General Physiology Week 1 Flashcards
The ability to maintain a relative consistency in the chemical and physical environment surronding the cells of our body, in the face of a variable external environment
Homeostasis
provides a communication network to tissues and organs
Neuroendocrine system
what is the normal lab value for a arterial blood pH?
7.4
What is the normal lab value for mean arterial blood pressure?
90 mmHg
What is the normal lab value for the glomerular filtration rate?
120 mL/min
What are the three neural and hormonal mechanisms?
negative feedback
positive feedback (action potential)
feed forward (digestive)
What are the components of a negative feedback control system?
Explain the two negative feedback systems
Explain the positive feed back mechanism
Explain the feed forward mechanism
Fluid can move freely form the interstitial to plasma compartments and helps to maintain blood volume during?
hemorrhage
What can move freely form the interstitial to plasma compartments and helps to maintain blood volume during hemorrhage?
fluids
A hemorrhaging patient must lose about __ L of __ before the ___ is decreased by _ L
5 L of ECF
Plasma volume 1 L
To replace ___L of ____ approximately ___ L of intravascular isotonic saline must be infused
1 L Plasma Volume
5 L
What is included in the interstital fluid of the body?
lymph, CSF, synovial fluid, aqueous and vitreous humor (eyes), pleural, peritoneal, and percardial fluids
What is the breakdown of the fluid compartments of the body?
What is the fluid mosaic model of the plasma membrane?
What are the different types of membrane proteins and their functions?
Prevent fluids and most molecules from moving between cells
tight junctions
“Rivets” that anchor cells together
Desmosomes
transmembrane proteins form pores that allow small molecules to pass from cell to cell
Gap Junctions
channel between cells that allows the spread of ions between cardiac or smooth muscle cells
Connexon
What is Microvilli?
What is flagella?
What are pseudopods?
What are nonmotile cilium?
What are motile cilia and where can they be found?
What floats on top of saline layer and traps mucous and dust?
Mucus
defects in structure and function of cilia
ciliopathies
hereditary disease in which cells make chloride pumps, but fail to installl pumps in plasma membrane which interupts saline production and leads to thick mucous secretions
cystic fibrosis
What are components of cystic fibrosis
- chloride pump fail to create adequate saline layer on cell surface. thick mucus plug pancreatic ducts ad respiratory tract
- adequate digestion of nutrients and absorption of o2, chronic respiratory infections. life expectancy of 30.
What are the two types of membrane transport systems?
What is simple diffusion?
most water moves across membranes via a transmembrane protein
aquaporin
Explain the solute transport across a plasma membrane
In simple diffusion, the rate of solute entry increases linearly with extracellular concentration of the solute. Assuming no change in intracellular concentration, increasing the extracellular concentration increases the gradient that drives solute entry. In facilitated diffusion, the rate of transport is much faster, and increases linearly as the extracellular solute concentration increases. The increase in transport is limited by the availability of channels and carriers. Once all are occupied by solute, further increases in extracellular concentration have no effect on the rate of transport. A maximum rate of transport (Vmax) is achieved that cannot be exceeded
What are the three channels for facilitated diffusion?
transport that moves a range of ions and organic solutes passively across membranes
carrier-meditated transport
2.8 The role of a carrier protein in facilitated diffusion of solute molecules across a plasma membrane. In this example, solute transport into the cell is driven by the high solute concentration outside compared with inside. (A) Binding of extracellular solute to the membrane-spanning integral protein triggers a change in conformation that exposes the bound solute to the interior of the cell. (B) Bound solute readily dissociates from the carrier because of the low intracellular concentration of solute. The release of solute allows the carrier to revert to its original conformation (A) to begin the cycle again.
What are the different types of active transport proteins?
Explain the sodium potassium pump
The sodium potassium pump helps to create a ____
resting membrane potential
Explain the secondary active transport
glucose moves through the protein from any area of high concentration to an area of low concentration by indirectly using ATP from the sodium. The pump takes sodium and glucose into the protein than changes shape depositing both sodium and glucose into the cell
What are the properties and differences between the three carriers?
properties: specificity and saturation
differ in: the direction they move solutes
the number of solutes they can move
What are the three kinds of carriers?and examples
carries one type of solute
uniport
carries two or more solutes simultaneously in same direction (cotransport)
symport
carries two or more solutes in opposite directions (countertransport)
antiport
Explain transcellular transport
In a polarized cell, the entry and exit of solutes such as glucose, amino acids, and Na+ occur at opposite sides of the cell. Active entry of glucose and amino acids is restricted to the apical membrane, and exit requires equilibrating carriers located only in the basolateral membrane. For example, glucose enters on sodium-dependent glucose transporter (SGLT) and exits on glucose transporter-2 (GLUT2). Na+ that enters via the apical symporters is pumped out by the Na+/K+-ATPase on the basolateral membrane. The result is a net movement of solutes from the luminal side of the cell to the basolateral side, ensuring efficient absorption of glucose, amino acids, and Na+ from the intestinal lumen.
Explain vesicular transport
Phagocytosis is the ingestion of large particles or microorganisms, usually occurring only in specialized cells such as macrophages (Fig. 2.4). An important function of macrophages is to remove invading bacteria from the body.
Foreign substances, such as diphtheria toxin and certain viruses, also enter cells by this pathway
There are two exocytic pathways—constitutive and regulated. The continuous secretion of mucus by goblet cells in the small intestine is an example of the constitutive pathway of exocytosis that is present in all cells. In other cells, macromolecules are stored inside the cell in secretory vesicles. These vesicles fuse with the cell membrane and release their contents only when a specific extracellular stimulus arrives at the cell membrane. This process, termed the regulated pathway, is responsible for the rapid “on-demand” secretion of many specific hormones, neurotransmitters, and digestive enzymes.
Explain the solute transport mechansim
particles are driven through membrane by physical pressure (forcing into the cell)
filtration
between cells
paracellular
through cells
transcellular
vesicular transport
transcytosis
Water movement across plasma membrane driven by differences in ____
osmotic pressure
Water follows the __ and travels through ___
solutes
aquaporins
total solute concentration of a solution per 1 L solvent
osmolarity
blood plasma, tissue fluid, and intracellular fluis are ___ milliosmoles per liter (mOsm/L)
300
pressure necessary to stop the net movement of water across a selectively permeable membrane that separates the solution from pure water
osmotic pressure
a difference between the measured and estimated osmolarity
osmolar gap
What causes osmolar gap? and what is an example?
-caused by the presence of additional solutes in plasma
-patients with alcohol intoxications or ethylene glycol poisoning will have an increased osmolar gap
ability of solution surrounding cell (ECF) to affect fluid volume and pressure in cell
tonicity
Tonicity depends and determines what?
depends on concentration of nonpermeating solutes
determines cell volume
What is an isotonic solution?
What is a hypotonic soluion?
What is a hypertonic solution?
Explain the concept of steady state
membrane potential at which the electrical driving force is equal and opposite to the chemical driving force
equilibrium potential (Ex)
Explain the different electrochemical driving forces
What are the different types of communications?
What are the different types of cell surface receptors?
What are the different classes of second messengers?
What are the examples of cellular signal amplifications?
Explain the production of cAMP?
What are the divisions of CNS and PNS?
What restricts access from the capillary into the brain?
blood-brain barrier
What are the different types of glial cell types in the CNS?
Explain the axonal transport?
Lable the neuronal structure
action potential generation zone and contain voltage gated channels
axon hillock
recieves incoming signals
dendrites
impulse conduction (action potentials)
axon
secreton of neurotransmitter
nerve termini
What gates are located in the neuron structures?
axon hillock- voltage gated
dendrites- ligand -gated and/or GPCR gated ion channels
axon- voltage gated and Na/K channels
nerve termini- voltage-gated Na, K and Ca channels
Ligand-gated channels are ___
ionotropic
G protein-coupled receptors are ___
metabotropic
Exaplain the excitatory and inhibitory postsynaptic potentials
What are the different phases of the action potential?
Explain the unidirectional propagation of action potentials?
What influences conduction velocity?
myelination and fiber diameter
moves faster the more myelinated and larger it is
myelination allows for ___
saltatory
What is particularly sensitive to local anesthetics, which block sodium channels?
unmyelinated fibers
What is more sensitive to compression, which can the cause loss of sensitivity to stimuli carried by those fibers?
larger fibers
What are the steps on synaptic transmission?
Explain the reuptake and recycling of glutamate through glial cells
Neurotransmitter actions can be terminated by?
diffusion, degradation, or cellular uptake
Explain how the receptor activation can produce inhibitory and excitatory effects?
CNS neurotransmitters interact with?
ionotropic and metabotropic receptors
What are the classical neurotransmitters?
histamine
purines
What are the non-classical neurotransmitters?
eicosanoids
cannabiniods
What are the neuropeptides?
opioids (endorphin, enkephalin, and dynorphin)
autonomic receptors that bind to adrenaline and noradrenaline
adrenergic receptors
What nervous system is responsible for adrenergic receptors?
Sympathetic nervous system
What are the responsible neurotransmitters in adrenergic receptors?
adrenaline and noradrenaline
What are the types of adrenergic receptors?
alpha and beta receptors
autonomic receptors that bind to acetylcholine
cholinergic receptors
What nervous system is responsible for cholenrgic receptors?
parasympahetic nervous system
What are the responsible neurotransmitters in cholinergic receptors?
acetylcholine
What are the responsible neurotransmitters in cholinergic receptors?
nicotinic and muscarinic receptors
What is a predominant second messenger in all cells?
cAMP
cGMP AND NO are important second messengesr in?
smooth muscle and sensory cells
