Respiratory System Flashcards
The primary functions of the respiratory system
1) smell
2) air conduction
3) the exchange of oxygen and carbon dioxide between the animal and the environment
It is the exchange of oxygen and carbon dioxide between the animal and the environment
respiration
This provides oxygen to body tissues for cellular respiration, removes the waste product carbon dioxide, and helps to maintain acid-base balance.
Respiration
What are the uses of the portions of the respiratory system?
Used for non-vital functions: sensing odors, speech production, and;
Used for straining: during childbirth or coughing
Where does respiration occur, which lies at the most distal part of the respiratory tract?
at the air-blood interface
The ultimate functional goal of the respiratory tract
Exchange of oxygen and carbon dioxide
The two crucial functions of the respiratory tract
air conduction and respiration
Therefore, the two crucial functions of the respiratory tract are air conduction and respiration. The importance of considering these two roles is apparent during ________.
respiratory disease
These are composed of a single layer of squamous epithelium (type 1 alveolar cells or pneomocytes), scattered cuboidal type II alveolar cells secrete surfactants and antimicrobial proteins; no gas exchange, secrete oily surfactant in humid/watery environment (liquid has the tendency to stick together, try to collapse alveoli) this can be prevented by surfactant. Has an extensive but small capillary network.
Alveoli walls
Has an extensive but small capillary network.
Alveoli walls
Alveoli walls are composed of what?
*single layer of squamous epithelium (type 1 alveolar cells or pneomocytes)
*scattered cuboidal type II alveolar cells
scattered cuboidal type II alveolar cells secretes what?
surfactants and antimicrobial proteins
surfactants and antimicrobial proteins are secreted by what?
cuboidal type II alveolar cells
liquid has the tendency to stick together, try to collapse alveoli, this can be prevented by what?
surfactant
It connects adjacent alveoli and equalizes air pressure throughout the lungs.
Alveolar pores
keep alveolar surfaces sterile, 2 million dead macrophages/hour carried by cilia – throat – swallowed.
Alveolar macrophages
A chamber that connect to multiple individual alveoli, surrounded by fine elastic fibers and pulmonary capillaries, only to respond to stretching, and recoil; skeletal muscles would be too thick, (we do not want this to prevent gas flow to capillaries)
Alveolar sacs
this is the relationship between the pressure and volume of a gas, gasses fill the container: if the container size is reduced – the pressure increases (P). Pressure varies inversely with volume. Changes in thoracic/lung volume of the pleural cavities – the movement of the chest wall or diaphragm will directly affect the volume of the lung by changing the volume of pleural cavities.
Boyle’s Law
trachea branches into two primary bronchi (right/left), one on each lung secondary bronchi branch off primary; enter lung lobes (2 on left lung, 3 on right), one to each lobe tertiary bronchi (9-10 branches each lung) supply bronchopulmonary segment - C shaped rings are now offset, protects from all directions - bronchioles branch into alveoli
Brochial tree
cuboidal epithelial cells with apical microvilli located within and distal to bronchioles
Club cells (Clara cells)
These are rich in metabolic enzymes (cytochrome P450 enzymes) and therefore serve a major role in the biotransformation of inhaled xenobiotics.
Club cells (clara cells)
What kind of epithelial tissue are the club cells?
cuboidal epithelial cells
The pathway moving air; no gas exchange, includes all structures from nasal cavity to larger bronchioles, this also cleanses, warms and humidifies the air and cools the air on way out (maintains homeostasis), facilitates the exchange, needs a head for diffusion, lines with respiratory mucosa with cilia; traps and get rid of particles before they go into lungs; pseudostratified ciliated columnar epithelium.
Conducting zone
What kind of epithelial tissue is the conducting zone?
pseudostratified ciliated columnar epithelium
columnar epithelial cells that produce and secrete mucin
Goblet cells
Goblet cells secretes what?
Mucin
It is a glycoprotein that is a major constituent of mucus.
mucin
Have swollen, basophilic to poorly staining cytoplasm (representing cytoplasmic mucin vesicles). These cells are abundant within the respiratory tract and gastrointestinal tract.
goblet cells
What kind of epithelial tissue do the goblet cells have?
columnar epithelial cells
oxygen and carbon dioxide exchange between lungs and blood
External Respiration
oxygen and carbon dioxide exchange between systemic blood vessels and tissues
Internal Respiration
The air enters through external nares or nostrils of the nose passes into the nasal cavity and then back into the pharynx. The epithelial layers are highly vascular; the mucus membrane binds large particles.
Nose/Pharynx
It increases surface area and swirls air through twists and turns
nasal conchae
It is a muscular tube shared by respiratory and digestive systems.
pharynx (throat)
Pharynx (throat) is lined with what type of epithelial tissue.
stratified squamous epithelium
Where does the air enter?
external nares or nostrils of the nose
The air enters larynx through what?
glottis (opening) uvula
end of soft palate, prevents air/food from going into the nasal cavity - made of 9 cartilages, ligaments, and skeletal muscles.
Larynx
projects over the glottis and covers the glottis during swallowing
elastic cartilage; all other structures have hyaline cartilage
Epiglottis
Scroll-like structures within the nasal cavity that are composed of a core of thin bone surrounded by connective tissue and lined by respiratory epithelium.
Nasal turbinates
function to help warm and humidify air and trap particulates.
nasal turbinates
Tall, pseudostratified sensory epithelium within the caudal portions of the nasal cavity that contains a population of chemoreceptor cells, olfactory receptor cells, that generate the sensation of smell.
Olfactory epithelium
A pseudostratified mucosal epithelium composed of columnar epithelial cells with apical cilia often admixed with goblet cells. This epithelium is characteristic of the upper respiratory tract (nasal cavity, sinuses, nasopharynx), eustachian tube, trachea, and large bronchi.
Respiratory epithelium
Where simple diffusion of gases takes place Diffusion occurs rapidly because the distance is small and both oxygen and carbon dioxide are lipid soluble
Respiratory membrane
Three layers of respiratory membrane:
- squamous epithelial cells lining the alveoli 2. endothelial cells of adjacent capillary
- fused basement membranes between alveolar and endothelial;
Oxygen and carbon dioxide in blood circulation
Transport
Flattened squamous epithelial cells that line pulmonary alveoli and facilitate gas exchange.
Type I alveolar cells (type I pneumocytes)
Polygonal to cuboidal epithelial cells within alveoli that secrete pulmonary surfactant and readily divide following tissue injury to type I alveolar cells.
Type II alveolar cells (type II pneumocytes)
forms anterior and lateral surfaces of larynx; where adam’s apple is
Thyroid cartilage
It makes it bigger
testosterone
windpipe
Trachea
extends from cartilage of the larynx to branches of primary bronchi - walls supported by C-shaped tracheal cartilages -open part of cartilages face posteriorly towards esophagus - not continuous cartilaginous tube (cartilage in “C” rings around tube) still have ciliated epithelia in tube
Trachea
- connects posterior of cartilage rings -
Tracheal muscles
contracts during coughing to expel mucus; coughing increases pressure, constricts the muscle, narrows diameter of trachea - sympathetic stimulation increases diameter for large volumes of air (relaxes trachealis) - skeletal muscle bridges back of “C” cartilage - esophagus is behind trachea; swallow, needs to expand, the esophagus can bulge into backside of trachea because of “c” ring that doesn’t go all the way around
Tracheal muscles
ciliated pseudostratified epithelium with goblet cells
Mucosal layer of trachea
- connective tissue with seromucous glands (serum mucus)
Submucosa layer of trachea
the outermost layer of connective tissue encases C-shaped rings of hyaline cartilage
Adventitia layer of trachea wall
- forms a right of cartilage just inferior to thyroid cartilage, pairs of arytenoid, cuneiform and corniculate cartilages
Cricoid cartilage
– this breathing movement of air into and out of the lungs
Pulmonary ventilation
– supply blood with oxygen for cellular respiration and dispose of carbon dioxide, a waste product of cellular respiration
Respiration
- increased volume-decreased pressure - an active process beginning with muscle contraction - changes in thoracic volume and sequence of events during inspiration
Inspiration
- quite expiration normally passive process - note: forced expiration is active process; uses abdominal (oblique and transverse) and internal intercostal muscles
Expiration
- at gas-liquid boundary, liquid molecules are more attracted to one another than gas resists any force that tends to increase surface area of liquid water- high surface tension;
Alveolar surface tension
coats alveolar walls →reduces them to smallest size without surfactant to reduce surface tensions, alveoli would collapse
Alveolar surface tension
expandability or “stretchiness” of the lungs higher lung compliance makes it easier to expand lungs normally high due to distensibility of lung tissue and surfactant low compliance leads to difficulty in breathing
Lung compliance
the total amount of exchangeable air or the maximum amount of air that can be moved during one respiratory cycle
Vital capacity
function in respiration, olfaction, and speech
Respiratory system
This is the site of the gas exchange, microscopic structures, respiratory bronchioles - alveolar ducts – alveoli.
Respiratory zone
Trachea, primary bronchi, smaller bronchi
Conducting system
Bronchioles and alveoli
Exchange surface
elastic fibers enclosed in epithelium deep to laryngeal mucosa; attach arytenoid cartilages to thyroid cartilage
vocal ligaments
vestibular folds; do not have a role in sound production; inelastic and reduce size of glottis during swallowing (more towards head)
false vocal cords
Vocal folds; are involved in sound production; no vasculature (true ligaments) - puberty lengthens and thickens vocal cords for men via testosterone; loudness controlled by amount of air.
true vocal cords
The respiratory system can be divided into what?
conducting zone and a respiratory zone.
What are the functions of the major organs of the respiratory system?
*provide oxygen to body tissues for cellular respiration
*remove the waste product carbon dioxide
*and help to maintain acid-base balance
• Portions of the respiratory system are also used for non-vital functions, what are these non-vital functions?
sensing odors, and speech production, and for straining such as coughing.
Air Conduction Portion
(Nasal cavity, paranasal sinuses, vomeronasal organ, larynx, trachea, bronchi, and bronchioles)
What is the main function of the conducting system?
‘condition’ the inspired air:
Air is conditioned by being what?
humidified (by serous and mucous secretions) warmed (by underlying blood vessels) and filtered (by particles being trapped in mucous secretions, and transported towards the throat, where the mucous is swallowed)
The respiratory system aids in breathing, also called ______.
pulmonary ventilation
In __________, the air is inhaled through the nasal and oral cavities (the nose and mouth). It moves through the pharynx, larynx, and trachea into the lungs. Then the air is exhaled, flowing back through the same pathway. Changes to the volume and air pressure in the lungs trigger this.
pulmonary ventilation
Inside the lungs, oxygen is exchanged for carbon dioxide waste through a process called ________.
external respiration
This respiratory process takes place through hundreds of millions of microscopic sacs called ________.
alveoli
It delivers oxygen to cells and removes waste carbon dioxide through internal respiration, another key function of the respiratory system. In this respiratory process, red blood cells carry oxygen absorbed from the lungs around the body, through the vasculature.
bloodstream
In paired external apertures of the nasal cavities in our domestic species are termed the ___________.
external nares (nostrils)
Traditional respiratory epithelium is composed of what epithelial tissue?
ciliated, pseudostratified columnar epithelium
It secrete mucus, and are characterized by cytoplasm filled with poorly staining, basophilic material (mucin)
Goblet cells
upper respiratory system, or upper respiratory tract, consists of the ff. These structures allow us to breathe and speak. They warm and clean the air we inhale. Mucous membranes lining upper respiratory structures trap some foreign particles, including smoke and other pollutants, before the air travels down to the lungs.
nose and nasal cavity
pharynx
larynx
It create openings to the outside world. Air is inhaled through here and warmed as it moves further into the nasal cavities.
nostrils, or nares
Scroll-shaped bones, protrude and form spaces through which the air passes.
nasal conchae
It swirl the air around to allow the air time to humidify, warm, and be cleaned before it enters the lungs
conchae
It is a specialized epithelium that facilitates the sense of smell. It is tall, pseudostratified epithelium that contains three distinct cell types.
olfactory epithelium/ mucosa
three distinct cell types of olfactory epithelium/ mucosa:
a. olfactory receptor cells
b. sustentacular cell
c. basal cells
These are modified neurons and chemoreceptor cells interspersed within the olfactory epithelium.
Olfactory receptor cells
These are histologically similar to the respiratory epithelium and have apical microvilli. These cells provide structural and metabolic support to the epithelium.
Sustentacular cells
These are cuboidal to short polygonal cells that reside adjacent to the basement membrane.
Basal cells
Epithelial cilia commonly called _________. .
“nose hair”
It produced by seromucous and other glands in the membrane, trap unwanted particles
cilia (nose hair), along with mucus
These are bone-encased, air-filled spaces within the skull that communicate with the nasal cavity.
sinuses
Species such as the _____ have well-developed and distinct paranasal sinuses that include the frontal, dorsal conchal, ventral conchal, rostral maxillary, caudal maxillary, and sphenopalatine.
horse
Species such as the ______ have only frontal and maxillary sinuses.
dog
sensory epithelium is similar to that of olfactory epithelium, with a thick pseudostratified epithelium that contains three populations of cells: what are these?
receptor cells
sustentacular cells
basal cells.
vomeronasal receptor cells, similar to olfactory receptor cells, are modified neurons that detect ________ and transmit to the brain via efferent axons.
pheromones
Access of air to this region of the nasal cavity is facilitated through a passage through ducts in the dorsal aspect of the oral cavity (roof) of some species by the behavioral action of the __________.
flehmen response
Examples of flehmen response include the ff.
curling of the upper lip in ungulates chattering of the mouth in dogs (tonguing) open-mouthed posture of cats
It is a complex, tubular organ, the structure of which is primarily composed of elastic and hyaline cartilage and skeletal muscle.
larynx
The larynx is composed of what?
elastic and hyaline cartilage and skeletal muscle
It connects the naso- and oro-pharynx with the trachea, functioning in air conduction, vocalization, and in obstructing the passage of ingesta into the trachea during deglutition.
larynx
What is the epithelium of the larynx?
stratified squamous epithelium
Dorsally, the ends of the incomplete cartilaginous rings of the trachea are connected by a band of smooth muscle: the _______.
trachealis muscle
Externally, the trachea is surrounded by a thin layer of fibrovascular connective tissue called ______.
adventitia
It is the process of contraction and subsequent narrowing of the airway lumen.
bronchoconstriction
It is a life-threatening effect of massive histamine release (e.g. anaphylaxis).
bronchoconstriction
These are thin-walled airways lined by variably ciliated or non-ciliated columnar epithelium. The walls are composed of tangentially arranged smooth muscle.
Bronchioles
air conduction happens in?
bronchioles
regions of air exchange happens in?
alveoli
The transition between regions of air conduction (i.e. bronchioles) and regions of air exchange (i.e. alveoli) in the lung progresses through sequentially distinct segments; from proximal to distal: what are these?
terminal bronchioles, respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli
It is the transition into respiratory bronchioles.
Terminal bronchioles
• Respiratory bronchioles are lined by two types of epithelial cells: what are these?
ciliated columnar cells and club cells (Clara cells)
These are cuboidal epithelial cells that lack cilia but contain microvilli
club cells
These are rich in cytochrome P450, an enzyme responsible for the biotransformation of inhaled and circulating toxins.
Club cells
an enzyme responsible for the biotransformation of inhaled and circulating toxins.
cytochrome P450
It is also abundant and highly active in hepatocytes, another cell type
P450
P450 is also abundant and highly active in ______, another cell type responsible for the biotransformation of toxins.
hepatocytes
Cell type responsible for the biotransformation of toxins.
Hepatocytes
Secondary functions of the club cells include the ff.
production of pulmonary secretions and progenitor (proliferating) cells that may repopulate after cell loss and/or injury.
site of gas exchange in the lung.
Alveoli
Alveoli are thin-walled, sac-like structures lined by a single layer of flattened squamous epithelial cells: type I ________.
type I pneumocytes
Alveoli also contain several additional cell types. What are these?
Type II pneumocytes are cuboidal epithelial cells
These are responsible for the secretion of surfactant.
Type II pneumocytes
It is a fluid composed of phospholipids and proteins that coats the surface of alveolar spaces to reduce surface tension, allowing for alveoli to expand and remain open.
It play a crucial role in tissue repair in the lung. Following damage to type I pneumocytes, it proliferate and differentiate into type I pneumocytes, thereby restoring alveolar structure.
type II pneumocytes
Alveolar spaces contain a resident population of macrophages, the ________.
alveolar macrophages
• The outer surface of the entire lung parenchyma is covered by the _________.
visceral pleura
lungs receive two distinct sources of blood supply: what are these?
pulmonary arterial supply and bronchial arterial supply
It is the body’s main energy source.
Glucose (blood sugar)
end products are carbon dioxide and water, which is known as ___________
Metabolic water amounts to about ________ daily throughout the body. The whole process is called __________.
300ml (10fl oz)
aerobic (oxygen-requiring) cellular, or internal, respiration
