1)Gas exchange for cellular respiration 2)Sound production 3)assistance in abdominal compression during micturition, defecation, and parturition 4)route for water and heat loss 5)coughing and sneezing out inhaled foreign matter
Internal respiration
process by which gases are exchanged between the blood and the cells
External respiration
gas exchange between the air in the alveoli and blood
Cellular respiration
cells use )2 for metabolism and give off CO2 as a waste product
Bronchial tree
trachea>right and left primary bronchi>secondary bronchi>tertiary bronchi>bronchioles>terminal bronchioles>alveolar ducts>alveolar sacs
Pulmonary alveoli
alveolar sacs are formed of many microscopic pulmonary alveoli
How many pulmonary alveoli are there
300 million with 6 times the surface area of the body
Type II alveolar cells secrete what and for what
secrete surfactant to lower the surface tension inside the alveolus
What remove dust particles and other debris from the pulmonary alveolus?
alveolar macrophages
External intercostals muscles
elevate during inspiration
Internal intercostals muscles
contract during expiration
Hypoxia
a deprivation of O2 in tissues and organs
Eupnea
normal breathing
Dyspnea
difficult or labored breathing
Apnea
temporary cessation of respiration that may follow hyperventilation
Cheyne-strokes
periods of dyspnea followed by periods of apnea (leads to death if not stopped)
Respiration rate
12-15 times per minute
O2 consumption
250 ml O2 per minute at rest
Bronchoconstriction
decreased radius, and increased resistance to flow. Allergy induced spasm of the airways-maybe from histamine release or from parasympathetic stimulation
Bronchodilation
increased radius, and decreased resistance to airflow. Sympathetic stimulation controlled through epinephrine and norepinephrine
Asthma
a disease characterized by recurrent attacks of dyspnea. Often an allergic response to plants, animals, or food products resulting in contraction of the bronchial muscles
Pneumonia
acute infection and inflammation of the lungs with exudation (accumulation of fluid)
Chronic bronchitis
a long term inflammatory condition of the lower respiratory airways, generally triggered by frequent exposure to irritating cigarette smoke, polluted air, or allergens.
Emphysema
collapse of the smaller airways and a breakdown of alveolar walls. Caused by excessive release of destruction enzymes such as trypsin from alveolar macrophages as a defense mechanism in response to chronic exposure to inhaled cigarette smoke or other irr
TV
tidal volume-volume of air moved into or out of the lungs during normal breathing 400-500ml
IRV
Inspiratory reserve volume-max volume beyond the tidal volume that can be inspired in one deep breath- 3000ml
ERV
expiratory reserve volume-max volume beyond the tidal volume that can be forcefully exhaled following a normal expiration- 1100 ml
RV
residual volume-air that remains in the lungs follwing a forceful expiration- 1200 ml
MRV
minute respiratory volume-volume of air moved in normal ventilation in one minute- 6000ml/min
AVV
alveolar ventilation volume-volume of air that actually ventilates the alveoli. A portion of inspired iar does not take part in gas exchange b/c it fills the air passageways (dead air). Dead air makes up about 30% of the tidal volume
How much of the tidal volume does dead air contribute
30%
TLC
total lung coapacity-sum of the four lung volumes TV+ERV+IRV+RV=TLV=5700ml
VC
vital capacity- total amount of air that can be exchanged by the lungs- sum of the TV+IRV+ERV=4600 ml
Spirogram
record of pulmonary volumes and capacities
6 Layers of the respiratory membrane
1)surfactant 2)thin layer of fluid-water 3)alveolar epithelium 4)interstitial space 5)capillary basement membrane 6)capillary endothelium
surfactant
phospholipid protein decreases the surface tenstion of the fluids lining the alveoli and respiratory passages (Hyaline membrane disease or Respiratory distress syndrome)
Four factors affecting gaseous diffusion across the respiratory membrane
1)thickness of the respiratory membrane 2)surface area of the membrane 3)diffusion coefficient of each gas 4)pressure difference across the membrane
Changes in the thickness of the respiratory membrane
edema in the lungs (left heart failure), pneumonia (edema in membrane and fluid in the lungs)
Changes in surface area of the membrane
emphysema-decrease in overall surface area
Changes in diffusion coefficient of each gas
O2 has a coefficient value of 1 (it’s the standard), CO2 has a coefficient of 20 (20 times more soluble than water)
Changes in pressure difference across the membrane
Pressure in Alveolus (O2=104, CO2=40) in capillary (O2=40 and goes to 104, CO2=45 and goes to 40)
Composition of atmospheric Air
N2=78.6, O2=20.8, CO2=0.04, H2O=0.5
Composition of Alveolar air
N2=74.9, O2=13.6, CO2=5.3, H2O=6.2
Composition of expired air
N2=74, O2=15.7, CO2=3.6, H2O=6.2
Percent of O2 dissolved in blood
1-3%
Percent of O2 carried by hemoglobin
97-99%
What determines whether oxygen is bound or released from hemoglobin?
partial pressure of O2
PO2 of O2 in atmospheric air
21% of 760 mmHg=160mmHg
Alveolar PO2 and PCO2
PO2=104mmHg, PCO2=40mmHg at sea level
Grams of Hb per 100 ml of blood
15 grams
Ml of O2 per 1 gram of Hb
1.34ml
Ml of O2 per 100 ml of blood
20ml
Arterial blood is how saturated with O2
97%
Venous blood is how saturated with O2
75%
During exercise how saturated is arterial blood with O2
97%
During exercise how saturated is venous blood with O2
25%
the most important factor determing the % Hb saturation of O2 is what?
PO2 of the blood
factors affecting the O2-Hb dissociation curve
pH, PCO2, temperature, and 2,3-DPG
bohr effect
the O2-Hg dissociation curve shifting to the right from increased acidity, PCO2, temp, or 2,3-DPG
three major ways CO2 is transported
dissolved in blood (7-8%), carried by Hg forming carbaminohemoglobin(23-25%), as bicorbonate ion (65-70%)
two types of respiration control
neural and chemical
basic rhythm of repiration is controlled by what
medullary respiratory center in the brain stem
two subgroups in medullary respiratory center
dorsal and ventral
two other repiratory control centers in the pons
apneustic and pneumotaxic
dorsal respiratory group consits mainly of what
inspiratory neurons whose descending fibers stimulate inspiratory muscles. Serves as the major rhythm regulators
the ventral respiratory group contains
both inspiratory and expiratory neurons, which are inactive during quiet breathing, but become active during periods in whcih demands on ventailation are increased
pneumotaxic center functions
sends impulses to the dorsal neurons that help "switch off" the inspiratory neurons, thereby limiting hte duration of inspiration
apneustic center function
prevents the inpiratory neurons from being switched off, thus providing an extra boost to the inspiratory drive
herring-breuer reflex
triggered to prevent overinflation of the lungs. Stretch receptors in the lungs are activated by the stretching of the lungs at large tidal volumes
two types of receptors in chemical control of respiration
peripheral and central
peripheral chemoreceptors
located in the carotid bodies of the aortic bodies and are stimulated by decreased PO2 and increased H+ concentrations
central chemoreceptors
located in the medulla and respond to changes in brain extracellular fluid levels of PCO2. Increased PCO2 stimulates respiration.
Beef Production
