Shared Flashcard Set

Details

Chapters 2,3,4,7
Cell Structure, Function, and Metabolism
184
Physiology
Undergraduate 1
01/23/2011

Additional Physiology Flashcards

 


 

Cards

Term
Lack cell walls and chloroplasts, and have smaller vacuoles
Definition
Animal Eukaryotic cell
Term

Forms bilayers in cell membranes

Forms micelles in aqueous solutions

Definition
Phospholipids
Term
Phospholipids have a ________ head outside and ______ tails inside
Definition

Hydrophilic

Hydrophobic

Term

Has a sugar head - often called an antigen

 lipid tail - important in immune response and cell recognition

Definition
Glycolipids
Term
Project toward either side of membrane, but do not go all the way through the membrane
Definition
Peripheral membrane proteins
Term
Go all the way through and project from each side of the membrane
Definition
Integral membrane proteins or transmembrane proteins
Term

Have specific sugars attached to outer surface

Function along with glycolipids in immune response and cell recognition

Sugar head often called an antigen

Definition

Recognition proteins & Glycoproteins

 

Ex:  Major histocompatibility comples (MHC)

       ABO blood groups

       Cell junctions (like desmosomes) are also often

       formed from glycoproteins

 

Term
Allow specific things which cannot pass directly through lipid portion of the plasma membrane (like ions) to move in and out of cell freely
Definition
Channel Proteins
Term
Has a specific binding site, and will physically carry specific molecules across the cell membrane which could not otherwise pass, requires ATP energy if moving a substance against its concentration gradient
Definition
Carrier Protein
Term
Accept specific shaped molecules called ligands then changes shape and function when molecule binds
Definition
Receptor Proteins
Term
Speeds up a reaction at the cell membrane (catalysts) by binding specific substrates at the enzyme's active site
Definition
Enzymatic Proteins
Term

Structural Support

Inside - to cytoskeleton

Outside - to other cells or fibers

Definition
Anchoring Proteins
Term
What are glycolipids, glycoproteins and glycocalyx
Definition
Carbohydrates (oligosaccharides)
Term
Both have carbohydrate portions extending outside the cell
Definition
glycolipids and glycoproteins
Term
whole outer layer of cell membrane, lubrication, recognition, anchoring, specificity
Definition
glycocalyx
Term
Include transporters, channels, receptors, enzymes, structural membrane-anchoring domains, proteins involved in accumulation and transduction of energy, and proteins responsible for cell adhesion.
Definition
Integral Membrane Proteins and Transmembrane Proteins
Term

Often important in integral membrane proteins, where they play a role in cell-cell interactions.

Occur in the cytosol

Definition
Glycoproteins
Term
They do not extend through the membrane.  They bond and drag molecules through the bilipid layer and release them on the opposite side
Definition
Carrier Proteins
Term

Molecules randomly move through the opening in a process called diffusion

Requires no energy

Molecules move from an area of high concentration to an area of low concentration

Definition
Channel Proteins
Term

These proteins are used in intercellular communicaiton.

(lock and key)

Definition
Receptor Proteins
Term

Forms impermeable junction

Molecules cannot cross epithelial sheet by slipping between cells

Definition
Tight Junction
Term
Strong, but permeable association between two cells which provides resistance to stretching and twisting
Definition
Desmosomes
Term
Channel proteins from adjacent cells fuse to allow for instantaneous communication between ICF of cells
Definition
Gap Junctions
Term
All the chemical reactions that occur in a cell, both synthesis and breakdown of organic molecules
Definition
Metabolism
Term
The building up of things - a succession of chemical reactions that constructs or synthesizes molecules from small components, usually requiring energy in the process
Definition

Anabolism

 

constructive metabolism

Term
The breaking down of things - a series of degradative chemical reactions that break down complex molecules into smaller units, and in most cases releasing energy in the process
Definition

Catabolism

 

destructive metabolism

Term
Lower the activation energy for a chemical reaction (catalyzes); therefore it increases the rate of a chemical reaction
Definition
Enzyme Function
Term
In enzymatic reactions, the molecules at the beginning of the process are called
Definition
Substrates
Term
Substrates are converted into different molecules called
Definition
Products
Term
A set of enzymes made in a cell determines which _________ ________ occur in that cell
Definition
Metabolic Pathway
Term
Incease or decrease the rates of chemical reactions
Definition
Catalyze
Term
Like all catalysts, enzymes work by lowering the ________ for a reaction, thus dramatically ________ the rate of the reaction 
Definition

Activation Energy

 

Increasing

Term
If all of the enzyme molecules are occupied with substrate what does this mean
Definition
The enzyme is saturated and adding more substrate will not increase the rate of reaction because the enzymes are already working full bore
Term
If an enzyme is unsaturated then adding more substarte would do what to the reaction rate
Definition
Increase
Term
The regulation of an enzyme or other protein by binding an effector molecule at a site other than the protein's active site is called
Definition

Allosteric Regulation

 

 

Term
A modulator alters the enzyme's shape, by binding at a regulatory site, such that the shape of the active site is changed in called
Definition
Allosteric regulation
Term
Organic molecules that are required by certain enzymes to carry out catalysis
Definition
coenzymes
Term
Inorganic substances that are required for, or increase the rate of, catalysis
Definition
cofactor
Term
What factors influence Enzymatic Activity
Definition
  • The availabilty of substates and cofactors usually determines how fast the reaction goes.  As product accumulates, the apparent rate of the enzymatic reaction will decrease due to lack of substate
  • covalent modification
  • allosterically
  • modulator proteins
  • genetic regulation
Term
_________ enzymes have quaternary structure and regulation is at a site other than the active site
Definition
Allosteric Enzymes
Term
Phosphorylation is accomplished by protein
Definition
Kinases
Term
Phosphoprotein phosphatases catalyze the reverse reation which does what
Definition
removes phosphoryl groups from proteins
Term
An enzyme that transfers phosphate to ADP or AMP or from ATP
Definition
Kinase
Term
An enzyme that hydrolyzes a phosphate off of a substrate
Definition
Phosphataxe or phosphoprotein phosphatase
Term
An enzyme that adds a phosphate to substrate but does not use ATP to do so
Definition
Phosphorylase
Term
A type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific substrates (process known as phosphorylation)
Definition
Kinase
Term
An enzyme that removes phosphate groups is known as
Definition
Phosphatase
Term
Unbalanced equation for cellular respiration
Definition
C6H12O6 + O2 --> H2O + CO2
Term
Describe how homeostasis and cellular respiration are important to each other in body temperature
Definition
  • body temperature - heat is generated by the cellular respiration reaction, combining oxygen and ATP and creating heat, carbon dioxide and water.  The Hypothalamus monitors body temperture and regulates that temperature by increasing or decreasing cellular respiration reactions which keeps the body temperture maintained within a few degrees of normal
Term
Describe how homeostasis and cellular respiration are important to each other in glucose levels in the blood
Definition
  • Glucose is the form of sugar that is found in blood and provides energy for cellular respiration.  When glucose levels are high - insulin is secreted by the pancreas.  Insulin stimulates the absorption of glucose by cells and the liver's conversion of glucose into glycogen (stored in the liver and blood cells).As glucose levels decrease, less insulin is secreted, glucagon is produced which causes the liver to convert glycogen back to glucose.
Term
What stage converts glucose C6H12O6 into pyruvate
Definition

Glycolysis

 

Term
Glycolysis
Definition
  • Carbohydrates start to breakdown
  • Occurs in the cytoplasm/cytosol
  • Does not require Oxygen - can occur anaerobic
  • Requires 2 ATP produces 4 ATP = gain of 2 ATP
Term
If oxygen is present during glycolysis what happens
Definition
Proceeds to Krebs and oxidative phosphorylation in mitochondria
Term
If oxygen is not present during glycolysis what happens
Definition
Very little ATP is formed and lactic acid is formed as a by product
Term
A series of enzymatic reactions that catalyzes the aerobic metabolism of fuel molecules to carbon dioxide and water, which generates the production of ATP.
Definition
Krebs Cycle
Term
What enzymes does the Krebs cycle use
Definition
  • Carbohydrates
  • Fats
  • Proteins
  • Pyruvate - which changes to acetyl coenzyme A before Krebs during the linking step
  • Oxygen
Term
What is produced during the Krebs cycle
Definition
2 ATP and CO2
Term

NADH + H+ ---->   NAD+

 

OIL RIG

Definition

Oxidation is loss of electrons

 

Reduction is gain of electrons

 

Since NADH is becoming more positive (or less negative), then it must be losing electrons, and therefore is being oxidized to NAD+

(Oxidation is Loss of eletrons)

Term
Oxidative Phosphorylation
Definition
  • carbohydrates continue to breakdown
  • some fatty acids begin breakdown
  • uses products of glycolysis and krebs cycle
  • occurs in the mitochondria
  • requires oxygen (aerobic)
  • produces H2O
  • produces 34 ATP
Term
In the liver and muscles, most of the glucose is changed into glycogen by the process of
Definition
glycogenesis (anabolism)
Term

Where is glycogen stored?

 

What two hormones are secreted to stimulate  the conversion of glycogen to glucose?

 

What is this process called?

Definition

Liver and Muscles

 

eqinephrine and glucogon

 

glycogenolysis

Term
What is glucose broken (catabolism) down to
Definition
glucose to pyruvate or lactate by glycolysis
Term
If glucose is needed immediately upon entering the cells to supply energy, it begins the metabolic process called
Definition
glycoylsis
Term
What are the end products of glycolysis
Definition
pyruvic acid and ATP
Term
During strenuous muscular activity, pyruvic acid is converted into lactic acid.  During the resting period, lactic acid is converted back to pyruvic acid which is converted back to glucose by the process called
Definition
gluconeogenesis
Term

Carbohydrates are broken down into __________

which then enters _____________

Definition

glucose

glycolysis (breaking down sugar)

Term
The first step in lipid metabolism is the hydrolysis of the lipid in the __________ to produce ______ and _______ ______
Definition

cytoplasm

glycerol

fatty acids

Term
Where are lipids stored
Definition
Adipocytes store lipids in adipose tissue
Term
The liver plays a major role in metabolism and has a number of functions in the body including
Definition
  • glycogen storage
  • decomposition of red blood cells
  • plasma protein synthesis
  • hormone production
  • detoxification
  • produces bile
Term
LDL
Definition

Low-density lipoprotein

 

Enables lipids like cholesterol and triglycerides to be transported within the water-based bloodstream

Term
HDL
Definition

High density lipoprotein

 

HDL particles are able to remove cholesterol from atheroma within the arteries and transport it back to the liver for excretion or re-utilization

Term
Proteins are broken down to amino acids by
Definition
proteases
Term
An amino acid is converted into the corresponding keto acid by the removal of the amine functional group as ammonia and the amine functional group is replaced by the ketone group - this is known as
Definition
Oxidative Deamination Reaction
Term
What is the product of oxidative deamination reactions
Definition

Ammonia

 

which is converted into urea in the liver which is then transported to the kidneys to be excreted

Term
What are the building blocks used to make proteins and peptides
Definition
Amino Acids
Term
Which type of vitamin can become toxic in high doses
Definition
A and D
Term
The plasma membrane is the boundary between what two fluids
Definition
Seperates the intracellular fluid from the extracellular fluid
Term
Molecules that can cross the membrane without any additional energy being expended uses what kind of transport
Definition
Passive
Term
In simplie diffusion, flux rate is limited only by the
Definition
concentration gradient
Term
In carrier-mediated transport, how is the flux rate affected
Definition
the number of available carries
Term
When the difference between the two one-way fluxes is zero the system has not reached
Definition
diffusion equilibrium
Term
The greater the difference between the two one-way fluxes the greater the
Definition
concentration gradient
Term
What accounts for solute movements in both directions?
Definition
Net Flux
Term

Most polar molecules ____ ____ diffuse into cells, or very slowly

 

Why?

Definition

do not

 

Electrical charge/polarity:  strongly-charged ions are polar and not lipid soluble and cannot cross directly through the lipid portion of the membrane; often cross through specific channel proteins

Term

_____ _____ molecules diffuse very well across membranes

 

Why?

Definition

non polar

 

Membranes are lipid-soluble (non-polar)

Term

Ions (NA+, K+, Cl-) diffuse across plasma membranes very fast even though they are very ____

Why?

Definition

polar

 

They have specific channel proteins

Term
A process whereby a substance passes through a membrane without the aid of an intermediary such as a integral membrane protein
Definition
Simple diffusion
Term
The force that drives the substance from one side of the membrane to the other is
Definition
Diffusion
Term
Carrier-mediated transport of large molecules through the cell membrane using transport proteins embedded within the cell membrane
Definition

Facilitated diffusion

 

EX:  the exchange of oxygen and carbon dioxide in the alveoli of the lungs

Term
Movement of a substance down its concentration gradient is an _______ process
Definition

exergonic process

 

Energy is released

Term
Movement of a substance against a concentration gradient is an ________ process
Definition

Endergonic Process

 

Uses energy from an outside source

Term

What type of transport does not involve any

  • chemical energy
  • relies on the innate permeability of the cell membrane
  • proteins and lipids
Definition
Passive Transport
Term
What are the four main types of passive transport
Definition
  • Diffusion
  • Facilitated
  • Osmosis
  • Filtration
Term
The movement of solute molecules and water across a membrane by normal cardiovascular pressure
Definition

filtration

 

the size of the membrane pores dictate the molecules that may pass

Term
These type of proteins have bonding sites for specific ions.  When these ions make contact with the bonding sites, it causes the protein to change conformation (shape).
Definition
Carrier Proteins
Term
What is the most common type of carrier proteins in the neuron membrane
Definition
sodium-potassium pump
Term
A chemical messenger is a _______
Definition
ligand
Term
What are the three characteristics of a molecule that determines the permeability of the membrane
Definition
  • polarity - (Hydrophobic vs Hydrophylic)
  • charge - (charge vs uncharged)
  • size - (large vs small)
Term
Large materials transported into the cell
Definition

Endocytosis

 

By three slightly different processes

 

Phagocytosis

Pinocytosis

Receptor-mediated endocytosis

Term
Material are expelled from the cell
Definition
Exocytosis
Term
Transmembrane channels that permit facilitated diffusion that can be open or closed
Definition
Gated Channels
Term
Many ion channels open or close in responce to binding a small signaling molecule called
Definition
ligand
Term
Deformation of the cells of stretch receptors open ion channels leading to the creation of nerve impulses are called
Definition
Mechanically-gated ion channels
Term
All called "excitable" cells (neurons and muslce cells) some channels open or close in response to changes in the charge (measured in volts) across the plasma membrane
Definition
Voltage-gated ion channels
Term
In all _______ _________ through channels, the channels are selective - the structure of the protein admits only certain types of molecules through
Definition
facilitated diffusion
Term
The plasma membrane of human red blood cells contain transmembrane proteins that permit the diffusion of glucose from cell what type of transport is this
Definition

facilitated

 

Term
The pumping of molecules or ions through a membrane against their concentraiton gradient is what type of transport
Definition

Active Transport

 

Use ATP

Term
The concentration gradients of the Na+/K+ ATPase pump helps establish a net charge across the plasma membrane with the interior of the cell being ________ charged with respect to the exterior
Definition
negatively
Term
Na+/K+ pump helps to establish the resting potential of a cell which prepares nerve and muscle cells for the propagation of ______ _______
Definition
Action Potentials
Term
The accumulation of sodium ions outside of the cell draws water out of the cell and thus enables it to maintain osmotic balance - this is accomplished how
Definition
Na+/K+ pump
Term
Also called direct active transport, directly uses energy to transport molecules across a membrane
Definition

Primary active  transport

 

  • Requires ATP
  • From low to high
  • An accumulation of particles on one side of the membrane
  • Requires carrier proteing and ATP
  • Carrier protein pumps particles from one side to the other
  • Carrier is shape-specific
Term
Utilizes a carrier protein which binds specific-shaped substance and helps it across membrane by changing conformation
Definition
Mediated-transport system
Term
No direct coupling of ATP, instead the electrochemical potential difference created by pumping ions out of the cell is used
Definition
Secondary active transport
Term

Secondary Active Transport

 

Describe the first step

Definition

carrier protein moves two substances at the same time in the same direction

 

for instance - first substance moves into cell from it high to low by facilitated diffusion through a carrier protein

 

second substance tags along

Term

Secondary Active Transport

 

describe the second step

Definition

first substance is actively pumped out of cell to maintain low in ICF - ACTIVE TRANSPORT

 

Term
During secondary active transport if the two substance are moving the same direction, it is considered
Definition
symport or cotransport
Term

During secondary active transport

 if the two substances are moving opposite direction it considered

Definition
anitport or countertransport
Term
The difference in electrical potential (voltage) across the membrane of a lining cell
Definition
Transmembrane Potential
Term

Chemical gradients

 

High ___ in the extracellular fluid exerts a pressure pushing ____ to the inside

 

High ____ in the intracellular fluid exerts a pressure pushing ____ to the outside

Definition

Na+

Na+

 

K+

K+

Term

Electrical Gradients

 

The intracellular negativity tends to pull ____ into the cell

 

 

Definition
Na+
Term

Electrical Gradients

 

The intracellular negativity tends to ______ the movement of ____ out of the cell

Definition

Hinder

 

K+

Term
Electrochemical gradient for Na+
Definition

The chemical gradient pushes Na+ into the cell

The electrical gradient pulls Na+ into the cell

Term
Electrochemical Gradient for K+
Definition

The chemical gradient pushes K+ out of the cell

The electrical retards the movement of K+ out of the cell

 

i.e. K+ is attracted by the intracellular protine (-)

K+ is repulsed by the accumulation of positive chages extracellularly

Term

Transport across an epithelial sheet

(lining the intestine)

Definition
  • Lumen
  • Apical surface
  • Epithelial cell ICF
  • Basolateral surface (and basement membrane)
  • Interstitial fluid
  • Capillary wall
  • Blood plasma
Term
Na+ come into epithelial cell by _________ and leaves the epithelial cell by __________ and moves passively into the ________
Definition

Diffusin

Primary Active Transport

blood plasma

Term
transepithelial Transport of Na+ Steps
Definition
  • Sodium moves into the body through the digestive tract, it comes in contact with an epithelial sheet
  • Na+ diffuses through a protein channel from the lumen of the digestive tract organ into epithelial cell
  • Na/K pump transports Na+ into the ISF
  • Na+ diffuses passively into blood plasma

 

Term
Transepithelial transport of Glucose & Amino Acids
Definition
  • Na+ diffuses through protein carriers from lumen of organ into epithelia cell and carries with it glucose, which is being moved against its concentration gradient
  • the second molecule is moving into the epithelial cell by secondary transport
  • the second molecule is then transported across basal surface and into the ISF, by facilitated diffusion and then into the blood
  • Na+ is then pumped out of epithelial cells by primary active transport
Term
Transepithelial transport of water
Definition
  • Water moves into cells through special protein channels called aquaporins
  • water passes through tight junctions
  • water follows the movement of solutes across epithelium
  • as Na+ goes from apical to basal surface, it generates osmotic pressure gradient and pulls water with it
Term
Movement of water and small solutes across membrane from an area of high (hydrostatic) pressure to area of low pressure
Definition
Filtration
Term
As K+ diffuses out of the cell, it leaves behind _______ ________ proteins
Definition

negatively charged

 

 

Term
Ions can diffuse with
Definition
  • concentration gradients
  • electrical gradients
  • gated channels
  • leak channels in the membrane

 

but not directly through the lipid portion of the membrane

Term
When a neuron is a rest, most ion channels are closed.  However, some _________ channels are open, permitting _______ ions to diffuse out of the cell _____ their concentration gradient
Definition

Potassium

Potassium

down

Term
When the neuron is at rest are sodium channels open or closed
Definition
closed
Term
The movement of potassium ions out of the cell increase the internal ________ charge.
Definition
negative
Term
The movement of potassium ions out of the cell increases the internal negative charge.  This does what to the electrical force on potassium
Definition
The positively charged potassium ions are attracted to the internal negative charge, and this electrical force pulls potassium ions back into the cell
Term
When a neuron is at rest, the plasma membrane is far more permeable to
Definition
potassium (K+) ions than to othe ions present
Term
The resting potential of a neuron is due mostly to
Definition
open potassium channels
Term
At equilibrium, when the neuron is at rest, the concentration of
Definition
K+ ions is higher inside the cell, but the diffusion force driving K+ ions out of the cell is balanced by an electrical force keeping K+ from leaving the cell
Term
At rest, the interior of a neuron is negatively charged relative to the exterior.  This negative charge is due mainly to
Definition
proteins
Term
When gated channels in the membrane are open, how do ions move
Definition

Chemical concentration - from high to low

 

Electrical gradient - toward an area of opposite electrical charge

 

"electrochemical gradient"

Term
All cell membranes are polarized what does this mean
Definition

have electrical difference between the sides of the membrane

 

Outside surface of cell membrane is slightly postive

 

Inside surface of cell membrane is slightly negative

Term
In a resting membrane all the sodium gates are _______ and some of the potassium gates are ______
Definition

Closed

 

Open

Term
Action potentials occur only when the membarne is stimulated (depolarized) enough so that sodium channels open completely.  The minimum stimulus needed to achieve an action potential is called a
Definition
threshold stimulus
Term
At the peak of the action potential, two processes occur simultaneoulsy what are they
Definition

First, many of the voltage-gated sodium channels begin to close

 

Second, many more potassium channels open, allowing positive charges to leave the cell

 

This causes the membrane potential to begin to shift back towards the resting membrane potential

Term
As the membrane potential approaches the resting potential, ______ ______ _____ channels are maximally activate and open which causes the membrane to repolarize
Definition

voltage-gated potassium

 

 

Term
When the axon (action) potential reaches the nerve terminal what does it trigger 
Definition
the release of neurotransmitter across the synaptic cleft, propagating the signal to the next neuron in the circuit
Term
At the peak of the action potential
Definition
sodium channels are inactivated, while gated potassium channels open
Term

What type of Potentials have these types of origins

 

  • arise mainly in dendrites and cell bodies
  • arise at trigger zones and progagate along axon
Definition

Graded

 

Action

Term

What type of potentials have these types of channels

 

Chemical, mechanical or light

 

Voltage gated ion channels

 

Definition

Graded

 

Action

Term
Do Graded potentials progagate
Definition
No, they do not progagate they are localized, thus permit communication over a few mm
Term
Action potentials propagate thus permit what type of communcation
Definition
long distance
Term
Graded Potentials Amplitude
Definition
Depends on strength of stimulus, varies from less than 1mV to more than 50mV
Term
Action Potentials Amplitude
Definition
All or none
Term
Graded Potentials Duration
Definition
Typically longer, ranging from msec to several min
Term
Action Potential Duration
Definition
Typically shorter ranging from 0.5 - 2 msec
Term
Graded Potential Polarity
Definition

May be hyperpolarizing (inhibitory to generation of action potential)

or

Depolarizing (excitatory to generation of action potential)

Term
Action Potential Polarity
Definition
Always consist of depolarizing phase followed by repolarizing phase and then return to resting membrane potential
Term
 Do Graded Potential have a Refractory Period
Definition
None - exhibit temporal and spatial summation
Term
Do Action Potentials have a refractory period
Definition
Yes, therefore not subject to summation
Term
Depolarization
Definition

Reduction in membrane potential

 

  • occurs when gated Na+ channels open and Na+ rushes inside cell
  • Inside of cell membrane and potential moves closer toward zero than -70mV
  • May continue until inside of membrane is postive
Term
Hyperpolarization
Definition

Membrane potential increases

 

  • occurs when an excess of K+ moves outside of cell, leaving a slight excess of negatively charged proteins trapped inside
  • Membrane potential goes below -70mV
  • Inside of cell membrane becomes more negative
Term
Repolarization
Definition

membrane potential moves back toward -70mV after depolarization occurs

 

 

Term
Graded Potentials
Definition
  • Short-lived local changes in membrane potential
  • Local flow of current that decreases with distance traveled, goes a short distance then dies out
  • Called "graded" because magnitude of current varies with intensity of stimulus that sets it off
  • Occur in all cells
  • May be depolarizing or hyperpolarizing 
Term
The membrane potential returns to the resting state due to
Definition
the diffusion of ions through leak channels
Term
Phase 2 of the action potential is known as
Definition
repolarization
Term
After resting membrane potential has benn accomplished, K+ diffusion _____ ______, while Na+ diffusion ______ ______, due to the electrical gradient just created
Definition

slows down

 

speeds up

Term
During which refractory period - absolute or relative - can a second action potential be stimuled if the strength is very great
Definition
relative
Term
During absolute refractory period why cannot another action potential be generated
Definition

voltage-gated sodium channels are open or inactivated and voltage-gated potassium channels may alos be open

 

Term
Hypokalemia
Definition

low K+ in ECF

 

 

Term
What causes Hypokalemia
Definition

Concentration gradient for K+ is steeper than usual so more K+ moves out of the cell which causes a hyperpolarized cell (-90mV)(inside more negative, outside more postive)

 

Harder to depolarize so no action potential can happen

Term

What are some of the symptoms of hypokaleima

 

What causes hypokaleima

Definition

muscle weakness, fatigue, sluggish reflexes, cardiac arrhythmias

 

decreased intake, persistent vomiting, diarrhea, diuretics, hormone imbalance

Term
Hyperkalemia
Definition

High K+ in ECF

 

 

Term
What causes hyperkalemia
Definition
Concentration gradient for K+ is less steep so K+ does not move back into the cell, so the cell does not repolarize after an action potential
Term
What are some of the symptoms of Hyperkalemia
Definition
changes in EKG, severe muscle weakness, which may lead to paralysis and cause death ( cardiac arrest)
Term
What are some of the reasons for Hyperkalemia
Definition
  • increased intake, especially when coupled with kidney insufficiency
  • death by lethal injection
  • severe and extensive damage to cell membranes, burns for example allow K+ to leak out
  • hormone imbalance (aldosterone)
Term
Hypocalcemia
Definition
Decreased Ca++ in ECF
Term
What causes Hypocalcemia
Definition
When Ca++ is low in ECF some gated Na+ channels open without stimulus, Na+ moves into the cell which makes the cell more postive inside which allows the cell to depolarize and send an action potential
Term
Sympotoms of Hypocalcemia
Definition
  • nerves and muscles have spontaneous, inappropriate action potentials
    • cramps
    • spasms
    • exagerrated reflexes
    • convulsions
    • tetany
Term
Causes of Hypocalcemia
Definition
  • decreased intake
  • lack of vitamin D
  • low parathyroid hormone
  • high calcitonin
Term
Hyponatremia
Definition
decreased Na+ in ECF
Term
What causes Hyponatremia
Definition

concentration gradient for Na+ not as steep as it should be

 

causes the cell to have a harder time to depolarize

Term
Symptons of Hyponatremia
Definition
  • muscle weakness
  • nausea
  • profound osmotic effect on water content of all cells
  • brain cells sell causing dramatic neurological symptons (act crazy)
  • low plasma volume
  • hypotension
Term
Causes of Hyponatremia
Definition
  • decreased take
  • excessive sweating
  • vomiting
  • diarrhea
  • diuretics
  • kidney failure
  • hormone imbalance
  • poor diet combined with alot of beer
  • ecstasy (most common electrolye imbalance)
Supporting users have an ad free experience!