Circulation NCERT Flashcards
All living cells have to be provided with —-, O2 and other essential substances. Also, the waste or —- substances produced, have to be removed continuously for healthy functioning of tissues.
nutrients, harmful
Hence, It is essential to have efficient mechanisms for the —– to the cells and from the cells.
movement of these substances
Different groups of animals have evolved different methods for this transport. Simple organisms like —— and — circulate water from their surroundings through their body cavities to facilitate the cells to exchange these substances.
sponges and coelenterates
More complex organisms use — fluids within their bodies to transport such materials
special
—–is the most commonly used body fluid by most of the higher organisms including humans for this purpose.
Blood
Another body fluid, —-, also helps in the transport of certain substances.
lymph
Blood is a special connective tissue consisting of a —–, —- and —–.
fluid matrix, plasma and formed elements
Plasma is a —- coloured, viscous fluid constituting nearly —– of
the blood.
straw, 55 per cent
90-92 per cent of plasma is —–and proteins contribute—- per cent of it.
water, 6-8
——-, —- and —- are the major proteins in blood
Fibrinogens, Albumins, Globulins
Fibrinogens are needed for —— of blood.
clotting or coagulation
Globulins primarly are involved in —– of the body and the albumins help in —– .
defense mechanisms
osmotic balance
Plasma also contains small amounts of —- like Na+, Ca++, Mg++, HCO3 , Cl–, etc.
minerals
Glucose, ——, lipids, etc., are also present in the plasma as they are always in —in the body.
amino acids,
transit
Factors for coagulation or clotting of blood are also present in the plasma in an —- form.
inactive
Plasma without the ——- is called serum.
clotting factors
——, —- and —- are collectively called formed
elements and they constitute nearly —- per cent of the blood.
Erythrocytes, leucocytes and platelets
45
——– or — are the most abundant of all the cells in blood.
Erythrocytes or red blood cells (RBC)
A healthy adult man has, on an average, —- of RBCs mm–3 of blood.
5 millions to 5.5 millions
RBCs are formed in the —– in the adults.
red bone marrow
RBCs are devoid of — in most of the mammals and are —- in shape
nucleus , biconcave
They have a red coloured, iron containing —– called haemoglobin, hence the colour and name of these cells
complex protein
A healthy individual has —- gms of haemoglobin in every 100 ml of blood.
12-16 gms
____ molecules play a significant role in transport of
respiratory gases
Haemoglobin
RBCs have an average life span of —- after which they are destroyed in the —– (graveyard of RBCs).
120 days
spleen
—- are also known as white blood cells (WBC) as they are colourless due to the lack of haemoglobin.
Leucocytes
WBC are nucleated and are relatively lesser in number which averages —-mm–3 of blood.
6000-8000
Leucocytes are generally —–.
short lived
We have two main categories of WBCs
– ——– and ——–.
granulocytes and agranulocytes
Neutrophils, —- and basophils
are different types of granulocytes, while lymphocytes and monocytes
are the —— .
eosinophils
agranulocytes
Neutrophils are the most abundant cells (—-
per cent) of the total WBCs and —– are the least (0.5-1 per cent)
among them.
60-65
basophils
Neutrophils and monocytes (—– per cent) are phagocytic
cells which destroy —–entering the body.
6-8
foreign organisms
Basophils secrete
histamine, serotonin, heparin, etc., and are involved in —-
reactions.
inflammatory
Eosinophils (—- per cent) resist infections and are also associated with _____
2-3
allergic reactions
Lymphocytes (—–per cent) are of two major types –—–.Both of which are responsible for —– of the body.
20-25
‘B’ and ‘T’ forms
immune responses
Platelets also called ——-, are cell fragments produced from ——- (special cells in the bone marrow).
thrombocytes
megakaryocytes
Blood normally
contains —- platelets mm–3.
1.5 L to 3.5 L
Platelets can release a varietyof substances most of which are involved in the —–
coagulation or clotting of blood
A reduction in the number of —– can lead to clotting disorders which
will lead to excessive loss of —- from the body.
Platelets
blood
ABO grouping is based on the presence or absence of two ——- on the RBCs namely A and B.
surface antigens
Antigens are chemicals that can ——
induce immune response
Similarly, the —– of different individuals contain two —- antibodies
plasma, natural
Antibodies are —– produced in response to antigens
proteins
the blood of a donor has to be carefully matched
with the blood of a recipient before any blood transfusion to avoid severe problems of ——- (destruction of RBC).
clumping
group ‘O’ blood can
be donated to persons with any other blood group and hence ‘O’ group individuals are called ‘———-’.
universal donors
Persons with ‘AB’ group can accept blood from persons with ——.
Therefore, such persons are called ‘universal recipients’.
AB as well as the other groups of blood
Another antigen, the Rh antigen similar to one present in ———
(hence Rh), is also observed on the surface of RBCs of majority (nearly —- per cent) of humans. Such individuals are called Rh positive (Rh+ve)
and those in whom this antigen is absent are called Rh negative (Rh-ve).
Rhesus monkeys, 80
An Rh-ve person, if exposed to Rh+ve blood, will form —- against the Rh antigens.
specific antibodies
A special case of Rh —-(mismatching)
has been observed between the —- blood of a pregnant mother with Rh+ve blood of the foetus.
incompatibility
Rh-ve
Rh antigens of the foetus do not get exposed to
the Rh-ve blood of the mother in the — pregnancy as the two bloods are
well separated by the —-
first, placenta
During the delivery of the first child, there is a possibility of —- to small amounts of the Rh+ve blood from the foetus.
In such cases, the mother
starts preparing antibodies against — in her blood.
exposure of the maternal blood
Rh antigen
In case of Rh-ve mother’s subsequent pregnancies, the Rh antibodies from the mother (Rh-ve)
can leak into the blood of the foetus (Rh+ve) and —- RBCs.
destroy the foetal
Rh-ve blood could be fatal to the foetus or could cause severe —- and — to the baby. This condition is called —.
anaemia and
jaundice
erythroblastosis foetalis
Erythroblastosis foetalis can be avoided by administering—- to the mother immediately after the delivery of the first child.
anti-Rh antibodies
Blood exhibits coagulation or clotting
in response to —–.
an injury or trauma
Clotting is a mechanism to prevent —- from the body.
excessive loss of blood
a dark reddish brown scum formed at the site of a cut or an injury over a period of time is a —- formed mainly of a network of threads
called —- in which dead and damaged formed elements of blood are
trapped.
clot or coagulam,
fibrins
Fibrins are formed by the conversion of inactive fibrinogens in
the plasma by the —–.
enzyme thrombin
Thrombins, in turn are formed from
another —– called prothrombin.
inactive substance present in the plasma
An ———, thrombokinase, is required for the above reaction. This
complex is formed by a series of linked enzymic reactions (——-) involving a number of factors present in the plasma in an — state.
enzyme complex
cascade process
inactive
An injury or a trauma stimulates the —- in the blood to release
certain factors which activate the mechanism of coagulation.
platelets
Certain factors released by —- at the site of injury also can initiate
coagulation.
the tissues
—— ions play a very important role in clotting
Calcium
As the blood passes through the capillaries in tissues, —– along with many — substances move out into the spaces
between the cells of tissues leaving the larger proteins and most of the formed elements in the —.
some water, small water soluble
blood vessels
This fluid released out of cappilaries is called the — or tissue fluid.
interstitial fluid
Tissue fluid has the same —distribution as
that in plasma.
mineral
Exchange of —–, —–, etc., between the blood and the cells always occur through tissue fluid.
nutrients, gases
An elaborate network of vessels called the — collects tissue fluid and drains it back to the
major veins.
lymphatic system
The fluid present in the lymphatic system is called the —-.
lymph
Lymph is a colourless fluid containing specialised —- which
are responsible for the immune responses of the body.
lymphocytes
—- is also an
important carrier for nutrients, hormones, etc.
Lymph
Fats are absorbed through lymph in the —-present in the intestinal villi.
lacteals
The circulatory patterns are of two types – – —.
open or closed
Open circulatory system is present in arthropods and molluscs in which blood pumped by the heart passes through — into open spaces or
body cavities called —-.
large vessels, sinuses
Annelids and chordates have a closed circulatory system in which the blood pumped by the heart is always
circulated through a — of blood vessels. This pattern is considered to be more advantageous as the —- regulated.
closed network
flow of fluid can be more precisely
All vertebrates possess a —-chambered heart.
muscular
Fishes have a —chambered heart with an atrium and a ventricle.
2
Amphibians and the reptiles (except —-) have a 3-chambered heart with two —- and a single —
crocodiles
atria, ventricle
Whereas crocodiles, —-and mammals possess a
4-chambered heart with two atria and two ventricles.
birds
In fishes the heart pumps out —- blood which is oxygenated by the —- and supplied to the body parts from where deoxygenated blood is returned to the heart (— circulation).
deoxygenated,gills
single
In amphibians and reptiles, the — atrium
receives oxygenated blood from the gills/lungs/skin and the — atrium gets the deoxygenated blood from other body parts. However, they get mixed
up in the—- which pumps out — blood (incomplete double circulation).
left, right
single ventricle
mixed
In —- and —-, oxygenated and deoxygenated blood
received by the left and right atria respectively passes on to the ventricles of
the same sides. The ventricles pump it out without any —–, i.e., two separate —- are present in these organisms, hence, these
animals have double circulation.
birds and mammals
mixing up
circulatory pathways
Human circulatory system, also called the —- consists of a muscular chambered heart, a network of — blood
vessels and —, the fluid which is circulated.
blood vascular system
closed branching
blood
Heart, the —– derived organ, is situated in the —cavity, in between the two lungs, slightly tilted to the —.
mesodermally
thoracic
left
The heart has the size of
a —- fist. It is protected by a —- walled membranous bag, ——, enclosing the pericardial fluid.
clenched
double
pericardium
Our heart has —-chambers, two relatively small —- chambers called —-and two larger —- chambers called —-.
four, upper, atria
lower, ventricles
A —-, muscular wall called the interatrial septum separates the right and the left atria, whereas a —-walled,
the inter-ventricular septum, separates the left and the right ventricles
thin
thick
The atrium and the ventricle of the same side are also separated by a — tissue called the atrio-ventricular septum.
thick fibrous
However, each of these septa are provided with an opening through which the —– are connected.
two chambers of the same side
The opening between the right atrium and the right ventricle is guarded by a valve formed of ——, the tricuspid valve, whereas a bicuspid or —– guards the opening between the left atrium and the left ventricle.
three muscular flaps or cusps
mitral valve
The openings of the right and the left ventricles into the pulmonary artery and the aorta respectively are provided with the
—- valves.
semilunar
The valves in the heart allows the flow of blood in — direction, i.e., from the atria to the ventricles and from the ventricles
to the —– or —-. These valves prevent any — flow
in one
pulmonary artery or aorta
backward
The entire heart is made of — muscles.
cardiac
The walls of —-
are much thicker than that of the — .
ventricles, atria
A specialised cardiac musculature called the —- is also distributed in the heart.
nodal tissue
A patch of nodal tissue is present in the —- upper corner of the right atrium
called the —- node.
right
sino-atrial node (SAN)
Another mass of the nodal tissue is seen in
the—-corner of the right atrium close to the —– septum called the atrio-ventricular node (AVN)
lower left
atrio-ventricular
A bundle of —-, atrioventricular bundle (AV bundle) continues from the AVN which passes through the atrio-ventricular septa to emerge on the top of the —- septum and immediately divides into a —- and — bundle.
nodal fibre
interventricular
right and left
The right and left bundle branches give rise to minute fibres throughout the ventricular
musculature of the respective sides and are called ——–
purkinje fibres
These fibres along with right and left bundles are known as ——.
bundle of His
The nodal musculature has the ability to generate ——– without
any external stimuli, i.e., it is ——.
action potentials
autoexcitable
However, the number of action potentials that could be generated in a minute of nodal musculature may vary at ———.
different parts of
the nodal system
The SAN can generate the maximum number of action potentials, i.e., ——/min and is responsible for —– and —- the rhythmic contractile activity of the heart. Therefore, it is
called the ——.
70-75
initiating and
maintaining
pacemaker
Our heart normally beats —– timea in a minute
(average 72 beats min–1).
70-75 times
All the four chambers of heart are in a relaxed state, i.e., they are in —–
As the —- and —- valves are open, blood from the pulmonary veins and vena cava flows into the left and the right ventricle respectively through the left and right atria. The —- valves are closed at this
stage.
joint diastole.
tricuspid and bicuspid
semilunar
The SAN now generates an action potential which stimulates —– to undergo a simultaneous contraction ———.
both the atria
the atrial systole
Atrial systole increases the flow of blood into the ventricles by —— per cent.
about 30
The action potential is conducted to the —- by the AVN and AV bundle from where the bundle of His transmits it through the entire ventricular musculature. This causes the ———to contract (—).
ventricular side
ventricular muscles
ventricular systole
The ——– occurs, coinciding with the ventricular systole.
atria undergoes relaxation (diastole)
Ventricular systole increases the ventricular pressure causing the closure of —– and —- valves due to
attempted backflow of blood into the —-.
tricuspid and bicuspid
atria
As the ventricular pressure increases further, the semilunar valves guarding the —(right side) and the —- (left side) are forced open, allowing the blood in
the ventricles to flow through these vessels into the circulatory pathways.
pulmonary artery, aorta
The ventricles now relax (——–) and the ventricular pressure falls causing the closure of —- valves which prevents the backflow
of blood into the —.
ventricular diastole
semilunar
ventricles
As the ventricular pressure declines further,
the tricuspid and bicuspid valves are pushed open by the ——– exerted by the blood which was being emptied into them by the veins.
pressure in the
atria
This sequential event in the heart which is cyclically repeated is called the —–
cardiac cycle
Cardiac cycle consists of —- and — of both the atria
and ventricles. The heart beats 72 times per minute, i.e., that many —– are performed per minute.
systole and diastole
cardiac cycles
Duration of a cardiac cycle is —–.
0.8 s
During a cardiac cycle, each ventricle pumps out approximately — of blood
which is called the ——.
70 mL, stroke volume.
The stroke volume multiplied by the
heart rate (no. of beats per min.) gives the —.
cardiac output
Cardiac output can be defined as the volume of blood pumped out by —— per minute and averages —- in a healthy individual.
each ventricle
5000 mL or 5 litres
The body has the ability to alter the stroke volume as well as the heart rate
and thereby the cardiac output. For example, the cardiac output of an
—– will be much higher than that of an ordinary man.
athlete
During each cardiac cycle two prominent sounds are produced which
can be easily heard through a —-.
stethoscope
The first heart sound (—-) is associated with the closure of the —– valves whereas the second heart sound (—) is associated with the closure of the
—- valves.
lub, tricuspid and bicuspid
dub, semilunar
The heart sounds are of —significance.
Clinical diagnostic
A patient is hooked up to a monitoring machine that shows voltage
traces on a screen and makes the sound “… pip… pip… peee” as the patient goes into —-. This type
of machine (——–) is used to obtain an —–
(ECG).
cardiac arrest
electro-cardiograph
electrocardiogram
ECG is a graphical representation of the —-activity of the
heart during a cardiac cycle.
electrical
To obtain a standard ECG, a patient is connected to the machine with—- electrical leads (locations:—-) that continuously
monitor the heart activity.
three
(one to each wrist and to the left ankle)
For a detailed
evaluation of the heart’s function, multiple
leads are attached to — region. Here,
we will talk only about a standard ECG
the chest
Each —- in the ECG is identified with a
letter from P to T that corresponds to a specific
—- of the heart.
peak, electrical activity
The P-wave represents the —– (or depolarisation) of the atria, which leads to the contraction of both the atria.
electrical excitation
The ——- represents the depolarisation of the ventricles, which initiates the ventricular contraction.
QRS complex
The contraction of ventricle starts shortly after —- and marks the beginning of the systole
Q
The T-wave represents the return of the ventricles from excited to
normal state (——-). The end of the T-wave marks the end of —-.
repolarisation
systole
Obviously, by counting the number of —– that occur in a given time period in ECG, one can determine the heart beat rate of an individual.
QRS complexes
Since the ECGs obtained from different individuals have ——- shape for a given lead configuration, any deviation from this shape indicates a possible —- or —–. Hence, it is of a great —- significance.
roughly the same
abnormality or disease
clinical
The blood pumped by the —– ventricle enters the
pulmonary artery, whereas the —- ventricle pumps blood into the aorta.
right, left
The deoxygenated blood pumped into the —— is passed on to the lungs from where the oxygenated blood is carried by the ——- into the left atrium. This pathway constitutes the —-circulation.
pulmonary artery
pulmonary veins
pulmonary
The oxygenated blood entering the aorta is carried by a network of arteries, arterioles and —-to the —– from where the deoxygenated blood is collected by a system of venules, veins and vena cava and emptied into the right atrium. This is the —
circulation
capillaries , tissues
systemic
The —- circulation provides nutrients, O2
and other essential substances to the tissues and takes CO2 and other
harmful substances away for elimination.
systemic
A unique —- connection exists between the —- and —-called hepatic portal system.
vascular
digestive tract and liver
The —– carries blood from intestine to the liver before it is delivered to the —- circulation.
hepatic portal vein, systemic
A special —- of blood vessels is present in our body exclusively for the circulation of blood to and from the cardiac musculature.
coronary system
Normal activities of the heart are regulated —-, i.e., auto regulated
by specialised muscles (nodal tissue), hence the heart is called —-.
intrinsically, myogenic
A special neural centre in the —– can moderate the cardiac function through ——.
medulla oblangata
autonomic nervous system (ANS)
Neural signals through
the —- (part of ANS) can increase the rate of heart beat, the strength of ventricular contraction and thereby the cardiac output.
sympathetic nerves
On the other hand, —-component (another of ANS) decrease the rate of heart beat, speed of conduction of action
potential and thereby the cardiac output.
parasympathetic neural signals
Adrenal medullary hormones
can also —-the cardiac output.
increase
High Blood Pressure (—-): higher than normal (—-).
Hypertension, 120/80
In this measurement 120
mm Hg (millimetres of mercury pressure) is the —- pressure and 80 mm Hg is the —– pressure.
systolic, or pumping
diastolic, or resting
If repeated checks of blood pressure of an individual is — or
higher, it shows hypertension.
140/90
High blood pressure leads to heart diseases
and also affects ———
vital organs like brain and kidney.
Coronary Artery Disease (CAD): often referred
to as —–, affects the vessels that supply blood to the —-.
atherosclerosis
heart muscle
Coronary artery disease is caused by deposits of —-, —-, —-, —–, which makes the lumen of arteries narrower.
Calcium, cholestrol, fat, and fibrous tissue
Angina pectoris:. A symptom of —— appears when no enough —- is reaching the heart muscle.
acute chest pain, oxygen
Angina can occur in men and women of —- age but it is more common among the —– and —-.
It occurs due to conditions that affect the
blood flow.
any
middle-aged and elderly
——- means the state of heart when it is not pumping blood effectively enough to meet the needs of the body
Heart failure
Heart failure is also called ——— because congestion of the —- is one of the main symptoms of this disease.
congestive heart failure, lungs
Cardiac arrest is when the
heart stops beating
Heart attack is when the
heart muscle is suddenly damaged by an inadequate blood supply
