Bio 6.4 Questions

Which conditions are correct for inspiration?

A. Muscles contracted: external intercostal Pressure in thorax: decreases

What occurs during the process of ventilation? A. Contraction of external intercostal muscles raises the ribcage. B. Relaxation of the abdominal muscles decreases the air volume in the lungs. C. Contraction of internal intercostal muscles raises the ribcage. D. Relaxation of the diaphragm decreases the air pressure in the lungs.

A. Contraction of external intercostal muscles raises the ribcage.

Which statement describes the movements of the rib cage during inhalation of air? A. External intercostal muscles contract moving the ribs up and outwards. B. Internal intercostal muscles contract moving the ribs down and inwards. C. External intercostal muscles relax moving ribs down and inwards. D. Internal intercostal muscles relax moving ribs up and outwards.

A. External intercostal muscles contract moving the ribs up and outwards.

What is the function of the structure labelled X? A. Gas exchange B. Ventilation C. Respiration D. Inspiration

A. Gas exchange

Where does gas exchange occur in the lungs? A. In type I pneumocytes B. In the bronchioles C. In the veins surrounding the alveoli D. In the surfactants

A. In type I pneumocytes

Which muscle action is associated with an increase in the volume of the thoracic cavity when breathing in? A. The diaphragm contracts. B. The external intercostal muscles relax. C. The internal intercostal muscles contract. D. The abdominal muscles contract.

A. The diaphragm contracts.

Which type of cell is specialized to facilitate gas exchange? A. Type I pneumocytes B. Type II pneumocytes C. Internal intercostal muscle fibres D. External intercostal muscle fibres

A. Type I pneumocytes

What changes take place in the thorax during inhalation?

B. External intercostal muscles contract Pressure decreases

The diagram shows the ventilation system in humans. What is the function of the structure labelled X? A. Protect the lungs B. Contract to cause inhalation C. Become flatter to move the ribcage up D. Relax in order to increase the thoracic capacity

B. Contract to cause inhalation

The graph shows the ventilation rate and the oxygen consumption of a subject before, during and after a period of exercise. Which could be a reason for the oxygen consumption to remain high for some time after the end of the period of exercise? A. Epinephrine keeps the ventilation rate high. B. Part of the exercise was done using anaerobic respiration. C. A low ventilation rate keeps the consumption high. D. More ATP is necessary for cross bridge formation while muscles cool down.

B. Part of the exercise was done using anaerobic respiration.

What normally prevents the membranes of the alveoli from sticking together during expiration? A. The thickness of the single-cell layer of alveoli membranes B. The secretion of fluids in the inner surface of the alveoli C. The pressure within the thoracic cavity D. The dense net of capillaries covering the alveoli

B. The secretion of fluids in the inner surface of the alveoli

Which muscles contract to cause air to pass into the lungs through the trachea? A. Internal intercostal muscles and diaphragm B. Internal intercostal muscles and abdomen wall muscles C. External intercostal muscles and diaphragm D. External intercostal muscles and abdomen wall muscles

C. External intercostal muscles and diaphragm

What change occurs to the pressure and volume of the lungs when the external intercostal muscles contract? A. Both pressure and volume increase. B. Pressure increases and volume decreases. C. Pressure decreases and volume increases. D. Both pressure and volume decrease.

C. Pressure decreases and volume increases.

What is a feature of alveoli? A. They occur in all animals because they are needed for gas exchange. B. They have a higher oxygen concentration than air in the atmosphere to increase the rate of diffusion. C. They have walls that are one cell thick for faster diffusion. D. They are small so keep the gases inside them more concentrated.

C. They have walls that are one cell thick for faster diffusion.

The image shows a section of the human respiratory system. Which letter identifies a bronchiole?

D

What happens to the external and internal intercostal muscles and diaphragm when inhaling?

D. External intercostal muscles: contract Internal intercostal muscles: relax Diaphragm: contracts

What feature of alveoli adapts them to efficient gas exchange? A. They have muscles which pump air in and out regularly. B. Their membranes are more permeable to gases than water. C. A constant blood supply flows through them. D. A dense network of capillaries surrounds them.

D. A dense network of capillaries surrounds them.

Which of the following features of the alveoli adapt them to gaseous exchange? I. Single layer of cells II. Film of moisture III. Dense network of capillaries

D. I, II and III

What muscle actions cause air to be expelled from the lungs? A. Internal intercostal muscles relax and diaphragm contracts B. External intercostal muscles contract and abdominal wall muscles contract C. External intercostal muscles contract and diaphragm relaxes D. Internal intercostal muscles contract and abdominal wall muscles contract

D. Internal intercostal muscles contract and abdominal wall muscles contract

What changes occur in the thorax of a mammal when the external intercostal muscles and diaphragm muscles contract? A. Pressure increases and volume decreases. B. Pressure and volume both increase. C. Pressure and volume both decrease. D. Pressure decreases and volume increases.

D. Pressure decreases and volume increases.

Outline the effect of hypoxia on body mass and erythrocyte percentage. [1]

Erythrocyte percentage increased AND body mass reduced/smaller increase in mass

Explain the processes that control changes in ventilation rate during exercise. [4

a. exercise increases aerobic respiration; b. CO2 concentration in blood increases; c. drop in pH of blood detected / blood more acidic; d. breathing centres send impulses to diaphragm and intercostal muscles; e. increase rate of contraction; f. increase in ventilation rate increases oxygen uptake/decreases CO2;

Describe what happens in alveoli. [4

a. gas exchange b. oxygen diffuses from air to blood and carbon dioxide diffuses from blood to air c. oxygen binds to hemoglobin in red blood cells d. pressure inside/volume of alveoli increases/decreases / air enters/exits alveoli during inspiration/expiration/ventilation e. blood flow through capillaries / concentration gradients of gases/oxygen/CO2 maintained f. type II pneumocytes secrete fluid/surfactant / secretion of surfactant to prevent sides of alveolus adhering

Explain the changes in ventilation rate during exercise. [2

a. increased (muscle) cell respiration releases more CO2/decreases pH (in blood); b. detected by (respiration centre in) brain/medulla; c. signal sent to respiratory muscles to contract at a faster rate; d. more oxygen carried by the blood / needed for aerobic (cell) respiration;

Explain the mechanism of ventilation in the lungs in order to promote gas exchange for cell respiration. [9

a. inspiration/inhalation brings air into lungs; b. external intercostal muscles contract; c. and move rib cage upwards and outwards; d. diaphragm flattens/contracts; e. increasing thoracic volume; f. pressure decreases from atmospheric pressure so air rushes into lungs; g. expiration/exhalation forces air out; h. internal intercostal muscles contract / external intercostal muscles and diaphragm relax; i. abdominal/abdomen wall muscles contract and push diaphragm upwards; j. decreasing thoracic volume; k. increasing pressure in lungs so air is forced out; l. a concentration gradient between air sacs and blood needs to be maintained;

A supply of oxygen is needed for aerobic respiration in mitochondria. Describe the features of alveoli in human lungs that adapt them for efficient absorption of oxygen.

a. large surface area from having many alveoli; b. single/flattened layer of (thin) cells in wall; Reject one-cell membrane/thin membrane. c. (surrounded by) dense network of capillaries/capillary bed; d. short distance for gases/oxygen/carbon dioxide to diffuse; e. moist lining / film of moisture on inside of alveolus; f. moisture allows oxygen/gases to dissolve; g. diffusion of oxygen down concentration gradient;

Define tidal volume and ventilation rate. Tidal volume: Ventilation rate: [2

a. tidal volume: volume of air taken in with each inhalation/out with each exhalation; b. ventilation rate: number of inhalations/exhalations/breaths per minute;

Explain the mechanism of ventilation of human lungs. [8

a. ventilation is movement of air into and out of lungs; b. volume of thorax/lungs/chest increased/decreased; c. pressure in thorax/lungs/chest decreased/increased; d. air flows from higher to lower pressure / air flows until the pressures are equal; During inspiration/inhalation: e. external intercostal muscles contract so ribcage moved up/out; f. diaphragm contracts so moves down/becomes flatter; g. internal intercostal/abdomen (wall) muscles relax; During expiration/exhalation: h. external intercostal muscles relax so ribcage moved down/in; i. diaphragm relaxes; j. recoil of elastic fibres that stretched during inspiration; k. internal intercostal muscles contract (during forced ventilation); l. abdomen (wall) muscles contract (during forced ventilation);

Describe the effects of training on the pulmonary system.

a. ventilation rate at rest is reduced; b. maximum ventilation rate (during exercise) increases; c. diaphragm and intercostal muscle strength increase; d. vital capacity may increase/ VO2 max may increase;

Explain the mechanism of ventilation in humans. [7

air enters/exits lungs through trachea, bronchi and bronchioles; during inspiration/inhalation external intercostal muscles contract; causing ribs to move upwards/outwards; during inspiration diaphragm contracts/flattens; causes increase in volume of thorax/lungs; decrease in pressure allows air to enter (passively); during expiration internal intercostal muscles contract/external intercostal muscles relax; causing ribs to move down/in; diaphragm relaxes/returns to original domed position; abdominal muscles contract to push diaphragm up; causes decrease in volume of thorax/lungs; increase in pressure forces air out of lungs;

Active skeletal muscle requires a good supply of oxygen. Outline the mechanism of ventilation in the lungs. [6

during inhalation: a. external intercostal muscles contract moving rib cage up and out; b. diaphragm contracts becoming lower/flatter; c. increase in volume and decrease in pressure (of thorax); d. air flows into lungs as atmospheric pressure is higher; during exhalation: e. internal intercostal muscles contract so ribs move in and down; f. diaphragm relaxes and returns to domed shape; g. decrease in volume and (therefore) increase in pressure (of thorax); h. air moves out until pressure in lungs falls/is equal to atmospheric pressure; i. abdominal muscles can be used to make a stronger/forced exhalation;

Explain the mechanisms involved in the ventilation of the lungs. [8

external intercostal muscles contract; internal intercostal muscles relax; pulling the rib cage upwards; diaphragm contracts and flattens; increase in volume of thoracic cavity; this reduces pressure; so air enters the lungs; internal intercostal muscles contract / external intercostal muscles relax; diaphragm relaxes; abdominal muscles/organs/liver push diaphragm upwards; decrease in volume of thoracic cavity; increases the pressure; so air leaves the lungs;

Describe three features of alveoli that adapt them to gas exchange. [3

high density of capillaries surrounding alveoli; large surface area due to shape / large number of alveoli; thin walls / walls one cell thick; (do not accept membranes) moist layer covering the (inner) surface of the alveoli;

Describe the need for a ventilation system in humans. [2

most cellular respiration is aerobic/requires oxygen / produces carbon dioxide; ventilation system exchanges gases between inhaled air and lungs/blood stream; ventilation system maintains high concentration gradient of gases in alveoli/ lungs;

Explain the need for a ventilation system and the mechanism of ventilation of the lungs in humans. [8

respiration needs absorption of oxygen and removal of CO2; gas exchange requires ventilation; alveoli provide surface area for gas exchange (with capillaries/blood); ventilation system maintains a high concentration of oxygen in the alveoli; bloodstream links alveoli to cells; inhalation by contraction of diaphragm; inhalation occurs with contraction of external intercostals; (these) increase the volume/reduce the pressure in thorax, pulling air into lungs; exhalation caused by relaxation of the diaphragm; exhalation occurs with relaxation of external intercostals; (these) decrease volume/increase pressure in the thorax, forcing air out of lungs;

Draw a labelled diagram to show the human ventilation system. [4

trachea; bronchi; bronchioles; lungs; alveoli - shown enlarged as inset; diaphragm; intercostal muscles; abdominal (wall) muscles;

Distinguish between ventilation, gas exchange and cell respiration. [4

ventilation is moving air into and out of lungs/inhalation and exhalation; involves (respiratory) muscle activity; gas exchange involves movement of carbon dioxide and oxygen; between alveoli and blood (in capillaries) / between blood (in capillaries) and cells; cell respiration is the release of energy from organic molecules/glucose; (aerobic) cell respiration occurs in mitochondria;