Ventilatory system Flashcards

Question

lung volumes & capacities

Answer 1

- tidal volume - inspiratory reserve volume - expiratory reserve volume - residual volume - vital capacity - minute ventilation - total lung capacity

Answer 2

Volume of air breathed in or out per breath

Answer 3

Volume of air that can be forcibly inspired after a normal breath

Answer 4

Volume of air that can be forcibly expired after a normal breath

Answer 5

Volume of air that remains in the lungs after maximum expiration

Answer 6

Volume of air forcibly expired after maximum inspiration in one breath

Answer 7

Volume of air breathed in or out per minute

Answer 8

Vital capacity + residual volume

Answer 9

rate at which oxygen is taken into the body and used

Answer 10

excellent indicator of fitness. must be measured with special equipment

Answer 11

Need to know that a substance called pleural fluid lies between the lungs and the chest wall When chest expands during breathing, the film of pleural fluid causes the membranous walls of lungs to be pulled outward along with chest walls. This means the space within the lungs increases Air molecules in the lungs now move momentarily farther apart, so that pressure of air in lungs falls below the pressure of atmosphere outside the body Air from outside riches down the trachea and into lungs until two pressures are equal again

Answer 12

fills the space between the two layers of pleural tissue

Answer 13

Observation of the skeleton reveals that each rib pivots about a vertebral joint. If it is lifted upward it also swings outward, with thoracic cavity being enlarged anteriorly & superiorly. This is the task in quiet breathing of the external intercostal muscles. At the same time ribs are lifted, the diaphragm (the muscular floor of thoracic cavity) contracts downward, enlarging thoracic cavity inferiorly.

Answer 14

Expiration is almost entirely a passive process that depends on elasticity of lungs & chest structures, as well as fluid film surface tensions within the lungs. When inspiratory muscles are relaxed, air simply leaves the lung, much as it would leave an untied balloon.

Answer 15

when one speaks or runs, abdominal muscles press upon abdominal contents, squeezing them upwards against diaphragm. internal intercostal muscles oppose external intercostals & pull ribcage downward, helping decrease the thoracic cavity volume & forcibly empty lungs. diaphragm may also function in forcible expiration. in laboured inspiration many muscles of upper trunk are also recruited.

Answer 16

- pectoralis major and minor - trapezius - rhomboideus

Answer 17

involuntary breathing controlled in the primitive part of brainstem (medulla). may also be controlled voluntary (cerebrum) but eventually involuntary control takes over.

Answer 18

send signals about blood pH, CO2 and O2 concentration to medulla.

Answer 19

- if pH goes down, or CO2 goes up, breathing increases. - if pH goes up, or CO2 goes down, breathing decreases. - O2 receptors = less impact on breathing rate vs. CO2. - stretch receptors in lungs tell medulla when lungs are expanded during normal breathing & stop inhalation.

Answer 20

- breathing rate increases during exercise as expiratory center sends impulses to expiratory muscles (internal intercostals) which speeds up expiratory process; - increase CO2 causes the acidity of blood to increase (decrease blood pH). - change in acidity of blood is detected by chemoreceptors which send nerve impulses to respiratory muscles which increase rate of ventilation (faster / deeper).

Answer 21

increase ventilation rate: greater frequency of breaths allows a more continuous exchange of gasses). increase tidal volume (increasing volume of air taken in & out per breath allows more air in lungs be exchanged).

Answer 22

Oxygen molecules bind to Iron containing a portion of hemoglobin and some Carbon Dioxide binds with certain amino acids in hemoglobin.

Answer 23

- about 98% of oxygen in blood is transported by hemoglobin as oxyhemoglobin, within red blood cells. - protein that allows oxygen to bind to a red blood cell. - contains a central iron ion which hold up 4 oxygen atoms. - these oxygen atoms are diffused into tissues once they reach their target. - while they are diffusing they are picking CO2 & returning it to lungs so you can exhale it. - only 20% of hemoglobin carries CO2. - most CO2 is carried in plasma and forms carbonic acid with water. - excess CO2 in blood will cause blood pH to drop.

Answer 24

- walls are very thin (1 cell) - huge surface area so allows for greater uptake of oxygen - supplied by a dense capillary network

Answer 25

- carried out by a complex of structures at end of each bronchioles. - oxygen exchange occurs - these alveoli inflate and deflate with inhalation & exhalation. - elastic recoil helps in exhalation. - gasses move by diffusion from where they have a high concentration to where they have a low concentration. - alveoli create a pressure gradient - once alveoli fill up with air during inhalation oxygen diffuses from air in alveoli and into blood. - CO2 diffuses from the arriving venous blood and into air which exits the body during exhalation.

Answer 26

- alveolar lining is moist (H2O) - because H2O is a polar liquid it has high surface tension (like magnets). - surface tension of H2O resists expansion of alveoli and can cause them to collapse.