: coordination of body function through synthesis and release of regulatory molecules
Endocrine system
Thymus, spleen, lymph nodes
Functions to defend against foreign invaders
Immune system
Skin
Protection from external environment
Integumentary system
Skeletal muscles and bone
Support and movement
Musculoskeletal system
Brain & spinal cord
Coordination of body function through electrical signals and release of regulatory molecules
Nervous system
Ovaries, uterus, testes
Perpetuation of species
Reproductive system
Lungs and airways
Exchange of oxygen and carbon dioxide between the internal and external environments
Respiratory system
Kidneys and bladder
Maintenance of water and allures in the internal environment; waste removal
Urinary system
Function is the “why” or the adaptive significance of the event
Thinking about the adaptive significance
Teleological approach
Examines the process, the “how”
Mechanistic approach
What are the themes in physiology?
1) . Structure & function (form fits function)
- molecular interactions
- compartmentation
2) . Energy storage, transfer, and use
3) . Information flow within the species, organism, and cell
4) . Homeostasis
- stability of internal environment
Organ systems in the body work to keep the internal environment constant despite changes in the external environment
Homeostasis
What does the body’s internal environment consist of?
Extracellular fluid (ECF- closely regulated by the body)
Intracellular fluid (ICF)
What separates the cell from the ECF?
Cell membrane
What goes in must come out
Open system
Output must equal input
Existing body load + intake or metabolic production - exertion or metabolic removal
Mass balance law
From outside the body (food, drink, gasses, lipids)
From inside the body (metabolism, CO2)
Intake/input
Excretion (urine, feces, lungs, skin)
Output
Any foreign substance in the body
Xenobiotic
Use to follow material throughout the body
=concentration of (y) x volume flow
Mass flow
The rate at which a substance disappears from the blood
Volume of (x) cleared per unit of time (indirect measure)
Clearance
Physiological normal range
Set point
What are the two groups of control mechanisms?
1) . Local (paracrine)
2) . Long-distance, reflex control (endocrine and nervous)
What are the basic components of all control systems?
1) . Input signal
2) . Integrating center
3) . Output signal - creates response
How do cells in local control respond?
Cells in the vicinity of the change initiate the response
How do cells respond in reflex control?
Cells at a distant site control the response
Type of response loop
Homeostatic
Negative feedback loops
Type of feedback loop
Not homeostatic
Positive feedback loop
When the response of a system goes in a direction opposite to the change that set it in motion
The response counteracts the stimulus, shutting off the response loop
Negative feedback
When the response of a system goes in the same direction as the change that set it in motion
The response reinforced the stimulus, sending the variable farther from the setpoint
Positive feedback
When the response loop starts in anticipation of the change
Ex- salivation
Feedforward
Changes in the set point of a regulated variable
Ex- circadian rhythm
Biological rhythms (biorhythms)
Quantified the distribution of one variable over a range of values
Histogram
Each point represents one member of a test population
Points never connect by lines
Has best fit line
Scatter plot
When the individual is both the experimental subject and control
Reduce variability
Crossover study
Subjects don’t know during the study
Blind study
Third party knows what is happening during the study
Double blind
Control first half switch to experimental group and vice verses
No one involved knows who is taking the active treatment
Double blind crossover study
Make comparisons at a single point in time
Allows researchers to compare many different variables at the same time
Cross sectional studies
Make comparisons over time
Researchers can detect developments or changes in the characteristics of the target population at both the group and the indivisible level
Can establish sequences of events
Longitudinal studies
Watch for outcomes during the study period and relates this to other factors such as suspected risk
Prospective studies
Looks backwards and examines exposure to suspected risk factors in relation to an outcome that is established at the start of the study
Retrospective study
