Comparative anatomy of the Lungs and Pleura Flashcards
collapse of tube (trachea) prevented by?
by C-shaped hyaline cartilaginous rings
ruminants and pigs have additional bronchia tree, known as?
tracheal bronchus
cranial to tracheal bifurcation to supply the right lungs to cranial lobe
what aspect of the lungs shows the hilus?
medial aspect
are lungs conical ?
yes
dogs’ lungs caudolateral margins extend to where?
they extend caudally to about the transverse level of the 12th thoracic vertebrae
what are lungs divided into and how is this defined?
divided into lobes
defined by the presence of lobar bronchi
cardiac notch of the lungs - what does it allow?
allows the heart and the pericardium to make contact with the thoracic wall
where is the base of the lungs found?
base is resting cranial side of diaphragm
where is the apex of the lungs found?
apex is located towards the thoracic inlet
what is the thoracic cavity lined with?
with pleura
what is pleura?
it is a thin membrane that consists of a single layer of mesothelial cells
what sacs are lungs located in?
in pleural sacs
what does each pleural sac that contains the lungs, consist of?
consists of visceral and parietal layers; the pleural cavity/space is found between the two layers of pleura
pleural space is a potential space and it contains?
a small amount of serous fluid
what is the mediastinum?
this is the space between the right and left pleural sacs
what types of pleura are there?
parietal pleura (mediastinal, costal and diaphragmatic)
visceral (pulmonary) pleura
what is the diaphragmatic line of pleural reflection formed by?
formed by reflection of the parietal costal pleura on the diaphragm to become the parietal diaphragmatic pleura
pleural membranes size compared to lungs?
pleural membranes are larger than the lungs which they encase because lungs need extra space to enlarge when they are breathing
pleural recesses?
potential spaces between the two pleural (parietal and visceral) layers known as recesses
what do recesses allow?
recesses are spaces in the pleural cavity that allow the lungs to expand during breathing
what occurs where parietal pleura is in contact with more parietal pleura?
folds exist here
(costodiaphragmatic)
where is the pleurae dome found?
beyond cranial thoracic openings of the 1st rib
clinical relevance of pleural cupula?
could be opened during surgeries
function of the pleural fluid?
serves to reduce friction when the lung rubs against the body wall
what does the pleural fluid provide?
it provides surface tension, keeping the lung suitably close to the wall of the thorax, despit the lungs not being directly fixed to it
what does the pleural fluid help reduce?
helps reduce the intra-thoracic pressure
what does the pleural fluid do during expiration?
it stops the lungs from collapsing
pleura allows what?
allows the volume of the lungs to change with the volume of the thoracic cavity, enabling ventilation
what is the diaphragm?
it is a dome shaped structure (cupula) separating the thoracic and abdominal cavities
what areas of the diaphragm are there?
muscular peripheral part and a tendinous central area
which are the muscular parts of the diaphragm?
the lumbar, costal and sternal parts
during inspiration, what does the diaphragm do?
it contracts to increase the volume of the thoracic cavity, thus decreasing its pressure to draw air in
(vice versa occurs for expiration w/ the diaphragm relaxing)
aortic hiatus?
the most dorsal opening, the aorta, the azygous vein and the thoracic duct
oesophageal hiatus?
oesophagus, dorsal and ventral vagal trunks
caval foramen?
lies within the central tendinous region of the diaphragm and contains the caudal vena cava
what is the blood supply of the lungs and diaphragm?
bronchoesophageal a. and v.
innervation of the lungs?
parasympathetic and sympathetic nerves from a pulmonary plexus
innervation of the diaphragm?
phrenic nerve
what is parietal pleura attached to apart from visceral pleura?
ribs - essentially lungs and ribs are attached to each other
where are the costodiaphragmatic and costomediastinal recess found?
between the basal border of the lung and diaphragmatic line of pleural reflection
what does the costodiaphragmatic and costomediastinal recess provide a potential route for?
for the pleural cavities without damaging lungs
what is the costomediastinal recess?
it is a diverticulum of the right pleural cavity containing the right accessory lung lobe
where does the costomediastinal recess occupy?
it occupies the 4th to 6th intercostal spaces on the left and on the right as well
which species have additional tracheal bronchus?
cow
which species lacking medial lobe?
horse
Which structures do NOT make up the boundaries of the area of auscultation named the ‘triangular field’?
ventral border: scapulae to mammary gland
bifurcation of trachea occurs at which rib?
5th
secondary bronchi is called?
lobar bronchi
Thoracic duct passes through which opening of the diaphragm?
aortic hiatus
Which species have a distinct connective tissue septa in the lung tissue?
cow
Which organs are most likely to move into thorax after a diaphragmatic rupture?
liver and intestines
what supplies motor innervation to all of the intrinsic muscles of the larynx except the cricothyroid muscle?
the caudal laryngeal nerves
briefly describe what the trachea is?
it is a flexible tube which continues from the larynx and connects to the bronchus
where does the trachea pass through?
it passes caudal as far as the base of the heart which is where it divides into two principal bronchi (bifurcation around 5th rib)
what does the principal bronchi branch into?
it branches into secondary (lobar) then tertiary and eventually into bronchioles
what are the lobes of the left lung of carnivores?
cranial lobe (which is divided) and the caudal lobe
what are the lobes of the right lung of carnivores?
cranial lobe
middle lobe
caudal lobe
accessory lobe
what are the lobes of the left lung of pigs?
cranial lobe (which is divided) and the caudal lobe
what are the lobes of the left lung of ruminants?
cranial lobe (which is divided) and the caudal lobe
what are the lobes of the right lung of pigs?
cranial, middle, caudal, accessory lobe (cranial lobe-tracheal bronchus)
what are the lobes of the right lung of ruminants?
cranial lobe - tracheal bronchus
caudal lobe
accessory lobe
what are the lobes of the left lung of horse?
cranial lobe and caudal lobe
what are the lobes of the right lung of horse?
cranial lobe
caudal lobe
accessory lobe
what does the line of pleural reflection represent?
it represents the most caudoventral extent of the pleural cavity
what separation does the line of pleural reflection represent?
it represents the separation of the abdominal and thoracic cavities
if a needle was entered caudodorsally along the line of pleural reflection where would it enter?
it would enter the abdomen
if a needle was placed cranial along the line of pleural reflection where would it enter?
it will enter the thorax
