Respiratory System Flashcards
what is the best description of respiration from an anatomists point of view?
act of inhalation and exhalation of air
how do respiratory gases move into the blood vessels and body tissues/
gas diffusion
what are the 6 methods of gas exchange/respiration?
simple diffusion respiration through skin papulae on body surface tracheae on body surface gills alveoli
what are the 4 key features of a respiratory membrane?
thin (short diffusion pathway) moist surface (gas must be dissolved in liquid to pass through cell membrane) highly vascular (vertebrates) some contact with the external environment
what are gills?
an aquatic respiratory organ
how do gills increase surface area for gas diffusion?
project into the water
what are the 2 types of gills?
simple
complex
where are simple gills seen?
papulae on echinoderms (starfish)
where are complex gills seen?
in fish
what are the 2 chambers of complex gills?
buccal cavity and opercular cavity
what is countercurrent flow in gills?
water flows through gills in one direction and blood moves the opposite way
what is the aim of countercurrent flow in gills?
to increase diffusion gradient and maximise oxyge diffusion into the blood
describe the movement of water through gills
operculum are closed so water is drawn into the buccal cavity through the mouth.
mouth is closed and operculum opens where water then flows out over the gills
what are the gill filaments?
highly vascular, thin membranes on the caudal edge of the gill which allow gas exchange to happen quickly
what is the name for the external opening of the tracheae in insects?
spiracle
what are tracheae?
extensive network of tubes throughout a air breathing animals body that fill with air to allow gas exchange
what does air move through to reach the alveoli?
branched tubular structures
what happens to the air before it reaches the respiratory surface?
becomes saturated with water
where is the large surface area for gas exchange located in the lungs?
alveoli
what shape is the mammalian thorax?
irregular cylinder with 2 openings
what is the thoracic cavity enclosed by?
walls, mostly skeletal
what are the 3 main compartments of the mammalian thorax?
media stinum
2 pleural cavities
by what type of joint are the ribs joined to the vertebra?
synovial
how many rib pairs are there in humans?
12
what does the number of rib pairs correspond to?
number of thoracic vertebra
what are the 3 types of ribs?
true, false and floating
what are true ribs
those that articulate directly with vertebra and sternum
what are false ribs?
those that attach to large common costal cartilage
what are floating ribs?
those that have no attachment to the sternum
what type of cell is the pleura made of?
simple squamous epithelium (mesothelial cells)
what is the pleural cavity?
space which the lungs occupy
what is the parietal pleura?
continuous layer that lines thoracic cavity and diaphragm
what is the visceral pleura?
tissue which covers the whole lung
where is the parietal pleura reflected on to the lung?
hilum
what is the pleural space?
potential space between visceral and parietal pleura formed of a thin layer of fluid which sticks the membranes together
what ribs move in a pump handle movement during respiration?
superior (true) ribs move anterior and superior to push sternum up and out
which ribs move in a bucket handle movement?
inferior ribs
what is the diaphragm?
large dome of skeletal muscle that forms the barrier of the thoracic cavity
what is the main muscle of respiration?
diaphragm
what does contraction of the diaphragm cause?
flattening of the dome of the diaphragm which pulls on the parietal pleura and increases volume
what two areas of tissue is the diaphragm formed of?
central tendon and muscular periphery
which nerves supply the diaphragm?
phrenic
where are the phrenic nerves located?
left and right sides proximal to the heart
what type of muscle is the diaphragm formed of?
skeletal
what are the 3 layers of intercostal muscle?
external, internal, innermost
what do intercostal muscles maintain?
intercostal space and prevent blowing in or out
what role do intercostal muscles play during pressure changes in the thorax?
maintain structural integrity of thorax
what does negative pressure rely on?
integrity of pleura and action of diaphragm
how do birds respire?
no tidal flow, continuous flow of air
through air sacks which act as bellows
lungs are rigid and there is no diaphragm
what animals use positive pressure breathing
amphibians
what 2 sections can the mammalian respiratory system be divided into?
upper and lower respiratory tract
what mainly occurs in the upper respiratory tract?
conduction of gases
what mainly occurs in the lower respiratory tract?
conduction of gases and site of gas exchange
what are the main components of the upper respiratory tract?
nasal cavity
oral cavity
pharynx
larynx
what type of epithelium is the nasal cavity lined with?
respiratory and olfactory (towards the rear of the nasal cavity)
what are the walls of the nasal cavity formed from?
bone
what is the nasal cavity divided into 2 sections by?
nasal septum in the saggital plane
what are the functions of the nasal cavity
to warm and humidify air filter air direct inspired air into pharynx provide a resonating chamber for phonation receives drainage from sinuses
what are concha?
bony projections in nasal cavity covered by mucosa
how many concha are there in the nasal cavity?
3 on each side
what are the names of the concha from superior to inferior aspect of nasal cavity?
superior concha
middle concha
inferior concha
what is the function of concha?
aid filtration and warming of air
What are meatus?
passages below each of the concha within the nasal cavity
how many meatus are there in the nasal cavity?
3 on each side
what are the names of the meatus from superior to inferior aspect of nasal cavity?
superior meatus
middle meatus
inferior meatus
what are paranasal sinuses?
hollowed spaces in the skull which communicate with the nasal cavity
what are paranasal sinuses named after?
their associated bone
what are paranasal sinuses lined with?
respiratory epithelium
why are paranasal sinuses prone to blockage?
because of the way they drain and their production of mucous by epithelium
what are the names of the paranasal sinuses?
sphenoid sinuses
frontal sinuses
ethimoid sinuses
maxillary sinuses
what are the functions of paranasal sinuses?
aid warming/humidification of air aid phonation of voice lighten facial skeleton provide a surface for muscle attachment offer mechanical protection
what are the 2 palates within the oral cavity?
hard and soft
what is the hard palette made of?
bone
what is the soft palette made of?
muscle
where are the hard and soft palettes located in the oral cavity?
hard: rostral/anterior
soft: posterior
what is the oral cavity lined with?
mucosa
what is the uvula part of?
soft palette
why are horses obligate nasal breathers?
epiglottis is located dorsal to soft palette - it prevents oral cavity from communicating with the trachea. Oral cavity cannot be recruited when needed unlike other mammals
where is the nasopharynx located?
posterior and open to nasal cavity
what structure of digestion is the pharynx continuous with?
oesphegus
what openings does the nasopharynx contain?
eustachian/auditory tube
what is the pharynx lined with?
respiratory epithelium
where is the oropharynx located?
posterior and open to oral cavity
where does the oropharynx extend from and to?
from soft palette to epiglottis
what is the oropharynx lined with?
non-keratinised stratified squamous epithelium
where is the laryngopharynx located?
posterior and open to larynx
where does the laryngopharynx extend from and to?
epiglottis to oesophegus
what is the laryngopharynx lined with?
non-keratinised stratified squamous epithelium
how does laryngopharynx move in order to direct food into the oesophegus?
moves upwards and the epiglottis closes
what is the larynx the connection between?
pharynx and tracheobronchial tree
how is the larynx suspended from the base of the cranium?
via hyoid bones and associated ligaments
what structures is the larynx continuous with inferiorly/caudally?
trachea
what structures is the larynx continuous with superiorly/cranially?
pharynx
what is the function of epiglottic cartilage?
covers laryngeal opening
what cartilage is epiglottic cartilage formed of?
elastic
how can thyroid cartilage move?
forwards and backwards on cricoid cartilage
what does the cricoid cartilage attach to?
trachea
what is the function of arytenoid cartilage?
they can rotate and are attached to the vocal cords. will close the larynx during straining activities
what do intrinsic muscles of the larynx attach to and what do they do?
the cartilages of the larynx and change the tension in the vocal folds
why are vocal cords mobile in the neck?
due to extrinsic laryngeal muscles
what is the lower respiratory tract formed of?
trachea
bronchus
bronchioles
alveoli
what is the function of the tracheobronchial tree?
conducts air to and from the alveoli
what are the alveoli the site of?
gaseous exchange
what are lobes seperated by?
fissures
what is a lobe the functional unit of?
the lung
how does a lung without external lobes appear?
no visible fissures (e.g. horse)
what does a lung with lobules look like?
surface is visibly marked with fascia, does not appear smooth
what are the names of the lobes in the left human lung?
superior and inferior
what are the names of the lobes in the right human lung?
superior lobe, middle lobe and inferior lobe
what is the name of the fissure which separates superior and inferior lobes?
oblique fissure
what is the name of the fissure which separates middle lobe from superior and inferior lobes?
horizontal fissure
from which germ layer is the tracheobrochial tree derived?
endoderm - formed by diverticulum of the gut tube in the embryo
from which germ layer is the lung connective tissue derived?
mesoderm
where in the thoracic cavity is the trachea located?
media stinum
what is the function of the C shaped cartilage on the trachea and bronchi?
holds lumen open
what type of epithelium lines the trachea?
pseudostratified ciliated columnar epithelium
what cells secrete mucus into the trachea?
goblet cells
what is the function of the trachealis muscle?
alters diameter of trachea
where is the trachealis muscle located?
posterior wall of trachea
what are primary bronchi also known as?
main or principal bronchi
where do the primary bronchi enter the lungs
at the hilum
what bronchi supply the lung?
primary/principal bronchi
what bronchi supply the lobes of the lungs?
secondary/lobar bronchi
what bronchi supply the segments of the lung?
tertiary/segmental bronchi
what species is the tracheal bronchi present in?
ruminants and pigs
what is the tracheal bronchi?
secondary/lobar bronchus directly from the trachea
what does the tracheal bronchi supply?
cranial lobe of right lung
as you move through the trachea towards the segmental bronchi and alveoli how does the amount of smooth muscle and cartilage change?
increased smooth muscle
decreased cartilage
how does the number of specialised cells change more proximal to alveoli?
decreases
what sort of epithelium are alveoli lined with?
simple squamous
where are alveolar capillaries visible?
in the septa between alveolar sacs
what is the role of surfactant?
prevents collapse of lung and reduces surface tension
what is the hilum the site of?
entry and exit to and from the lung
why is the hilum the only part of the lung not covered in pleura?
it is at the point where parietal pleura reflects onto visceral pleura
what can be seen at the hilum?
bronchus
pulmonary veins
pulmonary artery
how can the bronchus be identified at the hilum?
cut edges of cartilage are visible
how can the pulmonary arteries be differentiated from the pulmonary veins?
pulmonary artery is usually more superior/cranial and has a thicker wall compared to the vein
