Physiology Flashcards
It is the maintenance of a stable internal environment despite external changes.
Homeostasis
It is a lipid bilayer with embedded proteins which functions to control the passage of molecules in and out of the cell. It is
Selective Permeable, that is, it allows certain molecules to cross while restricting others.
Cell membrane
Intracellular and Extracellular Fluids
Intracellular Fluid (ICF): Fluid within cells, containing high levels of potassium.
Extracellular Fluid (ECF): Fluid outside cells, including interstitial fluid and plasma.
Ion Composition: ECF rich in sodium and chloride; ICF rich in potassium.
It is the voltage difference across a cell membrane due to uneven distribution of ions. It is essential for nerve and muscle function
Membrane potential
Resting Membrane Potential: Around -70mV in most cells, maintained by Na+/K+ pump.
It is a rapid, transient change in membrane potential in excitable cells (neurons, muscle cells).
It has 3 phases: depolarization, repolarization, hyperpolarization
It travels along the cell membrane, allowing signal transmission.
Action potential
A regulatory mechanism where the body responds to a stimulus by reversing its effects.
Ex. Regulation of body temperature through sweating and shivering
Negative Feedback
AKA viscous cylce. A regulatory mechanism where the body amplifies a response to a stimulus. It leads to instability.
Ex. Blood clotting cascade and uterine contractions during childbirth.
Positive feedback
The metabolic pathway that converts glucose and oxygen into carbon dioxide, water, and energy (ATP).
Stages: Glycolysis, citric acid cycle (Krebs cycle), electron transport chain (where majority of ATP is produced0
Cellular Respiration
Communication process where cells use chemical messengers to transmit information.
Types:
Autocrine (acts on the same cell)
Paracrine (acts on nearby cells),
Endocrine (acts on distant cells via bloodstream)
Cell Signaling
What is the difference between Hypertonic, Hypotonic, and Isotonic solutions?
Hypertonic: Solution with a higher solute concentration compared to the cytoplasm; causes water to move out of cells.
Hypotonic: Solution with a lower solute concentration compared to the cytoplasm; causes water to move into cells.
Isotonic: Solution with the same solute concentration as the cytoplasm; no net movement of water.
What are the three muscle types?
Skeletal, smooth, cardiac
