AP2 Lecture Chp.22 Respiratory

air in pleural cavity

Boyle’s Law: Pressure ____, Volume ____

Dissociates, releasing H+, increasing acidity

All living cells require carbon dioxide

Movement of air requires a________gas moves from high to low pressure

Ventilation-perfusion coupling: matching of alveolar ventilation with pulmonary blood perfusion

Mucus & cilia prevent microorganism entry into body

body’s detergent-like lipid and protein complex that helps reduce surface tension of alveolar fluid

Chemical factors: Chemoreceptors in aortic and carotid bodies sense arterial O2levels

Influence of higher brain centers: act through limbic system to modify rate and depth of respiration

Act to smooth out transition between inspiration and expiration and vice versa

Negative Pip is affected by opposing forces maintained by strong adhesive force between parietal and visceral pleurae

Much is not known about this group of neurons

Sets eupnea: normal respiratory rate and rhythm (12–15 breaths/minute)

Exchange of O2 and CO2between systemic blood vessels and tissues

Always eventually equalizes with Patm

Boyle’s Law: Pressure ____, Volume ____

decreased blood CO2 levels

May act as protective response more than as a normal regulatory mechanismPrevents overinflation via stretch receptors

Neurons influence, modify VRG activity

Pressure in pleural cavity and fluctuates with breathing

labored breathing (“air hunger”)

gases exit lungs

Smell is the result of molecules being drawn into nasal cavity

gases flow into lungs

Most patients develop hypoventilation accompanied by respiratory acidosis, hypoxemia

760 mm Hg at sea level = 1 atmosphere

Influence of higher brain centers: direct signals from cerebral motor cortex that bypass medullary controls

Ventilation-perfusion coupling: amount of gas reaching alveoli

Pressure exerted by air surrounding the body

Stimulates chemoreceptors to send signals to respiratory centers to lower blood PCO2, and pH rises to normal levels

Tends to draw liquid molecules closer together and reduce contact with dissimilar gas molecules

Insufficient quantity of surfactant in premature infants causes infant respiratory distress syndrome

Henry’s Law Each gas will_______in the liquid in proportion to its partial pressure

Exchange of O2 and CO2 between lungs and blood

External respiration DOES NOT occur at the respiratory membrane

____ of O2 and CO2 in blood

Produced by type II alveolar cells

Permanent enlargement of alveoli and destruction of alveolar walls result in decreased lung elasticity, w/3 consequences

Hyperventilation increased depth and rate of breathing that exceeds body’s need to remove CO2

*If fluid accumulates, positive Pip pressure develops and lung collapses

Atmospheric Pressure = 760 mmHg

–Rhythm-generating and integrative center–Excite inspiratory muscles (diaphragm, intercostals)

especially from fire•Hb has a 200X greater affinity for carbon monoxide than oxygen

Pressure in alveoli -----Also called intra-alveolar pressure

Water, which has very high surface tension, coats alveolar walls in a thin film

impaired or blocked circulation

blood and air in pleural cavity

Fluctuates with breathing

process of moving air into & out of lungs

One outward force tends to enlarge lungs

(breathing): movement of air into and out of lungs

lung collapse due to–Plugged bronchioles, which cause collapse of alveoli or pneumothorax

•Mucosae of lower respiratory passageways become inflamed and fibrosed–Cilia inhibited (paralyzed)& possibly destroyed

inadequate O2 delivery to tissues; can result in cyanosis

Exemplified by chronic emphysema and chronic bronchitis

Trapped air causes hyperinflation, which flattens diaphragm and causes expanded barrel chest.

breathing cessation that may occur when PCO2 levels drop abnormally low

Inhaled irritants cause chronic excessive mucus

Send inhibitory signals to medullary respiratory centers to end inhalation and allow expiration

Two inward forces promote lung collapse

Respiratory System assists in gas exchange

Hyperventilation–Treatment: breathing into paper bag increases CO2 levels being inspired

Ventilation-perfusion coupling: blood flow reaching alveoli

–Tends to cause alveoli to shrink to smallest size—that is, collapse

All living cells require

Boyle’s Law: At constant temperature, volume of a gas varies inversely with pressure

Total pressure is equal to

Resists force that tends to increase the surface area of liquid

Ventilation-perfusion coupling: controls ventilation by changing bronchiolar diameter

1.Lungs’ natural tendency to recoil–Because of elasticity, lungs always try to assume smallest size

Key feature is irreversible decrease in ability to force air out of lungs. History of smoking in 80% of patients.

blood in pleural cavity

Lesions in this area of brain lead to apneustic breathing, where patient takes prolonged inspirations

Partial pressure (PP) =

too few RBCs or abnormal or too little Hb

PCO2 levels increasing override voluntary control & cause breathing or loss of consciousness accomplishes the same

Elasticity of chest wall pulls thorax outward

Always a negative pressure (<Patm and <Ppul)----Usually always 4 mm Hg less than Ppul

Blood pH increases (becomes more basic; respiratory alkalosis)

If gradients not maintained, gases may not exchange or exchange may even go in the incorrect direction

Ventilation-perfusion coupling: controls perfusion by changing arteriolar diameter

Respiration involves ____ processes

Air movement past the vocal cords allows for sounds & speech

•Symptoms include frequent pulmonary infections•Risk factors include smoking and environmental pollutants

Attraction of liquid molecules to one another at a gas-liquid interface

Chemical factors: pH can modify respiratory rate and rhythm even if CO2 and O2 levels are normal

blood PCO2 levels rise, CO2 accumulates in brain and joins with water to become carbonic acid

2. Surface tension of alveolar fluid–Surface tension on alveoli to try to reduce alveolar size

Transmit impulses to VRG that modify and fine-tune breathing rhythms during vocalization, sleep, exercise

The fluid level must be kept at a minimum

CO2 levels in blood can alter blood pH

Stretch receptors in pleurae and airways are stimulated by lung inflation

Prevents alveolar collapse