circulatory system Flashcards
type of tissue blood is
specialised connective tissue
what does blood consist of
liquid matrix(plasma) and cellular portion of formed elements
percentage of plasma and formed elements
plasma 55%
formed elements 45%
describe the plasma
straw-coloured, viscous fluid,matrix of the blood
composition of plasma
90% water,8%proteins,minerals,glucose,amino acids,lipids
what are the proteins present in the plasma
fibrinogen: clotting factor produced by the liver
globulins: defence mechanism( alpha,beta and gamma. gamma are ANTIBODIES)
albumins: help in osmotic balance and blood volume by controlling the osmotic pressure
the minerals present in plasma
na,ca,mg,hco3,cl
plasma without clotting factor
serum
the formed elements
erythrocytes, leucocytes, thrombocytes
rbc count
most abundant, 5 to 5.5 million in mm-3 of blood
shape of rbc
biconcave and no nucleus,no mitochondria er ribosomes,centrioles
exceptions: camel and llama. they have oval and nucleus
advantages of no nucleus in RBC
they have more space for haemoglobin and respire anaerobically, therefore, more oxygen transported
role of carbonic anhydrase in RBC
transport of co2
quantity of haemoglobin per 100ml of blood
12-16gms
erythropoiesis
redbone marrow
graveyard of RBC
spleen
what is carbamino haemoglobin and carboxyhaemoglobin
co2 and co
lifespan of RBC
120 days
the oxidation state of fe in haemoglobin
2+
low haemoglobin conc
anaemia or iron deficiency anaemia
what is pernicious anaemia
low vit b12 , so RBC don’t mature
wbc colour
colourless
wbc count
6000 to 8000 per mm-3
wbc shape
rounded or irregular,nucleated can be granulated or granulated. they show ameboid movements and diapedisis
formation of wbc
bone marrow
lymp nodes,spleen,thymus,tonsils,peyers patches
describe the agranulocytes
1.lymphocytes: 20 to 25% of total wbc. second most numerous and are small cells with a large nucleus.
they are two types b and t lymphocytes which are responsible for immune response in the body
b lymphocytes mature in the bone marrow and t in the thymus. can last days to years
2.monocytes: 2-10% largest wbc and amoeboid in shape.horseshoe shaped nucleus. they enter tissues and become macrophages and phagocytic and engulf bacteria.20 hour life span
describe the granulocytes
- Neutrophils:60-65%many lobed nucleus takes all stains,fine granules most abundant. they show phagocytosis and are present for 4 to 8 hours in blood,5 days in tissues
- Eosinophils:2-3% bilobed acidic stain coarse granules. the same lifespan as above. have hydrolytic enzymes, peroxidases, antihistamines, lysosomes and fight allergic reactions. also, dissolve clots
- Basophils: least abundant (0-1%), basic staining granules, trilobed nucleus.secrete serotonin,heparin,histamines(dilation of blood vessels, which increases permeability and lowers blood pressure). lifespan of 8 hours
what is leucocytosis
Increase in wbc count
platelets count
1.5 lakhs to 3.5 lakhs per mm-3 smallest free element
formation of platelets
cell fragments, they are formed from megakaryocytes of bone marrow. oval disc like and lack nuclei
life span of thrombocytes
a week, destroyed in liver and spleen
function of platelets
blood clotting
result of thrombocytopenia
excessive blood loss (purpura-group of bleeding diseases)
what are blood groups based on
antigen A and B
two blood groupings
ABO and Rh+
who discovered the blood grouping system
karl Landsteiner
what happens when blood is cross matched
aggulation of blood and haemolysis of rbc
antigen of blood group A
A
antibodies of blood group B
anti A
antibodies of blood group O
anti A,B
what is Rh incompatibility
for example, b/w Rh negative blood of a pregnant mother and Rh+ blood of foetus. The Rh negative mother is not usually exposed to Rh antigeen of the foetus , but during birth, the blood may mix and then the mother can start producing antibodies against Rh+. during her second pregnancy, the antibodies can cross the placenta and kill the baby. Erythroblastosis foetalis.
coagulation of the blood pathway
contains network of threads called fibrins and damaged formed elements.
injury-platelets release thromboplastins-activate mechanism of coagulation by the formation of enzyme thrombokinase- thrombokinase+ca ions converts inactive plasma prothrombin(needs vit k for formation) to active thrombin enzyme- thrombin with ca converts soluble fibrinogen to insoluble fibrin
Sodium citrate anticog in blood banks
whats tissue fluid
the extracellular fluid which bathes the cells of most tissues, arriving via blood capillaries and being removed via the lymphatic vessels back to blood. b/w blood and cells
what is lymph
colourless liquid containing lymphocytes, responsible for immune response. its the tissue fluid in the lymphatic vessels
what does the lymphatic system contain
capillaries(closed end),vessels,ducts,nodes
what are lymphatic capillaries
The lymphatic capillaries form a network in intracellular spaces Of organs. the absorbed interstitial fluid proteins micro-organisms and fat, as they are composed of endothelial cells which are porous
pathway of lymph
the tissue fluid enters the lymph capillaries, they merge to form larger vessels.lymphatic vessels drain into the thoracic duct in the left and the right lymphatic duct these ducts further drain into the left and right subclavian veins. These veins connect and lead to Superior Vena cava
Where the lymph nodes present
neck groin armpits they contain phagocytic cells
the tonsils thymus and spleen are nodes, also the lymphoid organs
the thymus and bone marrow are considered primary lymphoid organs.
Secondary lymphoid organs include lymph nodes and spleen
Function of lymph
Transport metabolic waste into the venous system
provide immunity
destroy foreign matter entering the body
absorbs fats from the intestine via lacteals
What is the open circulatory pathway?
the blood pumped by the heart passes through large vessels into Open Spaces and bodies cavities called sinuses example anthropods and molluscs
What is the closed circulatory system?
in closed circulatory system the blood is pumped through close network of vessels in a precise and regulated manner example in annelids and chordates
what are the additional Chambers of lower vertebrates called
sinus venosus and conus arteriosus
What is single circulation?
single circulation occurs in a two-chambered heart for example fish
the blood is deoxygenated which is pumped to the gills from where it gets oxygenated and Goes to the body parts from where the deoxygenated blood returns to the heart
What is incomplete double circulation?
This is found in lungfish amphibians and reptiles except Crocodile. here the heart is three chambered two Atria and one ventricle
reptiles have a kind of septum in the ventricle
The left Atrium get oxygenated blood what are the right gets deoxygenated blood and the two blood mix in the ventricle
What is double circulation?
in double circulation the heart is four chambered as in a bird mammal and crocodiles
the right Atrium receives deoxygenated blood from where it goes to the right ventricle 10 to the lungs for oxygenation and then back to the heart where it comes to the left Atrium then to the left ventricle and then the oxygenated blood is distributed to the body
It is called double circulation as the blood passes through the heart twice.
where is the heart located?
in the thoracic cavity between the two lungs slightly tilted towards left it has the size of a clenched fist And derives From the mesoderm
How is a heart protected?
protected by the Rib cage
It has a double-walled membrane called the pericardium. fibrous layer- the outer parietal pericardium- the inner visceral pericardium attached to the heart (the heart muscles: epicardium myocardium(the actual contracting muscle) endocardium)
The pericardial cavity is present between the two layers filled with the pericardial fluid
it protects our heart from shocks and mechanical injury
Chambers of the heart
They are the Atrium and the ventricles .the ventricles are thick-walled and the Atriums or thin-walled
The Atriums are divided by the interatrial septum (thin muscular) whereas the ventricles are divided by the interventricular septum(thick) the ventricles and atria on each side or divided by the fibrous atrioventricular septum but they have openings guarded by valves.
The valves of the heart
They are the atrioventricular valves .on the right side we have the tricuspid valves and on the left side with bicuspid valve A k a mitral valve.
what are the chordae tendinae and papillary muscles
the chordae tendinae are special cords holding the valves/flaps at one end and the other end is held by papillary muscles. the chordae tendinae prevent the valves from collapsing in the atria during powerful ventricular contraction.
where are the semilunar valves
in the pulmonary artery and aorta, the only arteries with valves. it is to prevent the backflow of blood into the ventricles
what are foramen ovale and ductus arteriosus
what happens after birth
foreman ovale is found in foetus, in between the two auricles where the blood bypasses in the heart
ductus arteriosus is between pulmonary and systemic aorta
after birth, once the baby starts breathing , they become fossa ovalis and ligamentum arteriosum respectively
flow of blood aka the circulation
deoxy blood from the superior and inferior vena cavae, coronary sinus come to RA-tricuspid valve-RV- pulmonary artery-lungs-oxygenated blood-2 pulmonary veins-LA-bicuspid valve-LV-aorta-body then cycle repeated
where are the SAN and AVN nodes present
they are present in the cardiac muscles
the sinoatrial node is present on the upper right corner of the right atrium and the atrioventricular node is present lower-left corner of right atrium close to the atrioventricular septum
what is the atrio ventrical bundle
bunch of nodal fibres that arise from the AVN which then pass through the atrioventricular septa to emerge on top of the intraventricular septum and then immediately divide into right and left bundle.
what are purkinje fibres
minute fibres arising from the right and left bundles running throughout the ventricles’ muscles. they along with the right and left bundles are called the bundle of his.
speciality of the nodal tissues of the heart
autoexciteable(myogenic) can produce short-lived action potentials without and external stimuli.
which nodal tissue initiates cardiac contraction
all can, but SAN is preferred as it generates the maximum action potentials-72 times per minute,, natural pacemaker of the heart.
explain the cardiac cycle
repeated cycles of and systole diastole(relaxation) of 0.8 s each cycle.
- complete cardiac diastole of 0.4 seconds, the atriums are filled with blood
pressure increases - av valves open and blood flows to ventricles and semilunar valves close
3.SAN generates an action potential that causes the atria to undergo atrial systole(0.1 s) and increase the blood volume to the ventricles by 30%
4.the SAN conducts the impulse-to the AVN bundle-AV bundle-bundle of his-ventricular muscles and we get ventricular systole(0.3s) as well as atrial diastole. - semilunar valves open, pressure in the ventricles decrease
6.once again joint diastole.
what is stroke volume
volume of blood released by the ventricles each cycle
its 70 ml
what is cardiac output
amount of blood released per minute
its is 5040 ml
what are lubb and dub
lubb: closing of the AV valves at ventricular systole. low pitched and long duration
dubb: closing of semilunar valves at the beginning of ventricular diastole. high pitch long duration
what is heart murmur
defective lubb dubb sound due to defective valves
whats ECG
electrocardiograph is a machine detecting current travelling through the heart
break down the electrocardiogram
p wave:small upward bump
depolarisation and contraction of both atria
QRS: complex showing depolarization of ventricles. the dip in the q wave represents the start of the ventricle systole. gives the pulse rate
t wave: the return of the ventricles from excited state to a normal state. the end of t wave marks the end of ventricular systole.
defects in the ECG graph
enlargement of P wave means the Enlargement of atria
enlargement of QR waves means myocardial infarction(heart attack)
enlargement of ST waves means myocardial infarction(heart attack)
depression of T waves when the heart gets insufficient oxygen (myocardial ischemia)as in atherosclerotic diseases.
whats an artificial pacemaker
by chardack, its an implant to replace the SAN
which ventricle is thicker
left
the renal portal system is found in
fish and amphibians, reduced in birds and reptiles
hypophyseal portal system
the vein collects blood from the hypothalamus and enters the anterior lobe of the pituitary
hepatic portal system
the portal vein does not carry blood straight back to the heart but forms network of capillaries and goes to an intermediate organ before the heart–the liver here from the small intestines.
- converts excess glucose to glycogen
- NH3 to urea
- puts proteins into the blood
- detoxification
whats coronary circulation
blood from the heart muscles
the aorta splits and has left and right coronary arteries which supply blood to the heart
walls of blood vessels
tunica externa(connective tissue)-tunica media(smooth muscles)-tunica interna(two parts, the elastic membrane and endothelium)
the elastic membrane is made of elastic tissues of yellow fibres. they are thicker in the arteries
the endothelium is made up of flat squamous epithelial cells lining the lumen. more elongated in arteries.
which blood vessels are more muscular(thick tunica media)
arteries
which blood vessels are only made of the endothelium
capillaries, to facilitate faster diffusion with tissue fluid
flow blood in vessels
heart-arteries-arterioles-capillaries-venules-veins-heart
what control does the brain have over the heart
the medulla oblongata regulates the autonomic nervous system.
sympathetic nerves release noradrenaline,epinephrine which stimulate SAN and increase cardiac output
parasympathetic nervous system release acetylcholine which decreases heart rate.
whats blood pressure
sys/diastole
normal blood pressure
120/80
hypertension
140/90
angia pectoris
chest pain, insufficient oxygen to heart muscles
heart failure
when the body doesn’t pump enough blood to meet body’s requirements. congestive heart failure as its usually due congestion in lungs
heart attack
heart muscles suddenly damaged
cardiac arrest
complete stoppage of the heart
coronary heart disease
atherosclerosis, thickening of arteries supplying blood to the heart due to depositions
aneurysm
weak artery walls, ballooning of a portion of artery walls
Arteriosclerosis
condition in which the arteries narrow and harden, leading to poor circulation of blood throughout the body
varicose veins
accumaltion of blood in legs when the blood doesn’t reach back to the heart. hey veins stretch and valves fail. can lead to fainting and falling
isovolume systole
time b/w closing of av valves and opening of semilunar valves
isovolume diastole
time b/w closing of semilunar valves and opening of av valves.
what decrease heart rate
k and na
what increase heart rate
ca
