Chapter 10.2: Respiratory System

what is the exchange of gases between the outside environment and inside of an organism

respiration

what organ is located in the thoracic cavity and are covered by the ribcage

lungs

how many lobes does the left lung have

2

how many lobes does the right lung have

3

what covers the lungs and is a dual-layered membrane

pleura

what is a large skeletal muscle at the bottom of the lungs involved in inspiration and expiration unique to all mammals

diaphragm

what is a fluid-filled space in between the 2 layers of the pleura

pleural space

what does the pleural space being at a lower pressure than the atmosphere creates

intrapleural pressure

what does inspiration/inhalation involve

diaphragm and external intercostal muscles contraction

what does the diaphragm do during inspiration/inhalation

pulls lungs down

what does the external intercostal muscles do during inspiration/inhalation

expands rib cage

what does the contraction in inspiration/inhalation cause

decrease intrapleural space pressure, increase lung volume bringing air into lungs

what does expiration/exhalation involve

diaphragm and external intercostal muscles relaxation

what does the diaphragm do during expiration/exhalation

bring lungs back up

what does the external intercostal muscles do during expiration/exhalation

close rib cage

how does the external intercostal muscles close the rib cage during expiration/exhalation

elastic recoil

what does relaxation in expiration/exhalation cause

increase intrapleural space pressure, decrease lung volume driving air out of lungs

what can internal intercostal muscles do in expiration/exhalation

contract during a more forced expiration closing rib cage more

what is the pathway of air step 1

air inhaled through nose and mouth

what is the pathway of air step 2

food and air enter the pharynx

what organ is the beginning of the throat after the nasal cavity and mouth

pharynx

what is the pathway of air step 3

larynx receives air, epiglottis prevents anything but air from entering larynx and lungs

what organ contains the voice box

larynx

what organ diverts foods and liquids into the esophagus

epiglottis

what is the pathway of air step 4

trachea splits into bronchi

which organ is below the larynx

trachea

what is the pathway of air step 5

left and right bronchi split into smaller bronchioles and eventually into alveoli

what organ is the main lung tubes

bronchi

what organ is the branched and smaller lung tubes

bronchioles

what does the alveoli contain

specialized cells producing surfactant

what is surfactant

substance preventing alveoli from collapsing by reducing surface tension within them

what do nasal cavity, bronchi, bronchioles contain

goblet cells, ciliated epithelial cells

what do goblet cells do

secrete mucus

what do ciliated epithelial cells do

possess beating cilia

why do nasal cavity, bronchi, bronchioles contain goblet cells and ciliated epithelial cells

to trap and remove debris that enters the respiratory tract

what is the overall pathway of air in order

nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli

what is the gas exchange between blood and tissues

internal respiration

what is the gas exchange between insppired air and lung alveolar capillaries

external respiration

what is the pathway of oxygen in the body

air, blood, tissues

what is the pathway of carbon dioxide in the body

tissues, blood, air

what are erythrocytes

red blood cells

what cells contain hemoglobin

erythrocytes

how does carbon monoxide (CO) poisoning happens

when hemoglobin has a higher binding affinity for CO than for oxygen

which molecule transports most of the oxygen traveling in the blood

oxyhemoglobin (HbO2)

what describes the process by which the binding of 1 oxygen molecule to hemoglobin makes it easier for others to bind due to changes in the shape of the hemoglobin polypeptide

cooperativity

what happens when cooperativity works in reverse

allows efficient oxygen unloading in body tissues

what reveals the relationship between hemoglobin saturation with oxygen in the blood and partial pressure of oxygen

oxygen dissociation curve

what conditions shift the oxygen dissociation curve to the left

decreased CO2, increased pH, decreased temp, decreased 2,3-DPG

what conditions shift the oxygen dissociation curve to the right

increased CO2, decreased pH, increased temp, increased 2,3-DPG

what does a right-shifted curve of a oxygen dissociation curve corresponds to

lower affinity for oxygen in hemoglobin

why is decreased pH a reason for a right-shifted curve

higher H+ conc producing reduced hemoglobin which has lowered affinity for binding oxygen

why is high partial pressure of carbon dioxide a reason for a right-shifted curve

more CO2 converted to bicarbonate anions (HCO3-) and proteins lowering oxygen binding affinity through decreased pH

why is decreased in 2,3-diphosphoglycerate (2,3-DPG) / 2,3-biphosphoglycerate (2,3-BPG) a reason for a right-shifted curve

accumulates in cells that undergo anaerobic respiration as a result of oxygen loss decreasing oxygen binding affinity so more oxygen is released from hemoglobin to fuel aerobic respiration

why is increased body temperature a reason for a right-shifted curve

correlates to more cellular respiration using up oxygen producing more CO2 making hemoglobin need to unload more oxygen for tissues to use

what does a left-shifted curve of a oxygen dissociation curve corresponds to

increased affinity for oxygen in hemoglobin

why is increased pH a reason for a left-shifted curve

fewer protons to produce reduced hemoglobin for more oxyhemoglobin to remain

why is low partial pressure of carbon dioxide a reason for a left-shifted curve

less CO2 converted to HCO3- and H_ leading to increased oxygen bidning affinity through increased pH

why is fetal hemoglobin a reason for a left-shifted curve

binds oxygen better than adult hemoglobin to help give oxygen to fetus

why is decreased body temperature a reason for a left-shifted curve

less cellular respiration so hemoglobin isnt infleunced to unload more oxygen

what is the mnemonic to remember the conditions for right-shifted oxygen dissociation curve

CADET, face RIGHT

what is CADET, face RIGHT

Carbon dioxide, Acid, 2,3-Diphosphoglycerate, Exercise, Temperature. CADET increase Right shifted curve

what is it called when hemoglobin has decreased oxygen affinity when CO2 is high

Bohr effect

what happens in the Bohr effect

CO2 converts to bicarbonate anions and protons producing reduced hemoglobin

what is it called when hemoglobin has increased CO2 affinity when oxygen is low

haldane effect

what is the result of low oxygen in the haldane effect

reduced hemoglobin levels are higher having a greater affinity for CO2

what is the main extracellular buffering system in the body that maintains blood pH of 7.4

bicarbonate buffering system

what equation describes the blood pH

CO2 + H2O = H2CO3 = HCO3^- + H⁺

what is the bicarbonate buffering system catalyzed by

carbonic anhydrase in both directions based on concentrations

what is the result when the erythrocytes in the systemic circulation and CO2 partial pressure is low

CO2 continuously diffuses in from tissues and converted into bicarbonate and H+

which molecule can diffuse out of the cell and which cannot leave

bicarbonate, protons

what happens when bicarbonate diffused out of the cell

creates positive charge within erythrocyte making Cl- diffuse into the blood cell to cancel out + charge of protons known as chloride shift

what does the influx of protons from bicarbonate diffusing out of the cell cause in the erythrocyte

decreases pH which converts oxyhemoglobin into reduced hemoglobin

lung gas exchange step 1

blood travels to lungs through bulk flow

lung gas exchange step 2

bicarbonate ions re-enter erythrocytes at the lungs and Cl- leave through reverse chloride shift

lung gas exchange step 3

bicarbonate buffer system equation proceeds in reverse producing Co2 and H2O

what does the CO2 do when the bicarbonate buffer system equation proceeds in reverse

exits into alveoli as glas

what does the oxygen do when the bicarbonate buffer system equation proceeds in reverse

enters blood forming oxyhemoglobin

what structure is located in the brain and controls diaphragm to regulate respiratory rate

medulla oblongata

what signals to the medulla

central and peripheral chemoreceptors

what receptors are located in the medulla and are contained within the blood-brain barrier

central chemoreceptors

what happens as CO2 accumulates

acidity increases directly sensed by central chemoreceptors signaling medulla to increase breathing rate

which receptor surround the aortic arch and carotid arteries

peripheral chemoreceptors

what happens when CO2 is high and oxygen is low

peripheral chemoreceptors signal medulla to increase breathing rate

what is the the primary stimulator for breathing

CO2

what is respiratory acidosis

lowered blood pH occurs due to inadequate breathing

what is respiratory alkalosis

uncreased blood pH occurs due to rapid breathing

what is inadequate breathing

hypoventilation

what is rapid breathing

hyperventilation

what is metabolic acidosis

lowered blood pH

what is metabolic alkalosis

increased blood pH

what does metabolic acidosis and metabolic alkalosis occur as a result of

imbalances in CO2, O2, H+ levels