Respritory & Digestive Flashcards
Pleura
Provides Lubrication
Pleural fluids fills the pleural cavity
Visceral Pleura on external lung surface
External Respiration
O2 and CO2 exchange between the lungs and the blood
Internal Respiration
O2 and CO2 exchange between the systemic blood vessels and tissues
Transport
O2 and Co2 in the blood
What are the functions of the nose
provides and airway fr respiration moistens and warms the entering air filters and cleans the inspired air serves as a resonating chamber for speech houses olfactory receptors
olfactory mucosa
lines the superior nasal cavity
contains smell receptors
respiratory mucosa
Pseudostratified ciliated columnar epithelium
mucous and serous secretions contain lysozyme and defensins
Cilia move contaminated mucus posteriorly to throat
inspired air is warmed by plexuses of capillaries and veins
Function of Conchae
Filter hear, and moisten air
Larynx
Vocal fold may act as a sphincter to prevent air passage
Valsalvas maneuver
Glottis closes to prevent exhalation
Intra abdominal pressure rises
How many lobes on right lung?
3
How many lobes on left lung
2
Inspiration
gases flow into the lungs
Expiration
gases exit the lungs
What are the mechanical processes that depend on volume changes in the thoracic cavity?
Volume changes ->pressure changes
Pressure changes -> gases flow to equalize pressure
Boyle’s Law
Pressure (P) varies inversely with volume (V)
Expiration
quiet expiration is normally a passive process
inspiratoy muscles relax
Thoracic cavity volume
Spirometer
instrument used to measure respiratory volumes and capacities
Control of Respiration
Involves neurons in the reticular formation of the medulla and pons
Hyperventilation
Increased depth rate of breathing that exceeds the bodys need to remove CO2
Causes CO2 levels to decline (hypocapnia)
Apnea
period of breathing cessation that occurs when Pco2 is abnormally low
Influence of Po2
peripheral chemo-receptors in the aortic and carotid bodies are O2 sensors
When excited they cause the respiratory centers to increase ventilation
What is the most powerful respiratory stimulant?
Rising CO2 levels
Where alveolar O2 is high
arterioles dilate
where alveolar P2 is low
arterioles constrict
Where alveolar CO2 is high
bronchioles dilate
Where alveolar CO2 is low
bronchioles constrict
Surface tension
attracts liquid molecules to one another at a gas liquid interface
Resists any force that tends to increase the surface area of the liquid
Surfactant
reduced surface tension of alveolar fluid and discourages alveolar collapse
Insufficient quantity in premature infants causes infant respiratory distress syndrome
Pulmonary Irritant reflexes
receptors in the bronchioles respond to irritants
promote reflexive constriction of air passages
Respiratory adjustments: exercise
adjustments are geared to both the intensity and duration of exercise
Pco2 Po2 and pH remain surprisingly constant during exercise
Hyperpnea
increase in ventilation (10 to 20 fold( in response to metabolic needs
Respiratory Adjustments: High Altitude
Quick travel to altitudes to above 8000 feet may produce symptoms of acute mountain sickness
Acute Mountain Sickness (AMS)
Headaches, shortness of breath, nausea, and dizziness
In severe cases lethal cerebral and pulmonary edema
COPD - Chronic Obstructive Pulmonary Disease
History of smoking in 80% of patients
Asthma
Characterized by coughing, dyspnea, wheezing, and chest lightness
Active inflammation of the airway precedes bronchospasms
Airway inflammation is an immune response caused by production of IgE
Airways thickened
Tuberculosis
Infectious disease caused by the bacterium Mycobacterium tuberculosis
Symptoms include fever, night sweats, wight loss, a racking cough, and spitting up blood
Lung Cancer
90% of all cases are the result of smoking
Atelectasis - lung collapse
due to plugged bronchioles -> collapse of alveoli
Wound that admits air into pleural cavity
Hypoxia
inadequate )2 delivery to tissues due to: too few RBCs Abnormal or too little Hb Blocked circulation Metabolic poisons Pulmonary disease Carbon Monoxide
Henrys Law
When a mixture of gases is in contact with a liquid each gas will dissolve in the liquid
the amount of gas that will dissolve in a liquid also depends upon its solubility
CO2 is 30 times more soluble in water than O2
partial pressure gradient for O2 in the lungs is steep
Venous blood Po2=40 mm Hb
Alveolar P02=104 mm Hb
Partial pressure gradient for CO2 in the lungs is less steep
Venous blood Pco2=45 mm Hb
Alveolar Pco2=40 mm Hb
O2 transport
Molecular O2 is carried in the blood
1.5% dissolves in plasma
98.5% loosely bound to each Fe ol hemoglobin in RBCs
4 o2 per Hb
Transformation of RBCs causes release of O2
Loading and unloading of O2 is facilitated by
change in shape of Hb
In arterial blood Hb is
98% saturated
Further increases in Po2 (breathing deeply)
produce minimal increases in O2 binding
Only 20-25 % of bound O2 is unloaded during
one systemic circulation
CO2 Transport
CO2 is transported in the blood in three forms
7-10 % dissolve in plasma
20% bound to globin of hemoglobin
70% transported as bicarbonate ions in plasma
Henrys Law
When a mixture of gases is in contact with a liquid each gas will dissolve in the liquid
the amount of gas that will dissolve in a liquid also depends upon its solubility
CO2 is 30 times more soluble in water than O2
partial pressure gradient for O2 in the lungs is steep
Venous blood Po2=40 mm Hb
Alveolar P02=104 mm Hb
Partial pressure gradient for CO2 in the lungs is less steep
Venous blood Pco2=45 mm Hb
Alveolar Pco2=40 mm Hb
O2 transport
Molecular O2 is carried in the blood
1.5% dissolves in plasma
98.5% loosely bound to each Fe ol hemoglobin in RBCs
4 o2 per Hb
Transformation of RBCs causes release of O2
Loading and unloading of O2 is facilitated by
change in shape of Hb
In arterial blood Hb is
98% saturated
Further increases in Po2 (breathing deeply)
produce minimal increases in O2 binding
Only 20-25 % of bound O2 is unloaded during
one systemic circulation
CO2 Transport
CO2 is transported in the blood in three forms
7-10 % dissolve in plasma
20% bound to globin of hemoglobin
70% transported as bicarbonate ions in plasma
