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Flashcards in respi - phyanalec Deck (44):
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1. Ventilation /Breathing – movement of air into and out of the lungs
2. Exchange of O2 and CO2 in lungs and blood
3. Transport of O2 and CO2 in blood
4. Exchange of O2 and CO2 between blood and tissues

4 processes of respiration

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-process of moving air into and out of the lungs

VENTILATION OR BREATHING

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Two Phases VENTILATION OR BREATHING

1. Inspiration- movement of air into the lungs, inhalation
2. Expiration – movement of air out of the lungs, exhalation

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Muscles of Inspiration)

– diaphragm & muscles that innervate ribs and sternum (external intercostals

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– large dome of skeletal muscles that separates the thoracic cavity from abdominal cavity

• Diaphragm

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depress ribs and sternum (ex. Internal intercostals)

Muscles of Expiration –

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type of breathing
– all inspiratory muscles are active
-muscles contract more forcefully → greater increase in thoracic volume → faster and greater decrease in thoracic volume

labored

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Principles governing Airflow

1. ↑Pressure, ↑Volume
2. Air flows from an area of higher pressure to an area of lower pressure
Greater the pressure difference, greater rate of airflow

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phase
– alveolar pressure = atmospheric pressure

end of expi

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phase
– contraction of muscles of inspiration, ↑thoracic volume, ↑lung expansion, ↑alveolar volume, AVP

during inspi

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phase
– thorax and alveoli stop expanding
- AVP = ATP, airflow stops

end of inspi

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phase
↓ thoracic volume, ↓ alveolar volume, AVP > ATP, air leaves alveoli

4. During Expiration -

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-tendency for an expanded lung to decrease in size

LUNG RECOIL

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causes of LUNG RECOIL

elastic tissue
surface tension

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– exists because oppositely charged ends of water molecules are attracted to each other
-as water molecules pull together, they pull on alveolar walls, causing alveoli to recoil and become smaller

surface tension

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FACTORS THAT KEEP THE LUNGS FROM COLLAPSING

surfactant pleural pressure

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mixture of lipoprotein molecules produced by secretory cells of alveolar epithelium
-its molecules form a single layer on the surface of the thin fluid layer lining the alveoli, reducing surface tension

1. Surfactant –

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– pressure in the pleural cavity
-alveoli expands when PP

2. Pleural Pressure

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caused by fluid removal by lymphatic system and by lung recoil
-as lungs recoil, the visceral and parietal pleurae tend to be pulled apart
-this pull decreases pressure in the pleural cavity

SUCTION EFFECT –

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process of measuring volumes of air that move into and out of respiratory systems

SPIROMETRY

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– measures of amount of air movement during different portions of ventilation

Respiratory volumes

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sums of 2 or more respiratory volumes

Respiratory capacities –

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– rate at which lung volume changes during direct measurement of vital capacity

FORCED EXPIRATORY VITAL CAPACITY

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major area of gas exchange

Alveoli –

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volume of areas of respiratory passageways where gas exchange does not occur (trachea, bronchi, bronchioles)

Anatomical dead space –

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FACTORS influencing gas exhange

surface area
partial pressure
respiratory membrane thickness

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pressure exerted by a specific gas in a mixture of gases such as air

3. PARTIAL PRESSURE –

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collapse of lungs

pneumothorax

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– hemoglobin with oxygen bound to its heme groups

Oxyhemoglobin

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Normal rate of breathing

Adults: 12 – 20 breaths/min
• Children: 20 – 40 breaths/min

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determined by number of times respiratory muscles are stimulated

Rate of breathing –

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Medullary Respiratory Center – generates the basic pattern of spontaneous, rhythmic breathing

Medullary Respiratory Center –

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- longitudinal column of cells bilaterally in the dorsal part of medulla oblongata
-stimulating contraction of diaphragm

• Dorsal respiratory groups (2)

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- longitudinal column of cells bilaterally in the ventral part of medulla oblongata
-stimulating external/internal intercostals and abdominal muscles

• Ventral respiratory groups (2)

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part of ventral group, establish the basic rhythm of breathing

 Pre- Botzinger complex –

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– collection of neurons in the pons
-has connection with Medullary Respiratory Center
-plays a role in switching between inspiration and expiration

Pontine Respiratory Group

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supports rhythmic respiratory movements by limiting extent of inspiration

Hering-Breuer reflex –

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increase in CO2 level, results in a powerful urge to breather

Hypercapnia

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decrease in O2, aortic and carotid bodies strongly stimulated

Hypoxia –

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EFFECT OF EXERCISE ON BREATHING

1. Rapid increase
2. Gradual increase

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highest level of exercise that can be performed without causing a significant change in blood ph

Anaerobic threshold –

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GENERATION OF RHYTHMIC BREATHING

-neurons in MRC are constantly active
-MRC receives much stimulation from different sources
-stimulation can come from parts of brain concerned with respiratory movements

1. STARTING INSPIRATION

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GENERATION OF RHYTHMIC BREATHING

-once inspiration begins, more and more neurons are activated
-result: progressively stronger stimulation of respiratory muscles, lasts for 2 s

2. INCREASING INSPIRATION

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GENERATION OF RHYTHMIC BREATHING
-neurons for stimulating are also the neurons for stopping
-lasts for 3 s

3. STOPPING INSPIRATION

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