Ch. 22 marieb
What is the major function of the respiratory system?
-to supply the body with oxygen and dispose of carbon dioxide
What are 4 processes called respiration?
1. pulmonary ventilation
2. external respiration
3. transport of respiratory gases
4. internal respiration
-air is moved into and out of the lungs (during inspiration and expiration) so the gases there are continuously changed and refreshed
-oxygen diffuses from the lungs to the blood, and carbon dioxide diffuses from the blood to the lungs
Transport of Respiratory Gases
-oxygen is transported from the lungs to the tissue cells of the body; and carbon dioxide is transported from the tissue cells to the lungs
-the cardiovascular system accomplishes this transport using blood as the transporting fluid
-oxygen diffuses from blood to tissue cells, and carbon dioxide diffuses from tissue cells to blood
What 2 processes is the respiration system responsible for?
-the respiratory system is only responsible for the first 2 processes
What happens if the last 2 processes don't occur?
-the respiratory system can't accomplish its primary goal of obtaining oxygen and eliminating carbon dioxide unless the third and fourth processes occur
What system works simultaneously with the respiratory system?
-the circulatory system
-if either system fails, the body's cells begin to die from hypoxia
-use of oxygen and the production of carbon dioxide by tissue cells
-cornerstone of producing chemical reactions in the body
What two functions is the respiratory system involved in?
1. the sense of smell
What are the 9 parts of the respiratory system?
2. nasal cavity
3. paranasal sinuses
What two zones does the respiratory system consist of?
1. respiratory zone
2. conducting zone
-actual site of gas exchange
-made up of the bronchioles, alveolar ducts, and alveoli
-all other respiratory passageways
-allow air to reach the gas exchange sites
-cleanse, humidify, and warm incoming air
Why does the conducting zone humidify the air?
-so the air reaching the lungs has fewer irritants like dust and bacteria
-also so the air is warm and damp
-only external part of the respiratory system
What are 5 functions of the nose?
1. provides an airway for respiration
2. moistens and warms the entering air
3. filters and cleans inspired air
4. serves as a chamber for speech
5. house the olfactory smell receptors
What 2 parts is the nose divided into?
1. nasal cavity
2. external nose
-air enters the cavity by passing through the nostrils
-divide by the nasal septum
-continuous through the choanae
-air comes in and meets the pharynx
-the naval cavity is continuous through here towards the pharynx
-separates the nasal cavity from the oral cavity below
-supported by the by palatine and maxillary bones
-unsupported and muscular
-lined with sebaceous glands and hair follicles just superior to the nostrils
-filter coarse particles (dust and pollen) from inspired air
What 2 mucosa membranes is the nasal cavity lined with?
1. Olfactory Mucosa
2. Respiratory Mucosa
-lines the slitlike superior region of the nasal cavity
-contains olfactory receptors in the olfactory epithelium
-lines most of the nasal cavity
-pseudostratified ciliated columnar epithelium
-contains goblet cells with supply the nasal glands
What do the nasal mucosa do?
-warms and humidifies the air
What does the epithelium do?
-its highly vascular and contains mucus cells which trap inhaled irritants, foreign objects, and bacteria
Seromucous Nasal Glands
-contain mucus secreting mucus cells and serous cells that secrete a watery fluid that contains enzymes
-the stickiness of the mucus traps inspired dust, bacteria, and other debris
-mucus containing antibacterial enzyme
-chemically destroys and attacks bacteria
What does the epithelium do in the nose?
-the epithelium cells secrete defensins which are natural antibiotics that kill invading microbes
Why do we have a runny nose?
-when our nasal cilia, but when exposed to cold air they become sluggish, allowing mucus to accumulate in the nasal cavity and dribble out the nostrils
-also, the water vapor in the expired air tends to condense at lower temperatures which causes a runny nose
Why do we sneeze?
-the nasal mucosa is supplied with sensory nerve endings and when they contact with irritating particles it triggers a sneeze reflex
-this allows a way for the irritants to be expelled
-similar to cough reflex
-increase the mucosal surface area that is exposed to air
-enhances air turbulence
-forces the air to contact the nasal mucosa which allows large foreign particles to stick to it
-filter, heat, and moisten air, and reclaim heat and moisture which allows our body minimize the loss of both helping us to survive in the cold and dry climates
-frontal, sphenoid, ethmoid, and maxillary bones
-warm and moisten air
-they produce mucus that flows into the nasal cavity which is comes out when we blow our nose
-lighten the skull
-when you bring your together and your teeth hurt, your gonna get a sinus infection because the maxillary sits on top of the root tips of the teeth and it drains causing pressure
-contour the cartilage and bone to change the shape
-separate the left and right nostril
-unequal chambers, but you can change them to make them equal
What does it mean when something went down the wrong tube?
-the epiglottis didn't close fast enough
How is the cough reflex triggered?
-columnar cilia pushes the stuff up through the wrong tube to the pharynx to trigger the reflex
Post Nasal Drip
-during the night, the sinus fluid drains from the maxillary sinus and drains to the back of the throat and irritates and causes the inflammatory process but as the day goes on, it drains and you feel better
-composed of skeletal muscle tissue
-amplifies/enhances sound quality
-serves only as the air passageway
-contains the pharyngeal tonsil which traps and destroys pathogens entering the nasopharynx in air
-both swallowed food and inhaled air pass through it
-has a protective stratified squamous epithelium to accommodate the increased friction and chemical trauma of food passages
-contains the palatine tonsil
-passage for food and air
-connects food and fluids to the stomach
What are the 3 functions of the larynx?
1. provide an open airway
2. act as a switching mechanism to route air and food into the proper channels
3. voice production
-large, shield shaped, is formed by the fusion of two cartilage plates
-marks the fusion point
-obvious when you see the Adam's Apple
-crest down the middle
-perched atop and anchored to the trachea
-1st ring of cartilage
-made of elastic cartilage
-when air is flowing into the larynx, the larynx is wide open and epiglottis is upward
-when you swallow, the epiglottis covers the laryngeal inlets which keeps food out of the lower respiratory passages
-guardian of the airways
-the vocal folds and opening between them through the air passes
-medial opening between vocal ligaments
Epithelium of Larynx
-stratified squamous epithelium lines the upper part of the larynx because of food contact
-below the vocal folds, the epithelium is a pseudo stratified ciliated columnar type that filters dust
-the power stroke of cilia is upward toward the pharynx which moves mucus away from the lungs
What happens when we clear our throat?
-we help to move mucus up and out of the larynx
What is speech?
-involves the release of expired air as the glottis opens and closes
Why does a boys voice crack as they hit puberty?
-the boys larynx enlarges during puberty his vocal folds become longer and thicker
-causes them to vibrate more slowly, his voice becomes deeper
-until he learns to control his newly enlarged vocal folds, his voice cracks
-inflammation of the vocal folds causes the vocal folds to swell which interferes with their vibration
-caused by viral infections
Why do the vocal folds act as?
-acts as a sphincter that prevents air passage
-has rings of hyaline cartilage that protect it
How does smoking affect the cilia?
-it inhibits and destroys the cilia and without cilia, coughing is the only way to prevent mucus from accumulating in the lungs
-smokers with respiratory congestion should avoid medications that inhibit the cough reflex
-air comes in and meets at the pharynx
-glucose + oxygen
-inflammation of nasal mucosa accompanied by excessive mucous production, nasal congestion, and post nasal drip
-other cartilage with a superior position
What are the 3 pairs of small cartilages found in the larynx?
-pyramid shaped cartilages, which anchor the vocal folds
True Vocal Cords
-lack blood vessels so it appears white
-vibrate to produce sounds as air rushes up from lungs
False Vocal Cords
-no direct part in sound production but help to close the glottis when we swallow
What does the loudness of the voice depend on?
-the force with which the airstream rushes across the vocal folds
-the greater the force, the stronger the vibration and the louder the sound
-vocal folds don't move when we whisper, but vibrate when we yell
What does good enunciation depend on?
-muscles in the pharynx, tongue, soft palate, and lips that shape sound into recognizable consonants and vowels
-determined by length
Why do we temporarily close our larynx?
-during coughing, sneezing, and Vasalva's maneuver
-during abdominal straining associated with defecation, the glottis closes to prevent exhalation and the abdominal muscles contract causing the intra-abdominal pressure to rise
-help empty the rectum and can stabilize the body trunk when lifting a heavy load
-common to have a heart attack during bowel movement because it gives more abdominal strength
What are the 3 layers of the trachea?
Mucosa of the Trachea
-goblet cell containing pseudo stratified epithelium that occurs thru out most of the respiratory tacts
Submucosa of the Trachea
-connective tissue layer deep to the mucosa
-contains seromucous glands that produce mucus sets
Adventitia of the Trachea
-outer layer supported by the C shaped rings of hyaline cartilage
-smooth muscle fibers that connect the cartilage rings
-C shaped and incomplete
-allows for expansion, coughing, sneezing, and yelling
-need more air pressure, more air exhaled
-C shaped rings prevent trachea from crashing
-a procedure in which air in the victim's lungs is used to expel an obstructing piece of food
-23 times it branches
-air passageways in the lungs branch and branch again
-at the tips of the bronchial tree, conducting zones give way to respiratory zone structures
What does the trachea divide into?
-forms the right and left main bronchi
Right Main Bronchi
-wider, shorter, and more vertical than the left and it more common for a foreign object to get stuck there
-once inside the lungs, each main bronchi divide into these
-three on the right, and two on the left supplying each lung lobe
-secondary bronchi branch into these and they divide into bronchioles
-more smooth muscle
-lack cartilage support and mucus producing cells
-go into alveolar sac
Conducting Zone Structures
Respiratory Zone Structures
How many alveoli are there?
What are the 3 structural changes that occur to the conducting tubes as they get smaller?
1. support structures
2. epithelium type
3. amount of smooth muscle increases
-thin walled air sac
-air that reaches alveoli goes to blood stream
-make up most of lung volume
-tremendous surface area for gas exchange
-essential for getting CO2 out
-one cell layer
-the respiratory zone begins as the terminal bronchioles feed into these
-alveoli protrude from these
-respiratory bronchioles lead into these
-walls are made of smooth muscle cells, connective tissue fibers, and out pocketing alveoli
-alveolar ducts leave into these
-similar to a bunch of grapes
Can alveoli be damaged?
-yes smoking can damage them
-collapse, shrivel up, and sometimes we can reinflate them
Pores of Kohn
-opening on alveoli
-when air comes along and there is a mucus plug, the alveolar pores offer a backdoor so air and gas can get into the alveolus
-where the trachea split into the bronchi
What are the 2 types of alveolar cells?
1. type 1 alveolar cells
2. type 2 alveolar cells
Type 1 Alveolar Cells
-make up alveolus
-capacity to produce different things, all organellese, produce ACE, influence blood pressure
-an ACE inhibitor can inhibit production in the lungs
Type 2 Alveolar Cells
-secrete surfactant and antimicrobial proteins that help immunity
-coats the alveolus and blocks the water molecules from sticking together
-only cell capable of doing this
-last thing to develop
-blood air barrier
-driven by diffusion from high to low
-blood flows past on one side and gas on the other
-gas exchange occurs through diffusion across the membrane
-oxygen pass from the alveolus to the blood, and CO2 leaves the blood to enter the alveolus
What happens if you have too much CO2 in your blood?
-affects your pH
-makes your blood acidic
-denatures proteins and can induce a coma
CO2 In Your Plasma
-when CO2 combines with water it becomes carbonic acid
-if you hold CO2 in your plasma (bloodstream) H2CO3 which is carbonic acid
-a weak acid, dissociates partially into HCO3 (bicarbonate), but it frees up hydrogen ions, which directly affects your pH level
-can cause respiratory failure
-pulmonary fibrosis can lead to this
Why are alveoli covered with elastic fibers?
-can stretch, holds them open and holds their shape, shrink up alveoli which helps push air out, and helps it regain shape after being stretched
-the recoil helps to squeeze air out
What do the capillaries on the alveoli do?
-allow time to be shaved off in diffusion
-keep lungs sterile
-keep lungs dry
What do the lungs occupy?
-all of the thoracic cavity except the mediastinum
How do you make CO2?
-by product of ATP
-oxygen concentration is high in alveoli, carbon dioxide goes out and moves from capillary to alveoli
-vascular and bronchial attachments that connect the lung to the mediastinum
-anterior, lateral, and posterior lung surfaces lie in close contact with the ribs and form the continuously curving
-narrow superior tip of thel ungs
-concave, inferior surface that rests on the diaphragm
-an indentation where the pulmonary and systemic blood vessels, bronchi, lymphatics, and nerves enter and leave the lungs
Do the 2 lungs differ in size and shape?
-yes, because the apex of the heart is slightly to the left so the left lung is smaller than the right
-divided into superior and inferior lobes by the oblique fissure
-divided into the superior, middle, and inferior lobes by the oblique and horizontal fissure
-housed in separate pleural cavities
-lined with serosa
-parietal pleura: lines the walls
-visceral pleura: covers the lungs
-has its own artery and vein and receives air from a tertiary bronchi
Why are the segments important?
-pulmonary disease is often confined to one or a few segments
-can removed diseased segments to be surgically removed without damaging neighboring segments or impairing blood supply
-elastic connective tissue
-lungs are soft, spongy, elastic organs
What 2 circulations are lungs perfused by?
1. pulmonary circulation
2. bronchial circulation
-systemic venous blood that is to be oxygenated in the lungs
-branch profusely, along with the bronchi
-feed into the pulmonary capillary networks that surround the alveoli
-convey the freshly oxygenated blood from the respiratory zone of the lungs to the heart
-low pressure, high volume circulation
-provide oxygenated systemic blood to lung tissue
-arise from the aorta and run along the bronchi
-supply all lung tissues except alveoli
-high pressure, low volume supply of oxygenated blood to all lungs tissues except the alveoli
-drain some systemic venous blood from the lungs
-anastomose between the two circulations and most venous blood returns to the heart via the pulmonary veins
-dilute oxygenated blood going back to the heart
What happens when there is water in the lungs?
-cause the stickiness would cause alveoli to stick together causing respiratory failure
-would cause it collapse
What happened to premature babies before technology?
- in premature babies, they don’t have surfactant which when they try to breathe in the humidify air which causes the alveoli to collapse
-died of respiratory failure
-now they can put a premature child in an incubator that contains surfactant which allows them to breathe in surfactant that keeps the alveoli from sticking together until they can breathe by themselves
-a thin, double-layered serosa
-covers the thoracic wall
-cover the organs
-the period when air flows into the lungs
-the period when gases exit the lungs
What happens when you inhale?
-when you inhale, ribs rise and your diaphragm drops down which changes the volume of the thoracic cavity making it bigger
-the air pressure inside the lungs allows the cavity to expand it creates a drop in pressure
-the air pressure outside is higher than in the lungs (1 atm) and things diffuse from high to low so the air rushes in
What happens when the diaphragm contracts?
-the diaphragm contracts it produces ATP
-during contraction it goes form dome to flatten shaped controlled by the phrenic nerve
it gradullay goes back into the dome shape, thoracic cavity gets smaller, pressure gets higher because you shrink the cavity down, and forces the air out
What is the number one muscle in respiration?
-tells diaphragm to contract and flattens out by the phrenic nerve
-general term for fluid accumulation in the pleural cavity
-can't see lobes or diaphragm
What 2 forces act to pull long away from thoracic wall which promote the lung to collapse?
1. elasticity of lungs which allows them to assume possible size
2. surface tension of alveolar fluid draws alveoli to smallest size
-elasticity of chest wall pulls thorax outward to enlarge lungs
-strong adherence between parietal and visceral pleura
-holds them open
-pressure in the pleural cavity (750 mmHg)
-fluctuates with breathing phases
-we need negative intrapleural pressure related to intrapulmonary because it makes lungs expand
-pressure in the alveoli
-rises and falls with the phases of breathing, but it always equalizes with the atmospheric pressure eventually
Why is pleural pressure less?
-pressure needs to be different because if the same, nothing would happen
-slight change in pressure is enough to allow lungs to expand
-air in the pleural cavity
-reversed by drawing air out of the intrapleural space with chest tubes
-allows pleura to heal and the lungs to reinflate and resume normal function
-but one can collapse without the other one because they are in different cavities
-punctures the intrapleural pressure
-pressure to increase because air from outside rushes in because of diffusion which will inhibit the lung from inflating which will make it collapses
-no one hurt or touched them
-common in men
-pleural cavity remains intact
-blebs (blisters), you don’t you have them and one day the rupture causing an opening into the alveoli and lungs so when you breathe in air, the pressure causes the bleb to open and air sneaks out and goes into the pleural cavity causing a gradual pressure increase in the intrapleural pressure cavity
-major source of resistance is friction
As air resistance increase...
-breathing movements are more strenuous
Severely constricted/obstructed bronchioles...
-prevent life sustaining ventilation
-can occur during an acute asthma attack which stops ventilation
-smooth muscle is very sensitive to histamine
-release through the sympathetic nervous system and dilates bronchioles and reduces air resistance
What is the wheezing sound?
-air trying to squeeze through the bronchioles
-shrinks up tissues, and increase air resistance
-ease with which lungs can be expanded
-the measure of the change in lung volume that occur with a given change in transpulmonary pressure
What 2 factors affect lung compliance?
1. distensibility of lung tissue and surrounding thoracic cage
2. surface tension of the alveoli
-can you fill them and will they expand
-need people after surgeries to walk around so they can ventilate the ribs
-arthritis between the sternum and the ribs is the number one cause
-ossification of the costal cartilage
Reduce Lung Compliance
-scar tissue (fibrosis)
-blockage of respiratory passages
-reduced production of surfactant
-decreased flexibility of thoracic cage or its decreased ability demand
Anatomical Dead Space
-volume of the conducting respiratory passages (150 mL); air in bronchi
Does all the air find its way to the alveoli?
-no because no exchange is going on
Alveolar Dead Space
-alveoli that cease to act in gas exchange due to collapse or obstruction
Total Dead Space
-sum of alveolar & anatomical dead space
Alveolar Ventilation Rate
-measures flow of fresh gases into & out of the alveoli during a particular time; more accurate as it takes into account dead space
-frequency x (tidal volume(breaths/min)-dead space(ml/min))
-slow, deep breathing increase it, and rapid, shallow lower it
-decreases AVR as increase in volume increases amount of air reaching alveoli more than increase in frequency breathing rate
Pulmonary Function Test
-Spirometry can distinguish between:
-obstructive pulmonary disease: increased airway resistance
-restrictive disorders: reduction in total lung capacity from structural or functional lung changes
-total amount of gas flow into or out of the respiratory tract in 1 min
-12 breaths per minute (6L/min)
Force Vital Capacity
-gas forcibly expelled after taking a breath
Forced Expiratory Volume
-amount of gas expelled during specific time period of the FVC test
Why do we yawn?
-to delivery more oxygen to lungs
-adrenaline racing before race
-yawn when bored
-in reality, we don't know
-can lead to syncopy
-no pulse at all
-major vasodilation and their heart rate drops down
Nonrespiratory Air Movement
-movements that don't allow for gas exchange
How fast is a sneeze and how far does it go?
-35 mph and 17 feet
Dalton's Law of Partial Pressure
-total pressure exerted by mixture of gases is sum of pressures exerted independently by each gas mixture
-the partial pressure of each gas is directly proportional to its percentage in the mixture
-mixture of gas is in contact with a liquid, each gas will dissolve in liquid in proportion to its partial pressure
-the higher the concentration the faster it will go into solution and more of it will go into solution
-depends upon solubility, and temperature and pressure
Various Gases in Air Have Different Solubilites
-CO2 is the most
-O2 is 1/20th as CO2
-N is insoluble in plasma
Whats the hissing noise of pop?
-carbon dioxide by forcing it into the bottle and when you open it up it breaks out of the pressure and then it gets flat because there is no more CO2
Partial Pressure Gradients and Gas Solubilities
-if the concentration of 02 is 40mmHg and 30 mmHg on the other side and on the other its 40mmHg and 10 mmHg it would move faster on the second one because the concentration gradient is bigger, a steep concentration gradient
-this drives it across the membrane
Why is there a steep gradient between oxygen and carbon dioxide?
-partial pressure oxygen (PO2) of venous blood is 40mmHg; the partial pressure in the alveoli is 104mmHg
-steep gradient allows oxygen partial pressures to rapidly reach equilibrium (.25 seconds)
-blood can move three times as quickly (.75 seconds) through the pulmonary capillary and still be adequately oxygenated
-oxygen is higher and carbon is lower
Alveoli of Lungs
-oxygen is lower but higher than oxygen because alveoli takes a few molecules
-carbon dioxide is higher
Blood Leaving Tissues and Entering Lungs
-oxygen is lower than carbon dioxide
Blood Leaving Lungs and Entering Tissue Capillaries
-oxygen is higher and carbon is lower
-oxygen is less than 40 and carbon is greater than 45
-you are able to breathe into them because you have a lot of O2 that you breathe out
Ventilation vs. Perfusion
-how much air we breathe ion that get to alveoli perfuses tissue (gets to blood)
-we lose some, so not 100% get to tissues
-either too high or too low
-able to get air into lungs
-getting oxygen through respiratory membrane to the circulation
-blood supply to the lungs and ability to oxygenate the hemoglobin inside
Mismatch of Ventilation and Perfusion
-ventilation drop and or perfusion rise of alveoli causes local CO2 to increase and O2 rises
-pulmonary arterioles serving these alveoli constrict
-shunt the blood away from the alveolus
Ventilation Greater than Perfusion
-ventilation is high and or perfusion is low of alveoli causes local CO2 to be low and O2 high
-pulmonary arterioles serving these alveoli dilate
-to pick up as much oxygen as you can
Ventilation Perfusion Coupling
-they both must be tightly regulated for efficient gas exchange
-changes in CO2 causes changes in the diameter of the bronchioles
-where CO2 is high, dilate to get it out of the body
-where CO2 is low, constrict
What happens when oxygen levels are low?
-in the lungs where oxygen levels are low, the vessels will vasoconstrict in order to shunt the blood to areas where the concentration of oxygen is higher and increase the amount of oxygen and hence hemoglobin
-breathe really quickly, and rapidly
-frighten, pain, and anxiety
-changes in breathing rate
-light headedness due to breathing rapidly and hyperventilating
-caused by increase output of carbon dioxide that causes vomiting
-with profound pain, it produces vomiting as a reflex
-order this to rule out a pulmonary embolism that usually comes from the legs to the lungs
What are the 3 steps to the VQ scan?
1. radioactive compound inhaled into airspace of lung. In a normal lung this will distribute evenly to all regions
2. radioactive compound injected into vein. Travels to lung tissues in blood vessels. (pulmonary embolus is a blood in a pulmonary artery)
3. mismatch of inhaled and injected compounds on the lung scan images=pulmonary embolus
Why do lungs thicken?
-they become waterlogged and edematous, whereas by gas exchange is inadequate & oxygen deprivation results
-can be congestive heart failure or pneumonia
-oxygen bound to hemoglobin
-when all four hemes of the molecule are bound to oxygen
-ability for it to bind to hemoglobin
Partially Saturated Hemoglobin
-when one to three hemes are bound to oxygen
What is the rate that hemoglobin binds and releases regulated by?
-temperature influences the ability for it bind
-concentration of BPG which a by product of glycolysis
-increase partial pressure: increase O2 affinity to bind HMG
-decrease partial pressure of O2 will decreae
-increase in temperature decreases the affinity
-a decrease in pH increase affinity
CO2 Levels High
-concentration of O2
Lower Temp. In Lungs
-higher affinity of O2
O2 Deep in Tissue
-drop off O2
-higher, lower affinity of O2
Higher CO2 Concentration Deeper in Tissues
-they decrease the affinity of oxygen
-comes from aerobic respiration
Why does breathing increase the PO2?
-saturation of hemoglobin in arterial blood increase the PO2, but has little effect on O2 saturation in Hemoglobin
What percent of saturated arterial blood contains 20 mL O2?
How much is released as it flows through capillaries?
-5mL of O2
What happens once hemoglobin is saturated?
-has nowhere to go, forms O3 stripping away electrons from healthy molecules
-antioxidants prevent O3
At what number is hemoglobin almost completely saturated?
-PO2 of 70 mmHg
-if it increases in PO2, it will only produce small amounts of O2 in binding
When is O2 loading and delivery to tissues adequate?
-when PO2 is below normal levels
Carbon Monoxide Poisoning
-not as much CO2
-affinity for hemoglobin, but carbon monoxide has greater affinity
-damage done as binding receptors for O2 with CO
-more O2 pops off
-now body is deprived of O2
Hemoglobin Saturation Curve
-if O2 levels drop, we go to reserve
-more O2 dissociates from hemoglobin and used by cells
-respiratory rate or cardiac output does not increases
High Temperature, H, PCO2, BPG
-decrease in hemoglobin affinity for O2
-enhance O2 unloading form blood
-as cells metabolize glucose, CO2 is released causing a decline in pH (acidosis), which weakens the hemoglobin and oxygen bond
-increase in PCO2 and H concentration in capillary blood
-metabolizing cells have heat as a by product
What 3 ways in carbon dioxide transported?
1. dissolved in plasma (7-10%)
2. chemically bound to hemoglobin (20% carried in RBCs as carbaminohemoglobin HbCO2)
3. as bicarbonate ions in plasma (70%) transported as bicarbonated
Carbonic Acid/Bicarbonate Buffer System
-enzyme that speeds up equation reaction
-H binds to plasma proteins
-free H bind to plasma protein, no enzyme
-H binds with hemoglobin from HbO2->O2+Hb(buffer_
-O2 gives H a spot
-bicarb rejected bring chloride shift
-H binds with Hb open b/c O2 is knocked off Bicarb to plasma
-HCO3 moves into the plasma where it then goes to the lungs
-to balance this, chloride ions move from the plasma into the RBCs
-occurs thru an RBC protein
Fast Reaction to Lungs
-reverse chloride shift
-the lower PO2 & Hb saturation with O3, the more CO2 can be carried in blood
-dissociation of O2 from Hb allows more CO2 to bind
-as O2 jumps off Hb, CO2 can bind because their is more and it changes the shape
-bohr effect can effect this by change in pH
-low pH affects affinity
-allows CO2 to accumulate dropping pH
Control Respiration in Medulla
-CO2 concentrations in plasma influence what happens in brain
-CO2 levels in plasma circulate and diffuse through BBB to CSF
-CSF responds to H concentration thru chemoreceptors and they response to high in CO2
-cause vasoconstriction (-) effect
-receptors in muscles and joints