Chapter 42 Flashcards

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1
Q

Ventilation

A

air or water moves through specialized
gas-exchange organ (lungs or gills, etc

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1
Q

Gas exchange

A

CO2 & O2 diffuse between air or water
& blood at respiratory surface

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2
Q

circulation

A

dissolved O2 & CO2 are transported
throughout body

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3
Q

Where gas exchange (diffusion) between blood and cells occur

A

Tissues where cell respiration occurs

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4
Q

How does gas exchange occur between environment and cells

A

Diffusion since

Oxygen is high in environment; low in tissues

Carbon dioxide is high in tissues; low in environment

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5
Q

Gills

A

outgrowths of body surface in aquatic animals

Have extremely large surface area for gasses to diffuse across extremely thin epithelium

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6
Q

Invertebrate gills

A

diverse; can be external or internal

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7
Q

Bony fish gills

A

Have internal gills on both sides of head

Water must be driven over them

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8
Q

How do fish ventilate gills

A

by opening & closing their
mouth & operculum (stiff flap over gills)

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9
Q

Ram ventilation

A

Process where fast swimmers force water through gills by swimming with
mouths open

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10
Q

Countercurrent
exchange system

A

Flow of blood
through capillaries is
in opposite direction
to flow of water over
gill surface; sets up

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11
Q

What does Countercurrent exchange system create

A

large pressure differences of oxygen & carbon dioxide in water vs blood

result is efficient exchange of gases over gills!

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12
Q

Insect tracheal system

A

Contains tracheae-series of tubes extending throughout body; connects to exterior through openings (spiracles)

Trachae allow gas exchange to take
place directly across cells’
plasma membranes; circulatory
system NOT involved

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13
Q

Vertebrate lung process

A
  1. Air enters through lungs
  2. Trachea carries inhaled air to tubes called bronchi; bronchi branch into even narrower tubes (bronchioles)
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14
Q

Bronchi lung structure

A

Mammal lungs divided into tiny sacs called alveoli that greatly increase surface area for gas

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15
Q

Negative pressure ventilation

A

Occurs in only mammals

Pumping action achieved by muscle - diaphragm

Inhalation: Diaphragm contracts, ribcage expands as rib muscles contract

Exhalation: Diaphragm relaxes (moves up) as rib muscles relax

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16
Q

Functions of blood

A

-Transport oxygen & carbon dioxide
– Transport nutrients to cells from digestive system
– Convey hormones to target tissues & organs
– Deliver cells of immune system
– Distribute heat

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17
Q

Structure of blood

A
  • Platelets- cell fragments that minimize blood loss
    – White blood cells (WBCs)- part of immune system
    – Red blood cells (RBCs) transport oxygen from lungs to body tissues; participate in transporting carbon dioxide from tissues to lungs
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18
Q

Hemoglobin

A

Oxygen carrying molecule in red blood cells

Consists of four polypeptide chains, each has iron (Fe2+) containing group (heme)

Each hemoglobin can bind up to four O2 molecules

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19
Q

Carbonic anhydrase

A

Catalyzes the formation bicarbonate ions & hydrogen ions from Co2

Important because it maintains a strong partial pressure gradient favoring the entry of more CO2 into the red blood cells

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20
Q

How is CO2 transportaed in the plasma

A

It is transported in form of bicarbonate ion, HCO3−

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21
Q

What do protons produced by carbonic anhydrase do?

A

Induce Bohr shift, or acidity makes hemoglobin more likely to release oxygen

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22
Q

How does Pco2 in blood drop?

A

when CO2 converted to bicarbonate, maintaining strong partial pressure gradient favoring entry of Co2 into RBCs

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23
Q

How tiny and large animals maximize diffusion

A
  • Tiny animals have small enough volume that diffusion over body surface is adequate to keep them alive

– Larger animals require a circulatory system in order to achieve a large ratio of surface area to volume

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24
Q

What are walls of arteries or areries made of

A

Smooth muscle tissue since it allows for elasticity of vessels

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25
Q

Aorta

A

Largest artery; receives blood directly from heart

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26
Q

What do the sphincters?

A

Muscles in arterioles that allow diameter of vessel to be regulated

27
Q

Where are capillaries located

A

in circulatory system where materials
are exchanged between blood & other tissues

28
Q

Structure of veins

A

thinner walls & larger interior diameters than
arteries because blood is under relatively low pressure when it leaves the body tissues

29
Q

What helps the return of blood in veins

A

Compressing of skeletal muscle in extremities and valves - thin flaps of tissue that
prevent backflow of blood

30
Q

Open system

A

fluid pumped by heart(s) throughout body
in open vessels, hemolymph comes in direct contact with body tissues (most invertebrates)

31
Q

Closed system

A

fluid (blood) flows in continuous circuit
of closed vessels via pumping action of heart (vertebrates)

32
Q

2 chambers of heart

A
  1. Atrium receives blood returning
    from circulation
  2. Ventricle generates force to
    propel blood through system
33
Q

What heart structure does fish contain

A

2-chambered heart with a single circulatory circuit

34
Q

Double circulatory system

A

Land vertebrates have this

Contains

  1. Pulmonary circulation:
    to & from lungs
  2. Systemic circulation: higher-pressure circuit
    to & from rest of body
35
Q

How are pulmonary circulation and systemic circulation separated

A

4 chambered hearts in birds and mammal

Partially separated into 3 chambered hearts in amphibians

36
Q

Pulmonary and Systemic circulation process

A

Flow of blood

  1. Body to right atrium via superior vena cava
  2. Right atrium to right ventricle via right AV vale
  3. Right ventricle to lungs via pulmonary valve and pulmonary artery

Systemic circulation
4. Oxygenated blood from lungs to left atrium via pulmonary veins
5. Left atrium to left ventricular via left AV valve
6. Left ventricle to body via aorta and aortic valve

37
Q

Diastole

A

relaxation, or filling, phase

38
Q

Systole

A

contraction, or pumping phase

39
Q

What might be the function of the muscle contraction in the walls of veins?

A

Muscle contraction reduces the volume of veins, increasing blood pressure and, thereby, increasing the velocity of blood flow.

40
Q

Where is the velocity of blood flow the slowest in your body?

A

The very high total cross-sectional area of capillaries means that blood flow there is very slow, providing opportunity for diffusion into and out of the blood.

41
Q

Disadvantage of breathing air

A

Can dehydrate animal tissues exposed to air at the respiratory surfaces.

42
Q

What promotes oxygen release from hemoglobin

A

An increase in carbonic anhydrase activity

A decrease in pH

Oxygen-rich tissues

43
Q

Bohr effect

A

hemoglobin’s lower affinity for oxygen secondary to increases in the partial pressure of carbon dioxide and/or decreased blood pH.

44
Q

Disadvantages of open circulatory system

A
  1. Because the pressure is lower in an open circulatory system, there is a slower flow of hemolymph.
  2. An open circulatory system cannot direct the hemolymph toward specific organs.
45
Q

Partial pressure of oxygen or PO2 meaning

A

Measurement of oxygen pressure in arterial blood

Indicates how well oxygen is able to move from the lungs to the blood

46
Q

What is the main factor for controlling ventilation rate in mammals

A

Change in partial pressure of Co2 in blood

Partial pressure of Co2 can increase while exercising, thus increasing ventilation rate

47
Q

In insects, what is the adaptive significance of spiracles?

A

They close off tracheae to minimize water loss.

48
Q

Primary function of nasal cavity

A

Warm, filter, humidify air

49
Q

What happens if hydrogen ions are not carried by hemoglobin

A

The hydrogen ions could reduce the ph or increase the acidity of the blood

50
Q

Which barrier(s) must O2
and CO2 cross to pass between air and blood inside lungs?

A

capillary wall
epithelial cells
extracellular fluid

51
Q

What is the driving force for the diffusion of oxygen into tissues?

A

Difference in PO2 levels between the blood (100 mm Hg when oxygenated) and body tissues (40 mm Hg at rest).

52
Q

What is cooperative binding

A

When the binding of one oxygen molecule to hemoglobin stimulates the binding of other oxygen molecules.

53
Q

What happens during inhalation

A
  1. The diaphragm and rib muscles contract, increasing the volume of the lungs.
  2. Air enters the nose or mouth and flows down the trachea, bronchi, and bronchioles, and into the alveoli.
54
Q

What happens during exhalation

A

The diaphragm and rib muscles relax, decreasing the volume of the lungs.

Air leaves the alveoli and flows up the bronchioles, bronchi, and trachea, and exits through the nose or mouth.

55
Q

Why is cooperative binding of oxygen to hemoglobin an important adaptation for gas exchange

A

allows hemoglobin to release much more oxygen to an animal’s body tissues.

56
Q

What happens as blood flows through the lungs

A

There is a decrease in blood pressure

57
Q

Why do vertebrates have separate circuits to lungs and rest of body

A

The changes in blood pressure as blood moves through the lungs of land-dwelling vertebrates make it necessary to have
separate circuits to the lungs and the rest of the body.

58
Q

What structure prevents backflow of blood into atria

A

Valves

59
Q

What happens in the diastole phase of heart

A

Relaxation phase of heart where chambers of the heart are relaxed and blood can enter them passively.

60
Q

Which event of the cardiac cycle occurs when systolic blood pressure is measured

A

The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria since systolic blood pressure is peak blood pressure, resulting from contraction of the ventricles

61
Q

What is hemoglobin most likely to bind too

A

Most likely to bind to oxygen where the partial pressure is high like in the lungs, and is more likely to release oxygen when it the pO2 is lower

62
Q

What is the cause of enlarged hearts in people with cardiovascular disease

A

In people with cardiovascular disease, the heart muscle often enlarges as it works harder to pump blood through hardened arteries.

63
Q
A
64
Q
A