Chapter 1 Structures Flashcards
Lower tip of left ventricle
Apex of the heart
Tough, inelastic and outer connective tissue
Fibrous pericardium
Two functions of the pericardium
1) Anchoring in place (attached to the diaphragm)
2) Prevents the heart from over stretching
Two parts of the pericardium
1) Fibrous pericardium
2) Serous pericardium
Thinner, delicate and forms double layer around heart
Serous pericardium
Fused to fibrous pericardium
Parietal layer
Adheres tightly to the heart
Visceral layer (epicardium)
Three layers of the heart
1) Epicardium
2) Myocardium
3) Endocardium
What layer of the heart forms two separate networks via gap junctions and intercalated disks: Atrial and Ventricular
Myocardium
Lines the inside of myocardium and covers valves
Endocardium
Four chambers of the heart
2 Atria and 2 ventricles
What separates the chambers of the heart
Interatrial and interventricular septum
How many valves are in the heart?
4
Two atrioventricular valves
1) Tricuspid valve
2) Bicuspid valve (also known as mitral valve)
What connects to papillary muscles on the ventricle side that prevents valve cusps from pushing up into the atria when ventricles contract?
Chordae tendineae
Drain deoxygenated blood from the upper and lower body into the right atrium
Superior and inferior vena cava
Drains deoxygenated blood from the coronary veins into the right atrium
Coronary Sinus
Blood is pumped from the right atrium to the right ventricle to:
Pulmonary trunk which then branches into the pulmonary arteries
Carries oxygenated blood from the lungs and transports it to the left atrium
Pulmonary veins
Carries oxygenated blood to the entire body from the left ventricle
Aorta
Blood that flows through the myocardium
Coronary circulation
Collects the heart’s deoxygenated blood and returns it to the right atrium
Coronary sinus
Where does cardiac excitation begin?
Sinoatrial (SA) node
What does the SA node stimulate?
1) Atria (via Bachmann’s bundle) causing contraction
2) Atrioventricular (AV) node
3) AV bundle branches (Bundle of his)
4) Right and left bundle branches
5) Purkinje fibers
ECG wave that represents atrial depolarization
P wave
ECG, wave that represents ventricular depolarization
QRS Complex
ECG wave that represents ventricular repolarization
T wave
Typical cardiac cycle (one heartbeat) is how long?
0.8 seconds
Three phases in a cardiac cycle
1) Relaxation period
2) Atrial systole
3) Ventricular systole
Relaxation period is noted as what wave on an ECG?
T wave
Atrial systole is noted on an ECG as what wave?
P wave
Ventricular systole is noted on the ECG as what wave?
QRS complex
How much blood is ejected into circulation per pump?
70 ml
The amount of blood ejected from the left ventricle into the aorta per minute
Cardiac Output (CO)
Cardiac output formula
Stroke volume x heart rate
Thick, triple layered vessels that carry blood away from the heart
Arteries
Thin vessels formed by arteries branching down in size
Arterioles
Hair-like microscopic vessels found through the body. Also known as “Exchange Vessels”.
Capillaries
Very thin vessels formed when capillaries reunite
Venules
Designated vessels that return deoxygenated blood to the heart to be oxygenated
Veins
Difference in the structure of veins and arteries
Veins have thinner middle and inner layers, and the lumen is generally larger
What percentage of blood is stored in veins?
64%
What moves nutrients and other substances out of blood efficiently?
Capillaries
The ability of local tissues to adjust blood flow (constrict or dilate) into the area according to metabolic demands via vasodilators and vasoconstrictors
Autoregulation
Where can you find the slowest rate of blood flow?
Capillaries
What factors determine the amount of fluid in circulation?
1) BP
2) Osmosis
The average volume of blood
5 liters (5.3 quarts)
What percentage of blood loss is potentially life threatening?
10%
Factors that regulate blood flow and BP
1) Cardiac output
2) Vascular resistance (opposition to flow)
Vascular resistance depends on what?
1) Smaller lumen (Vasoconstriction)
2) Greater vessel length (weight gain)
3) Higher viscosity (as with high hematocrit)
What part of the brain regulates blood flow to the body?
Medulla Oblongata
Receptors that monitor movement of joints and muscles
Proprioceptors
Pressure receptors found in the aorta and carotid arteries
Baroreceptors
Receptors located in the arch of the aorta and carotid bodies that stimulate sympathetic and parasympathetic response to chemical changes in the body.
Chemoreceptors
All systemic arteries branch off of:
Aorta
All systemic veins empty into right atrium via:
1) Superior vena cave
2) Inferior vena cava
3) Coronary sinus
Where gas exchange takes place to re-oxygenate blood
Pulmonary capillaries
Four principal branches of the aorta
1) Ascending Aorta
2) Arch of the Aorta
3) Thoracic Descending Aorta
4) Abdominal Descending Aorta
Coronary arteries branch off from where?
Ascending Aorta
Where does the Brachiocephalic trunk branch off of?
Arch of the Aorta
Where do Bronchial arteries, Esophageal arteries, Posterior intercostal arteries, and superior phrenic arteries branch off of?
Thoracic Aorta
Veins transport blood back to the heart via pressure generated by:
1) Contractions of the heart
2) The skeletal muscle pump (contracting muscles for veins)
3) The respiratory pump
What is the largest vein in the body?
Inferior vena cava
Superficial Veins.
Drains the lateral aspect of upper limb
Cephalic veins
Superficial Veins.
Drains medial aspect of upper limb
Basilic veins
Superficial Veins.
Drains palms and forearms
Median antecubital veins
Deep vein.
Drains lateral aspect of forearm
Radial veins
Deep vein.
Drains medial aspect of forearm
Ulnar veins
Deep vein.
Drains forearms, elbow joints, and arms
Brachial veins
Deep vein.
Drains arms, axillae, and upper part of chest wall
Axillary veins
Deep vein.
Drains arms, neck, and thoracic wall
Subclavian veins
1) Blood drains from GI tract and spleen
2) Delivered to liver to process and absorb substances from GI tract
3) Blood then returns to circulation via hepatic vein
Hepatic portal circulation
Superficial veins.
Drain leg, thigh, groin, external genitals, and abdominal wall.
Great Saphenous veins
Superficial veins.
Drain foot and leg
Small Saphenous veins
Deep Veins.
Drain foot and posterior leg muscles
Posterior tibial veins
Deep Veins.
Drain ankle joint, knee joint, tibiofibular joint, and anterior leg
Anterior tibial veins
Deep Veins.
Drain skin, muscles, and bones of the knee
Popliteal veins
Deep Veins.
Drain muscles of the thigh, femurs, external genitalia, and superficial lymph nodes.
Femoral veins
1) Inferior phrenic arteries (diaphragm)
2) Common hepatic artery: liver, stomach, duodenum, and pancreas
3) Left gastric artery: stomach esophagus
4) Splenic artery: spleen, pancreas, and stomach
Comes from where?
Celiac trunk, which is branched off of the abdominal aorta.
Artery that supplies the small intestine, cecum, ascending and transverse colons, and pancreas
Superior mesenteric artery, which is branched off of the abdominal artery
What artery supplies the adrenal glands?
Suprarenal arteries
Artery that supplies kidneys
Renal arteries
Arteries that supply testicular arteries or ovarian arteries
Gonadal arteries
Artery that supplies the large intestine, part of the rectum, and descending colon
Inferior mesenteric artery
What arteries branch to form the abdominal aorta?
Common iliac arteries
How often should regular exercise occur to improve overall cardiovascular health?
At least 20 minutes 3-5 times a week
What increases our body’s ability to dissolve blood clots by increasing fibrinolytic activity?
Exercise
