Animal: Lecture 5

Question 1

Diffusion is only rapid over..?

Answer 1

Diffusion is only rapid over short distances.

Question 2

Molecules move randomly?

Answer 2

Molecules move randomly due to their kinetic energy.

Question 3

What does random movement cause?

Answer 3

Random movement causes a new flow from an area of high concentration to an area of low concentration.

Question 4

Rate of diffusion proportional to distance?

Answer 4

Rate of diffusion is inversely proportional to distance.
- further distance = slower rate
- shorter distance = faster rate

Question 5

Water example?

Answer 5

a. Crystal of due is placed in water
b. Diffusion of water and dye molecules occurs
c. Equal distribution of molecules results.

Question 6

Movement of particles is always?

Answer 6

Movement is random, but will always even out.
- always moves from high to low.

Question 7

Diffusion is also affected by?

Answer 7

Diffusion across a surface is also affected by the area of the surface (ex. cell membrane)

Question 8

Rate of diffusion, surface area, and distance?

Answer 8

Rate of diffusion and surface area are proportional to one another.

Rate of diffusion and distance are inversely proportional to one another.

Question 9

To maximize diffusion rate, exchange surfaces should have..?

Answer 9

A large surface area and be thin.

Question 10

Cells must do what with the environment?

Answer 10

Each cell in a multicellular organism must exchange molecules with the environment.
- Molecules include nutrients, gases, and water, which must be brought in
- Waste must be able to get out.

Question 11

How many strategies are there for allowing the exchange of molecules with the environment?

Answer 11

There are two different strategies that allow animals to need to be able to bring things in and out.

Question 12

Staying small strategy?

Answer 12

Some animals have a body size and shape that keeps most cells in contact with the environment (environment might be the lining of the gut or outside of the organism).
- these are SMALL animals

Question 13

Planaria and flatworm?

Answer 13

Small and flat shape of them allows them to exchange nutrients so that almost all cells are in contact with the environment.
- This means that there is no need for a circulatory or respiratory systems.
- they are abosolutely tiny (~7mm)

Question 14

Large animals?

Answer 14

Animals with many cell layers require a circulatory system to transport materials between all the body cells and the organs that exchange those materials with the environment.

Note: materials only need to diffuse over short distances as they enter or exit the circulatory system. By the time that blood reaches the cels, they are really small in distance - therefore exchanges can occur over small distances.

Question 15

How is the circulatory system connected to everything else?

Answer 15

The circulatory system is connected to everything else, and transports materials all throughout the body.

Question 16

Animals exhibit variation in their circulatory systems… but have what?

Answer 16

Animals exhibit much variation in their circulatory systems, but all have three basic components.

Question 17

What are the three basic components that all have?

Answer 17

1. A circulatory fluid
2. Set of interconnecting vessels
3. A muscular pump.

Question 18

Circulatory fluids ?

Answer 18

• Blood in a closed circulatory system (closed means enclosed in the vessels). Ex. Mammals, birds, earthworms, fishes, octopi.
• Hemolymph in an open circulatory system (mix of open cavities with organs and closed vessels that carry it around the body). Ex. crabs, insects, spiders.

Question 19

Se of interconnecting fluids?

Answer 19

They bring fluids parts of the body.

Question 20

Muscular pump?

Answer 20

Ex. heart - pumps fluid for circulation

Question 21

Open system?

Answer 21

Everything is open in cavities. Hemolymph is in the sinuses surrounding the organs. They’re are smaller pores, which open into sinus cavities. Then, they exchange fluid.

Question 22

Closed system?

Answer 22

Heart pumps blood into the vessels and through them and capillaries in a closed loop. All blood is contained in the vessels and nutrients have to cross the interstitial fluid to move from one area to another.

Question 23

Double circuit?

Answer 23

There are two circuits of flow to and from the heart.
- Pulmonary: leads to lungs and allows blood to become oxygenated.
- Systemic: leads to the body and allows the bodily mechanisms to function.

Question 24

Blood mixing?

Answer 24

Oxygenated and deoxygenated blood do not mix within the heart. This is very important as it keeps use healthy.

Question 25

Blood circuit in heart?

Answer 25

1. Deoxygenated blood returning from the systemic circuit enters via the superior (head) vena cava and the inferior (legs) vena cava. 2. The blood flows into the right atrium. 3. When the right atrium contracts, blood is pushed into the right ventricle. 4. When the right ventricle contracts, blood is pushed into the pulmonary arteries, sending it to the lungs. 5. Oxygenated blood returns from the pulmonary circuit and enters via the pulmonary veins. 6. The blood flows into the left atrium 7. When the left atrium contracts, blood is pushed into the left ventricle. 8. When the left ventricle contracts, blood is pushed into the aorta (largest artery) sending it to the systemic circuit (brain, limbs, etc.)

Question 26

Veins and arteries?

Answer 26

Veins ~> toward heart Arteries ~> away from heart

Question 27

What are valves?

Answer 27

Valves ensure unidirectional flow of blood through the heart by closing to prevent back flow. - There are two kinds of valves!

Question 28

Atrioventricular (AV) valves?

Answer 28

Separate the atria from the ventricles and prevent backflow into atria when the atria relax and ventricles contract

Question 29

Semilunar valves?

Answer 29

They look like half-moons. Separate ventricles from the arteries and prevent backflow into the ventricles when the ventricles relax

Question 30

The cardiac cycle?

Answer 30

Right and left happen at the same time. 1. Atrial and ventricular diastole (0.4) 2. Atrial systole and ventricular diastole (0.1) 3. Ventricular systole and atrial diastole to push blood out of the arteries (0.3)

Question 31

Diastole and Systole?

Answer 31

Diastole = relaxation Systole = contraction

Question 32

Blood vessel structure...?

Answer 32

Reflects their functions.

Question 33

Artery components and why they are the way they are?

Answer 33

They have three layers of tissues: 1. Endothelium 2. Smooth muscle 3. Connective tissue - The layers are thicker on arteries than veins. - They are thicker to withstand pressures that help them stay firm. - Speed slows down as we progress from artery to capillaries.

Question 34

Capillary components?

Answer 34

Made up of two "layers" 1. Endothelium 2. Basa lamina (membrane) - Allows easy diffusion of nutrients and gases - Has to slow down here - Causes pressure to decrease greatly.

Question 35

Vein components and why they are the way they are?

Answer 35

Made up of three layers: 1. Endothelium 2. Smooth muscle 3. Connective tissue - Lines the inside of the vessel - A lot thinner because not much pressure - Large because it's better to do it one go. - Flow has rot speed up here, which is very possible with this structure.

Question 36

How does area change from aorta to venae cavae?

Answer 36

Increased branching increases area: capillaries have greater area than arteries and veins. - Looks like a bell curve

Question 37

How does velocity change from aorta to venae cave?

Answer 37

Same volume of fluid flows more slowly through a greater area: velocity is slowest within the capillaries. - This facilitates the rate of diffusion - Can't be too fast at capillaries for gas exchange.

Question 38

How does pressure change from aorta to venae cavae?

Answer 38

The increase in area in the capillaries causes pressure to drop off. Blood is not re-pressurized until it returns to the heart.

Question 39

What is blood flow regulated y?

Answer 39

Blood flow is regulated by nerve impulses, hormones, and local chemicals that affect arteriole diameter and pre-capillary sphincters.

Question 40

Relaxed vs contracted sphincters?

Answer 40

Relaxed: blood flow can spread to capillaries (all of them). Contracted: blood flow is direct, as sphincters are closing off some capillaries.

Question 41

How many capillaries are active at any given time?

Answer 41

At any one time, only about 5-10% of the body’s capillaries have blood flowing through them.

Question 42

What allows for the exchange of materials between blood and interstitial fluid?

Answer 42

Thin capillary walls and slow blood velocity allow for exchange of materials between blood and interstitial fluid. Items from the capillaries have to cross the interstitial fluid to get to body cells (a short distance is advantageous).

Question 43

Blood is a...?

Answer 43

Blood is a tissue consisting of cells suspended in a liquid called plasma.

Question 44

55% of blood is..?

Answer 44

Plasma makes up 55% of the blood. Plasma consists of: - Water - Ions - Proteins - Nutrients, metabolites, and wastes

Question 45

45% of blood is..?

Answer 45

Cellular elements make up 45% of blood. Cellular elements include: - Erythrocytes (red blood cells) - Leukocytes (white blood cells) - Platelets

Question 46

Circulatory systems require energy and materials to build and run.... so why didn't all animals just stay small/simple?

Answer 46

A. Larger animals with circulatory systems exchange materials more efficiently than small/simple animals B. Increasing size and complexity allows animals to exploit new niches C. Bigger is always better! ANSWER: B

Question 47

During the fight or flight response, in which organs would you expect the hormone epinephrine to constrict the arterioles and pre-capillary sphincters?

Answer 47

A. Brain B. Intestine C. Skeletal muscle D. Skin E. Lungs ANSWER: B and D

Question 48

What are respiratory surfaces specialized for..?

Answer 48

Respiratory surfaces are specialized for gas exchange. Ex. Gills, tracheae, and lungs

Question 49

Gills, tracheae and lungs all have?

Answer 49

1. Very large surface areas * Greater than rest of body exterior (e.g., 50x greater than skin in humans) 2. Very thin exchange surfaces * A single epithelial layer (allows easy diffusion)

Question 50

Respiratory media vary in..?

Answer 50

Respiratory media vary in their O2 concentration. Respiratory media (source of O2): - Air has a high concentration of O2 (21%) - Water has a much lower concentration of O2 (<1%)

Question 51

Animals obtaining from different respiratory media?

Answer 51

Animals that obtain O2 from water need to be much more efficient than animals that obtain O2 from air – 80% vs. 25%

Question 52

Gills efficiency?

Answer 52

Gills are efficient at extracting O2 but are unsuitable in terrestrial environments

Question 53

Respiratory surfaces must be..?

Answer 53

Respiratory surfaces must be moist Respiratory surfaces of terrestrial animals are enclosed within the body to prevent excess water loss – E.g., Tracheae and Lungs

Question 54

Mammalian Respiratory System?

Answer 54

- Pharynx - Larynx - Trachea (large tube) - Bronchus/Bronchi (two smaller tubes) - Bronchiole (smallest branches) - Diaphragm (controls when we inhale and exhale) - Alveoli (where the gas exchange occurs and blood becomes oxygenated) are covered in capillaries that supply the deoxygenated blood.

Question 55

Red blood cells are packed with what protein..?

Answer 55

Red blood cells are packed with the protein hemoglobin. - This is why the circulatory and respiratory systems are linked!

Question 56

O2 binds to hemoglobin?

Answer 56

O2 has a natural tendency to bind to hemoglobin for transport in red blood cells.

Question 57

Process O2 binding to hemoglobin?

Answer 57

Oxygen from lungs goes through cell membrane, attaches themselves to the hemoglobin and can then be transported throughout the body. Oxygen is released to tissue cells - when going through respiration there is a hostile (hot and acidic) environment. This change released O2 from hemoglobin, which causes the necessary drop off off the O2 to cells that need it.

Question 58

Shape and mechanics of hemoglobin?

Answer 58

Hemoglobin has our oxygen binding sites which will hold 4 O2. - They have iron built in as well, which is why we need to maintain our iron levels for effective blood flow.

Question 59

Red blood cells are also important for CO2 transport?

Answer 59

CO2 (waste of cellular respiration) produced in body cells travels: 1. bound to amino acids of hemoglobin (23%) 2. in blood plasma as CO2 (7%) 3. In blood plasma as bicarbonate (HCO3-) (70%) CO2 + H2O ⇌ H2CO3 ⇌ HCO3- + H+

Question 60

Process of loading and unloading respiratory gases?

Answer 60

1. Inhaled air 2. Alveolar spaces 3. Pulmonary veins 4. Systemic arteries 5. Body tissue 6. Systemic veins 7. Pulmonary arteries 8. Exhaled air

Question 61

Circulatory systems are necessary?

Answer 61

Circulatory systems are necessary because diffusion is only rapid over very short distances.

Question 62

Circulatory systems consist of? q

Answer 62

Circulatory systems consist of a pump, vessels, and a circulatory fluid; most vertebrates have double circulation (systemic and pulmonary)

Question 63

Blood vessel structure reflects?

Answer 63

The function.

Question 64

Exchange surfaces tend to..?

Answer 64

Exchange surfaces tend to be thin and have a large surface area.

Question 65

Hemoglobin is..?

Answer 65

Hemoglobin is the blood protein that transports O2 (as well as some CO2).