Comp Vert Anat. Final Exam Lecture 20

Front 1

How many circuits do gill breathing fish have?

Back 1

single circuit in which the blood is only pumped through the heart once and travels through the ventral aorta, picks up oxygen the gills, to the dorsal aorta, then out to the body

Front 2

primitively how many aortic arches did fish have through the gill chambers?

Back 2

fish had a system of six aortic arches through each of the gill chambers

as do all vertebrates during development

Front 3

With the advent of air breathing, a second circuit, the __________,evolved.
this required the appearance of what new vessels

Back 3

the pulmonary circuit, evolved that carries blood to the lungs, then back to the heart to be pumped a second time

pulmonary artery and vein

Front 4

Mechanisms are required for separating oxygenated and de-oxygenated blood and making sure it went from the heart into the correct circuit.
what complex do amphibians use?

Back 4

spiral valves in the conus arteriosus that preferentially divert blood into one or the other circuit

Front 5

the system of ____ and _____ in lungfish provides a highly flexible system that allows lungfish and gills as necessary to obtain oxygen.

This pattern foreshadows the pattern in tetrapods, including the beginnings of ______ of the heart in the partially divided atrium.

Back 5

valves and shunts

septation

Front 6

what kind of heart do lungfish, amphibians and most non avian reptiles have?

Back 6

incompletely divided heart, and this used to be considered an imperfect system on the way to the more efficient bird and mammal style heart with completely separate pulmonary and systemic circuits.

Front 7

what characteristic do animals with partially divided hearts share?

Back 7

of having periods of apnea (lungs are not ventilated)

Front 8

what is apnea

what is the purpose of the system of shunts and valves?

Back 8

animals with partially divided hearts share the characteristic of having periods of apnea in which the lungs are not ventilated and these systems of shunts and valves provide an efficient way for blood to BYPASS the lungs and SAVE THE ENERGY of pumping blood through them when they are NOT being ventilated.

Front 9

the hearts of amphibians have ____ that are completely separated into two compartments by an __________.

Back 9

atria
interatrial septum

Front 10

In amphibians, the right atrium receives blood from the by way of the ________ and the left atrium receives oxygenated blood from the _______.

Back 10

sinus venosus

pulmonary vein

Front 11

is the ventricle of amphibians divided?

Back 11

no, it is undivided

-but studies have shown that deoxygenated and oxygenated blood remain largely separated due to the
-timing of blood flow into and out of the ventricle & also by
-a system of valves that direct blood differently according to its oxygen content

Front 12

In amphibians
A complex spiral valve in the ventral aorta directs the most oxygen rich blood to the _______.

-why is this

mixed blood goes to the ________

& oxygen poor blood to the _________.

Back 12

carotid arteries, making sure that the brain gets the blood with the most oxygen

systemic circuti

pulmocutaneous circuit

Front 13

t or f

reptiles develop functional gills during ontogeny

Back 13

false

reptiles never develop functional gills during ontogeny.


-aortic arches develop in a pattern similar to adult amphibians

Front 14

Which arches are entirely lost in amphibians?

Back 14

1st 2nd & 5th

Front 15

In amphibians

the third becomes the ______, and the sixth becomes the ______.

Back 15

internal carotid

pulmonary artery

Front 16

t or f (amphibians

the ductus arteriosus is present in adults

Back 16

false

the ductus arteriosus is PRESENT in embryos, but DISAPPEARS in adults

Front 17

The section of the dorsal aorta between the third and fourth arches, the ______, often persists in adults. (amphibians)

Back 17

carotid duct.

Front 18

Non-archosaurian reptiles

slide 8

The conus arteriosus becomes incorporated into the ___ and no longer functions as a separate chamber

Back 18

ventricle

Front 19

non-archosaurian reptiles

Once the vental aorta becomes tripartite, going from right to left, the first branch gives off the _________(derived from the 6th arch), which crosses in front of the other two divisions becomes the left and right ____.

The next division becomes the _____(derived from the left side of the fourth arch) and crosses over to the left to form part of the _____.

Back 19

pulmonary trunk
pulmonary arteries

systemic arch
dorsal aorta

Front 20

Non archosaurian reptiles

slide 8

The division on the left crosses over to the right and first gives off the left and right common _____, the continues on to become the right _______, joining with one on the left to become the dorsal aorta.

Back 20

carotid arteries

systemic artery

Front 21

Non-archosaurian reptiles

Why is there so much crossing over?

Back 21

Although these reptiles have a completely divided atrium, they still have an incompletely divided ventricle

Front 22

Non archosaurian reptiles

slide 8

The interventricular septum is complete caudally, but opens cranially into an _________

Back 22

interventricular canal

Front 23

Non archosaurian reptiles:
slide 8
The blood left most part of the ventricle comes from the _____ and has had the _____ contact with the deoxygenated blood coming from the ____ atrium.

This arrangement ensures that the most oxygenated blood enters the carotid system and gets plenty of oxygen to the brain.

The more mixed blood in the center goes to the ____, and the oxygen depleted blood from the right atrium goes to the ___

Back 23

left atrium
least
right atrium

systemic circuit
pulmonary circuit

Front 24

what is the purpose of shunts of the circulatory system of non-archosaurian reptiles?

Back 24

To divert blood away from the lungs instead of expending engergy to send blood to the lungs when they are not being ventilated

Front 25

Which vertebrates have partially divided hearts?

Back 25

lungfish
amphibians
most non avian reptiles

Front 26

The ventricle of amphibians is undivided but studies have shown that oxygenated and deoxygenated remain largely separated.

How is this possible?
(2 reasons)

Back 26

1) timing of blood flow into and out of the ventricle

2)by a system of valves that direct blood differently according to its oxygen content.

Front 27

Which vertebrates has a complex spiral valve in the ventral aorta?

(hint: their truncus arteriosus separate betweeen carotid,systemic, and pulomonary arteries)

Back 27

Amphibians

Front 28

Non-archosaurian reptiles

In order to help direct the blood to the right place the heart of non-archosaurian reptiles have positions of the different parts of the ventral aorta (tripartite).

In addition to this, what exists to help direct blood to the right circuit?

Back 28

there are also valves near the opening of the ventricle

Front 29

Slide 9-10
non archosaurian reptiles

Surrounding the interventricular canal, there is an ______________.

Explain what happens when this valve has fliped down and what happens when this valve is fliped up.

Back 29

atrioventricular valve

down:

-blocks the interventricular canal
-prevents blood from moving between the left and right sides of the ventricle

up:

-prevents blood from flowing from the atria to the ventricles
-but opening the interventricular canal allowing oxygenated and deoxygenated blood to mix.

Front 30

Non archosaurian reptiles slides 9-10

When the ventricle is filling is the fliped up or down?

what is the result of this?

Back 30

When the ventricle is FILLING, the valve is fliped DOWN, and deoxygenated blood fills the right side of the venticle and oxygenated blood fills the left, but the two do not mix.

Front 31

Non archosaurian reptiles slide 9-10

As the ventricle starts to contract, is the valve fliped up or down?

what happens?

Back 31

The valve is fliped UP, opening the interventricular canal preventing backflow into the atria

Front 32

Non archosaurian reptiles
slide 11

During normal conditions where lungs are being used, which circuit has a lower resistance (pulmonary or systemic)?

Therefore, deoxygenated blood, as well as, blood from the left is pulled in what direction (which artery)?

Explain how this causes blood to become saturated with oxygen.

This is called a _to _ shunt
-transfers blood from __to__circuit.

Back 32

Because resistance in the pulmonary circuit is lower that in the systemic circuit, the deoxygenated blood is drawn preferentially into the pulmonary artery, but blood from the left is also pulled in that direction. Some of the oxygenated blood from the left side of the ventricle is recycled back to the pulmonary circuit, thoroughly saturating the blood with oxygen.

This is called a left to right shunt

Transfers blood from the systemic to the pulmonary circuit.

Front 33

Non archosaurian reptiles slide 11

During apnea (lungs are not being ventilated), what happens to the resistance to blood flow in the lungs?

Therefore which circuit has less resistance?

In this case where does the blood in the right side of the ventricle flow through?

This is called a ___to ___shunt, where blood is transferred from ____to ___circuit.

Back 33

when the lungs are not being ventilated, the resistance to blood flow is increased in the lungs because of the constriction of the blood vessels there, so that the resistance of the systemic circuit is less than that of the pulmonary circuit.

In this case the blood in the right side of the ventricle flow preferentially through the two systemic arteries and the lungs are bypassed.

This is called a right to left shunt and transfers blood from the pulmonary to systemic circuit.

Front 34

crocodilians (slide 12)

what is the major difference in the circulatory system of the crocodilians and the other reptiles?

Back 34

crocodilians have a fully divided ventricle

their interventricular septum is complete

Front 35

Crocodilian slide 12

venous blood comes in through the _____, into the _____where it gets pumped through the pulmonary artery out to the ____. Blood then returns to the heart through the pulmonary veins and into the ____, then finally into the ____. (hint exactly the same as in mammals)

but after this circulation is very different form mammals

Back 35

right atrium
right ventricle
lungs
left atrium
left ventricle

Front 36

Crocodilians slide 12

Where does the right systemic arch emerge from?

where does the left systemic arch come out of? the pulmonary artery?

Back 36

right systemic arch: emerges from the left ventricle

left systemic arch & pulmonary artery come out of the right ventricle

Front 37

Crocodilians slide 12

The right and left systemic arches are joined by an opening called the ______ .

Back 37

FORAMEN OF PANIZZA

Front 38

Crocodilians slide 12

when a crocodilian is at rest and breathing air

which ventricle has greater pressure?

So blood is forced through the _____, and into the ____ systemic arch.

what happens next?

Back 38

the pressure from the left ventricle is greater that from the right,

so blood is forced through the foramen of panizza and into the left systemic arch.

the high pressure in the left systemic arch closes off a valve at the base of the vessel, leaving the pulmonary artery as the only exit from the right ventricle.

right and left systemic arches carry highly oxygenated blood.

Front 39

Crocodilians slide 12

when the animal is not breathing, the pressure in the right ventricle _____ due to the high resistance in the lungs when the vessels constrict.

In this case, the pressure in to the left systemic arch is ____than in the right systemic arch and blood is forced through the foramen of panizza from the ____systemic arch to the ___systemic arch, (hint : bypassing lungs)

this is another example of what kind of shunt?

Back 39

increases

greater

left
right

right to left in which lungs are by passed

Front 40

Bird slide 13

t or f

both birds and mammals ventilate their lungs continuously and there is no need for any sort of shunting system to bypass the lungs

Back 40

true

Front 41

Birds slide 13

Birds and mammals are both very active ____animals and they have both independently evolved circulatory systems with ______pulmonary and systemic circuits in adults

Back 41

endothermic
completely separate

Front 42

birds only use one systemic arch, retaining only the ____arch and losing the ____entirely

Back 42

retaining right

losing the left

Front 43

birds have a similar pattern in the other arches to that in reptiles. The third arch gives rise to the _____system.

(hint: in birds the subclavian arteries that go out to the wings also arise from the third arch)

The right side of the ___aortic arch becomes the single aorta in birds and the sixth, as in all tetrapods, becomes the ______.

Back 43

carotid

4th
6th: pulmonary artery

Front 44

slide 14

mammals have convergently lost one of the two sides of the systemic arch and a single aorta, but they retain the ___ systemic arch rather than the ____ as in birds.

Back 44

retain: left

right

Front 45

mammals
slide 14

unlike in birds, in mammals the side of the systemic arch that does not become the aorta is retained, but it loses its caudal connection to the aorta and become the ______that supplies the ____forelimb

Back 45

subclavian

right

Front 46

Mammals

the left subclavian branches separately from the arch of the ____. the 3rd arch becomes the ______. and the 6th the _____

Back 46

aorta

carotid arteries

pulmonary