Set: Anatomy and Physiology II Ch. 20 - Part 2

Familiarize

Learn

Test

Play Scatter

Play Space Race
Combine with other sets Login to add to Favorites
Print: Term List | Flashcards Editing not allowed
Export Deleting not allowed

Share these flash cards

With group: None
HTML link to set: Plain link:
Share on Facebook Share on MySpace

All 36 Terms

Term Definition
Intercalated discs Thickened area on the membrane surrounding the muscle fiber, where muscle fibers connect to each other
Desmosomes Cell junctions that hold fibers tightly together
Gap junctions Allows nerve impulses to travel from one fiber to the next
Sinoatrial node (SA node) "Pacemaker of the heart"; located in the upper right attrium that receives impulses from the ANS and sends them to the left side of the heart, causing the atria to contract
Atrioventricular node (AV node) Located in the lower right attrium; receives impulses from the SA node and sends them to the Bundle of His
Bundle of His Sends impulses down the top of the interventricular septum; bundle splits into left and right bundle branches
Perkinje fibers End of the conduction system; sends impulses through the ventricles, causing them to contract
Electrocardiogram Graphic record of the heart's electrical activity; EKG
P wave Represents atrial contraction (depolarization)
QRS complex Represents ventricular contraction (depolarization)
T wave Represents ventricular relaxation (repolarization)
Cardiac cycle Series of events that occur during one heart beat
Atrial systole Time when atria are contracting; most blood moves from atria into ventricles passively due to gravity; depolarization of the SA node causes atrial contraction, putting pressure on remain blood inside atria, and causing it to move into the ventricles
Ventricular systole Time when ventricles are contracting and atria are relaxed; triggered by ventricular depolarization; as contraction begins, cuspid valve closes and pressure rises in ventricles; once pressure is higher than the exiting vessels, ventricular ejection occurs and blood is forced out through semilunar valves; 70ml of blood exits, while 60ml remains in the ventricle
Relaxation period (diastole) Time when both atria and ventricles are relaxed; ventricular repolarization; pressure within the ventricles drops and some blood begins to flow backwards; backflow of blood catches in the semilunar valves, and forces them closed; once ventricular pressure falls below atrial pressure, cuspid valves open
Cardiac output Volume of blood ejected from a ventricle each minute; heart rate x stroke volume (CO=HR x SV); value is equal to blood volume at rest
Heart rate Times of heart beats per minute
Stroke volume Volume of blood ejected by a ventricle with each contraction
Cardiac reserve The difference between a person's maximun cardiac output and cardiac output at rest; the average person has a value 4-5 times the resting value; is limited or absent in ppl with severe heart disease
Regulation of stroke volume If extra blood enters ventricle, more blood will exit; whatever enters the heart must eventually go out; stroke volume tends to be about 60% of the total volume of blood that enters the ventricles, while 40% remains in the ventricle
Preload Degree of stretch on the heart right before contraction; greater stretch on cardiac muscle fibers determines greater strength of contraction
Frank-Starling Law of the heart The more the heart fills with blood, the greater the contraction due to the increased amount of stretching
Contractility Forcefulness of contraction of the cardiac muscle fibers
Positive inotropic agents Increases the strength of heart contraction; e.g. epinephrine (adrenaline), digitalis; sympathetic nervous system is activated
Negative inotropic agents Decreases strength of heart contraction; e.g. anesthetics; anoxia (insufficient oxygen); inhibition of sympathetic nervous system
Afterload Pressure that must occur in the ventricles to force open the semilunar valves; ejection of blood; blood leaves ventricles when pressure in the right ventricle is greater than in the pulmonary trunk and when pressure in the left ventricle is greater than in aorta
Average heart rate 75 BPM (resting)
Tachycardia High (fast) heart rate greater than 100 BPM
Bradycardia Low (slow) heart rate less than 60 BPM
Cardiovascular center Located in the medulla oblongata; can increase or decrease nerve impulses that signal the heart
Chemoreceptors Receptors that monitor chemical changes in blood; e.g. oxygen and nutrient levels
Baroreceptors Monitors stretching of blood vessels caused by blood pressure
Epinephrine Hormone that increases HR and contractility
Cations Chemicals that control HR; e.g. sodium, potassium, and calcium
Lower HR Caused by physical factors such as increased fitness or increased age
Higher HR Caused by physical factors such as gender (females), increased body temperature, excercise, or increased body mass

Set Information

Terms 36
Creator typestereo
Created June 1, 2008
Groups None
Subjects anatomy, physiology
Access Anyone
Edit Creator Only
Pop out

Discuss

typestereo : Changed QRS complex → Ventricular contraction (depolarization) to QRS complex → Represents ventricular contraction (depolarization)
typestereo : Changed Cardiac output → Volume of blood ejected from a ventricle each minute; heart rate x stroke volume (CO=HR x SV); cardiac output equal to blood volume at rest to Cardiac output → Volume of blood ejected from a ventricle each minute; heart rate x stroke volume (CO=HR x SV); value is equal to blood volume at rest
Last Message: 7 months ago

You must be logged in to discuss this set.

Kaplan Test Prep and Admissions (Kaptest.com)

Top Users

  1. typestereo - 202 scores

Most Missed Words

  1. T wave → Represents ventricular relaxation (repolarization) - 3 misses
  2. Ventricular systole → Time when ventricles are contracting and atria are relaxed; triggered by ventricular depolarization; as contraction begins, cuspid valve closes and pressure rises in ventricles; once pressure is higher than the exiting vessels, ventricular ejection occurs and blood is forced out through semilunar valves; 70ml of blood exits, while 60ml remains in the ventricle - 2 misses
  3. Desmosomes → Cell junctions that hold fibers tightly together - 2 misses
  4. Perkinje fibers → End of the conduction system; sends impulses through the ventricles, causing them to contract - 2 misses
  5. QRS complex → Represents ventricular contraction (depolarization) - 2 misses
  6. Cardiac reserve → The difference between a person's maximun cardiac output and cardiac output at rest; the average person has a value 4-5 times the resting value; is limited or absent in ppl with severe heart disease - 2 misses
  7. Relaxation period (diastole) → Time when both atria and ventricles are relaxed; ventricular repolarization; pressure within the ventricles drops and some blood begins to flow backwards; backflow of blood catches in the semilunar valves, and forces them closed; once ventricular pressure falls below atrial pressure, cuspid valves open - 1 miss