Ch: 21 Circulation

Question 1

What is the difference between an open and closed circulatory system?

Answer 1

Open circulatory systems contain hemolymph or “interstitial fluid”

Closed circulatory systems contain blood

Question 2

What organisms contain an open circulatory system?

Answer 2

Arthropods and mollusks

Question 3

What organisms contain an closed circulatory system?

Answer 3

Annelids and vertebrates

Question 4

What are the most successful organisms in the world?

Answer 4

Arthropods

Question 5

Arteries carry blood __To/Away__ from the heart.

Answer 5

Arteries carry blood away from the heart

Question 6

What blood vessels contain the highest amount of resistance?

Answer 6

Arterioles

Question 7

What blood vessels is the speed of blood the slowest?

Answer 7

Capillaries

makes sense bc thats where the most O2 and nutrients are exchanged

Question 8

What blood vessels contain the LARGEST cross-sectional area?

Answer 8

Capillaries

more surface area = more nutrient exchange

Question 9

Capillaries converge into what is called a ______… which merge to form veins.

Answer 9

Venule

Question 10

Which of the following blood vessels is THICKER, contains MORE smooth muscle, and is more elastic?

A. Arteries
B. Veins

Answer 10

A. Arteries

Arteries have thicker walls and are more elastic than veins bc of blood pressure

Question 11

Which of the following blood vessels contains valves?

A. Arteries
B. Veins

Answer 11

B. Veins

Valves in the veins prevent backward flow of blood, while pressure from muscle contractions helps to move the blood through veins TOWARD the heart

Question 12

Which of the following blood vessels has the lowest blood pressure?

A. Arteries
B. Veins

Answer 12

B. Veins

Question 13

How many heart chambers are in the following organisms?

• Fish
• Reptiles and amphibians
• Mammals and birds

Answer 13

Fish = 2 chambered hearts (two-hearted ale)

Reptiles and amphibians contain 3 chambered hearts EXCEPT crocodiles and alligators (4 chambered)

Mammals and birds = 4 chambered hearts

“A MUST KNOW FOR THE DAT”

Question 14

Discuss each of the following terms:

1. Atria
2. Ventricle

Answer 14

Atria = upper chamber

Ventricle = lower chamber

Question 15

Discuss each of the following terms:

1. Superior Vena Cava
2. Inferior Vena Cava

Answer 15

Superior vena cava: brings blood low in O2 to right atria from UPPER body

Inferior vena cava: brings blood low in O2 to the right atria from the LOWER body

Question 16

Discuss each of the following terms:

1. Tricuspid valve
2. Mitral Valve (bicuspid)

Answer 16

Tricuspid valve: between left atria and right ventricle

Bicuspid valve (mitral): between left atria and left ventricle

Question 17

What is the Lub-Dup sounds of the heart indicate?

Answer 17

Lub: 1st sound; AV valves close

Dup: 2nd sound; Semilunar valves close

Question 18

What is the difference between systolic pressure and diastolic pressure?

Answer 18

Systolic = ventricles contract

Diastolic = ventricles relax

Question 19

***What type of muscle is the cardiac muscle?

Answer 19

***Mononucleated, striated, loads of mitochondria

Question 20

Which of the following is the pacemaker?

A. SA node
B. AV node

Answer 20

A. SA node

found in right atrium

Question 21

What is the pathway of the heart’s electrical system?

Answer 21

SA node –> AV node –> Bundle of His and Purkinje fibers

The ventricles contract when impulses reach the His bundles and Purkinje fibers

Question 22

What are the steps of blood flow through the heart?

Answer 22

1. Superior Vena Cava –> Right atrium
2. Right atrium –> Tricuspid valve
3. Tricuspid valve –> right ventricle
4. Right ventricle –> pulmonary artery –> out of heart
5. Pulmonary Vein –> left atrium –> Mitral (bicuspid)
   - -> left ventricle –> aortic valve –> Aorta –> out of heart

Question 23

What is the largest artery in the body?

Answer 23

Aorta

Question 24

Let us trace a drop of blood in the heart circuit:

What are the 5 steps

Answer 24

1. Blood from the upper and lower body is low in O2.. high in CO2, is brought to the Right Atria via the Superior and Inferior Vena Cava
2. Right Atria to the Right Ventricle through the Tricuspid valve
3. From the Right Ventricle, blood is propelled to the Right and Left Pulmonary Arteries, which are low in O2, and taken to the lungs
4. Blood is oxygenated within the lung capillaries and transported to the Left Atrium, via the Pulmonary Veins
5. Blood now goes from the Left Atrium to the Left Ventricle. Oxygenated blood now leaves the left ventricle thought the Ascending Aorta

Question 25

***In the lungs O2 and CO2 are exchanged in tiny sacs called _______.

Answer 25

Alveoli

Question 26

***What is the functional unit of the respiratory system?

Answer 26

Alveoli

Question 27

***Gas exchange in the lungs via alveoli occurs by _________ diffusion.

Answer 27

Passive

Question 28

Which of the following blood vessels is high in O2?

A. Pulmonary Artery
B. Pulmonary Vein

Answer 28

B. Pulmonary Vein

(Usually arteries are high in O2… but it is the opposite when it comes to the Pulmonary arteries and veins)

“FOR THE DAT”

Question 29

The RIGHT side of the heart carries _______ blood.

Answer 29

Deoxygenated

RIGHT = deoxygenated blood

LEFT = Oxygenated blood