Introduction to the Cardiovascular system Flashcards
what does the thoracic cavity contain?
contains the heart, lungs and other associated structures
what is the entrance known as into the thoracic cavity?
known as thoracic inlet
what is the thoracic inlet formed by?
formed by the first pair of ribs and thoracic vertebrae
what is the thoracic cavity lined with?
lined with serosa - serous membrane PLEURA
Caudal border of thoracic cavity is filled with?
filled with diaphragm and ventrally sternum
in which direction does the diaphragm arch in?
diaphragm arches cranially separating the two cavities
pleura is lubricated by what?
with a small amount of pleural fluid
what is pleura attached to?
it is attached to bony and muscular parts of the thorax by endothoracic fascia
what does pleura consist of?
pleura consists of two separate sacs, one surrounding each lung
lungs never enter the…
the pleural cavities
visceral pleura?
lines the lungs-pulmonary
parietal pleura?
lines the thorax
costal, diaphragmatic and mediastinal pleura
where is the pleural cavity found?
between visceral pleura and parietal pleura
pericardial pleura?
part of mediastinal pleura on either side of the pericardium
connecting pleura?
double layer of serosa connecting visceral and parietal pleura (pulmonary ligaments)
describe the junction of the two pleural sacs:
near the midline of the thorax and it forms a double layer, the mediastinum
what is the mediastinum?
a connective tissue partition which separates the pleural cavities
it is the space between the right and left pleural sacs that encloses a number of structures
both parietal and visceral pleura meet with the…
the mediastinal pleura
what is within the cranial mediastinum?
oesophagus, trachea, great vessels, thoracic duct, some lymph nodes, nerves and thymus
what is within the medial mediastinum?
oesophagus, the termination of the trachea, pulmonary vessels, aortic arch, thoracic duct, azygous vein, lymph nodes, nerves, heart and pericardium
what is within the caudal mediastinum?
oesophagus, aorta, vagus trunks, some lymph nodes and the left phrenic nerve
describe the mediastinum in the dog?
the barrier is delicate but said to be complete
describe the mediastinum in the horse?
the caudal mediastinal partition is very delicate and fenestrated, allowing communication between cavities
describe the mediastinum in ruminants:
openings occur rarely in sheep, but never in ox or goat
what is not in the mediastinum space?
both right and left lungs, the caudal vena cava and the right phrenic nerve is not in this space
what is the cardiovascular system?
it is the heart
network of joined vessels (arteries, veins and capillaries)
auxiliary system of vessels (lymphatics)
the heart functions as two separate pumps, what are these two pumps?
through the right side of the heart to the lungs (pulmonic circulation)
through the left side of the heart to the heart itself and to the rest of the body (systemic circulation)
pulmonary circulation?
consists of the vessels associated with the lungs
what does the right ventricle do?
it pumps the blood to the lungs, where the concentrations of oxygen and co2 is adjusted
what does the left ventricle do?
it pumps the oxygenated blood from the lungs to all organs in the body
when blood returns from systemic circulation, where does it enter?
it enters the right side of the heart
from the pulmonary circulation, where does blood enter the heart?
blood enters the heart from the left side, hence from the left side blood is pumped into the systemic circulation to begin the loops again
what do capillaries allow?
permit diffusion between blood and interstitial fluids
arteries conduct blood…
away from the heart
what is the criterion which separates arteries from veins?
direction of blood flow
common carotid supplies what?
the head
vein with their respective arteries?
always larger than their arteries and are often duplicated
where do systemic veins return the blood to?
to the heart (via cranial and the caudal vena cava and coronary sinus of the heart)
arteries structure?
thick walled
thick layers of muscle and elastic fibres
veins structure?
thin walled
thin layers of muscle and elastic fibres
valves
what is the lymphatic vascular system?
responsible for the immunological defense of the body
extensive network of one-way vessels
returning remaining interstitial fluid to the blood
and fluid is called lymph
blind beginnings?
lymphatic vessels have blind beginnings (lymph capillaries)
small lymph vessels empty into?
small veins
large lymph vessels empty into?
large veins
vessels tend to be… to veins
parallel
overlapping edges of the endothelial cells of the lymph vessels create…
create valve like openings
thoracic duct?
major lymph-collecting channel
right lymphatic duct?
empties into right side of the heart via jugular v. or cranial vena cava
right lymphatic duct?
right side of the head, neck and thorax and right limb
tracheal ducts?
empties into either thoracic duct or the large veins near the heart
tracheal duct drains…
drains the head and neck
thoracic duct arises where?
arises in the abdomen, receives lymph from abdomen, the pelvis and the hind limbs
where is the thoracic duct initially located?
initially located to the right of the median plane, more specifically on the right dorsal border of the thoracic aorta
where does the thoracic duct pass through?
pass through the aortic hiatus into the mediastinum
where does the thoracic duct mostly enter through?
enters the left jugular or cranial vena cava
what does the thoracic duct drain?
cisterna chyli
what is the cisterna chyli?
thin-walled structure not easily observed
located on the left side, dorsal to renal a. between aorta and thoracolumbar junction
both the intestinal and lumbar lymphatic trunks drain into the cisterna chyli
what is part of the parietal pleura?
costal, diaphragmatic and mediastinal
which species mediastinal partition is very delicate and fenestrated?
horse
lungs and the caudal vena cava and the right phrenic nerve are in the mediastinum - true/false?
false - lungs is deffo outside and left phrenic nerve is but right is not
venous blood from the body enters the heart via…
right atrium from the vena cava
what is the name of the main lymphatic duct origin that arises in the abdomen?
thoracic duct
