Cardiovascular System
Q: What are the major components of the cardiovascular system?
A: The heart, blood vessels (arteries, veins, capillaries), blood, and lymphatic system.
Q: What are the main components of blood?
A: Plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets.
Q: What are the functions of plasma?
A: Carries nutrients, hormones, and waste; helps maintain blood pressure and volume.
Q: Compare and contrast arteries and veins.
A: Arteries carry blood away from the heart, have thick walls, and elastic fibers; veins carry blood to the heart, have thinner walls, less elastic tissue, and one-way valves.
Q: Describe the structure and function of capillaries.
A: Thin-walled (one cell thick) vessels that allow gas, nutrient, and heat exchange between blood and tissues.
Q: Explain the difference between single and double circulation.
A:
Single: Blood passes through the heart once per cycle (heart → gills → body → heart).
Double: Blood passes through the heart twice (heart → lungs → heart → body → heart).
Q: Describe the flow of blood through a fish heart.
A: Sinus venosus → atrium → ventricle → conus/bulbus arteriosus → gills → body → sinus venosus. (1 atrium + 1 ventricle = 2 chambers)
Q: What are the specializations of the fish heart in hagfish and lamprey?
A: They have accessory hearts (cardinal, caudal, and portal hearts) that are contractile but lack cardiac muscle.
Q: How is the lungfish heart specialized for breathing air?
A: It has partial interatrial and interventricular septa and a spiral valve that reduce mixing and direct blood based on oxygen needs.
Q: What is the purpose of the ductus arteriosus in lungfish?
A: Connects the pulmonary artery to the systemic circulation, allowing blood to bypass the gills when not in use.
Q: Describe the structure of the amphibian heart.
A: Three chambers—two atria and one ventricle—with a spiral valve in the conus arteriosus.
Q: How does the spiral valve in the amphibian heart function?
A: It directs oxygenated blood to systemic circulation and deoxygenated blood to pulmocutaneous circulation, limiting mixing.
Q: Compare the hearts of chelonians/squamates and crocodilians.
A:
Chelonians/squamates: 3 chambers (2 atria, 1 ventricle divided into cavum venosum, cavum pulmonale, and cavum arteriosum).
Crocodilians: 4 chambers (2 atria, 2 ventricles) with a Foramen of Panizza connecting systemic arches.
Q: What is the Foramen of Panizza?
A: An opening between the left and right systemic aortas in crocodilians that allows blood shunting during diving.
Q: How do reptiles shunt blood during diving?
A: Pulmonary resistance increases, causing a right-to-left shunt that bypasses the lungs; this helps conserve oxygen and regulate temperature, acid-base balance, and digestion.
Q: Describe the structure of the avian and mammalian heart.
A: Four chambers—right atrium, right ventricle, left atrium, left ventricle—with complete separation of oxygenated and deoxygenated blood.
Q: What are the four chambers of the avian/mammalian heart and their functions?
A:
Right atrium: Receives deoxygenated blood from the body.
Right ventricle: Pumps blood to the lungs.
Left atrium: Receives oxygenated blood from the lungs.
Left ventricle: Pumps blood to the body.
Q: Describe the flow of blood through the avian/mammalian heart.
A: Vena cava → right atrium → tricuspid valve → right ventricle → pulmonic valve → pulmonary artery → lungs → pulmonary vein → left atrium → mitral valve → left ventricle → aortic valve → aorta → body.
Q: List the four valves of the avian/mammalian heart and their locations.
A:
Tricuspid: Between right atrium and right ventricle.
Pulmonic (semilunar): Between right ventricle and pulmonary artery.
Mitral (bicuspid): Between left atrium and left ventricle.
Aortic (semilunar): Between left ventricle and aorta.
Q: What are the major arteries and their destinations?
A:
Aorta: From heart to body.
Pulmonary artery: To lungs.
Hepatic artery: To liver.
Renal artery: To kidneys.
Carotid artery: To head.
Q: What are the major veins and their sources?
A:
Cranial/caudal vena cavae: Return blood from body to heart.
Pulmonary vein: From lungs to heart.
Hepatic vein: From liver.
Renal vein: From kidneys.
Jugular vein: From head.
Q: Which artery carries deoxygenated blood?
A: Pulmonary artery.
Q: Which vein carries oxygenated blood?
A: Pulmonary vein.
Q: Describe the hepatic portal system and its function.
A: Drains the stomach, spleen, pancreas, and intestines into the liver for nutrient processing before systemic circulation.
Q: What is the “first-pass effect”?
A: Drugs absorbed from the GI tract are metabolized by the liver before entering systemic circulation.
Q: What is the renal portal system?
A: A system where blood from hind limbs or tail passes through kidneys before returning to the heart; important for avoiding nephrotoxic drug effects.
Q: Describe the circulatory changes in fetal mammals.
A: The placenta supplies oxygen via the umbilical vein; blood bypasses the lungs via the ductus arteriosus and foramen ovale.
Q: What is the function of the ductus arteriosus in fetuses?
A: Connects the pulmonary artery to the aorta to bypass the lungs.
Q: What is the function of the foramen ovale in fetuses?
A: Connects the right and left atria to bypass pulmonary circulation.
Q: What is Patent Ductus Arteriosus (PDA)?
A: Failure of the ductus arteriosus to close after birth, causing a left-to-right shunt and heart murmur.
Q: What are the functions of the lymphatic system?
A: Returns interstitial fluid to blood, prevents edema, absorbs GI fats, and supports immune defense.
Q: What are the major lymph nodes in dogs?
A: Sublingual, submandibular, prescapular, axillary, inguinal, and popliteal.
Q: What is lymphadenopathy?
A: Enlargement of lymph nodes due to infection, inflammation, or neoplasia (cancer).
Q: What is venipuncture?
A: The collection of blood from a vein for testing.
Q: Common venipuncture sites in fish?
A: Caudal tail vein (ventral coccygeal).
Q: Common venipuncture sites in amphibians?
A: Caudal tail vein (salamanders), ventral abdominal vein, or heart.
Q: Common venipuncture sites in reptiles?
A: Caudal tail vein, jugular vein, ventral abdominal vein, subcarapacial sinus (turtles), or post-occipital sinus.
Q: Common venipuncture sites in birds?
A: Right jugular vein, basilic (ulnar) vein, or medial metatarsal vein.
Q: Common venipuncture sites in small mammals?
A: Cephalic vein, jugular vein, lateral tail vein, or ear veins.