Homeostasis + Cell Membrane 1 Flashcards
What is physiology?
The study of the normal functioning of living organisms
What are tissues?
Collection of cells carrying out related functions
What is emergent properties
Smaller parts that don’t exhibit “bigger” properties. Ex. Car parts that become an engine
What is a functionist view?
“Why” ex. Why do red blood cells transport oxygen
What is a mechanism view?
“How” ex how do red blood cells transport oxygen
What is homeostasis?
The ability to maintain a relatively stable internal environment
What is a pathophysiological state?
A disease state
What are external changes for homeostasis?
Toxic chemicals
Physical trauma
Foreign invaders (bacteria or viruses)
What is an internal change in homeostasis?
Abnormal cell growth
Autoimmune disorders
Genetic disorders
What does a change in homeostasis lead to?
First, organism attempts to compensate. If that fails, it leads to illness or disease
Are most cells tolerant to changes in their surroundings?
Nope
What are the 2 types of extracellular fluids?
Interstitial
Plasma
What is a dynamic steady state?
Materials constantly moving back and fourth
Define extracellular fluid
Extracellular fluid surrounds the cell and acts as a buffer between cells and the external environment
What is interstitial fluid?
The fluid surrounding cells
What is plasma?
Liquid component of blood
What is the law of mass balance
Amount of substance in the body is to remain constant
When does something actually become internal in your body?
When it enters your extracellular fluid
What are some inputs in the body? (Homeostasis)
Intestine, lungs, skin
What are some outputs in the body? (Homeostasis)
Excretion by kidney, liver, lungs, skin
Does homeostasis mean equilibrium? (Is every thing equal between the extracellular and intercellular fluid?)
No, goal is dynamic steady state (stable disequilibrium)
What are the 2 control systems?
Local or reflex
What is local control?
Small changes that are restricted to a small area of the body
Which cells send local signals?
Endothelial
Is reflex control long signalling or short signalling?
Long distance signalling
Which control system for changes widespread throughout the body?
Reflex control
Which control system controls blood pressure?
Reflex
What are the two parts of reflex control?
Response loop
Feedback loop
What is the response loop?
First part of reflex control
Stimulus, sensor…, response
What is the feedback loop?
Second part of reflex control
It is when the response impacts or influences the stimulus
What are the 3 types of reflex control?
Negative feedback
Positive feedback
Feedforward control
What does a negative feedback loop do? (2)
The response counteracts the stimulus, shutting off the response loop
Stabilizes the system
Is a negative feedback loop homeostatic?
Yes. Goal is to get back to normal
Are positive feedback loops homeostatic?
Nope
Which feedback loop requires an intervention to stop it from continuing?
Positive
What does a positive feedback loop do?
Reinforces the stimulus to drive the system away from a normal value rather then removing it
What is an example of a positive feedback loop?
Birth ( baby coming out is the intervention)
What is feedforward control?
Body predicts that a change is about to occur.it is
Initiated before the initial stimulus
EX. Mouth salivating
What are biorhythms?
Variables that change predictably and create repeating patterns or cycles of changes
What is the average composition of the cell membrane? (3 parts)
55% protein
45% lipids
Small amount of carbohydrates
The more metabolically active the membrane is the more ___________ it contains
Protein
What are the 3 types of lipids found in the cell membrane?
Phospholipid
Sphingolipid
Cholesterol
What does it mean to be amphipathic?
One region that really likes water and one region that doesn’t
Polar heads of the bilayer are _________ (hydrophobic or hydrophilic )
Hydrophilic (it faces the liquid)
Fatty acid tails of the bilayer are __________ ( hydrophobic or hydrophilic)
Hydrophobic (they face each other)
Why is cholesterol needed in the cell membrane?
They make it more rigid because phospholipids are so fluid
Which lipids are lipid rafts?
Sphingolipids
What is the cell membrane also called?
Fluid mosaic model
What are the 2 types of cell membrane proteins
Integral
Peripheral
What are lipid rafts important for?
Cell signalling
What are the two integral proteins?
Transmembrane proteins
Lipid anchored proteins
