Module 9 Flashcards
what are the two phases of breathing?
- inspiration (inhalation)
2. expiration (exhalation)
which phase of breathing involves drawing oxygen rich air into the lungs?
inhalation/inspiration
which phase of breathing involves forcing oxygen poor air out of the lungs
expiration
what are the 5 functions of the respiratory system
- gas exchange
- gas conditioning
- sound production
- olfaction
- defence
what is gas exchange??
the movement of gasses across membranes
what two things are involved in external respiration?
air and blood
what two things are involved in internal respiration?
blood and cells of the body
how does external respiration work?
- inspired oxygen (o2) moves across the cellular membranes of the alveolus of the lung and its associated capillaries into the blood
- waste carbon dioxide (Co2) moves in the opposite direction and out of the body
what is gas conditioning?
gases entering the lungs need to be warmed and cleansed in order to prevent damage to the lungs
where does gas conditioning occur?
in the nasal cavities and paranasal sinuses
how does gas conditioning work?
air is swirled around to become warmed, humidified and cleansed of particulate matter via contact with the mucosal lining of respiratory epithelium
how does sounds production work?
occurs by forceful expiration of air through the vocal cords in the larynx causing them to vibrate
different ______ of the vocal cords provide different sounds with the help from the _____, _____ and ______
tensions
teeth, lips, and tongue
what kind of epithelium covers the top of the nasal cavity? What important thing is located here?
olfactory epithelium. Receptors for smell are located within this epithelium
how does olfaction work?
- when air is inhaled into the nasal cavity, airborne molecules dissolve in the mucus lining the cavity and stimulate the receptors
- signals from these receptors travel to the brain through the olfactory nerve (CN I)
what is the role of the respiratory system in terms of defense?
the course hairs of the nostrils, the ciliated cells of the respiratory epithelium, and mucus all help to trap particles and microorganisms from entering the respiratory system
what two kinds of epithelium are found in the respiratory tract?
- pseudostratified ciliated columnar epithelium
2. goblet mucus cells
what does “pseudostratified” mean in terms of epithelium?
all cells are attached to the basal lamina but only some reach the surface
what is the benefit of pseudostratified ciliated columnar epithelium in the respiratory tract?
- covered in cilia, providing an increase in surface area for conditioning air
- cilia also function to trap inhaled particles and microorganisms caught in mucus and sweep them back up the respiratory tract
where are goblet mucus cells located?
found interspersed throughout the pseudostratified epithelium
what do goblet mucus cells produce? What do they look like in staining?
- produce mucus
- stain lightly in histological image
what is the benefit of goblet mucus cells in the respiratory tract?
- the mucus forms a protective layer over the epithelium and traps particulae matter or microorganisms that may be inhaled
- also provides moisture to humidify air before it reaches the lungs
what are the two main regions of the respiratory system?
- the conducting portion
2. the respiratory portion
what is the function of the conducting portion?
transfer inhaled air from the outside world to the lung tissue and vice versa
- also where humidification and trapping of debris happens (no gas exchange)
what structures are included in the conducting portion?
- nose/nasal cavity
- paranasal sinuses
- pharynx
- larynx
- trachea
- primary, secondary, tertiary bronchi
- terminal bronchioles
what are the structure in the respiratory portion?
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
what is the function of the respiratory portion?
transfer gases between the lungs and pulmonary capilaries
what are the paranasal sinuses?
collection of air filled spaces within the bones of the skull communicating with the nasal cavity
what is the function of the paranasal sinuses?
- aid in the conditioning of air
- defense against pathogens
the paranasal sinuses are lined with what?
respiratory epithelium
the paranasal sinuses are _____
paired
what are the paranasal sinuses named after?
the bones that contain them
what are the 5 paranasal sinuses?
- frontal
- maxillary
- ethmoid
- sphenoid
- nasal
function of nose and nasal cavity
- first line of defence against invading pathogens and debris
how does air flow through the nose and nasal cavity?
air enters the vestibules (openings) of the nostrils and is passed into the nasal cavity where it is conditioned
what are the six nasal cavity boundaries?
- roof
- floor
- medial wall
- lateral wall
- anterior
- posterior
roof of nasal cavity?
bone in the skull called the ethmoid
floor of nasal cavity
composed of the hard palate (roof of mouth)
medial wall of nasal cavity
makes up the nasal septum, which is composed of the vertical bones in the skull
- separates the two halves of the nasal cavity
lateral wall of nasal cavity
contains nasal conchae, which create turbulence in the air as it passes through the cavity, allowing for conditioning and catching debris
anterior boundary of nasal cavity
made by the nasla choanae, the opening between the nose and the nasal cavity
posterior boundary of nasal cavity
opening to the nasopharynx, which connects to the pharynx
nasal cavity histology. why?
mostly covered in respiratory epithelium because of its role in protection from airborne debris and microorganisms, as well as the condition of air
what is the pharynx?
muscular tube that connects the nasal cavity and the larynx
what structure connects the oral cavity with the esophgus
pharynx
what are the three components of the pharynx?
- nasopharynx
- oropharynx
- laryngopharynx
nasopharynx
most superior aspect of the pharynx
oropharynx
middle aspect of the pharynx
- part of both the respiratory and digestive systems
what does the oropharynx do?
passes air from the nasopharynx and food from the oral cavity into the laryngopharynx
laryngopharynx
most inferior aspect of the pharynx
- passes both food and air into their respective systems
histology of the nasopharynx?
respiratory epithelium
histology of the oropharynx and the laryngopharynx? why?
stratified squamous epithelium .
due to the need for durability when swallowing food
what does the larynx do
produces sounds
aka voice box
what is the pharynx made up of
variety of cartilages, ligaments, and muscles
where is the larynx located?
anterior to the esophagus, connecting the pharynx with the trachea
what are the three types of cartilage found in the larynx?
- epiglottis
- thyroid cartilage
- cricoid cartilage
what is the epiglottis? what is its function?
large spoon-shaped elastic cartilage that functions to protect food from passing into the trachea
what happens with the epiglottis during swallowing?
flips downward and covers the opening of the trachea
what is the thyroid cartilage?
shield-shaped hyaline cartilage that provides attachment for many muscles as well as vocal cords
what is cricoid cartilage? What shape is it?
a complete ring of hyaline cartilage (narrow anteriorly and broad posteriorly)
purpose of cricoid cartilage
attachment for muscles and the vocal cords
what are the vocal cords?
small ligaments attached to laryngeal cartilages that vibrate when air is forced out of the lungs
when the vocal cords _____, _____ is produces
vibrate, sound
how are different sounds produced?
by altering the tension on the vocal cords
true vocal cords?
protected by a membranous flap called the false vocal cords
where is the trachea?
extends from the larynx to approximately the level of T4/T5, where it splits at a junction called the carina
main function of trachea
conduction of air to the lungs
what is the structure of the trachea? Why is it this way?
- made up of 15 - 20 cartilage rings, which are incomplete posteriorly
- rings function to keep the airway open
what connects the rings of the trachea posteriorly?
the trachealis muscles
what are the three histological layers of the trachea?
- mucosa
- submucosa
- adventitia
what is the mucosa of the trachea
lined with respiratory epithelium in order to clear any debris or pathogens that make it into the lower respiratory tract
submucosa of the trachea is made up of what?
made up of connective tissue, containing larger vessels and nerves, as well as mucus secreting glands
adventitia of the trachea
outer layer of connective tissue surrounding the trachea
- also encloses the c-shaped rings,
why are the cartilage rings of the trachea important?
make the trachea flexible and durable which is important as the organs in the thoracic cavity shift with the movements of breathing
how many primary bronchi are there?
2 - left and right
function of the primary bronchi?
same as trachea
histology of the primary bronchi?
same as trachea
where do the primary bronchi enter the lung?
on the medial side at the hilus
how does the right primary bronchus differ from the left?
right is shorter, wider and more vertical than the left
what is the order in which the bronchi divide into smaller tubes?
- primary bronchi
- secondary bronchi
- tertiary bronchi
- terminal bronchioles
how do the walls of the structured in the respiratory portion differ from those in the conducting portion?
the walls are one cell layer thick and gasses are able to cross the membrane easily
where are the lungs located
on either side of the heart within the thoracic cavity
how is the right lung different from the left lung?
the right lung is slightly larger than the left due to the positioning of the heart
- left lung has cardiac notch
what are the four surfaces of the lungs?
- apex
- diaphragmatic
- costal
- mediastinal
apex of the lung?
the superior point.
sits just above the first rib
diaphragmatic of the lungs
base of lung because it is the surface in contact with the diaphragm
costal of the lungs
curves around the lateral aspect of the lung
mediastinal of the lungs?
the medial surface. contains the entry and exit points for all vessels and airways at a structure known as the hilus
what are the pleura?
membranous sacs surrounding the lungs to cushion them and protect them
how are the plaura beneficial
provide a frictionless surface to ensure that the changes in lung size during inhalation and exhalation do not damage the lungs as they rub up against surrounding structures.
what are the pleura membranes?
- pleura consists of two continuous membranes that form a sac around each lung
what do the pleura membranes secrete?
pleural fluid to fill the pleural space in between the membranes
what does the pleural fluid do?
helps lubricate the contact with the thoracic wall during inflation and deflation of the lungs
what are the two pleaura membranes?
parietal pleura (outer) and visceral pleura (inner)
what is the parietal membrane? what is it continuous with?
outer serious membrane attaches to the walls and floor of the thoracic cavity and lungs. continuous with visceral pleura at the hilus where it is reflected inwards
what is the visceral pleura?
serious membrane attached to the surface of the lung
what kind of epithelium is found in the respiratory bronchioles?
thin walled ducts with simple squamous epithelium
respiratory bronchioles
- branch of the terminal bronchioles
- first structures to contribute to gas exchange in the lungs
what is the alveolar duct?
divisions of the respiratory bronchioles lead to appearance of alveolar ducts (ducts with walls completely covered in alveoli for gas exchange)
where does alveolar duct terminate?
the alveolar sac
what is the alveolar sac
a cluster of alveoli surrounded by smooth muscle and capillaries
what part of the lung does gas exchange take place?
alveoli
what surrounded the alveoli? Why is this?
capillaries in order to maximize the amount of oxygen going into the body and carbon dioxide leaving the body
