Cardiovascular System

What are the major components of the cardiovascular system?

The heart, blood vessels (arteries, veins, capillaries), blood, and lymphatic system.

What are the main components of blood?

Plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets.

What are the functions of plasma?

Carries nutrients, hormones, and waste; helps maintain blood pressure and volume.

Compare and contrast arteries and veins.

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.

Describe the structure and function of capillaries.

Thin-walled (one cell thick) vessels that allow gas, nutrient, and heat exchange between blood and tissues.

Explain the difference between single and double circulation.

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).

Describe the flow of blood through a fish heart.

Sinus venosus → atrium → ventricle → conus/bulbus arteriosus → gills → body → sinus venosus. (1 atrium + 1 ventricle = 2 chambers)

What are the specializations of the fish heart in hagfish and lamprey?

They have accessory hearts (cardinal, caudal, and portal hearts) that are contractile but lack cardiac muscle.

How is the lungfish heart specialized for breathing air?

It has partial interatrial and interventricular septa and a spiral valve that reduce mixing and direct blood based on oxygen needs.

What is the purpose of the ductus arteriosus in lungfish?

Connects the pulmonary artery to the systemic circulation, allowing blood to bypass the gills when not in use.

Describe the structure of the amphibian heart.

Three chambers—two atria and one ventricle—with a spiral valve in the conus arteriosus.

How does the spiral valve in the amphibian heart function?

It directs oxygenated blood to systemic circulation and deoxygenated blood to pulmocutaneous circulation, limiting mixing.

Compare the hearts of chelonians/squamates and crocodilians.

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.

What is the Foramen of Panizza?

An opening between the left and right systemic aortas in crocodilians that allows blood shunting during diving.

How do reptiles shunt blood during diving?

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.

Describe the structure of the avian and mammalian heart.

Four chambers—right atrium, right ventricle, left atrium, left ventricle—with complete separation of oxygenated and deoxygenated blood.

What are the four chambers of the avian/mammalian heart and their functions?

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.

Describe the flow of blood through the avian/mammalian heart.

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.

List the four valves of the avian/mammalian heart and their locations.

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.

What are the major arteries and their destinations?

Aorta: From heart to body. Pulmonary artery: To lungs. Hepatic artery: To liver. Renal artery: To kidneys. Carotid artery: To head.

What are the major veins and their sources?

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.

Which artery carries deoxygenated blood?

Pulmonary artery.

Which vein carries oxygenated blood?

Pulmonary vein.

Describe the hepatic portal system and its function.

Drains the stomach, spleen, pancreas, and intestines into the liver for nutrient processing before systemic circulation.

In general, fish have a single | double | triple | figure-of-8 circulatory loop system. 

single

List the number of normal heart chambers for each of these species:
Blank 1: Fish (non-lungfish): ___         

Blank 2: Reptiles (crocodilians): ___    
Blank 3: Amphibians: ___                    

Blank 4: Reptiles (chelonians/squamates): ___   

Blank 5: Birds: ___ 

Blank 6: Mammals: ___

#1: 2

#2: 4

#3: 3

#4: 3

#5: 4

#6: 4

Lungfish have a _______ _______ located within the conus arteriosus that facilitates separation of oxygenated and deoxygenated blood

spiral value

In which of these would you also find a spiral valve?

shark intestine

As you auscult, he has questions. Thinking of the "lub dub" sound that makes a dog's heartbeat…which of these best describes what makes the sounds?

Closing of tricuspid/bicuspid valves and closing of aortic/pulmonic valves

Blood in the right atrium is oxygenated | non-oxygenated | mixed.

Non-oxygenated 

Using the graphic above, fill in the appropriate heart chamber or valve. (Don't forget to indicate left or right where appropriate).

Right atrium, tricuspid value, right ventricle, pulmonary valve, left atrium, mitral valve, left ventricle, aortic value

Examine this normal canine chest radiograph compared to Midnight's abnormal one. Which side of the heart appears enlarged?  

Right

This diagram illustrates what's happening in the abnormal radiograph.  In dogs, adult heartworms take up residence in which chamber of the heart and which blood vessel (as indicated)?

Chamber: __________    (Blank 1)

Blood vessel: ___________ (Blank 2)

#1: right ventricle

#2: pulmonary artery

This infliction may lead to pulmonic stenosis (narrowing) of the outflow of the blood vessel listed above/in the previous question.
Using the graphic we discussed in class (in the PowerPoint), define WHERE would be the best place to  auscult (listen) for pulmonic stenosis:
Between ribs _____ and _____ near the ________ _______  junction, on the _____ side.

B#1: 2

B#2: four

B#3: costochondral

B#4: left

The doctor asks you to get a heart rate for the iguana by placing a Doppler probe over a blood vessel. What is responsible for the sound you hear?

Movement of blood through the blood vessel, propelled by contraction

Lastly, examine this transverse section of an avian heart.  You are looking at the inside (lumen) of the left and right ventricle.  Identify which is which:

A. is the right ventricle

B. is the left ventricle

Match the major blood vessels with the appropriate name: Pulmonary artery

Carries blood to lungs

Match the major blood vessels with the appropriate name: Renal artery

Carries blood to kidneys

Match the major blood vessels with the appropriate name: Afferent artery

Carries blood to the gills 

Match the major blood vessels with the appropriate name: Hepatic portal vein

Carries blood from stomach, pancreas, spleen, to liver

Carotid artery

Carries blood to the head

Match the major blood vessels with the appropriate name: Renal vein

Carries blood from kidneys toward heart

Match the major blood vessels with the appropriate name: Hepatic vein

Carries blood from liver toward heart

Match the major blood vessels with the appropriate name: Jugular vein

Drains blood from head

Match the major blood vessels with the appropriate name: Vena cava

Carries blood to right atrium

Match the major blood vessels with the appropriate name: Iliac artery

Carries blood to hind limbs