Vertebrate Form and Function Exam 3

1. What is a portal system?

system that begins & ends in capillaries, does not include the heart

What are the major blood vessels leaving the amphibian heart? What vessels do they correspond to in a mammal heart. Why does one of them include the word cutaneous? What is the main difference between an amphibian heart and a mammal heart?

systemic: aortic in humans pulmocutaneous arches: pulmonary in humans (Cutaneous means skin; reptiles can use skin to breath through)

You are responsible for understanding blood flow through the four chambered heart of a mammal.

****Blood enters the right atrium and passes through the right ventricle. The right ventricle pumps the blood to the lungs where it becomes oxygenated. The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium. From the left atrium blood flows into the left ventricle. The left ventricle pumps the blood to the aorta which will distribute the oxygenated blood to all parts of the body.

What are the four parts of a fish heart. What is the significant difference between a fish heart and an embryonic heart?

1. Atrium 2. Ventricle 3. Conus arteriosus 4. Sinus venosus Difference is Bulbus Cordis switched to Conus arteriosus

1. Describe the hepatic portal system. What two major things does it connect?

1. begins with capillaries that drain the digestive organ, 2. capillaries empty into the hepatic portal vein, 3. carries nutrient rich blood to the liver, 4. hepatic portal empties into capillaries, 5. blood here is conditioned by the liver, 6. capillaries join to empty into the hepatic vein that ultimately returns to the heart Connects intestine and liver

KNOW HOW BLOOD FLOWS THROUGH THE MAMMAL HEART. KNOW ALL OF THE PARTS THAT ARE MENTIONED ON YOUR HANDOUT ON THE HEART AND WHAT THEY DO.

1. deoxygenated blood flows through inferior/superior vena cava, 2. into the right atrium, 3. through the tricuspid valve, 4. into the right ventricle, 5. through the semilunar valve, 6. into the pulmonary artery, 7. flows through the lungs, 8. oxygenated blood flows through the pulmonary vein, 9. into left atrium, 10. through bicuspid valve, 11. into left ventricle, 12. through semilunar valve, 13. into the aorta, 14. out to the arteries, 15. to the arterials, 16. to the capillaries, 17. to the venules, 18. to the veins, 19. and then again through the superior/inferior vena cava

1. What are the three types of formed elements in blood?

1. erythrocytes 2. leucocytes 3. platelets

1. Why does blood pressure drop as blood moves away from heart? (2 reasons)

1. friction between blood and walls of blood vessels 2. increase in total cross sectional area of blood vessels

1. What are the three parts of the cardiovascular system?

1. heart 2. blood vessels 3. blood

1. What two things are needed for gas exchange?

1. moist membrane 2. difference in partial pressure of gasses on 2 sides of membrane (high to low concentration)

1. What are the four parts of the fish heart? Be able to label. In the fish heart what does the embryonic bulbus cordis give rise to (two possibilities)?

1. sinus venosus2. atrium3. ventricle4. bulbus cordis (gives rise to the conus arteriosus and bulbous arteriosus)

1. What are the four major functions of the cardiovascular system? Why is drinking alcohol a bad idea if you are in danger of freezing to death?

1.Transportation of oxygen, CO2, nutrients, hormones 2. Protections against invading microorganisms and toxins 3. Maintain homeostasis 4. Prevents own loss through clotting mechanisms. Alcohol may make your body feel warm inside, but it causes your blood vessels to expand, resulting in more rapid heat loss from the surface of your skin

1. What are two important factors influencing the efficiency of gas exchange? What is the partial pressure of a gas? How do you determine the partial pressure of a specific gas?

1.surface area 2. each gas mixture exerts its own partial pressure; if atmosphere is 760mmhg O2 is 21% of atmosphere (760X.21= 160mmhg/O2)

What is one way that crocodylians mitigate the impact of deoxygenated blood being delivered to the tissues? Correlated with that, how is the brain protected?

Blood higher in O2 from right aorta supplies the brain which is most sensitive to a lack of O2. • Blood lower in O2 supplies the viscera which is less sensitive to low O2. .

1. What major blood vessel returns blood to the heart?

Common cardinal Vein

What must blood passing through the arches with gills pass through? What is the function of that structure? When does it close and when does it open? What happens to the blood when it closes? Opens?

Ductus arteriosus (to direct it); closes and opens when o2 is there or not in blood

1. What is the only major artery that carries deoxygenated blood?

Pulmonary artery

What are the major blood vessels exiting the heart in reptiles? How does this compare to mammals? What is the one little difference? What kind of blood is carried by these vessels?

Right and left systemic and pulmonart artery; mammals have pulmonary artery; bulbous cordis stays doesnt change to conus arteriosus

How does the basic structure of the avian and mammalian heart compare?

The conus arteriosus is absent in both; both keep 1 aortic arch but opposite sides; both retain pacemaker function

1. Describe the embryonic heart. What are its four chambers

Tubular and has inherent rhythmic beat. 1. sinus venosus 2. atrium 3. ventricle 4. bulbus cordis

What is the function of the ductus venosus and where is it located? What is its remnant called?

allows approximately 50% of blood entering the fetus to bypass the liver and go to the heart via the inferior vena cava.

1. What are small arteries called?

arterioles

1. What is hypotensive shock?

blood pressure drops

1. What are the smallest blood vessels called? How many cells thick are they? What occurs only in the capillaries? What tissues in the body do not contain capillaries?

capillaries; single-layer of cells thick; exchange of respiratory gases, nutrients, and wastes between the blood and tissues; Cornea and lens contain no capillaries

1. Why is the hepatic portal system necessary?

carries blood to the liver, toxins are removed from blood here

1. What is the definition of an artery? What fiber is especially prevalent in large arteries? Why?

carry blood away from heart; Elastic fibers: they allow blood vessels to stretch when the heart beats & recoil following the heart beat

List the three compartments within the ventricle and tell what kind of blood each receives and from which atrium. Are these compartments interconnected? Which two work together and in what order does the blood pass through them and to into which blood vessel does it then go?

cavum venosum: deoxygenated; rt. atrium cavum pulmonale: deoxygenated, rt. atrium cavum arteriosum: oxygenated, left atrium pulmoale and arteriosum work together then goes to pulmonary artery

What is the function of the sinus venosus in vertebrates? What is the only group that lacks a recognizable structure called the sinus venosus?

collects venous blood and delivers it to the atrium.

What is another name for the aorta that is commonly used?

coronary artery

What kind of blood enters the lungfish heart via the sinus venosus and into which chamber or partial chamber does it go?

deoxygenated blood

1. What is the main function of the respiratory system?

exchange gas b/w organism and its environment

1. What does the first number in a blood pressure reading represent? The second number? Which one is higher?

first - pressure when the heart beats second - pressure between beats

1. How does the arrangement of the chambers in the fish heart show a step towards the arrangement seen in higher vertebrates?

fish heart is s-shaped, which moves the ventricle under the atrium. This is found in advanced tetrapods

1. What is the function of the atrium?

functions as a receiving chamber

1. Distinguish between internal and external respiration.

internal: respiration b/w blood and cells external: b/w organism and its environment

1. How does arteriosclerosis affect arterial elasticity? What are two negative effects of plaque?

it does not allow the artery to stretch or recoil to mediate blood pressure & spikes in blood pressure cannot be handled (cant expand and narrows area)

How does the lungfish avoid sending oxygenated blood from the lungs to the gills since the blood flow requires blood to pass to through the pharyngeal arches to get to the dorsal aorta?

it goes through arches that lack Gills; deoxygenated goes through arches that have gills

In what way is the amphibian heart unique among vertebrates with lungs? What is the one known exception?

lack at least a partial interventricular septum (siren genus is the exception)

1. What's unusual about mammal erythrocytes compared to most vertebrates? What do erythrocytes contain?

lack nucleus; erythrocytes contain hemoglobin

What are the exceptions to the amphibian heart having three chambers? Why is each of these groups different—one reason for each group?

lungless salamanders the left atrium is absent; no lungs no left side of heart; they mostly use gills and there is not much separation between the right and left side.

What do the Dipnoi have that might affect the structure of the heart?

lungs

Where does oxygenated blood entering lungfish heart come from? Why isn't it the gills? Which chamber or partial chamber of the heart does oxygenated blood enter regardless of the group?

lungs (bc pushing deoxygenated blood to gills to get oxygenated); left side of the heart

What is the primary source of oxygenated blood in all reptiles? Which part of the heart is this blood sent to?

lungs; left side

1. Which group has a heart similar to the embryonic heart?

most fishes

When a crocodylian is diving (holding breath), what happens to blood flow through foramen of Panizza?

most of the blood forces its way into the left aortic arch by exceeding the pressure of blood trying to move through the foramen of Panizza

1. What is the function of oxygen?

needed for production of ATP

Do lungfish always breath air? Is there always oxygen available in the water?

no bc also has gills; no not enough in water sometimes

What is the role of the conus arteriosus in Chelonians and Squamates?

none of them have conus arteriosius; forms the bases of the three major arteries leaving the ventricle (pulmonary trunk, and right, left aortic)

1. Does blood go in a circle when it passes through the body?

nope

What would happen if oxygenated blood exiting the heart passed through gills when there was little to no oxygen in the water? What would happen if oxygenated blood exiting the heart passes through the gills when there was oxygen present in the water. Is there any potential loss to sending the oxygenated blood to the gills? Is there any potential gain to sending oxygenated blood to the gills?

oxygen could be lost; its redundant

1. Which of these makes up the matrix of blood?

plasma

1. Briefly describe what precapillary sphincters and shunts are. Explain how they function and why their roles are important.

precapillary sphincters - smooth muscles that close to prevents blood from entering some capillaries shunts - they bypass capillary beds (can lead to hypotensive shock)

1. What is the function of the sinus venosus?

receives returning blood

What chamber does the pulmonary trunk (artery) exit from?

right ventricle

1. Distinguish between single and double circulation. What group has single circulation? What groups have double circulation? What groups are intermediate?

single (fish) - heart pumps blood that passes to the gills, gets oxygenated, and goes out to body before returning to the heart Double (mammals & birds) - right side pumps blood to the lungs, comes back to left side which pumps to body Intermediate - lungfish & amphibians & reptiles

What does each of the four parts do? In which direction does blood move?

sinus venosis: recieives blood Atrium: Recieving chamber Ventricle: Propels blood out of heart Conus arteriosus: direct blood

1. Do all animals need a respiratory and/or cardiovascular system? Why?

small animals or embryos do not; bc they can get needed gasses and get rid of bad ones through diffusion

1. Which germ layer does the heart develop from? Be specific.

splanchnic mesoderm

What is the function of the ductus arteriosus in the mammal fetus and where is it located? What is its remnant called?

this connects the pulmonary trunk and the aorta and also functions to allow fetal blood to bypass the lungs. The ligamentum arteriosum of the adult is the remnant of this fetal structure.

What is the function of the foramen ovale and where is it located? What is its remnant called? What is a patent foramen ovale?

this hole in the interatrial septum allows fetal blood to bypass pulmonary circulation. The fossa ovalis in the adult is a remnant of the foramen ovale. Patent foramen ovale is where hole doesn't seal up and it leaks.

What blood vessel brings blood rich in oxygen and nutrients from mother to fetus? What blood carries blood poor in oxygen and nutrients from fetus to mother?

umbilical vein; Blood from posterior part of fetus goes to mother via umbilical artery to pick up O2 and nutrients.

What do veins have that arteries do not? What are four things that help move venous blood back to the heart?

valves; 1.valves 2.contraction of muscle 3.changes in pressure to the thorax (yawning) 4.smooth muscle in tunica media

1. What are veins? How does their tunica media compare to tunica media in arteries?

veins carry blood towards the heart; Tunica media is thicker and contains more contractile tissue in arteries than in veins

What is unusual about the ventricle?

very complex?

Blood leaving which arches flows directly into the dorsal aorta and out to the body?

2 and 3

How many chambers does the amphibian heart contain? Are they complete?

3 chambers; yes atrium with complete interatrial septum

How does blood flow change in aquatic reptiles (non crocodylians) when they dive? Specifically, what happens to the blood normally passing from cavum venosum to cavum pulmonale and out the pulmonary trunk?

Blood flow out the pulmonary trunk is resisted; causes blood to slosh over into the wrong place; some leakage

Why does much of the blood in a fetus bypass the lungs and liver?

Blood rich in oxygen and nutrients returns to fetus from mother via the umbilical vein (vein because moving towards fetal heart)

What additional blood vessel sometimes also exits the heart in reptiles? What does it usually branch of? How does this compare to mammals?

Conus arteriosus; blood vessels branch from it

In which group is the first four chambered heart found?

Crocodylian heart

What connects the two arches?

Foramen of Panizza.

What are the three blood vessels exiting the heart in crocydilians? How does this compare to the situation in mammals(specifically what is the only difference)? Note that having two aortic arches is typical of anamniote tetrapods.

L + R aortic trunk and pulmonary trunk; left aortic arch comes from the right side; foramen of panizza is different as well; 2 aortic arches

What causes varicose veins?

Leaky/faulty venous valves (blood flows backwards causing the veins to distend)

How do Crocodylians potentially turn the negative of deoxygenated blood passing to tissues into a positive?

Low O2 blood in left aorta is carried to digestive organs. This may aid digestion by using the CO2 to create a more acid environment in the stomach

1. What are the two major components of blood?

Plasma and Formed elements

1. What is the function of platelets? What is a thrombus? An embolus? What can they cause?

Platelets: make factors that cause blood to clot Thrombus: clot in an unbroken vessel (can lead to stroke or pulmonary embolism, etc.) Embolus: Moving thrombus

Do the hearts of mammal and bird hearts share a common ancestry?

While bird and mammal hearts are structurally and functionally very similar, their embryology demonstrates that they arose independently from different lineages.

1. What are the waste products of respiration?

water and CO2

1. What is the function of leucocytes?

(white blood cells) protect from disease/infection

1. What system is responsible for distributing the oxygen to all parts of the body?

Cardiovascular system

What are the two roles of the sinus venosus in chelonians and squamates? How does this compare with its role in fishes? How does the sinus venosus in chelonians and squamates compare to the sinus venosus of earlier vertebrates? What kind of blood passes through the sinus venosus and into which chamber does it go?

1. first receiving chamber & empties into right atrium 2. pacemaker; basically the same in fishes

When you add lungs what must the heart have? Why? What do lungfish have that complicates the addition of lungs?

Adds a left side to the heart for blood coming from lungs; gills complicate things

Why is the fish heart efficient? What is its big shortcoming and what causes that?

Efficient - no mixing of oxygenated and deoxygenated blood. heart pumps to the gills (gets oxgenated), then flows throughout the body; Deficiency - low pressure. blood doesn't return to the heart so it doesn't have enough pressure to move throughout the body

1. Why is it important that hemoglobin be contained in cells as opposed to free in the plasma? Which respiratory gas is hemoglobin most important in transporting?

Hemoglobin contains iron, which allows it to pick up oxygen from the air. important in the transportation of respiratory gases - especially oxygen. Otherwise it would be excreted by kidneys.

What are the two major differences mentioned?

In birds the sinus venosus remains as a small but still identifiable area. • In mammals it is reduced to a patch of purkinje fibers that form the sinoatrial node often abbreviated SA node.

What has become of the conus arteriosum? The sinus venosus? Is this similar to other reptiles? What about amphibians?

In crocodilians the conus arteriosum is absent, replaced by the three major vessels leaving the heart (left and right aortic trunks and pulmonary trunk (artery).The sinus venosus is still present and empties into the right atrium.

What is the basic flow of blood in a fish?

Posterior to anterior

How do the chambers present in a lungfish heart compare to those present in a fish. Important note—chambers specifically refers to atria and ventricles. Why were these changes important to lungfish?

They have atrium divided by interatrial septum; also the ventricle partially divided by interventricular septum; septum's help prevent mixing of blood