Unit 1 - Intro to Physiology - (Course Notes) Important Terms and Concepts Flashcards
Physiology
The branch of biology that deals with the normal functions of living organisms and their parts
Homeostasis
Any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival
Acclimatization
The process in which an individual organism adjusts to a change in its environment WITH NO GENETIC CHANGE (such as a change in altitude, temperature, humidity, photoperiod, or pH), allowing it to maintain fitness across a range of environmental conditions
Local control
The effects are exerted on neighbouring cells, e.g. paracrine control of blood vessel diameter in response to low O2
Cell membrane
Found in all cells and separates the interior of the cell from the outside environment, consists of a lipid bilayer that is semipermeable and regulates the transport of materials entering and exiting the cell
Receptor
Usually trans-membrane proteins (or glycoproteins), usually found in plasma membrane but can be intracellular (cytosolic or nuclear)
Gap Junctions
Known as direct cell-cell communication, occur via protein channels (connexons) between adjacent cells, capable of opening and closing, found in many cell types. Communicating cell–cell junction allows ions and small molecules to pass from the cytoplasm of one cell to the cytoplasm of the next. Found joining virtually all cells in solid tissues
Anchoring Junctions
Connects two cells together or connects cells to the substratum or extracellular matrix. Mechanically attaches cells together along with their neighbouring cells (and their cytoskeletons) or attaches cells to the extracellular matrix
Tight Junctions
Cell–cell junction that seals adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other. Function as a barrier for the paracellular transport of solutes
Connective Tissue
Provides structural support and barriers, has an excessive extracellular matrix (ECM) that contains proteoglycans, collagen, elastin, and fibronectin. Five types: loose, dense, adipose, blood, supporting
Neural
Carry information from one part of the body to another, very little ECM. Two types: neurons, glial cells
Autocrine
Chemicals that act on the cells that produces them
Specificity
Only respond to a chemical signal if they have the appropriate receptor
Organ Systems
10 major systems in the human body:
1. Nervous system
2. Musculoskeletal system
3. Circulatory system
4. Respiratory system
5. Immune system
6. Endocrine system
7. Reproductive system
8. Digestive system
9. Urinary system
10. Integumentary system
Setpoint
Oscillation around a [……..] is the result of homeostatic control and can change with time
Reflex Control
The reaction in one or more organs controlled from elsewhere in the body. Can be any long-distance path of the nervous and/or endocrine system(s)
Positive Feedback
Response sends a signal which reinforces the stimulus, sending the variable further from the set point until an external signal turns the response off. NOT homeostatic. The response reinforcing the stimulus temporarily sends the system out of control (e.g. labor)
Negative Feedback
Results in a change that opposes or removes the signal thus returning the variable to its original value. Allows for homeostatic control. Keeps a system near or at the set-point. Results in oscillation around the set-point (e.g. blood pressure)
Feedforward Control
Anticipatory control: predicts that change is about to happen, starts the response loop, prevents change (e.g. sight, smell or thought of food)
Epithelia
Protects the internal environment of the individual. Regulates the exchange of material between external and internal environment. Consists of one or more layers of cells connected to one another and to a basal lamina
Muscle
3 types: skeletal, smooth, cardiac
Have the ability to contract to produce force and movement.
Paracrine
Allows cells to communicate with each other by releasing signalling molecules that bind to and activate surrounding cells when a cell targets a near by cell.
Endocrine
A cell targets a distant cell through the bloodstream. The signalling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to act on target cells at distant body sites.
Response
The end of the line for a signal brought to the target cell by a signaling molecule. Once the signal has gone through transduction in the target cell, it is now ready to be put into action
