Cardiovascular System Flashcards
what are the main functions of the cardiovascular system?
carries oxygen carries nutrients carries waste products from metabolism carries hormones homeostasis immunity thermoregulation
what components form the cardiovascular system?
blood
vessels
heart
lymphatic system
what is the function of the lymphatic system?
collects interstitial fluid and aids the immune system
what is blood formed of?
plasma and formed elements
how much does plasma contribute to total blood volume?
55%
what are the 2 types of blood cells?
erythrocytes (RBC)
leukocytes (WBC)
how much of total blood volume is formed from blood cells?
45%
how much of plasma is water?
91% water
what is the other 9% of plasma volume made of?
proteins, ions, nutrients etc
what are the 3 plasma proteins?
albumins
globulins
fibrinogen
what is the role of albumin in blood plasma?
maintains blood colloid osmotic pressure to ensure water in plasma stays in the blood
transport of other molecules
what is the role of globulin in blood plasma?
immunity
what is the role of fibrinogen in blood plasma?
clotting
what is the difference between plasma and serum?
serum is plasma with clotting factors removed
what percentage of blood volume do erythrocytes make up
95%
what do erythrocytes contain to aid oxygen transport?
haemoglobin
what are the only animal erythrocytes that don’t contain a nucleus?
mature mammalian erythrocytes
how do erythrocytes vary between species?
in size
What are leukocytes part of?
the immune response
is there haemoglobin in leukocytes?
no
is there a nucleus in leukocytes?
no
what are platelets involved in?
clotting and sealing breakages in small vessels
what are platelets formed of?
haemoblast
what are the names of the 3 layers of artery and vein walls?
tunica intima
tunica media
tunica adventitia
describe the tunica intima
thin endothelium with a basement membrane, lamina propina and internal elastic membrane
what type of cell is the epithelium of the tunica intima made up of?
simple squamous
describe what the tunica media is made up of
smooth muscle
variable elastic fibres
external elastic membrane
describe what the tunica adventitia is made up of
connective tissue
variable from dense to loose
what type of epithelium are capillaries made up of?
simple stratified squamous
what do the endothelial cells of capillaries rest on?
basement membrane
what are the 3 types of capillaries?
continuous
fenestrated
sinusoidal
which of the 3 types of capillary have the largest and smallest holes in and so let the largest and smallest molecules through?
continuous have smallest holes and allow through smallest molecules
sinusoidal have largest gaps and let largest molecules through
what do capillaries allow to enter and leave blood?
nutrients and waste products
what is the amount of blood entering capillary networks controlled by?
caliber of arterioles and venules and by precapillary sphincters
what are the 2 circuits of the mammalian cardiovascular system?
systemic and pulmonary
what are the 4 chambers of the mammalian heart?
left atrium, right atrium
left ventricle, right ventricle
how many pumps make up the human heart
2 in series
where is the heart located in mammalian quadrupeds?
obliquely in the ventral mediastinum with the right side of the heart more cranial and the left side of the heart more caudal. Rests on the sternum with the apex on the diaphragm
where is the heart located in humans?
in mediastinum, lies obliquely with the apex towards the left of the thorax
what does the thoracic cavity contain?
2 pleural cavities
mediastinum
what is contained within the 2 pleural cavities?
lungs
what does the mediastinum contain?
the heart
what are the 3 types of pericardium?
fibrous
parietal
visceral
what is the pericardium?
sac which surrounds the heart
what is the role of the fibrous pericardium and where is it found?
tough outermost layer of the pericardium that protects the heart, non-distensable
what is the role of the parietal pericardium and where is it found?
continuous with the fibrous pericardium, produces fluid
where is the visceral pericardium found?
continuous with the epicardium
what does the pericardial cavity contain?
fluid which aids lubrication when the heart is moving
where is the pericardial cavity located?
between parietal and visceral pericardium
what is the name of the ligament that attaches the heart to the sternum in humans and large animals?
sternopericardiac ligament
what is the name of the ligament that attaches the heart to the diaphragm small animals?
phrenopericardiac
what are the 3 tissue layers of the heart wall?
endocardium, myocardium, epicardium
where is the endocardium found within the heart?
inner surface
what is the endocardium continuous with?
endothelium of blood vessels
where is the myocardium found in the heart?
middle tissue layer made of cardiac myocytes
what is the epicardium of the heart and where is it found?
visceral serous pericardium, smooth outer surface of the heart
what are the major veins that can be seen externally to the heart?
caudal/posterior and cranial /anterior vena cava
azygos vein
pulmonary veins
what are the major arteries that can be seen externally to the heart?
aorta (and branches)
pulmonary trunk
what blood vessels can be seen on the surface of the outside of the heart?
coronary vessels
what view of the human heart is equivalent to the left lateral view of the quadruped heart?
anterior
what are the coronary vessels contained within in the surface of the heart?
grooves (sulci)
where is the left intraventricular paraconal groove located?
next to the conus arteriosis between the right and left ventricles
where is the coronary sulcus located?
between the atria and ventricles
where is the right interventricular subsinosal groove located?
right lateral view - marks the edges of the left and right ventricles
label a diagram of the left lateral view of a quadruped heart, what are the 11 key structures?
cranial vena cava brachiocephallic trunk left subclavian artery aorta caudal vena cava right auricle right ventricle conus leading to pulmonary trunk left auricle left atrium left ventricle
label a diagram of the right lateral view of a quadruped heart, what are the 9 key structures?
cranial vena cava aorta caudal vena cava right auricle right ventricle left atrium Apex (left ventricle) right atrium pulmonary veins
what blood vessels are most easily seen at left and right lateral views of the quadruped heart?
left: arteries
right: veins
what is the heart skeleton formed of?
fibrous connective tissue
where is the heart skeleton located?
between atria and ventricles
what is the function of the heart skeleton?
electrical insulation between atria and ventricles
what do the fibrous rings of the heart skeleton support?
support valves and provide site for muscle attachment of myocardium
how does the heart skeleton electrically insulate the ventricles?
prevents the random spread of electrical impulse throughout the heart
what are the ossa cordis?
small bones found within the heart muscle of ruminants
what is the function of ossa cordis?
supports the aortic valves
what sort of bone is the ossa cordis made of?
splanchnic
where is blood carried from in the azygos vein?
blood from the abdomen
what does the coronary sinus do?
allows blood to return from the coronary circulation into the right atrium
what is the intravenous tubercle?
ridge of cardiac tissue between the cranial/caudal vena cava
what is the fossa ovalis?
interatrial foetal structure that allows blood to bypass the pulmonary circulation while in utero
what is the function of the intravenous tubercle?
diverts the blood from both vena cavae into atria and reduces terbulance
name the 2 atrio-ventricular valves
right: tricuspid valve
left: bicuspid (mitral) valve
what is the function of the atrio-ventricular valves?
gateway between atria and ventricles. Prevent backflow of blood
what are the cusps of the valve formed from?
endocardium
what is the function of the cordae tendinae?
support the edge of the cusps
prevent the inversion of cusps into atria when they contract
extend from cusps to the projections of the ventricular wall
what is the function of the papillary muscles?
prevent backflow
pull on cusps via cordae tendonae during ventricular contraction
what is the conus arteriosus?
cone shaped exit of right ventricle leading to pulmonary trunk
where does blood exit the right ventricle?
via the pulmonary valve into the pulmonary trunk
what sort of valve is the pulmonary valve?
semi-lunar valve
what are trabecular carnae?
muscular ridges on the walls of ventricles that reduce turbulance
what are the trabeculae septomarginarlis?
short cut for the transmission of action potential so it can travel directly from the septum to the wall of ventricle
name the semilunar valves of the heart
Right semi-lunar valve/ pulmonary valve
left semi-lunar valve/ aortic valve
which semi-lunar valve has the most cusps and why?
right, as the entrance from the ventricles is larger
which veins arrive in the left atrium?
pulmonary veins
which ventricle produces more contractile force and why?
left as the walls are thicker and there is a circular action of contraction as opposed to the more ‘bellows like’ action of the right ventricle
where does blood exit the left ventricle?
aortic valve
what is the ligamentum arteriosum?
a remnant of foetal circulation between aorta and pulmonary artery that aids bypass of the pulmonary circulation by blood
what is the ligamentum arteriosum known as while in utero?
ductus arteriosus
where is the ligamentum arteriosum located?
between the aorta and pulmonary artery
what does the coronary circulation supply?
the myocardium (heart tissue)
where are coronary vessels found?
within sulci on the heart surface
where is blood for coronary circulation taken from?
directly from the aorta as requires as much oxygen as possible
what is myocardial infarction caused by?
blockage of the coronary arteries
name the coronary blood vessels that can be seen on a left lateral view of the canine heart
left coronary artery
left interventricular (paraconal) branch
circumflex branch
great cardiac vein
name the first branch of the coronary artery
left interventricular (paraconal) branch
name the second branch of the coronary artery
circumflex branch
where does the great cardiac vein travel around the heart?
coronary sulcus
name the coronary blood vessels that can be seen on a right lateral view of the canine heart
great cardiac vein
coronary sinus
middle cardiac vein
circumflex branch of left coronary artery
right interventricular (subsinosal) branch of left coronary artery
right coronary artery
where doess the coronary sinus drain into?
right atrium
where in the heart are the highest concentration of intercalated discs and so most efficient conduction of action potential?
purkinji fibres
describe the blood flow through a mammalian heart
superior and inferior vena cava right atrium tricuspid valve right ventricle pulmonary semilunar valves pulmonary trunk pulmonary arteries lung tissue (pulmonary circulation) pulmonary veins left atrium bicuspid valve left ventricle aortic semi-lunar valves aorta body tissues (systemic circulation)
name the branches of the aortic arch in all animals (no order)
brachiocephallic trunk
subclavian arteries (internal thoracic artery)
common carotid arteries
what are the branches of the aorta once it is passed the aortic arch?
dorsal intercostal arteries
broncho-oesopageal artery
what is the function of the broncho-oesopageal artery?
supplies lung tissue with blood
in the dog, what is the first branch of the aortic arch?
bracheocephallic trunk
in the dog, what arteries originate from the bracheocephallic trunk?
left and right common carotid artery
right subclavian artery
in the dog, what is the second branch of the aortic arch?
left subclavian artery
how does the aortic arch differ in horses when compared to dogs?
there is only one branch in the aortic arch
how does the aortic arch differ in humans when compared to dogs?
3 branches of the aortic arch
what are the major veins in the thorax?
cranial/superior vena cava caudal/inferior vena cava right and left brachiocephallic veins external jugular veins subclavian veins
in the dog which veins drain into the cranial vena cava?
bilateral external jugular veins
bilateral subclavian veins
bracheocephallic vein
where does the azygos vein drain blood from?
dorsal/posterior thorax
dorsal /posterior intercostal veins
where does the azygos vein drain into?
right atrium or cranial/superior vena cava
how many azygos veins are there in pigs?
left and right (left drains into coronary sinus)
what are the major paired arteries in the abdomen?
L&R phrenicoabdominal L&R renal L&R ovarian testicular L&R deep circumflex L&R external illiac L&R internal illiac
what are the unpaired arteries in the abdomen?
coeliac
cranial messenteric
caudal messenteric
median sacral
what 2 paired arteries from the common illiac arteries in humans?
L&R external illiac
L&R internal illiac
what is provided with blood by the L&R phrenicoabdominal artery?
dorsal/posterior abdominal wall
adrenal glands
what is provided with blood by the L&R deep circumflex artery?
caudal/inferior abdominal wall
what is provided with blood by the L&R external illiac artery?
hind limbs
what is provided with blood by the L&R internal illiac artery?
pelvic organs
name the paired veins in the abdomen
L&R phrenicoabdominal phrenic abdominal L&R renal ovarian/testicular L&R deep circumflex L&R common illiac L&R external illiac L&R internal illiac median sacral hepatic
which artery supplies the liver tissue with nutrients and oxygen?
hepatic
which vein links the small intestine to the liver so that blood can be filtered of nutrients?
hepatic portal
what are the functions of the lymphatic system?
drainage of body tissue fluid
absorption and transport of fat
immune system
what are the components of the lymphatic system?
lymph lymphatic capillaries lymphatic vessels lymphoid organs lymph nodes lymphocytes
what are the largest lymphatic vessels?
thoracic duct
right lymphatic duct
what is the thoracic duct a continuation of?
cisterna chyli
what are the 2 divisions of lymphoid organs?
primary
secondary
what are the primary lymphoid organs?
bone marrow
thymus
what are the secondary lymphoid organs?
spleen
tonsils
lymph nodes
what are the secondary lymphoid organs used for?
storage of lymphocytes
what are the primary lymphoid organs used for?
production of lymphocytes
what other body fluid does lymph have the same constituents as?
plasma
what structure are lymphatic capillaries closely associated with?
capillary beds
what are lymphatic capillaries formed of?
overlapping epithelial cells
do lymphatic capillaries contain valves?
yes
what does the overlapping epithelial cells of lymphatic capillaries allow?
molecules are able to enter the capillaries
how is fluid moved through lymphatic vessels?
skeletal muscle contraction
what sort of lymphocytes are produced in the bone marrow?
b lymphocytes
what sort of lymphocytes are produced in the thymus?
t lymphocytes
where is the thymus located?
cranial mediastinum
what are the key parts of a lymph node?
afferent and efferent lymph vessels
cortex
medulla
how do lymph nodes respond to pathogens?
pathogens enter by afferent lymph vessels and trigger lymph nodes to work. This causes a release of lymphocytes through efferent lymph vessels
what colour of blood cell are lymphocytes?
white
what percentage of blood cells are made up of lymphocytes?
20-25%
where are most of the lymphocytes located?
within lymphatic tissues
what role in immunity do b lymphocytes play?
produce antibodies
what role in immunity do T lymphocytes play?
attack and destroy foreign cells
what embryological germ layer does the heart form from?
lateral plate mesoderm
what is the name of the process by which blood cells are created?
haematopoesis
what is formed from lateral plate mesoderm in the first stage of formation of cardiovascular system?
blood islands
what is the name of the process by which blood vessels and the heart are formed from lateral plate mesoderm?
angiogenesis
what is the placenta formed from?
vascular network of blood islands
where does the heart arise from?
splanchnic mesoderm
what do the medial pairs of endocardial tubes go on to form in the adult heart?
endocardium
what is the name for the thickened splanchnic mesoderm?
epimyocardium
what does epimyocardium form?
will become heart muscle
what is the shape of the first embryonic heart?
tubular
what does autonomous heart mean?
heart is not under nervous input initially in the embryo
how many adjoining chambers are there in the tubular embryonic heart?
4
what are the 4 adjoining chambers in the tubular embryonic heart?
sinus venosus
atrium
ventricle
bulbus cordis
where does blood enter the embryonic heart?
sinus venosus
which of the 4 chambers of the heart grows fastest?
ventricle
what does the fastest growth of the ventricle of the embryonic heart mean for it’s position relative to the other chambers?
bends to the right, twists and atria are moved dorsal and cranial into adult position
when in adult position what happens to the atria?
expand and form bilateral pouches (the right and left atria)
what are the bilateral pouches formed in the atrium divided by?
septum
when does the development of the reptilian heart cease?
once atria have split leaving them with 2 atria and one ventricle
what is the final stage of the development of the heart in birds and mammals?
formation of ventricular septum (divides left and right ventricles)
what does the sinus venosus become in mammals?
the sino-atrial node (pacemaker)
what is the function of the sinus venosus in the embryo and more primitive hearts?
pacemaker
which animals have double circulation with 3 chambered hearts?
amphibians
reptiles
what is the cavum venosum?
received de oxygenated blood from the right atrium in chelonian and squamate hearts
what is the cavum arteriosum in chelonian and squamate hearts?
receives blood from the left atrium
what is the cavum pulmonale?
area after muscular ridge in chelonian and squamate hearts that directs de-oxygenated blood towards pulmonary vessels
what does the inter ventricular canal do?
connects cavum venosum with cavum arteriosum
what physiological adjustments are made during diving?
bradycardia
shunting of blood to only necessary tissues (brain and respiring muscles)
anaerobic metabolism
what occurs during cardiac shunt?
sphincter in pulmonary artery closes to enourage blood to take path of least resistance and flow back round to tissues, bypassing the lungs.
what are the only 2 cardiovascular adjustments that can be made in diving mammals and birds?
bradycardia
shunting of blood to only necessary tissues (brain and respiring muscles)
