>the Cardiovascular System
Compare and contrast continuous, fenestrated and sinusoidal capillaries in terms of structure and location.
1) Continuous capillaries = plasma membranes form a continuous, uninterrupted ring around the lumen. Found in skeletal, smooth muscle, CT, and lungs. 2) Fenestrated capillary = endothelial plasma membranes contain pores. Found in glomeruli of kidneys and villi of small intestine. 3) Sinusoids= contain spaces between the endothelial cells with basement membranes being incomplete or absent. Found in liver and spleen.
stinguish between AV and SL valves in terms of location, structure, and when they close.
AV valves- between atrium and ventricles, associated with the chordae tendineae, and papillary muscle. Close during each pump of the heart. SL valves lie within the pulmonary trunk or the aorta- close when ventricles are relaxed.
Explain the significance of each component of the cardiac conduction system and trace how the cardiac impulse travels through the myocardium.
1. Sinoatrial Node (SA): located in uppermost atrial wall. It is the pacemaker component. Impulses travel throughout the atrial fibers via gap junctions in intercalated discs to the 2. Atrioventricular Node (AV): located in interarterial septum. Serves as delay signal that allows for ventricular filling. Cardiac impulse then moves to the 3. Atrioventricular bundle: only electrical connection b/w atria & ventricles. Located in superior interventricular septum. Impulses enter both 4. R&L bundle branches lead downward through interventricular septum toward apex & finally impulse reaches 5. Purkinje fibers: large diameter conduction myofibers located within papillary muscles of ventricles. Conducts impulse to mass of ventricular muscle tissue. Causes ventricles to contract which forces blood out.
Compare and contrast the 3 types of blood vessels in terms of the following: a. direction of blood-flow (in terms of the heart), b. wall structure (# of layers and components of those layers), c. gas concentrations and d. pressure
Arteries: a. moves the blood away from the heart b. 3 distinct layers/tunics c. high in concentration and low in carbon dioxide d. under great pressure Vein: a. moves blood towards heart b. same 3 layers/tunics as arteries. but it also equipped with valves c. high in carbon dioxide, low in oxygen d. low pressure, this is why it needs valves Capillary: a. exchange site for gases, nutrients, and wastes between blood and tissues. connects arterioles and venules. b. only the tunica intima (single layer of endothelium c. n/a d. n/a
Name the branches of the ascending aorta, aortic arch, thoracic aorta, and abdominal aorta, and denote what body region they supply with blood
Ascending aorta A. RIGHT CORONARY ARTERY B LEFT CORONARY ARTERY Ascending aorta A. RIGHT CORONARY ARTERY B LEFT CORONARY ARTERY Thoracic Aorta A PHRENIC ARTERY B ESOPHAGEAL ARTERY C INTERCOSTAL ARTERIES D BRONCHIAL ARTERIES Abdominal Aorta A INFERIOR PHRENIC ARTERY B CELIAC ARTERY (TRUNK) C SUPERIOR MESENTERIC ARTERY D SUPRARENAL ARTERIES E RENAL ARTERIES F GONADAL ARTERIES G INFERIOR MESENTERIC ARTERIES Common Iliac Arteries EXTERNAL ILIAC ARTERY INTERNAL ILIAC ARTERY
Explain why the atria are passive chambers, while the ventricles are active.
Atria are passive bc they receive blood from the veins. The ventricles are active because they pump blood from the heart into arteries.
Define the terms blood flow and circulation time and give the value of the normal circulation time in a resting adult.
Blood flow - Circulation of blood through the closed cv Circulation time -The time it takes for a drop of blood to pass between two given points
Define the term blood pressure, name the type of blood vessels where blood pressure is significant, and name the normal (average) value in a resting adult
Blood pressure = pressure exerted by blood on the wall of a blood vessel. Pulse= pressure wave that travels through arteries following left ventricular systole. Strongest in arteries closest to heart. Most commonly referred to is arterial blood pressure (blood pressure in veins is essentially insignificant). Arterial blood pressure rises to maximum during systole (contraction) and falls to its lowest during diastole (relaxation). In a normal adult at rest, the BP = 120 mm Hg / 80 mm Hg.
Define the term blood resistance and discuss the three major factors that determine it
Blood resistance = the resistance which must be overcome to push blood through the circulatory system and create flow. The three major factors are 1. vessel diameter 2. vessel length 3. viscosity of blood
Discuss the major event that occurs at capillaries
Capillaries permit the exchange of gases, nutrients, and wastes between blood and tissues. Connects arterioles to venules.
Name the term referring to all of the events associated with one heartbeat
Cardiac cycle. A complete cardiac cycle includes systole and diastole of both atria, and systole and diastole of both ventricles.
Name the two structure associated with atrioventricular valves
Chordae Tendinae = tendon-like, fibrous cords that connect the cusps of the AV valves to the papillary muscle Papillary muscle = the muscular columns that are located on the inner surface of the ventricles
Describe the size of the heart.
Closed fist, about 300g
Describe Lub
Closing of AV valves (ventricular systole) - loud and long
Describe Dub
Closing of SL valves (ventricular diastole) - short and sharp.
Define systole
Contraction of the heart
Define/describe the terms chordae tendineae, papillary muscle, and trabeculae carneae.
Cordae tendineae - cord-like structures that anchor cusps of av valves to papillary muscle Papillary muscle - columns of muscle in ventricles that anchor susps of av valves Trabeculae carneae - characteristic "fleshy beans" appearance of inner ventricular wall
Discuss the factors that affect cardiac output
Factors affect cardiac output by changing heart rate and stroke volume. Primary factors include blood volume reflexes, autonomic innervation, and hormones. Secondary factors include extra cellular fluid ion concentration, body temperature, emotions, sex, and age.
Explain what is meant by the human cardiovascular system being a "closed system".
HEART - LUNGS - BODY - HEART. As long no vessel is damages, the blood stays within this closed network
List the organs that compose the cardiovascular system and discuss the general functions of this system
Heart. Blood Vessels. Blood vessels carry blood from the heart to the peripheral tissue
Discuss hypertension
High blood pressure puts undo stress on major arteries, can lead to strokes
List the hormones involved in regulation of blood pressure and blood flow
Hormones that increase BP: Epinephrine and norephinephrine, antiduretic hormone, angeiotensin II, and aldosterone. Hormones that decrease BP: Atrial natriuretic peptide (ANP) and Histamine (causes vasodilation of arterioles, plays a key role in inflammation)
Discuss the physiological stages of cardiac muscle contraction and trace how they appear on graph plotting mv vs. time.
IT STARTS AT -90mV. SA Node fires, opening Na+ ion channels causing rapid depolarization (up to +30mV); Na+ channels close and calcium channels open for a long plateau period (allowing for the contraction mechanism to become activated; the Ca++ channels close and Potassium (K+) channels open causing repolarization.
Name (and locate) the veins that deposit their blood into the atria of the heart (which atria? deox- or oxygenated?).
Inferior vena cava brings deoxygenated blood from the trunk and lower limbs into the right atrium. The coronary sinus brings deoxygenated blood from the myocardium into the right atrium. The pulmonary veins bring oxygenated blood into the left atrium - there are two from the right lung and two from the left lung.
Describe the structure and function of the interventricular septum.
Interventricular septum is a muscular wall that separates right and left ventricles. It prevents the mixing of oxygenated and deoxygenated blood.
Define the terms ischemia and hypoxia, and explain how they are related to the pathologic conditions of angina pectoris and myocardial infarction.
Ischemia: Reduction of blood flow. Hypoxia: reduced oxygen supply due to ischemia. Angina pectoris: "strangled chest" - severe pain that accompanies myocardial ischemia. Angina pectoris notes: a) crushing chest pain radiating down left arm, b) labored breathing, weakness, dizziness, perspiration, c) occurs during exertion, fades with rest, d) relieved by nitroglycerin. Myocardial infarction 0 heart attack- death portion of myocardium, usually caused by a thrombus or embolus (moving blood clot) in a coronary artery.
Locate the neural cardiovascular center on a mid-sagittarius diagram of the brain, explain where impulses sent to it are first detected, and explain where its outgoing impulses are directed and what happens when they get there
Located in the medulla of the brain stem They send impulses to the cardiovascular center to regulate blood pressure
Describe the location of the heart.
Located within the mediastinum between the pleural cavities
Discuss heart sounds in terms of what they represent, how they sound, how they are detected and their significance.
Lub= closing of AV valves (ventricular systole) - loud and long. Dup = closing of SL valves (ventricular diastole) - short and sharp. Heard with stethoscope. If the closing of the valve cusps is incomplete, some blood may leak back (this is a heart murmur).
Another name for the bicuspid valve is
Mitral Valve
Discuss what causes reperfusion damage.
Occurs when an oxygen deprived tissue's blood supply is reestablished. Due to the formation of oxygen free radicals, there is damage to enzymes, neurotransmitters, nucleic acids, and phospholipids. Implicated in a variety of diseases including heart disease, Alzheimer's, Parkinson's, etc. Anti-oxidants defend body against this damage.
Trace a typical ECG and label each wave or complex and explain what event of the CCS corresponds to each wave
P wave- represents atrial depolarization, spreads from SA node throughout both atria; QRS complex- begins downward deflection, continues as large, upright, triangular wave, ends as downward wave, represents onset of ventricular depolarization; T wave- dome-shaped, upward deflection, represents ventricular repolarization
Distinguish between pulmonary, coronary, and systemic circulation.
Pulmonary circulation occurs between the heart and the lungs. Coronary circulation occurs within the heart itself. Systemic occurs throughout the whole body.
Explain why the refractory period between cardiac muscle contractions is so long
Refractory period = time following a contraction when a second contraction cannot be triggered. It is longer than the contraction itself because it is necessary for ventricles to relax and fill with blood before again contracting to eject the blood.
Define diastole
Relaxation of the heart
Track a drop of blood through the heart/ lungs/ heart
Right atrium (tricuspid) -> right ventricle -> pulmonary trunk (semilunar valve) -> right and left pulmonary arteries -> capillaries in lungs -> right and left pulmonary veins -> left atrium (bicuspid) -> left ventricle -> aorta (semilunar valve)
Track a drop of blood to the body (in general)
Right atrium (tricuspid) -> right ventricle -> pulmonary trunk (semilunar valve) -> right and left pulmonary arteries -> capillaries in lungs -> right and left pulmonary veins -> left atrium (bicuspid) -> left ventricle -> aorta (semilunar valve) -> arteries -> arterioles -> capillaries in body tissues -> venues -> veins -> vena cavae (superior vena cavae and inferior vena cavae) -> right atrium
Define the term hemodynamics.
Study of the forces involved in carrying blood away from the heart, transporting it to all of the body tissues, then returning it to the heart.
Define the terms tachycardia and bradycardia
Tachycardia = pulse higher than 100 bpm. Bradycardia = pulse lower than 60 bpm.
Name (and locate) the arteries that take blood away from the heart (from which ventricle? deox-or oxygenated blood?).
The aorta carries oxygenated blood away from the left ventricle to the body. The coronary arteries carry oxygenated blood to the myocardium. The pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs via the pulmonary trunk.
Describe how arterioles play a major role in regulating blood flow to capillaries.
The vasomotor center can cause vasoconstriction to increase blood pressure and cause vasodilation to decrease blood pressure.
Define the term anastomoses
Vascular anastomoses - union or joining together of blood vessels in certain body areas
Define cardiac output
amount of blood pumped out by each ventricle in one minute
the aortic semilunar valve lies within the __________
aorta
Track a drop of blood through myocardium
aorta (semilunar valve) -> right and left coronary arteries -> capillaries myocardium -> cardiac veins -> coronary sinus
Ventricles pump blood from the heart into the
arteries (active)
What separates the right and left atria
interatrial septum
What separates the right and left ventricle
interventricular septum
Name the function of the serous fluid around the heart
lubrication
Define heart rate
number of beats per minute
Name the common term for the sinoatrial (SA) node.
pacemaker
Describe the general function of the heart valves
prevent back flow of blood
Distinguish between the pulmonary and systemic circuits
pulmonary - right side of heart; carries blood to lungs for gas exchange systemic - left side of heart; supplies blood to all organs of body
the pulmonary semilunar valve lies within the _______
pulmonary trunk
Name the atrioventricular valves (AV valves)
the Tricuspid valve and the bicuspid valve
Describe the structure of the heart in terms of its chambers.
the heart has four chambers; right and left atria right and left ventricles
Describe the structure of the heart in terms of its coverings
the heart is surrounded by 3 membranes; fibrous pericardium (outermost layer, tough, fibrous protective connective tissue layer that prevents overstretching of the heart), serous pericardium (which contains the visceral [innermost, delicate epithelium] and parietal [inner lining of fibrous pericardium])
Describe the structure of the heart in terms of its layers.
the heart wall has three layers; epicardium: visceral pericardium myocardium: cardiac muscle tissue, the bulk of the heart endocardium: smooth inner lining of heart chambers and valves
The bicuspid valve lies between the ____________ and ________.
the left atrium and the left ventricle
Name the Semilunar valves
the pulmonary semilunar valve and the aortic semilunar valve
The tricuspid valve lies between the ___________ and ___________.
the right atrium and right ventricle
Define the term cardiology
the study of the heart and the diseases associated with it
Atria receive blood from
the veins (passive)
Define stroke volume
the volume of blood the heart ejects with each beat.
Ventricles have ___ walls
thick walls
Atria have ___ walls
thin
Give another name for epicardium
visceral pericardium
