Term
| Structural properties of the circulatory system (4) |
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Definition
A main propulsive organ
High speed delivery: arterial system
Exchange system: capillaries
Return: venous system |
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Term
| Functional properties of the circulatory system (4) |
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Definition
Forces imparted by rhythmic contractions of the heart
Elastic recoil of arteries following filling by heart
Squeezing of blood vessels by body movements (skeletal muscle contractions)
Peristaltic contractions of smooth muscle of the vessels. |
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Term
Open circulatory system
______ circulates through vessels which open to a space called ________. |
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Definition
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Term
| ECF vs circulatory fluid in an open circulatory system |
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Definition
| No distinction between ECF and circulatory fluid. |
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Term
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Definition
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Term
| Most, though not all of the invertebrates have a ______ circulatory system |
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Definition
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Term
| The closed circulation of cephalopods is characterized by a _____ blood pressure and _____ efficient delivery of oxygen compared with open circulatory system |
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Definition
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Term
| The closed circulatory system in mammals includes a full divided ______, which permits different ______ to be maintained in the pulmonary and systematic circuits. The associated lymphatic system returns fluid from the extracellular space to the bloodstream via the |
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Definition
fully
pressures
thoracic duct |
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Term
| The multi-chambered mammalian heart permits the pressure to ________ as blood moves from the venous to arterial . Impulses originate in the ________ region, located in the _________ node, and spread to the _______ node, from which they're transmitted to the _______. |
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Definition
increase
pacemaker
SA
AV
ventricles |
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Term
| Two types of cardiac cells |
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Definition
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Term
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Definition
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Term
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Definition
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Term
| 6 characteristics of cardiac cells |
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Definition
-Sarcomere – striated tissue
-Single nucleus
-Intercalated disks – connected physically and electrically
-Branched
-Autorhythmic
-Large amount of mitochondria – resistant to fatigue |
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Term
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Definition
| pacemaker cells undergo spontaneous depolarization of the membrane which triggers cardiac potential autorhythmically |
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Term
| Parasympathetic stimulation via the _____ nerve and sympathetic stimulation have ______ effects on the pacemaker potential and heart rate. |
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Definition
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Term
| Vagus stimulation produces (3) |
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Definition
a rise in diastolic transmembrane potential
a decrease in the rate of depolarization
a decrease in duration and frequency of the action potential |
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Term
| Sympathetic stimulation produces |
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Definition
| an increase in the frequency of firing of the pacemaker cells |
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Term
| Do action potentials differ in skeletal and cardiac muscle? |
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Definition
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Term
| Action potentials in skeletal muscle duration |
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Definition
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Term
| Cardiac action potential duration |
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Definition
a prolonged repolarization (plataeu phase) during which the muscle fiber is refractory to stimulation.
For this reason, repetitive stimulation during a contraction and summation of contractions can occur in skeletal muscles but not cardiac muscles |
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Term
1
APs in Contractile Myocardial Cells |
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Definition
Much longer AP
Refractory period and contraction end simultaneously |
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Term
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Definition
| Depolarization due to voltage-gated Na+ channels |
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Term
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Definition
| Partial Repolarization as Na+ channels close and some K transient current occurs (Kto channels) |
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Term
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Definition
| Ca2+ permeability (Ca2+L channels) |
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Term
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Definition
| Repolarization: Back to resting potential due to gK (due to K channels open) and Ca2+ channels close |
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Term
| Membrane potential of Myocardial Autorhythmic (pacemaker) Cells |
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Definition
-Fluctuates around – 60 mV
-More depolarized than most cells |
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Term
| Unstable resting membrane potential (= pacemaker potential) due to |
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Definition
-Ca2+L and Ca2+T channels
-The cell membranes are “leaky”
-Unique membrane channels that are permeable to both Na+ and K+ |
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Term
| An electrocardiogram represents |
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Definition
| the summation of the electrical activity in various parts of the heart |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| Do mammalian cardiac or skeletal muscles action potentials last longer? |
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Definition
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Term
| Two ways valves promote unidirectional flow of blood |
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Definition
1. Open in one direction = Pressure gradient
2. Restrained by chordae tendinae attached to papillary muscles (during ventricular contraction) |
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