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65 Cards in this Set
- Front
- Back
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When the K+ moves across the heart, what does it drop down into?
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Transverse tubules
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does the voltage change when the K+ moves into the T-tubules? explain
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yes from -70mV to -50mV
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when the k+ moves down the t-tubules and voltage changes to -50mV, what is released?
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Ca++
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Is Ca++ release the same way as K+ in the artia?
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yes
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what triggers the contraction of the heart?
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Ca++
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Does the contraction happen in a particular way? explain
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yes,it contracts downward because we want the ventrcial to contract upward
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what is the difference between Ca++ gates in cardic muscle Vs. skeletal muscle cells? Explain
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Ca++ gates in cardic are slower allowing more Ca++ to close.
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Which muscle cell (Cardic or skeletal) is able to release more Ca++?
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Cardic
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what is the major reason that Ca++ gates are slow to close?
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the more Ca++ released the harder the contraction.
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Which muscle has a greater force of contraction?
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Cardic
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What cause the ca++ to have a greater contraction? Explain
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the more Ca++ released, the more actin and myosin that can bind.
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What are the speclized cells that the K+ moves down through?
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Bundle of hess or bundle branches
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What is the reason for ventrical diastole?
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when the K+ moves down through the bundles of hess no contraction can occure.
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When does the K+ move up through the ventricular muscle?
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when the K+ gets to the Apex of the heart.
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what follows the K+ moving up through the ventricular muscle? Why?
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Ca++ to trigger the contraction.
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when the ventrcals can not contract, what is this called?
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A bundle branch block.
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what keeps the 3 Na+ out and 2 K+ in on the SA nodes?
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Na+ K+ pump
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what is the major diffrence between the SA node cell Vs. and other cell? explain
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there is a force field around the cell, not allowing K+ to defuss out
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what is impermiable in the SA node?
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K+
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What is decresed in the SA node?
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K+ permiablity
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what happens to the voltage in the SA node when the Na+ dufusses in and the K+ is impermiable?
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The voltage goes up to -50mV to trigger action potentals.
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when does the K+ start to flow in the SA node?
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after the action potental
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when their is a decrease in K+ permiability, what does this cause?
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a heart beat
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what turns of K+ from being defussed out in the heart?
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SA nodes cells
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At what rate is the K+ defused out? why?
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72 times per minute
because that is how often a heart beats per minute |
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How is a heart beat triggered?
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by K+ permibility
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what is the heart rate of men and women in their 40's?
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men 72
women 82 |
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what is the trigger herat rate for GAS?
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92 beats per/min
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how do you increase heart rate?
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Block K+ (decrease K+ permibility) from leaving the cells more times then 72 times per/min
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how do you decreade heart rate?
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increase K+ permibility
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What is the AV node for? what is it rate?
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It is a back up system
52 beats per/min |
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what happends when the SA node goes bad?
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you have to get a pacemaker.
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what is a negative for the AV node to take over?
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it starts in the wrong place, now the atria can't contract. this can cause death
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When do people usually find out that their SA node is bad?
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when they are sleeping
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what is the SA node naturally called?
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The pacemaker
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what does a pacemaker do?
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it sends a electrical charge to change voltage to trigger an action potential.
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Is there communication between the SA node and the AV node?
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no
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how do you increase the rate at which the SA node beats at?
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their are receptors for EPI and Nor Epi on the SA node cells
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what happens when Epi and Nor Epi bind to the receptors on the SA node?
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it will decrease K+ permibility more times per/min causing, a faster heart rate.
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what controls the SA nodes cells?
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the symthethic nerve system and the adrenal medulla
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what if you what your heart rate to go down?
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their are receptors for acytocholine, inturn causing the heart rate to decrease
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whare is acytocholine released from?
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the parasympatic nerve system
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what does acytocholine do in the heart?
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it lowers the heart rate by increasing K+ permability
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What is the name of the receptor for acytocholine?
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Alpha receptors
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What is the name of the receptor for EPI and Nor Epi?
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Beta receptors
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what is the responce of the heart if you give a person a beta blocker?
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the heart rate would decrease
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what is the correrlation between heart rate and blood pressure?
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If heart rate goes up blood pressure goes up
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what maintains the health of the Alpha and Beta receptors on the SA nodes?
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by thyroid hormones
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what happens if your thyroid hormones go down?
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you can loose receptors on the heart. especially beta receptors
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When you look at a EKG what do you see?
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the changes in voltage
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On the EKG what is the rise on the P wave?
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atrial depolarzation. the movement of K+ from the right to left side of heart
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what does Q repersent?
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the wave down the bundle of hess.
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what is the Q R S complex representing?
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Ventricular depolarzation.
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What is the lowering of the P wave?
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The K+ going down the atria
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what happens after the P wave?
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a contraction thre the valve will snap shut.
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what does the R represent?
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the movement through the purkinge fibers. up and out
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what does the S represent?
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the contractions of the papuary muscles.
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How often do you have an S on an EKG?
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seldom
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what does the T wave repersent?
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ventricular repolarzation
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do we have a atrail repolarization? Why
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no, it under the Q R S complex
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what are PVC?
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preventricular contractions
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1. explain the contractile proceses of cardic muscle. Then explain the changes
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essay part 1
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2. Begin with the pacemaker cells, and how the ions flow through the muscle to cause contraction.
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essay part 2
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3. that must occur do to the sym and para sym. nerver system
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essay part 3
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what are the ventricular cells called?
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purkinje cells
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