DPT 5000 Quiz 2- Cell Physiology/Homeostasis Flashcards
Physiology
Study of how living organisms function.
Effects of PT treatment @ cellular level
- Muscle Cells
- Nerve Cells
- Epithelial Cells
- Connective Tissue Cells
Levels of Cellular Organization
- Single cell division & growth
- Differentiation
- Tissues
- Organs
- Organ Systems (10 in body)
- Total organism
Types of Cells
- Prokaryotic (bacterial)
2. Eukaryotic cells (animals and plants)
Overall structures inside the cell
- Nucleus
- Cytoplasm- everything else
A) cell organelles
B) cytosol- fluid surrounding organelles - Plasma Membrane
Functions of Cell Membranes
1) Selective Barrier
2) Detect chemical messengers
3) Link adjacent cells/ anchor cells to extracellular matrix
Plasma Membrane
- Phospholipid bilayer w/ proteins
- Proteins (ion channels, signals, cell shape)
- Carbohydrates (short sugar chain/cell identification)
- Cholesterol (vesicle formation)
Nucleus
Storage & transmission of DNA
- nuclear envelope (allows RNA & proteins to move between nucleus and cytoplasm)
- chromatin (DNA-protein threads)
- Nucleolus (contains DNA for ribosomal RNA)
Endoplasmic Reticulum & Ribosomes
Ribosomes- cell protein factories
RER- Rough ER (has ribosomes; package proteins)
SER- Smooth ER (no ribosomes; lipid synthesis; CA++ ion storage)
Golgi Apparatus
Flattened membranous sacks
- modifies proteins from rER
- sorts into transport vesicles
i.e. sort neurotransmitters to be sent out of cell
Mitochondria
Make ATP by cellular respiration
muscle cells –> lots of mitochondria!
Lysosomes
Contain highly acidic fluid+digestive enzymes
breaks down bacteria, dead cell debris, etc.
Peroxisomes
similar to lysosomes
Cytoskeleton
maintains cell shape and produce cell movement
- microfilaments
- intermediate filaments
- microtubules
Cell Function
1) Chemical Rxns
2) Movement across Membrane
a) diffusion/osmosis
b) facilitated diffusion/ active transport
c) endocytosis & exocytosis
Chemical Rxns
Catabolism
- breaking chemical bonds
Anabolism
- forming new chemical bonds & molecules
Require the transfer & balance of matter and energy.
Chemical Rxns: Law of Chemistry and Physics: Reaction Rate Affected by…
- Reactant conc. (higher=faster)
- Activation energy (higher energy require= slower rate)
- Temperature (higher= faster rate)
i.e. fever –> increases speed of immune syst. - Catalyst (present= faster rate)
Enzyme- protein catalyst
Enzymes and Cofactors
Enzymes- proteins that lower activation energy and increase rxn rate
Cofactors- binds to enzyme & allows it to function
Diffusion
net movement of molecules from region of high conc. to region of low conc.
Diffusion Flux & Rate
- Temperature
- Molecule size
- Surface area of membrane
- Medium moving through (air faster than water)
- Distance (larger distance= slower diffusion)
Osmosis
net diffusion of water across membrane
- isotonic
- hypotonic
- hypertonic
Other ways to cross membrane
- Ion diffusion through protein channels
- Facilitated diffusion
- Active transport
Endocytosis & Exocytosis
Endocytosis-plasma membrane folds into cell & produces membrane-bound vesicle (pinocytosis, phagocytosis)
Exocytosis- vesicle fuses w/ plasma membrane & releases contents into extracellular fluid.
Homeostasis
Maintain stable internal environmental conditions.
Feedback and Feedforward
Feedback
negative- increase or decrease in variable causes response to move variable back toward original value (i.e. drop in body temp –> body shivers returns body temp to original value)
positive- less common; actually accelerates a process (i.e. child birth/ contractions & oxytocin release)
Feedforward
Anticipates changes in regulate variabls and acts to minimize them (i.e. smell food –> stomach increases acid content).
Feedback –> Reflexes
Stimulus causes autonomic response
Built-in: unlearned (pull away from hot stove)
Acquired- result of learning (driving)
pathways are not exclusive to nervous system
Cellular Communication
- hormones (though blood)
- neurotransmitters (through nerves)
- paracrine agents (via diffusion on local cells)
Autocrine
