Phys 3 Exam 3 (copy)

What are the functions of respiratory system?

1. gas exchange

2. acid-base balance

3. blood pressure regulation

What is ventilation?

movement of gases between alveoli and blood

What is physiological respiration?

transportation of oxygen to tissue for energy production

What three processes for physiological respiration?

1. Ventilation (atmosphere to lung)

2. Gas exchange (alveoli and pulmonary capillaries)

3. Cellular respiration (oxygen used to produce ATP)

Body tissues need ___ and will release ___

oxygen; carbon dioxide

Lungs will take in ___ and then will exchange it with __ __ in the bloodstream

oxygen; carbon dioxide

Which bronchus is wider and more vertical?

Right main bronchus

T/F Foreign objects lodge in the right main bronchus more often than the left

true

Which lung is shorter because liver rises higher?

right lung

Which lung is tall and narrow because the heart tilts towards that side and occupies more space?

left lung

How many lobes does each lung have?

Right→ 3 lobes

Left→ 2 lobes

How many lobar bronchi in each lung?

Right→ 3

Left→ 2

How many segmental bronchi on each lung?

Right→ 10

Left→ 8

The bronchial tree is lined with ___

ciliated pseudostratified columnar epithelium

The brochial tree has large amounts of ___ for recoil and ___ to be able to relax and contract as needed

elastic connective tissue

smooth muscle

What are some features of bronchioles?

lack cartilage

have simple cuboidal lining

has smooth muscle

has club cells (bronchilar exocrine cells)

Bronchioles divide into ___

50-80 terminal bronchioles

What do the 50-80 terminal bronchioles divide into ___

2 or more smaller respiratory bronchioles

(beginning of respiratory zone)

Respiratory bronchioles have ___ budding from their wall

alveoli→ participate in gas exchange

What are some features of the conducting zone?

structures that serve for airflow

NO GAS EXCHANGE

nostrils to terminal bronchioles

What are the structures of the conducting zone?

1. nasal cavity

2. pharynx

3. trachea

4. main bronchus

5. lobar bronchus

6. segmental bronchus

7. bronchiole

8. terminal bronchiole

What are some features of respiratory zone?

structures that participate in gas exchange

respiratory bronchioles to alveoli

What are the structures in the respiratory zone?

1. Respiratory bronchile

2. alveolar duct

3. atrium

4. alveoli

How many alveoli are in each lung?

150 million

What cell covers 95% of alveoulus surface area?

squamous (type 1) alveolar cell

What cell secretes surfactant? (TQ)

Great (type 2) alveolar cell

What cell keeps alveoli free from debris?

Alveolar macrophage (dust cells)

What cell is the most numerous of the lung?

alveolar macrophages

The respiratory membrane consists of ___

1. squamous alveolar cell

2. Shared basement membrane

3. capillary endothelial cells

What is the prime mover of respiration?

diaphragm

What happens during contraction of diaphragm?

increased thoracic cavity volume

decreased pressure

pulls air into lungs

What occurs when the diaphragm is relaxed?

decreased thoracic cavity volume

increased pressure

expels air from lungs

What muscle is important for inspiration and accounts for about 1/3 of air that ventilates the lungs?

external intercostal muscles

What muscles are used during forced inhalation?

1. SCM

2. Scalenes

3. Erector spiane

4. serratus anterior

5. pec major and minor

6. latissimus dorsi

What muscles are used during forced exhalation?

1. internal intercostals and innermost intercostals

2. rectus abdominis

3. external oblique

4. internal oblique

5. transversus abdominis

What muscles are used during quiet inhalation and exhalation?

1. Internal intercostals

2. external intercostals

3. diaphragm

What occurs during forced expiration?

increased abdominal pressure→ pushes viscera up against diaphragm increasing thoracic presure forcing air out

“important for abdominal breathing”

How does normal quiet expiration work?

energy saving passive process achieved by elasticity of lungs and thoracic cage

What is valsalva maneuver? Examples?

taking a deep breath, holding it by closing glottis, then contracting abdominal muscles to raise abdominal pressure and push organ contents out

Ex→ childbirth, urination, defecation, vomiting

Automatic, involuntary cycle of breathing is controlled by respiratory centers ____

reticular formation of medulla oblongata and pons

What are the two respiratory networks of the medulla?

1. Dorsal respiratory group (DRG)

2. Ventral respiratory group (VRG)

What are the two pontine respiratory groups?

1. Apneustic center

2. Pneumotaxic center

What effect on respiration does the medulla groups have?

DRG→ stimulates inspiratory movements (timing)

VRG→ stimulates expiratory movements (forced exhalation) and acts to increase the force of inspiration

What is the primary respiratory control center?

medulla

What is inspiratory medullary rhythmicity area (Inspiratory center→DRG)? How does it work?

integrates input from stretch receptors and chemoreceptors

inspiratory neurons fire every 2 secs→ impulse travels along phrenic and intercostal nerves to excite diaphragm, external intercostal muscles, and internal intercostal muscles

What is expiratory medullary rhythmicity area (expiratory center→VRG)?

impulses cause contraction of the internal intercostals and abdominal muscles = decreased TCV and cause forceful exhalation

What controls rate/speed of involuntary respiration?

pons

What is the apneustic area?

stimulatory impulses to inspiratory area that activates and prolong inhalation= long, deep inhalation

What is the pneumotaxic area?

transmits inhibitory impulses to the inspiratory area every 3 secs

effect of impulses is to helps turn off the inspiratory area before the lungs become too full of air

Respiratory rhythm is at __ breaths per minute

12 breaths

What are the 3 chemical factors controlling respiration?

1. concentration of carbon dioxide in blood

2. concentration of H+ ion (pH)

3. concentration of oxygen in blood

How does Co2 affect peripheral and central chemoreceptors?

If CO2 increases→ stimulates chemoreceptors→ activates respiratory centers→ increases ventilation to expel CO2

How does H+/pH impact peripheral and central chemoreceptors?

increase in H+(low pH)→ stimulates chemoreceptors→activates respiratory centers→ ventilation increases to expel CO2 which leads to reduction of H+ and pH increases to normal

How does O2 impact peripheral and central chemoreceptors?

O2 low→ stimulates chemoreceptors→activates respiratory centers→ ventilation increases to increase oxygen uptake

What is the role of stretch receptors in respiration?

respond to inflation of lungs

found in the smooth muscle of bronchi, bronchioles, and visceral pleura

What is the hering-breuer inflation reflex?

protective reflex that prevents over inflation

What are irritant receptors?

epithelial cells of the airway

respond to dust, pollen, etc

can trigger protective reflexes like bronchoconstriction, slows breathing or coughing

What is atmospheric pressure at sea level?

760 mm Hg

What should intrapulmonary pressure (Ppul) match at the end of inspiration and expiration?

Patm

What is boyle’s law?

the pressure of a given quantity of gas is inversely proportional to its volume

increase volume=decrease pressure

decrease volume= increase pressure

What pressure is always lower than atmospheric pressure?

Intrapleural pressure (Pip)

As this pressure decreases, air flow into the passageways of the lungs

intrapulmonary pressure (Ppul)

If this pressure becomes equal to the atmospheric pressure= lungs collapse

intrapleural pressure

During inspiration, what happens to ribs?

ribs are pulled upward and outward and sternum is pulled forward to allow for the lungs in inflate= increased TCV

During inspiration, what happens to the diaphragm?

diaphragm moves down, flattens

diaphragm contracts and moves down allowing increase TCV and decrease ACV

During expiration, what happens to the ribs? Diaphragm?

ribs return to normal position

diaphragm relaxes and moves back upward

decrease TCV

increase ACV

What two factors influence airway resistance? (TQ)

bronchiole diameter and pulmonary compliance

What relationship does bronchoconstriction have with airflow?

increases resistance

decreases airflow

What relationship does bronchodilation have with airflow?

reduces resistance

increases airflow

What is pulmonary compliance?

ease with which lungs can expnd

What is surfactant’s role in pulmonary compliance?

secreted by great cells of the alveoli (type 2)

disrupts H+ bonds between the water molecules of the water film inside the alveoli

reduces surface tension

What is anatomic dead space? (TQ)

air in the conductive zone that cannot participate in gas exchange

What is pathological alveolar dead space/functional dead space?

gas that ends up on alveoli where pulmonary diseases are causing damage to alveoli making them unable for gas exchange

What is physiological total dead space?

anatomic dead space + pathological alveolar/functional dead space

What is alveolar ventilation rate?

air that ventilates the alveoli for gas exchange

350ml/breath x 12 breath/min= 4200 mL/min

What is inspiratory capacity?

total amount of air you can bring in

TV+IRV

What is expiratory capacity?

total amount of air you can blow out

TV + ERV

What is functional residual capacity?

total amount of air you forcefully exhale and residual volume

ERV+RV

What is vital capacity?

total amount of air you bring in and out forcefully

IRV+TV+ERV

What is total lung capacity?

TV+IRV+ERV+RV

What is tidal volume?

respiratory volume inhaled and exhaled during normal breathing

What is residual volume?

gas volume that allows gas exchange to go on continuously

What are the two types of COPD?

1. chronic bronchitis

2. emphysema

What is COPD?

chronic obstructive pulmonary disease

lung disease that damages airways causing long term obstruction of airflow and substantial reduction in pulmonary ventilation

What can COPD cause?

1. hypoxemia→ polycythemia

2. hypercapnia

3. respiratory acidosis

What is chronic bronchitis?

severe, persistent inflammation of lower respiratory tract

goblet cells enlarge and produce excess mucus

cough with sputum

What is emphysema?

alveolar walls lose their elasticity due to damage to the alveolar walls→creates holes

lungs become flabby and cavitated

obstructs outflow of air→barrel chested

T/F emphysema affects air sacs while chronic bronchitis affects the airways

true

What effect does obstructive lung disease have on airflow?

reduction of airflow

hyperinflation of lungs→ ERV and RV increase, IRV decrease

What are restrictive lung disease?

diseases that reduce pulmonary compliance

all lung volume and capacities are decreased

What is external pulmonary gas exchange?

exchange of gases between alveoli and pulmonary capillaries

What is internal respiration exchange?

exchange of gases between systemic capillaries and tissue cells

How does external respiration occur? (LONG CARD)

As oxygen crosses the respiratory membrane and loads/binds to hemoglobin, the bonds between hemoglobin and hydrogen are broken.

Hydrogen is now free to combine with bicarbonate when it diffuses back into the RBC (in exchange for chloride- reverse chloride shift) = creating carbonic acid which dissociates (carbonic anhydrase catalyzes this) into water and carbon dioxide which diffuse into the alveoli and exhaled. HALDANE EFFECT

As oxygen crosses the respiratory membrane and loads/binds to hemoglobin, the bonds between hemoglobin and carbon dioxide are broken, carbon dioxide diffuses/unloaded into the alveoli and exhaled.

Carbon dioxide dissolved in the plasma diffuses into the alveoli and exhaled.

What is dalton’s law?

total atmospheric pressure is the sum of the contributions of individual gases

What is the atmospheric partial pressure of oxygen and carbon dioxide?

Oxygen→159 mm/Hg

Carbon dioxide→ 0.3 mm/Hg

How is alveolar air different from inspired air?

1. air is humidified

2. air in alveoli mixes with residual air left from previous respiratory cycle

3. alveolar air exchanges O2 and CO2 with blood

What factors influence external respiration?

1. ventilation perfusion coupling

2. respiratory membrane thickness

3. respiratory membrane surface area

4. solubility of gases

What is ventilation perfusion coupling?

abilitiy to match air flow and blood flow to each other

T/F external respiration has a thin respiratory membrane

true→ pulmonary edema can cause it to thicken

T/F O2 is 20x more soluble as CO2

false→ CO2 is more soluble