Chapter 36

Question 1

What is Respiration?

Answer 1

The physiological process by which an animal exchanges oxygen and carbon dioxide with its environment.

Question 2

What is Respiration dependant on?

Answer 2

It depends on the tendency of gaseous oxygen and carbon dioxide to diffuse down their concentration gradients between the external and internal environments.

Question 3

True or False: More O2 dissolves in cooler, fast flowing water than in warm, still water.

Answer 3

True.

Question 4

What is a Respiratory Surface?

Answer 4

A moistened layer thin enough for gases to diffuse across, this is where gases enter and exit an internal environment. Gases diffuse only across small distances, and only if dissolved in liquid.

Question 5

What three factors affect diffusion rates?

Answer 5

1. Surface to Volume Ratio - more molecules diffuse across a large respiratory surface than a small one. 2. Ventilation - moving air or water past a respiratory surface keeps the pressure gradient across the surface high and thus increases the rate of gas exchange.3. Respiratory Proteins - they help maintain a steep partial pressure gradient for oxygen between the cells and blood.

Question 6

What are Respiratory Proteins?

Answer 6

Proteins that house one or more metal ions that bind oxygen atoms when oxygen levels are high and release them when oxygen levels fall.

Question 7

List the two Respiratory Proteins.

Answer 7

1. Hemoglobin - an iron-containing respiratory protein that occurs in vertebrate red blood cells and circles freely in other organisms. Hemerythrin (iron) or hemocyanin (copper) is used in other invertebrates.2. Myoglobin - a heme-containing protein in muscle of vertebrates and some invertebrates that helps stabilize the oxygen level inside cells.

Question 8

What is Integumentary Exchange?

Answer 8

A mode of respiration that occurs in small-bodied invertebrates of aquatic or continually moist habitats where gases just diffuse across the body surface covering (the integument). This is the simplest form of respiration.

Question 9

What do many aquatic invertebrates call their thin-walled, moist respiratory organs?

Answer 9

Gills. Extensively folded gill walls increase the respiratory surface area and gas exchange rates between body fluids and the outside.

Question 10

What is a Tracheal System?

Answer 10

An internal respiratory surface that consists of repeatedly branching, air-filled tubes. They have no need for respiratory proteins to carry gases.

Question 11

What are Book Lungs and what can they be found in?

Answer 11

They can be found in spiders; book lungs are respiratory organs where the air and blood flow through spaces separated only by thin sheets of tissue. Hemocyanin is used.

Question 12

What is a defining trait of chordates?

Answer 12

Gill Slits (openings across a pharynx).

Question 13

True or False: Most adult fish have external gills.

Answer 13

False, most adult fish have internal gills located inside a slit or a pouch that opens to the body surface.

Question 14

What is Countercurrent Exchange? (Happens in fish)

Answer 14

A process where two fluids flow in opposite directions and exchange substances. It boosts the oxygen uptake from water.

Question 15

What is this? A saclike respiratory organ located inside a body cavity and connected by airways to the outside air.

Answer 15

The lung.

Question 16

True or False: Reptiles, birds, and mammals have waterproof skin and no gills as adults and exchange gases in two well-developed lungs.

Answer 16

True, chest muscles draw the air inward. The respiratory surface area is large and serviced by many blood capillaries.

Question 17

True or False: Birds exchange gas at the ends of the smallest airways.

Answer 17

False. In reptiles and mammals gas exchange occurs at the ends of the smallest airways, but in birds there are no “dead ends” and instead there are tiny tubes that convey air through the lungs to air sacs that serve as the respiratory surface.

Question 18

What role does the rib cage have in respiration?

Answer 18

Their rhythmic contraction and relaxation cause air to move into and out of the paired lungs.

Question 19

List some of the additional roles of the respiratory system.

Answer 19

The human respiratory system functions in gas exchange. It also has roles in sense of smell, voice production, body defenses, acid–base balance, and temperature regulation.

Question 20

What is the Oral Cavity?

Answer 20

The mouth, supplemental airway when breathing is laboured.

Question 21

What is the Nasal Cavity?

Answer 21

Chamber in which air is moistened, warmed, and filtered, and in which sounds resonate.

Question 22

What is the Pharynx?

Answer 22

The throat, an airway connecting nasal cavity and mouth with larynx; enhances sounds; also connects with esophagus.

Question 23

What is the Epiglottis?

Answer 23

Closes off larynx during swallowing.

Question 24

What is the Pleural Membrane?

Answer 24

Double layer membrane that separates lungs from other organs; the narrow, fluid-filled space between its two layers has roles in breathing.

Question 25

What is the Larynx?

Answer 25

The voice box, airway where sound is produced; closed off during swallowing.

Question 26

What is the Trachea?

Answer 26

The windpipe, airway connects larynx with two bronchi that lead into the lungs.

Question 27

What are the Intercostal Muscles?

Answer 27

At rib cage, skeletal muscles with roles in breathing. There are two sets of intercostal muscles (external and internal).

Question 28

What are the Lungs?

Answer 28

Lobed, elastic organ of breathing; enhances gas exchange between internal environment and outside air. Cone shaped and located in the thoracic cavity on either side of the heart.

Question 29

What is the Diaphragm?

Answer 29

A Muscle sheet between the chest cavity and abdominal cavity with roles in breathing. It can be controlled voluntarily.

Question 30

What is the Bronchial Tree?

Answer 30

Increasingly branched airways starting with two bronchi and ending at air sacs (alveoli [where gas is exchange]) of lung tissue.

Question 31

What are Vocal Cords?

Answer 31

A skeletal muscle with a cover of mucus-secreting epithelium.

Question 32

What is the Glottis?

Answer 32

The gap between the vocal cord that changes size when the vocal cords contract. An open glottis lets air flow through with no sound, as it narrows the vocal cords vibrate and the larynx’s position changes, letting sound happen.

Question 33

What is Laryngitis?

Answer 33

Overuse or infection has inflamed the vocal cords; the swollen cords cannot vibrate as they should, making speaking difficult.

Question 34

True or False: Air enters through the nose or mouth. It flows through the pharynx (throat) and larynx (voicebox) to a trachea that branches into two bronchioles, one to each lung.

Answer 34

True.

Question 35

Where do gases diffuse between an alveolus and a pulmonary capillary?

Answer 35

At the lung’s respiratory membrane, a thin membrane made up of alveolar epithelium, capillary endothelium, and fused basement membranes of the alveolus and capillary. Secretions keep the alveolus moist so gases can diffuse.

Question 36

What does the hemoglobin molecule consist of?

Answer 36

Four polypeptide chains, each with one heme group that has one iron atom (this reversibly binds O2).

Question 37

What is hemoglobin with oxygen bonded to it called?

Answer 37

Oxyhemoglobin, or HbO2.

Question 38

Which holds onto oxygen more tightly: Hemoglobin or Myoglobin?

Answer 38

Myoglobin, the O2 given up by the hemoglobin diffuses through cardiac muscle cels and binds to myoglobin. This O2 is released when blood flow cannot keep up with a cell’s O2 needs.

Question 39

True or False: Carbon dioxide diffuses into blood capillaries in any tissue where its partial pressure is higher than it is in blood.

Answer 39

True.

Question 40

What three forms is Carbon dioxide transported to the lungs in?

Answer 40

10% remains dissolved in plasma, 30% binds to hemoglobin to form carbaminohemoglobin (HbCO2), 60% is transported back as bicarbonate (HCO3-).

Question 41

What enzyme speeds the formation of HCO3-?

Answer 41

Carbonic anhydrase, an enzyme inside red blood cells.

Question 42

What happens when CO builds in the air?

Answer 42

It fills O2 binding sites on hemoglobin, preventing the transport of O2 and causing carbon monoxide poisoning.

Question 43

What is a respiratory cycle?

Answer 43

One breath in and one breath out. Inhalation is always active, and muscle contractions drive it.

Question 44

True or False: Exhalation is usually aggressive.

Answer 44

False, exhalation is usually passive. When the muscles that caused inhalation relax, the lungs passively recoil and lung volume decreases. This compresses alveolar sacs, causing the air pressure inside them to increase above atmospheric pressure. Air moves down the pressure gradient, out of the lungs.

Question 45

True or False: Exhalation is active only when you exercise vigorously or consciously attempt to expel more air.

Answer 45

True. During active exhalation, muscles of the abdominal wall contract, increasing the pressure and exerting an upwards directed force on the diaphragm. Internal intercostal muscles contract at the same time.

Question 46

Define Vital Capacity.

Answer 46

The maximum volume of air that the lungs can hold (averages 5.7L in a heathy adult).

Question 47

What is the term for the volume that moves into and out of lungs during a respiratory cycle?

Answer 47

Tidal volume, it averages about 0.5 L.

Question 48

What controls the rate and depth of breathing?

Answer 48

Respiratory centres in the the brain stem. A respiratory pacemaker establishes the initial rhythm, which is adjusted in response to changes in activity levels.

Question 49

True or False: Inhalation is always an active, energy-requiring process.

Answer 49

True. It primarily requires contractions of the diaphragm and the external intercostal muscles.

Question 50

What is apnea?

Answer 50

A disorder where breathing repeatedly stops and restarts spontaneously, especially during sleep. SIDS occurs when an infant does not wake from an apneic episode.

Question 51

True or False: Each time breathing stops, blood pressure soars.

Answer 51

True, this leads to an increase in risk for heart attacks and strokes.

Question 52

What is Mycobacterium tuberculosis?

Answer 52

The cause of tuberculosis, one third of the human population is infected by it. About 10% of them will develop the disease.

Question 53

What is Pneumonia?

Answer 53

A general term for lung inflammation.

Question 54

True or False: Human’s hemoglobin binds oxygen more efficiently than llamas.

Answer 54

False. Llamas are able to live at high altitudes because their hemoglobin binds oxygen more efficiently, and because their hearts and lungs are unusually large relative to their body size.

Question 55

Hypoxia is the result of what?

Answer 55

Also called cellular oxygen deficiency, occurs when people ascend too fast to high altitudes. The brain will command the heart and respiratory muscles to work faster, and people begin to breathe faster and more deeply. They hyperventilate, causing CO2 to be exhaled faster than it forms.

Question 56

True or False: People who grow up at low elevations develop more alveoli and blood vessels in their lungs.

Answer 56

False, people who grow up at high altitudes develop more alveoli and blood vessels. The heart develops larger ventricles and pumps greater volumes of blood.

Question 57

How can people adapt to higher altitudes?

Answer 57

Through acclimatization, the acute compensatory response that the body made to a markedly different environment slowly gives way to adjustments in cardiac output, the rhythmic pattern of breathing, and the magnitude of breathing. Acclimatization causes more red blood cells to form, which thickens the blood and can increase the risk of heart attacks.

Question 58

What is erythropoietin?

Answer 58

A hormone secreted by kidney cells that induces stem cells in bone marrow to divide repeatedly, and induces the descendant cells to develop as red blood cells. When hypoxia causes more to be secreted, the formation of red blood cells can be multiplied by six.

Question 59

What four things let certain animals dive longer than humans?

Answer 59

1. Deep breaths 2. Store great amounts of oxygen inside their blood and muscles3. More O2 is distributed to the heart, brain, and other essential organs. The metabolic rate and the heart rate decrease.4. The animal sinks and dives instead of actively swims.