Comparative Vertebrate Anatomy Lecture 21 Digestive System

Front 1

Evolution of the heart (slide 11)

Blood enters the right side from the superior and inferior __ ___ and enter the ___ ____.

The right atrium pumps blood into the ___ ____.

Between the right atrium and the right ventricle there are valves called the ______, which are supported by these strands called ______ which attach to muscles called _____ in the wall of the ventricle.

The tricuspid valves close as the ventricle contracts. where is the blood pushed through after this. (hint one valve 2 places)

The blood then returns to the heart through which blood vessels and into what chamber of the heart?

The left atrium is seperated from the left ventricle by a set of valves called the _____,

Blood then travels through another set of semilunar valves and up into the arch of the ____ to be distributed through the body.

Back 1

venae cavae

right atrium

right ventricle

tricuspid valves

chordae tendonae

papillary muscles

semilunar valves; pulmonary truck and the lungs

pulmonary veins; left atrium

bicuspid valves

aorta

Front 2

Shark Heart (slide 12)

Describe the difference in the appearance (apparent relative positions) in the shark heart and the mammalian heart

Back 2

While the shark heart looks like a tube with sequential chambers; the mammalian heart looks more like a solid mass of muscle with a bunch of chambers inside.

Front 3

Shark Heart (slide 12)

The shark heart is curved into an ___ with the ventricle ____ & the atrium ____

Back 3

S shape

ventral;dorsal

Front 4

Shark heart (slide 12)

Describe the possible process in which the shark heart evolved in to the mammalian heart

Back 4

imagine ends fixed in place;
heart enlarges and bunches up between the ends;
ventricle grows more than atrium pushing the atrium cranially;
the whole heart folds in itself resulting the the atrium cranial and dorsal to the greatly enlarged ventricle

Front 5

Fetal circulation of mammals (slide 13)

___ and ____ have similar mechanisms for bypassing the unused lungs.

When do these organisms begin to use their lungs?

Back 5

birds and "reptiles"

they begin to use the lungs gradually while they are still in the egg

Front 6

________ in mammals involves the most dramatic and sudden shift from the fetal arrangement to suddenly using the lungs

Back 6

fetal circulation in mammals

Front 7

Fetal circulation in mammals (slide 13)

Where does a mammalian fetus get its oxygen ?

Back 7

placenta

Front 8

In terms of fetal circulation of mammals, what is the first thing we need in order to deliver oxygen and carry away carbon dioxide?

Back 8

vessels going to and from the placenta

Front 9

Fetal circulation in mammals (slide 13)

Does oxygenated blood from the placenta mix deoxygenated blood coming back from the rest of the fetus, on is way to the heart?

Through which blood vessel does it arrive to the heart

Back 9

yes; inferior (caudal) vena cava

In the right atrium is mixes even before with deoxygenated blood coming from the head through the SUPERIOR (CRANIAL) VENA CAVA

Front 10

Fetal circulation of mammals (slide 13)

What 2 shunts allow blood to by pass the lungs?

The first is an opening in the interatrial septum called the ___ _____ the allows blood the pass directly from the right to left atrium.

Back 10

right to left shunts allow blood to by pass the lungs

Foramen ovale

Front 11

Fetal circulation in mammals (slide 13)

After blood passes the foramen ovale and passes directly to the left atrium, the blood that does enter the right ventricle gets pumps into the pulmonary artery, which has a direct connection with the aorta via the _______.

During fetal circulation explain why blood flows through the shunts.

Back 11

Ductus arteriosous

The resistance in the lungs is high because they are not being ventilated, so the blood will flow perferentially through the shunts

Front 12

Fetal circualtion in mammals (slide 13)

When a baby mammal is born abrupt changes occur in pressure of various regions of the heart as it takes its first breath.

As the lungs inflate, what happens to the resistance in the pulmonary circuit?

After the lungs inflate, blood from the right ventricle now goes the ____ instead of through the ______ to the body.

Back 12

the resistance in the pulmonary circuit decreases abruptly

lungs; ductus arteriosous

Front 13

Fetal circulation in mammals (slide 13)

Once the blood has gone to the lungs, a large volume of blood is returned to which chamber of the heart?

What happens to the pressure on the left side of the heart?

what is the immediate result of this event ?

Back 13

left ventricle

increase of pressure on the left side of the heart

snaps shut a vavle that closes off the foramen ovale

Front 14

Fetal circulation in mammals (slide 13)

After the Foramen ovale is closes off, the vavle eventually fuses to form a _____ & a small depression remains where the opening was called the ______.

The increase of pressure on the left side also reverses the flow in the ductus arteriosous. Describe the flow of blood before and after it is reversed.

The duct remain a short time after birth, the closes off to become the __________.

Back 14

complete interatrial septum

fossa ovalis

Rather than carrying from the pulmonary artery to the aorta (right to left shunt)
- it now carries the blood from the aorta back to the pulmonary artery and back through the lungs (left to right shunt)

ligamentum arteriosum

Front 15

Digestion

what a four sort of processes that digestion entails?

Back 15

-acquisistion of food
-mechanical/chemical breakdown of food
-absorbtion
-metabolism

Front 16

Digestion

What is one feature of vertebrates that permits the acquisition of large body size?

Back 16

extracellular digestion

rather than digesting minute particle of food within individual cells, we now have a whole system for food intake & processing

Front 17

what are two benefits of extracellular digestion?

Back 17

1) can eat larger food-opens up new resources
2) allows animals to get larger (for intracellular digestion nutrient have to reach all cells in the body)

Front 18

In vertebrates we see a system that combines __&__ to allow the evolution of a large body size.

Back 18

bulk flow & diffusion

Front 19

At its most basic level, vertebrate digestive systems consist of

1) A oral apparatus to bring food items into the system and in some cases begins the mechanical breakdown of the food.

2) a ______ _______ that continues the breakdown of the food items both mechanically and chemically (and is responsible for the absorption of nutrients.

name two others
and how they function

Back 19

gut tube
3) a system of glands that secrete enzymes into the gut tube for chemical breakdown of the food (also remove toxins)

4)and a part of the tube that eliminates indigestible wastes.

Front 20

Digestion:

what is the name of the primitive gut produced during gastrulation?

Back 20

archenteron

Front 21

Digestion

During development the gut tube becomes differentiated into the foregut, midgut, and hindgut.

3 major ___ ____ that supply blood to the gut tube and these correspond to the three developmental divisions of the gut.

Back 21

unpaired arteries

Front 22

Digestion

The ______ provides blood supply to the foregut region

The _______ to the midgut

& the _____is the blood supply to the hindgut.

Back 22

celiac artery-foregut
anterior mesenteric artery-midgut
posterior mesenteric artery-hindgut

Front 23

Digestion:

What parts of the tube make up the foregut? the hindgut? the midgut?

Back 23

foregut: pharynx, esophagus, &stomach

midgut: sm. intestine

hinggut: lrg. intestine

Front 24

Digestion


Where do all the structure that develop as outpocketings from the gut tube emerge from?

from the respiration lecture:
lungs and swim bladders develop as outpouchings (or diverticula) from the ____.

Back 24

foregut

pharynx

Front 25

Digestion

What two major digestive organs arise from the gut tube?

Back 25

liver and pancreas