Unit 5 - Respiratory System Flashcards
What does the upper resp system passages consist of?
nostrils
nasal cavity
pharynx
larynx
trachea
How does the resp system maintain homeostasis?
O2 and CO2 saturation in the blood
What are the size and shape of the nostrils dictated by?
nasal cartilages
What are some characteristics of the nasal cavity?
- separated longitudinally on the right and left by the nasal septum
- separated from the oral cavity/mouth by the hard palate
What is the hard palate made out of?
calcified cartilage
What does the palate consist of?
Hard palate and soft palate
What is the septum made out of?
cranial part of the septum is cartilaginous
caudal part of the septum is ossified
What does the mucous membrane cover in the nasal cavity?
conchae
What are the three parts of the conchae
ventral nasal concha
dorsal nasal concha
middle nasal concha
What are turbinates?
thin, scroll-like bones covered with nasal epithelium that occupy most of the lumen of the nasal passages
How do turbinates regulate the air temperature of the nasal cavity?
blood vessels swell up
What are the meatuses?
air space that the conchae divides
What are the three sections of the meatuses?
ventral nasal meatus
middle nasal meatus
dorsal nasal meatus
How is a nasogastric feeding tube inserted anatomically?
introduced into the nasal cavity through the nostrils, passes through the ventral meatus, the pharynx and is directed to the esophagus
What are the functions of the meatuses?
keep air,
warm
clean
humidified
What does the lining of the nasal cavity consist of?
presence of mucus - produced by mucus glands
pseudostratified columnar epithelium with cilia projecting from the cell surfaces
presence of blood vessels beneath the nasal epithelium
What are the functions of the mucus and cilia in the lining of the nasal cavity?
clean and humidify the air
What is the function of the nasal cavity?
warming
humidifying
filtering
Why are the turbinates scroll-shaped?
increase the surface area of the nasal lining
How does the warming, humidifying and filtering happen in the nasal cavity?
air gets humidified by the mucus on the epithelial surface
The blood flow is responsible for warming the air
filtering the air is important to prevent particles from reaching the lungs
the twists and turns of the turbinates combined with the mucus and cilia acts to filter the inhaled air
What is the function of the sinuses?
air-filled cavities of the nasal passages located in the skull bones
also have cilia and mucus to deal with dirt and foreign debris
What is the function of the pharynx?
a common soft tissue conduit for food and air, lying caudal to the oral and nasal cavities
divided by the soft palate into the nasal and oral pharynx (nasopharynx and oropharynx)
Where does the pharynx open?
dorsal into the digestive pathway
opens ventrally into the respiratory passageway
What does the epiglottis do?
changes depending on respiration vs swallowing
What are some characteristics of the larynx?
short irregular tube that connects the pharynx with the trachea
It is made up mainly of segments of cartilage that are connected to each other and the surrounding tissues by muscles
What is the function of the epiglottis?
projects forward from the ventral portion of the larynx
when the animal swallows the epiglottis covers the opening from the larynx
What are the three main functions of the larynx?
- control of airflow to and from the lungs
- prevention of foreign material being inhaled
- produces the basic sound of an animals voice
What is the structure of the trachea?
- wide cylindrical tube extending from larynx and then divides into right & left bronchi
- the gap between the ends of each ring is bridged by smooth muscle
What is the trachea made out of?
made up of dorsally incomplete C-shaped hyaline cartilage rings to keep trachea open
What is the purpose of the smooth muscle at the bridging at the C-shape cartilage?
allows the expansion of the esophagus needed depending on the size of the food bolus
What is the trachea lined with?
lined by ciliated epithelium to catch debris which get directed to pharynx to be swallowed
What are the parts of the lower respiratory tract?
lungs, lung structure (bronchi, ends with alveoli)
What is the bronchial tree?
- trachea divides into the right and left bronchi
- bronchi divide into secondary and tertiary bronchi
- branching into terminal brionchioles
What are the alveolar ducts?
the smallest air passageways that the bronchioles subdivide into
What are alveoli?
Groups that alveolar ducts end in
What are alveolar sacs?
groups of alveoli
What is the structure of alveoli?
tiny, thing-walled sac surrounded by network of capillaries, very thin wall allows gas exchange by diffusion
What is the function of alveoli?
site of external respiration: gas exchange between lungs and blood, exchange of gas through diffusion
Gradient of O2 and CO2 allows for exchange
O2 in inhaled air is going to make its way into these numerous alveoli
What is the structure of the walls of the alveoli?
made up of the thinnest epithelium in the body to facilitate diffusion, main barrier between the air and the blood, O2 freely diffuses between the air and blood
What is the concentration gradient of the alveoli gas exchange?
high to low
- high level of O2 in air diffuses into blood where level is lower
- high level of CO2 in blood diffuses into air where level is lower
What is the percentage of O2 and CO2 that inhaled air contains?
21% O2
0.03% CO2
What are the levels of O2 and CO2 in the capillary blood around the aoveoli?
low O2
high CO2
Where are blood vessels in the lungs?
everywhere, the blood vessels follow and subdivide along with the bronchial tree
What is the name for the subsections that the lungs are divided into?
lobes, they can be identified by external grooves
Which lung is slightly larger?
The right lung is slightly larger, it has 3 lobes, because heart is on the left side
How many lobes do cats, cows, dogs, goats, pigs and sheep have in their lungs?
3 lobes in left lung
4 lobes in right lung
How many lobes do horses have in their lungs?
2 lobes in left lung
3 lobes in right lung
What are three characteristics of the lungs?
- spongy, air-filled organs
- within the lungs, the blood vessels basically follow and subdivide along with the bronchial tree
- it has an expandable capacity and will inflate with the inhaled air
What are the contents of the thoracic cavity?
its contents include the lungs, heart, trachea and esophagus
What is the thoracic cavity bound by?
- thorcic vertebrae dorsally
- the ribs and intercostal muscles laterally
- the sternum ventrally
What is the diaphragm?
thin sheet of skeletal muscle that forms the caudal boundary of the thorax
What does the diaphragm separate?
It separates the thoracic cavity and the abdomen
What is the function of the diaphragm?
helps the lungs to get air inside, when it contracts it creates a negative (lower) pressure allowing the air to come in
What are intercostal muscles?
muscles in between the ribs, allow the ribs to expand
What is the pleura?
a single layer of cells fused to the surface of a connective tissue that envelopes the lungs
What are the two layers of the pleura?
parietal pleura - lines the cavity (outside)
visceral pleura - covers the thoracic organs and structures (inside)
What’s the intrapleural space?
space between the parietal and visceral pleura
What is inside the intrapleural space?
lubrification fluid
What is the function of the intrapleural space and the pleura fluid?
When the thoracic cavity expands, it pulls the walls of the lungs outwards through fluid tension
What is the main feature of pulmonary ventilation?
air flows from an area of higher pressure to an area of low pressure, causes the volume changes that causes the changes in pressure
What occurs in the rib cage and diaphragm during resting mode of pulmonary ventilation?
rib cage and diaphragm are at rest
What is the pressure inside and outside during resting mode in pulmonary ventilation?
pressures inside and outside lungs are equal
Is there any air movement in resting mode in pulmonary ventilation?
no
What happens during inspiration?
elevation of the rib cage and contraction/flattening of the diaphragm occurs (enlargement of the thoracic cavity), which increases the volume of the thoracic cavity, this lowers the intrapulmonary pressure within the lungs and the air flows in
What happens during expiration?
The rib cage returns to its original position and the diaphragm relaxes, this decreases the volume of the thoracic cavity and increases the intrapulmonic pressure within the lungs and the air flows out
Draw the graph of the ventilation process (expiration and inspiration)
draw!
Where does the voice production process start and what are the structures involved?
in the larynx, two fibrous connective tissue bands called the vocal cords stretch across the lumen of the larynx and vibrate as air passes over them - produces the basic sound of an animal, thorax, nose, mouth, pharynx and sinuses contribute too
What are the three functions of the larynx?
voice production, prevention of foreign materials being inhaled, and control of airflow to and from the lungs
What are the main cartilages of the larynx?
epiglottis, arytenoid, thyroid, cricoid cartilages
What is the trachea made up of?
tube of fibrous tissue and smooth muscle held open by hyaline C-shaped cartilage rings and lined by the same kind of ciliated epithelium that is present in the nasal passages
What is the gap of the C shaped hyaline cartilage of the trachea bridged by?
smooth muscle
How are the bronchi diameter adjusted?
The diameter of the bronchi can be adjusted by smooth muscle fibres in its wall
What walls are the thinnesst epithelium in the body?
The walls of the alveolus is the thinnest epithelium in the body - simple squamous epithelium
What is each alveolus lined with?
thin layer of fluid that contains surfactant
what is surfactant?
helps reduce surface tension of the fluid that prevents the alveoli from collapsing as air moves in/out during breathing
What is pleura?
Thin membrane called pleura covers the organs - visceral layer of pleura lines the organs and parietal layer of pleura line the thoracic cavity, pleural fluid exists between the membranes
What are the inspiratory muscles?
diaphragm and the external intercostal muscles
How do the inspiratory muscles expand the thoracic cavity?
diaphragm is dome shaped when relaxed, enlarges the thoracic cavity by flattening its dome shape
external intercostal muscles move the ribs upward to expand thoracic cavity
What are the expiratory muscles?
internal intercostal muscles and the abdominal muscles
How do the expiratory muscles decrease the size of the thoracic cavity?
internal intercostal muscles rotate the ribs backward which decreases the size of the thoracic cavity and pushes air out of the lungs
abdominal muscles push abdominal organs against the diaphragm which pushed it back upward to a cone shape
Which direction of concentration does gas exchange take place?
area of high concentration to area of low concentration
