Respiration Flashcards

1
Q

Describe the 7 functions of the respiratory system

A

a. Provide body with oxygen:
b. Eliminate carbon dioxide from body:
c. Regulate hydrogen ion concentration in blood (pH):
d. Facilitate speech:
e. Provide a defense against microbes:
f. Influence chemical messengers in blood:
g. Trap and dissolve small blood clots:

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2
Q

What is the use of providing oxygen to the body?

A

To make ATP (most critical function)

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3
Q

Describe elimination of CO2 from the body as a function of resp system

A

CO2 is a by-product of cellular respiration, must be eliminated because when combined with H2O, creates carbonic acid which dissociates to HCO3- and H+ which can acidify body

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4
Q

Describe the function of pH regulation by the resp system

A

helps eliminate H+ from other sources in conjunction with kidney

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5
Q

Describe the function of facilitating speech by the resp system

A

larynx positioned at top of trachea, air exchange used to drive speech, function in exhalation

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6
Q

Describe the function of providing defense against microbes by the resp system

A

epithelial secretions- secrete antibacterial factors and mucous (epithelial layers), lymphoid tissue (in mucosa, resident lymphocytes), reflexes- coughing and sneezing

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7
Q

Describe the function of influencing chemical messengers in the blood by the resp system

A

convert ATI to ATII via ACE, ATII aldosterone secretion; inactivates hormones and cytokines (PGs)- clearance site for small molecules

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8
Q

Describe the function of trapping and dissolving blood clots by the resp system

A

Venules in lungs good at clearing blood clots because a lot of plasmin, slow blood flow time to break down clots

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9
Q

List the structures associated with the conducting zone

A

nose, mouth , pharynx, larynx, trachea, bronchii, bronchioles, terminal bronchioles

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10
Q

Describe the basic functions of the structures of the conducting zone

A
  • -no gas exchange, air moving by bulk flow- mechanical pressure gradient,
  • -trachea and bronchi include cartilaginous rings and mucous glands- holds tube open skeletal structure, smooth muscle associated that can manipulate diameter
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11
Q

List the structures associated with the respiratory zone

A

respiratory bronchioles, alveolar ducts, alveoli

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12
Q

Describe the basic functions of the structures of the respiratory zone

A
  • -gas exchange occurs because walls are thin enough for diffusion to occur,
  • -smooth muscles in bronchioles regulate airflow, high SA,
  • -highly vascularized- lots of gas exchange, blood flow, and pressure low due to branching,
  • -low flow rate=lots of time for gas exchange
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13
Q

Describe the properties of alveoli that increase respiratory surface area and enhance gas exchange.

A

a. Branching is important for respiratory function- 1 tube→ 8 million tubes; 300,000 alveoli per lung
b. Increased SA, lots of epithelium with blood around it where gas can exchange

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14
Q

List the 3 types of cells found in an alveolus

A
  1. Type I
  2. Type II
  3. Macrophages
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15
Q

What is the function of type I cells in the alveolus?

A

gas exchange, epithelial cells, most common, squamous pink cells

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16
Q

What is the function of type II cells in the alveolus?

A

secrete surfactant- watery substance lining wall of alveoli, detergent like, keeps it slippery, decreases surface tension, allows them to be open with no air in them

17
Q

Describe the components of the alveolar-capillary interface (i.e., what does a molecule of gas pass through?).

A

O2 and CO2 must cross: layer of fluid in alveolus, alveolar epithelium and basal lamina, interstitial fluid, capillary basal lamina and endothelium

18
Q

What is the difference between bulk flow and diffusion of gases?

A

a. Bulk flow: mechanical pressure gradient, no diffusion of gases
b. Diffusion of gases: where gas exchange occurs, CO2 and O2 exchange

19
Q

What is the relationship of the lung to the pleural sac (which contains intrapleural fluid) to the thoracic cage.

A

a. Pleural sacs surround lungs, 2 sacs (right and left), completely surround lungs, has inner and outer layer, air tight
b. 2 layers to pleural sac:
i. Parietal (outer)- attached to thoracic wall and diaphragm
ii. Visceral (inner) attached to lung
c. Intrapleural fluid fills sac (10-20um thick)
i. Lubricates surfaces: reduces friction during respiration
ii. Subject to pressure changes when thoracic cage expands or contracts- dictates expansion of lung

20
Q
  1. Describe the mathematical relationship between airflow, a pressure difference, and resistance to flow
A

F=delta P/R

i. Delta P is gas pressure in alveoli minus gas pressure in atmosphere: P alv-Patm
ii. F= air flow
iii. R= resistance to flow

21
Q

Describe relationship of Palv to air movement in lungs

A

air moves into and out of the lungs because Palv is alternately less than and greater than atmospheric pressure
a. If PalvPatm, air flows out of lung- positive # for delta P, pushes air out

22
Q

What causes Palv to change (according to boyles law)?

A

P atm- constant because of change in lung volume due to change in thoracic cavity volume

23
Q

Describe atmospheric pressure in respiration

A

Atmospheric: pressure that the atmosphere puts on things in it, constant

24
Q

Describe alveolar pressure in respiration

A

Alveolar: pressure generated by air in alveolus

25
Q

Describe intrapleural pressure in respiration

A

Intrapleural: how much P on fluid/gasses in intrapleural fluid

26
Q

Describe transpulmonary pressure in respiration

A

Transpulmonary: calculated as Palv-Pip= Ptp

27
Q

Explain why intrapleural pressure is always subatmospheric under normal conditions.

A

Because 2 opposing forces pulling on the fluid in the sac, making it sub atmospheric unless there is pneumothorax

28
Q

Describe what happens to Pip and PTP during a pneumothorax.

A

a. Pip= Patm because air comes in, Pip=0

b. Ptp= 0-0=0→ lung collapses because pressures are the same, rib cage expands

29
Q

List the muscles of respiration and describe their roles during inspiration and expiration.

A

a. Inspiration: external intercostals, shoulder muscles, make chamber bigger
b. Expiration: internal intercostals, abdominal muscles, compress thorax

30
Q

Describe the pressure and volume relationships between breaths during a single respiratory cycle (7 steps)

A

Between breaths:

i. Patm is 0 by definition because no normal changes
ii. Palv equal Patm between breaths because no air moves
iii. Pip below atmosphere pressure -4mmHg
iv. Ptp=Palv-Pip, lungs remain expanded, +4mmHg, don’t completely deflate some pressure holding it open
v. Lungs tend to recoid inward- very stretchy/elastic tissue, pulling away from visceral pleura
vi. Chest wall tends to recoil outward- being pushed in by Patm
vii. Net result is Pip is always subatmospheric

31
Q

Describe the pressure and volume relationships during inspiration in a single respiratory cycle (5 steps)

A

b. Inspiration
i. Diaphragm contracts- thorax expands because pulls dome down against abdominal organ, volume increase so pressure decreases
ii. Pip becomes more negative (more subatmospheric), because increase volume so decrease pressure
iii. Ptp increases
iv. Lung volume increases because of muscle contraction
v. Air flows in until Palv=Patm then air stops moving

32
Q

Describe the pressure and volume relationships during expiration in a single respiratory cycle (5 steps)

A

Expiration

i. Diaphragm relaxes- thorax compresses, dome moves back up, decrease volume, increase pressure
ii. Pip becomes less negative- still subatmospheric
iii. Ptp decreases
iv. Lung volume decreases
v. Air flows out until Palv=Patm

33
Q

Define lung compliance and list the determinants of compliance.

A

a. Lung compliance = change in lung volume/ transpulmonary pressure
i. C= delta V/ (Palv- Pip)
b. How well does it respond to a change in pressure
c. Compliant- expansion readily occurs with small change in pressure