MCA BIO CH. 12 PART 1 Flashcards
What parts of glucose metabolism produce carbon dioxide?
Pyruvate dehydrogenase and Krebs cycle during oxidative respiration
What parts of glucose metabolism utilizes oxygen?
Oxygen is reduced to water by cytochrome c oxidase
What is the conduction zone based on respiratory system?
Parts that participate only in ventilation
What is ventilation?
Air into and out of the lungs
What is the respiratory zone?
Parts that participate in gas exchange
What happens to the blood when Co2 is exhaled?
Amount of carbonic acid in the blood decreases so pH increases
How does hyperventilation and hypoventilation affect the blood?
Causes alkalization fo the blood, increase pH; acidification fo the blood, decreases pH
What is respiratory alkalosis?
Alkalization of the blood
What is respiratory acidosis?
Acidification of the blood
How can the reparatory organ be considered thermoregulation?
Breathing can result in significant heat loss
Heat loss from respiratory system occurs through…?
Evaporative water loss
How can the respiratory system be considered protection from disease and particulate matter?
The mucociliary escalator and alveolar macrophages protect from harmful inhaled particles
What is the pathway of the inhaled air, starting with the pharynx?
Pharynx, larynx, trachea, bronchi, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveoli
What in the nose acts as filters?
Nasal hairs and sticky mucus
What is the pharynx?
The throat
What are the three functions of the larynx?
- Keeps airway open
- Seals trachea during eating
- Produces sound
How can the larynx produce sound?
Contains vocal cords
How can the larynx seal the trachea during eating?
Contains epiglottis to do so
What is the trachea?
A passageway which must remain open to permit air flow
What prevents the trachea from collapsing?
Rings of cartilage prevent its collapse
What does the trachea branch off into?
Two primary bronchi
What prevents collapsing of bronchi?
Small plates of cartilage
What are bronchioles?
Small bronchi
What allows the diameter bronchioles to be regulated?
The walls are made out of smooth muscle; adjust airflow into the system
What are terminal bronchioles?
The smallest branches of the conduction zone
Gas exchange can occur in terminal bronchioles?
False: smooth muscle of the walls are too thick to allow adequate diffusion of gases - it is strictly for ventilation
Based on the respiratory system, which structure has gas exchange?
Alveolus
What is the alveolar duct?
Duct leading to the alveoli
What leads into the alveolar duct?
Respiratory bronchiole
What allows the respiratory bronchiole to perform gas exchange?
It is part of the respiratory zone
The respiratory tract lined by what?
Epithelial cells
How are the epithelial cells from the nose to the bronchioles?
Tall columnar
What is the purpose of the tall columnar?
Conduit for air
What is the purpose of goblet cells?
Secrete a layer of sticky mucus
What is the purpose of the cilia on the columnar epithelial cells of the upper respiratory tract?
Sweep the layer of mucus towards the pharynx
What is the mucociliary escalator?
Mucus containing pathogens and inhaled particles can be swallowed or coughed out
What are the three structures involved in gas exchange?
Alveoli, alveolar ducts and smallest bronchioles
What is simple squamous epithelium?
A single layer of squamous epithelial cells
What prevents alveoli from being covered in pathogens?
Alveolar macrophages patrol the alveoli and engulf foreign particles
What is the purpose of surfactant?
Coats the alveoli to reduce surface tension
What is surfactant made out of?
Complex mixture of phospholipids, proteins and ions secreted by cells in the alveolar wall
What is pulmonary ventilation?
Circulation of air into and out of the lungs to continually replace the gases in the alveoli
What is inspiration? and expiration?
Inspiration: Air into the lungs Expiration: Air out of the lungs
What type of process is inspiration and why?
Active process: driven by the contraction of the diaphragm which enlarges the chest cavity
What type of process is expiration and why?
Passive process: driven by the elastic recoil of the lungs and does not require active muscle contraction
What allows the lungs to not collapse on itself?
Chest cavity; inflate during inspiration and expiration
What are the membranes surrounded by each lung?
- Parietal pleura 2. Visceral pleura
Where is the parietal pleura?
Lines the inside of the chest cavity
Where is the visceral pleura?
Lines the surface of the lungs
What is between the two pleura spaces?
Pleural space
What allows both pleural membranes to be tightly drawn together?
Pleural pressure is negative and drawn tightly together by a vacuum
The negative pressure keeps what, based on the pleural membranes?
Keeps the outer surface of the lungs drawn up against the inside of the chest wall
Why is there a layer of fluid between the two pleura?
Helps hold them together through surface tension
What is inspiration caused by?
Muscular expansion of the chest wall
What does the muscular expansion of the chest wall allow the lungs to do?
Draws the lungs outward and causes air to enter the system
The expansion of the chest during inspiration is driven primarily by…?
Contraction of the diaphragm
What is the diaphragm?
Large skeletal muscle that is stretched below the ribs between the abdomen and the chest cavity
Where are the intercostal muscles?
Between the ribs
What happens to the intercostal muscles during inspiration?
They contract, pulling the ribs upward and further expanding the chest cavity
Why is resting expiration considered a passive process?
No muscle contraction is required
What happens when the diaphragm relaxes?
Elastic recoil of lungs draws chest cavity inward; volume of the lungs are reduced and air pushes out
Why does abdominal muscles contracting helps during exertion? (Example; expiration process)
Pressing up on the diaphragm, shrinking the size of the lungs and forcing more air out
What is forced expiration?
Abdominal muscles contraction and forcing more air out
What is spirometry?
Measurement of the volume of air entering and exiting the lungs at various stages of ventilation
Where can data from a spirometer be plotted?
On a spirometric graph
What is tidal volume?
Amount of air that moves in and out of the lungs with normal light breathing (TV)
What is the tidal volume equal to based on total volume?
Equal to about 10% of the total volume of the lungs
What does ERV of the lungs stand for?
Expiratory reserve volume
What is the ERV?
The volume of air that can be expired after a passive resting expiration
What does IRV of the lungs stand for?
Inspiratory reserve volume
What is the IRV?
The volume of air that can be inspired after a relaxed inspiration
What does FRC of the lungs stand for?
Functional residual capacity
What is the FRC?
The volume of air left in the lungs after a resting expiration
What does IC of the lungs stand for?
Inspiratory capacity
What is the IC?
Maximal volume of air which can be inhaled after a resting expiration
What does RV of the lungs stand for?
Residual volume
What is the RV?
Amount of air that remains in the lungs after the strongest possible expiration
What does VC of the lungs stand for?
Vital capacity
What is the VC?
Maximum amount of air that can be forced out of that aligns after first taking the deepest possible breath
What does TLC of the lungs stand for?
Total lung capacity
What is the TLC?
The vital capacity plus the residual volume (TLC = VC + RV)
What carries bad blood towards the lungs?
Pulmonary artery
What does the pulmonary arteries lead into?
Pulmonary capillaries
What do pulmonary arteries drain into?
Venules, which drain into pulmonary veins
Other than the pulmonary arteries, what other things is the lungs supplied by?
Lymphatic vessels
What is pulmonary edema?
Fluid in the lungs resulting from increased blood pressure
Which system prevents pulmonary edema and how?
Lymphatic system by carrying interstitial fluid out of the lungs
What does the lungs have in order to expose blood to air?
Enormous surface area
What is the goal of the lungs in exposing the blood to a large amount of air?
Allow oxygen from the atmosphere to diffuse into pulmonary capillaries to be bound in RBCs
What happens simultaneously when RBC takes the oxygen from diffusion?
Carbon dioxide diffuses from the blood to the alveolar gas
How is CO2 carried in the blood?
Most is transported as HCO3- + H+ (carbonic anhydrase)
What is partial pressure?
The contribution of each individual gas to the total pressure
What partial pressure of Gas X is abbreviated…?
Px
How much oxygen is in the atmospheric gas composition?
20%
How much nitrogen is in the atmospheric gas composition?
80%
How much water is in the atmospheric gas composition?
0.5%
How much carbon dioxide is in the atmospheric gas composition?
0.04%
In order to diffuse into a cell, gas molecules must what?
Dissolve into a liquid (extracellular fluid)
What is Henry’s Law?
Amount of gas that will dissolve into liquid is dependent on the partial pressure of that gas and solubility of that gas in that liquid
What is the henry’s law equation of oxygen?
[O2] = PsubscriptO2 X SsubscriptO2
What does [O2] stand for in the henry’s law of equation of oxygen?
The concentration of dissolved oxygen
What does P subscript O2 stand for in the henry’s law of equation of oxygen?
Partial pressure of oxygen in the air above the fluid
What does S subscript O2 stand for in the henry’s law of equation of oxygen?
The solubility of oxygen in that liquid
Based on the Henry’s law equation for oxygen, an increase in pressure increases the amount of…?
Gas dissolved in a liquid
What happens to gases solubility to liquid when temperature increases?
Becomes less soluble to liquids
Why does gases dissolved into the blood and extracellular fluids more readily at depth?
Because of the high pressure of the surrounding water
What happens to scuba divers when they ascend too quickly?
The gases come out of solution before they can be transported to the respiratory system
What drives the net diffusion of oxygen into the blood when the blood passes through the alveolar capillariesÉ
The oxygen pressure gradient between the alveolar air and the blood
How is the arterial PO2 denoted?
PaO2
What is the respiratory control center and where is it located?
Involuntary process for breathing; located in the medulla of the brain stem
What are the types of stimuli that affect ventilation rate?
Mechanical and chemical
What are the principal chemical stimuli that affect ventilation rate?
Increased PCO2, decreased pH, and decreased PO2
What are the primary regulators of the ventilation rate and what are the secondary ones?
Co2 and pH are primary, O2 is secondary
How are the chemical stimuli of ventilation monitored?
- Peripheral chemoreceptors
2. Central chemoreceptors
Where are peripheral chemoreceptors located?
Located in the aorta and the carotid arteries
What do the peripheral chemoreceptors monitor?
The PCO2, pH and PO2 of the blood
Where are central chemoreceptors located?
Located in the medullary respiratory control center
What do the central chemoreceptors monitor?
Monitor PCO2 and pH of the cerebrospinal fluid
How are the pH and PCO2 connected?
Through the carbonic acid buffer system of the blood
What is the carbonic acid buffer system equation?
CO2 + H2O = H2CO3 = H+ + HCO3-
How can ventilation rate have effects on pH?
Due to increase or decrease in PCO2; resulting in the shift to maintain the equilibrium of carbonic acid buffer system
Why do people having an anxiety attack are told to breathe in a paper bag?
It forces them to rebreathe their exhaled CO2 and pushes the equilibrium to the right and brings pH back down to normal
What are the principal mechanical stimuli that affect ventilation rate?
Lungs and irritants
What happens during the mechanical stretching of lung tissue?
Stimulates stretch receptors that inhabit further excitatory signals from the respiratory center to the muscles involved in inspiration
What do the walls of bronchi and larger bronchioles contain?
Smooth muscle
What is bronchoconstriction?
Contraction of smooth muscles of the walls of bronchi or larger bronchioles
What happens when there’s irritation of the inner lining of the lung?
Stimulates irritant receptors and reflexive contraction of bronchial smooth muscle
Why does the bronchial smooth muscle contract when there’s irritation of the inner lining of the lung?
Prevents irritants from continuing to enter the passageways
The contractile response of the bronchial smooth muscle is determined by what?
Parasympathetic nerves that release ACh
What are the two hormones that affect bronchoconstriction?
Histamine contracts
Epinephrine opposes
How does epinephrine affect bronchoconstriction?
Causes it to relax; increases ventilation with bronchodilation
What is asthma caused by?
Spasm of airway smooth muscles
What triggers coughing or bronchoconstriction based on an irritating chemical being detected?
Irritant receptors
What stimuli might cause an increase in respirator rate?
Decrease in pH or PO2
What does the epidermis lie on?
Dermis
What does the dermis lie on?
On subcutaneous tissue or hypodermis
What is the hypodermic?
Protecting insulting layer of fat - adipose tissue
What is the epidermis composed of?
Stratified squamous epithelial cells
What replenishes the epithelial cells from the epidermis?
Stratum basal
Why are stratified squamous cells of the epidermis are keratinized?
Thick coating of the tough, hydrophobic protein keratin; keratin helps make the skin waterproof
What does melanin do?
Absorb UV light of the sun to prevent damage of underlying tissues
What does the dermis contain?
Various cell-types in a connective tissue matrix, blood vessels, sensory receptors, sweat glads, oil glands and hair follicles
What is the name of wax glands and where are they located?
Ceruminous; specialized regions of skin - external ear canal
What is the name for the sweat gland?
Sudoriferous gland
What is the sudoriferous gland composed of?
A tube-like structure that originates in the dermis and leads through the epidermis to a pore on the surface of the skin
What does sweat contain?
Water, electrolytes and urea
What hormone is sweat responsive to?
Aldosterone
People living in hot climates, why do they have high level of aldosterone?
So sweat does not waste salt
Humans are homeotherms, what does that mean?
They body temperature is relatively constant
How is heat generated in humans?
Metabolic processes and muscle contraction
What can homeotherms burn to maintain their temperature?
Burning special fat called brown adipose tissue
What is the name of the process of burning special fat to maintain their temperature?
Chemical thermogenesis or nonshivering thermogenesis
What are the four mechanisms available to humans to cope against cold weather?
- Contraction
- Skin insulates
- Cutaneous vasoconstriction
- Clothing
What is cutaneous vasoconstriction?
Heat loss by conduction is minimized by constriction blood vessels in the dermis
What are the mechanisms for dissipation available to humans?
- Sweating
2. Cutaneous vasodilation
What is cutaneous vasodilation?
Dilation of blood vessels in the dermis, results in heat loss by conduction or convection
