Respiratory System

• larger species have a slower respiration rate
• --of the same species, females have faster respiratory rates and immature individuals have faster respiratory rates than the mature

•   decreased oxygen to the blood
• --hemoglobin is not saturated --
• due to: --parasites --pneumonia --high altitude

•   decreased hemoglobin in the blood --
• due to : --anemia --hemorrhage

•   decreased blood flow -
• -due to: --congestive heart failure

•   body cell damage—
• enough so cells cannot accept enough oxygen
• --causes: --anesthetic over dose --poisons --alcohol

•   --cyanosis = blue color to skin
• --loss of consciousness
• --pale
• --dsyemia

1. Pulmonary respiration = inspiration & expiration --occurs between lungs &atmosphere
2. External respiration = exchange of gases between blood and the lungs --pulmonary circulation
3. Internal respiration = exchange of gases between blood capillaries and the body tissues --systemic circulation

1. Nasal cavity

is a muscular funnel -- is part of respiratory   & digestive systems -- has 3 regions

1. nasopharynx
2. oropharynx
3. laryngopharynx

1. nasopharynx
2. oropharynx
3. laryngopharynx

•   wind pipe --made up of _cartilage C rings -

-divides up into bronchi at about the heart level

•   alveoli
• alveoli are the ‘true respiratory organs’ → exchange of gases (in capillary networks)

•   Right has 3 lobes
• Left has 2 lobes --is smaller --has a cardiac notch

1. Decrease friction= allows for lung expansion and contraction
2. Create a pressure gradient = helps in inspiration
3. Compartmentalizes = separates thoracic organs

•   musculomembranous structure
•   divides the thoracic and the abdominal cavities
• as four openings: --aorta --inferior vena cava --esophagus --lymphatic vessels

•   is an active process because it involves muscles external intercostals
• contract and lift the ribs diaphragm
• --contracts and lowers
• pushes ribs out
• increases lung volume there is an expansion in the thoracic cavity and a decrease in the abdominal cavity area --enlarged air ways and alveoli --atmospheric pressure is > than pressure in the lungs What is the direction of air flow??? Greater to lowers-atmosphere into the lungs

• the thoracic cavity and a decrease in the abdominal cavity area
• enlarged air ways and alveoli --atmospheric pressure is > than pressure in the lungs
• What is the direction of air flow??? Greater to lowers-atmosphere into the lungs
--

•   is a passive process because no muscles are involved
• --lungs and diaphragm recoil back
• --pressure in the lungs is > than atmospheric pressure
• What is the direction of air flow??? Lungs to atmosphere

•   is an active process because muscles are involved →  internal intercostals
• --contract & depress the ribs and abdominal muscles --
• decreased lung volume there is an expansion in the abdominal cavity and a decrease in the thoracic cavity area

1. Decreased pulmonary compliance --lungs loose ability to distend (reflate) and recoil
2. Bronchiole diameter --bronchoconstriction will increase resistance --bronchodilation will decrease resistance
3. Surface tension of water in alveoli & bronchioles = surface tension is associated with the water molecules being attracted to each other due to hydrogen bonds

•   fluid secreted by aveolar cells that decrease surface tension and so allows alveoli to expand and decreases chances of alveoli collapse
• --any surfactant breaks up hydrogen bonds in water molecules

•   Tidal Volume minus Anatomic Dead Space        
•   = 500ml – 150ml = 350ml per breath average respiratory rate = 12 breaths per minute          
• = 350ml X 12             = 4200ml per minute

•   air remaining in the lungs even after thoracic cavity is opened
• --if baby was born alive, lungs will have minimum air volume = will float

•   dependent on the partial pressure (pP) of gases and is related to ATM P (atmospheric pressure) which is 760 mmHg

•   pP to an area of lower pP

1.   Pulmonary respiration → between atmosphere and lungs
2. External respiration →lungs and blood
3. Internal respiration →blood and tissues

1. pP of a gas lungs = deoxygenated blood=pulmonary arteries

pP O2 ~ 40 mmHg in blood pP O2 in alveolar air = 105 mmHG

How will oxygen diffuse? The partial pressure from the alveoli to the blood

•   pP CO2 in deoxygenated blood is 45 mmHg pP
• CO2 in alveoli is 40 mmHG
• How will CO2 diffuse? From the blood to the alveoli 

•   decrease
•   ex:  pP O2 at sea level is 159 mmHg           at 10,000 feet = 110           at 20,000 feet = 73

•   --alveolar pP O2 drops (decreases) = less oxygen gets to the blood
• = less oxygen available for tissues
• this is known as High Altitude Sickness
• Treatment:  hyperbaric chamber --provides high oxygen (2000-3000 mmHg)

• surface area --increased area = more gas exchange
• possible = increased oxygen into blood

•   --normally, membranes are very thin
• --if thickness pulmonary capillaries gas exchange cannot equlize fast enough = drop in total gas exchange

•   --increased solubility = increased diffusion = increased gas exchange

•       ventilate-= blood
• perfusion=       air
•   --amounts of gas should equalize once their in the blood

•   there will be and blood will be rerouted to a healthy area of the ______________ (this is opposite to systemic circulation)

•   This is between blood and tissues
• pP O2 in oxygenated blood is 100 mmHg
• pP o2 in tissues is 40 mmHg

•   --this ‘free’ oxygen is dissolved in plasma
• --only ~ 1.5% if ‘free’ oxygen so most of the oxygen carried in RBC’s cannot go into tisuues

•   4 protein portions called globins and 4 iron containing portions called heme
• --each heme carries one oxygen molecule
• = one hemoglobin molecule can carry 4 oxygen molecules

•   = oxyhemoglobin dissociation curve
•   --when there is low pP O2 = hemoglobin is partially saturated = more ‘free’ oxygen
• --when there is high pP O2 = increase hemoglobin saturation = less ‘free’ oxygen
•   Which is better for very active muscles– a low pP O2

•   --active tissues produce more CO2 = increase acidity = lower pH
• --with low pH = hemoglobin saturation is decreased = more free oxygen

•   low pH decreases the bond between hemoglobin and oxygen so free H+ will bind with hemoglobin = oxygen carrying capacity of hemoglobin decreases = increases free oxygen available to the tissues

•   --with increased pP CO2 in the blood = less hemoglobin saturation = more free oxygen
• --this is due to more CO2 in blood → less oxyhemoglobin → increased pP CO2

•   --with increased temperature → decreased hemoglobin saturation = more free oxygen
• --note:  active tissues are warmer

•   --is produced by red blood cells and binds to hemoglobin
• = decrease oxygen carrying capacity
• = increase free oxygen

•   = decrease oxygen carrying capacity
• --body cannot take in enough oxygen from atmosphere
• = less oxygen to blood → less oxygen to cell
• Results in hypoxia in the body

Amount of air inhaled/exhaled in one breath

Amount of extra air inhaled with maximum effort (beyond normal TV)

Amount of air in lungs after ERV – can’t be voluntarily exhaled

Maximum amount of air inhaled after normal tidal expiration

  Amount of air left in lungs after normal tidal expiration:  RV+ERV=FRC

Normal inspiration plus forced exhalation (deepest possible breath):  TV+IRV+ERV=VC

Maximum air amount lungs can handle:  RV+VC=TLC

  Air inhaled per minute

1. Anoxia = hypoxia
2.   Oxygen toxicity
3. Chronic obstructive pulmonary disease (COPD)

•   --already discussed

•   --occurs when 100% oxygen is taken in for a few hours
• --causes formation of free radicals and hydrogen peroxide (which are toxic forms of oxygen)
• --can lead to seizures, coma, death

•   --any long term obstruction to airflow which leads to reduction in ventilation
• --ex:  emphysema, asthma, chronic bronchitis
• --smoking is to blame for many of the COPD’s
• --can lead to cor pulmonale = hypertrophy and possible failure of the right side of the heart due to obstruction in pulmonary circulation

•   --may follow COPD
• --most common is squamous cell carcinoma