Quiz 4 Flashcards
(30 cards)
In what order does the heart pump blood through the blood vessels?
arteries → arterioles → capillaries → venules → veins → back to heart
The L side of the heart contains _ blood, while the R side of the heart contains _ blood.
A) Deoxygenated ; Oxygenated
B) Oxygenated ; Deoxygenated
B) Oxygenated ; Deoxygenated
What’s the difference between pericardium & visceral pericardium?
Pericardium: Covering over heart and large blood vessels
Visceral pericardium: Inner layer of serous membrane; attached to surface of heart; also called the epicardium
What are the 3 distinct heart walls?
Epicardium
Myocardium
Endocardium
Outer layer - thin layer
AKA “visceral pericardium”
Serous membrane of connective tissue covered w/ epithelium & include blood capillaries, lymph capillaries, & nerve fibers
* Forms protective outer covering
* Secrete serous fluid
Epicardium
Middle layer - thickest layer
Composed of cardiac muscle tissue
Cardiac muscle tissue separated by connective tissue & include blood capillaries, lymph capillaries, & nerve fibers
* Contracts to pump blood from the heart chambers
Myocardium
Inner layer - thin layer
Membrane of epithelium & underlying connective tissue, Including blood vessels
* Forms protective inner lining of all heart chambers & valves
Endocardium
What are the 4 chambers of the heart & their function?
Right atrium: Receives blood returning from systemic circuit (from the superior and inferior vena cavae and coronary sinus); pumps blood to right ventricle.
Right ventricle: Receives blood from the right atrium; pumps blood to lungs.
Left atrium: Receives blood from the pulmonary veins; pumps blood to left ventricle.
Left ventricle: Receives blood from the left atrium; pumps blood to systemic circuit
What are the 4 valves or the heart & their function?
Tricuspid Valve:
* Prevents blood from moving from R ventricle into the R atrium during ventricular contraction
* Located in R atrioventricular Orifice
Pulmonary Valve:
* Prevents blood from moving from the pulmonary trunk into the R ventricle during ventricular relaxation
* Located in entrance to pulmonary trunk
Mitral Valve / Bicuspid Valve:
* Prevents blood from moving from the L ventricle into the L atrium during ventricular contraction
* Located in L atrioventricular Orifice
Aortic Valve:
* Prevents blood from moving from aorta into L ventricle during ventricular relaxation
* Located in entrance to aorta
How does blood flow through the heart?
- Blood from systemic circuit
- Venae cavae & coronary sinus
- R atrium (through tricuspid valve)
- R ventricle (through pulmonary valve)
- Pulmonary trunk
- Pulmonary arteries
- Pulmonary capillaries / Lungs
- Pulmonary veins
- L atrium (through mitral / bicuspid valve)
- L ventricle (through aortic valve)
- Aorta
- Blood from systemic circuit
The _ _ drains blood from the heart wall to the coronary sinus.
A) Cardiac veins
B) Cardiac artery
C) Coronary sinus
D) Coronary artery
A) Cardiac veins
The _ _ returns deoxygenated blood to the R atrium.
A) Cardiac veins
B) Cardiac artery
C) Coronary sinus
D) Coronary artery
C) Coronary sinus
What happens during atrial systole and ventricular diastole of the cardiac cycle?
The ventricles are relaxed.
The A-V valves open and the semilunar valves close.
About 70% of blood flows passively from atria into ventricles.
Atrial systole pushes the remaining 30% of blood into the ventricles, causing ventricular pressure to increase
What happens during ventricular systole and atrial diastole of the cardiac cycle?
The A-V valves close.
The chordae tendineae prevent the cusps of the valves from bulging too far backward into the atria.
The atria relax.
Blood flows into atria from venae cavae and pulmonary veins.
The ventricular pressure increases and opens the semilunar valves.
Blood flows into the pulmonary trunk and aorta.
A group of clumps and strands of specialized cardiac muscle tissue, which initiates and distributes impulses throughout the myocardium
* Coordinates the events of the cardiac cycle.
- SA Node
- Atrial syncytium (In atrial walls)
- Junctional fibers
- AV Node
- AV bundle
- Bundle branches
- Purkinje fibers
- Ventricular syncytium (In ventricular walls)
Cardiac Conduction System
Define the following components of the cardiac conduction system:
SA Node
Internodal Atrial Muscle
Junctional fibers
AV (Atrioventricular) Node:
AV (Atrioventricular) Bundle (of His)
Left and Right Bundle Branches
Purkinje fibers
SA (Sinoatrial) Node: Pace maker; Initiates rhythmic contractions of the heart
Internodal Atrial Muscle: Conducts impulses from SA node to atria
Junctional fibers: Conducts impulses from SA node to AV node
AV (Atrioventricular) Node: Delays impulse, so that atria finish contracting before ventricles contract. Conducts impulses to AV Bundle
AV (Atrioventricular) Bundle (of His): Conducts impulses rapidly between SA node and bundle branches.
Left and Right Bundle Branches: Split off from AV bundle, conduct impulses to Purkinje fibers on both sides of heart.
Purkinje fibers: Large fibers that conduct impulses to ventricular myocardium.
What are the waves of an EKG called?
P wave: Atrial depolarization; occurs just prior to atrial contraction.
QRS complex (3 waves): Ventricular depolarization; occurs just prior to ventricular contraction.
T wave: Ventricular repolarization; occurs just prior to ventricular relaxation
ST segment: Ventricular contraction
What are the intervals of an EKG?
PQ (PR) interval: 0.12-0.20 s
QRS wave: < 0.12 s
QT interval: 0.34-0.43 s
List & describe the 5 types of blood vessels:
Arteries: carry blood away from the ventricles of the heart.
Arterioles: receive blood from the arteries, and carry it to the capillaries.
Capillaries: sites of exchange of substances between the blood and the body cells.
Venules: receive blood from the capillaries, and conduct it to veins.
Veins: receive blood from venules, and carry it back to the atria of the heart.
Which of the following helps make up an artery? (SATA)
A) Lumen
B) Valve
C) Endothelium of tunica interna
D) Connective tissue (Elastic & collagen fibers)
E) Tunica media
F) Tunica externa
A) Lumen
C) Endothelium of tunica interna
D) Connective tissue (Elastic & collagen fibers)
E) Tunica media
F) Tunica externa
Which of the following helps make up a vein? (SATA)
A) Lumen
B) Valve
C) Endothelium of tunica interna
D) Connective tissue (Elastic & collagen fibers)
E) Tunica media
F) Tunica externa
All of the above
What are the 3 layers (or tunica) of an artery?
Tunica interna (intima): innermost layer
Tunica media: smooth muscle & elastic tissue
Tunica externa (adventitia): outer layer, connective tissue
Blood vessel form what 2 pathways?
Pulmonary circuit.
Systemic circuit
Blood in pulmonary arteries and arterioles is low in O2 and high in CO2.
Gas exchange occurs in pulmonary (alveolar) capillaries.
Blood in pulmonary venules and veins is rich in O2 and low in CO2.
Right ventricle → pulmonary trunk → right and left pulmonary arteries → lobar branches, repeated divisions → pulmonary arterioles → pulmonary capillaries → pulmonary venules and veins → left atrium.
Pulmonary circuit
