Human circulatory system by MOHD. MAFUZ MSC.HUMAN GENETICS UNIVERSITY OF JAMMU

1. INSTITUTE OF HUMAN GENETICS
UNIVERSITY OF JAMMU
SEMINAR TOPIC:
Human circulatory system
SUBMITTED BY : MOHD.MAFUZ
ROLL NO. : 0005-HUG-2017
 SUBMITTED TO : DR.ROOPALI FOTRA
DR.JYOT KAUR
DR.RAKESH PANJALIYA

2. CIRCULATORY SYSTEM
WHAT IT CONSISTS OF;
 HEART
BLOOD VESSELS
BLOOD
So we can define circulatory
system , as a system consisting of the heart
,blood vessels and the blood that circulates
through out the body, deliver nutrients and
other essential materials to cells and
removes waste products-Also called the
CARDIOVASCULAR SYSTEM.

3. Functions of circulatory system:
• 1. Transport of nutrients from the digestive organs to different tissues.
• 2. Transport of waste products from different tissues to the excretory
organs.
• 3. Transport of respiratory gas namely, O2 from the respiratory organs to
the tissues andCO2 from the tissues to the respiratory organs for its
removal.
• 4. Transport of hormones from the site of origin (i.e. endocrine glands) to
the tissues, which they stimulate (i.e. target-organs).
5. Distribution of water to the tissues to prevent their desiccation
(drying).
• 6. Maintenance of temperature by distributing heat uniformly all over
the body.
• 7. Transport of electrolytes for maintenance of homeostasis in the body.
• 8. Protection of the body as it contains W.B.C.s, which destroy
microorganisms.
• 9. Besides these, the circulatory fluids help in the clinical diagnosis of
variety of diseases

4. CLOSED CIRCULATORY SYSEM
IN Human beings we find closed type of
circulatory system ,where blood always keeps
on circulating but in the closed vessels.
 Blood flows with pressure and shows high
efficiency.
Blood flows through blood vessels like
Arteries ,veins and capillaries.
Exchange of substances takes place
through the thin walls of capillaries.

5. BLOOD
• Blood is a fluid connective tissue.
•Bright red in colour when oxygenated and some
what purplish when deoxygenated.
•Opaque, sticky in nature ,viscous (viscosity=4.7)
and slightly heavier than water.
•Saltish in taste and slightly alkaline (ph=7.36)in
nature.
•An average adult person has about 6.8 ltr. Of blood
which constitutes about 6-8% of the body weight.
•Study of blood is called as haematology.

6. COMPOSITION OF BLOOD
BLOOD PLASMA(55%).
BLOOD CORPUSCLES(45%).

7. PLASMA1. 55%of blood, straw coloured, alkaline fluid.
2. 90%- 92% water and 8%-10% suspended and dissolved substances.
3. Plasma proteins (7%)
a) Fibrinogens - clotting or coagulation of blood.
b) Globulins -defence mechanisms of the body
c) Albumin - osmotic balance.
d) Factors for coagulation or clotting of blood are also present in the
plasma in an inactive form.
Plasma without the clotting factors is called serum.
4. Other solutes are - nutrients like glucose (0.1%),amino acids, fatty
acids and glycerol;
- nitrogenous wastes such as urea, uric acid, ammonia and creatinine;
- gases like oxygen, carbon dioxide nitrogen;
- regulatory substances like enzymes & hormones,
- immune components like antibodies;
- inorganic substances like HCO3 , Cl-, PO4 & SO4 of Na+ , K+, Ca++,
Mg++ etc.

8. RED BLOOD
CORPUSCLES/ERYTHROCYTES
STRUCTURE:
- Circular, biconcave, non-nucleated cells.
- Diameter is 7.2 μm and thickness is 2-2.2 μm.
- count in adult males is 5.0 to 5.5 million per mm3
- in adult females is 4.5 to 5.0 million per mm3.
- life span of a single RBC is 100 to 120 days.

9. Characteristics:
- Formation of RBC's is called erythropoiesis.
- In foetus - yolk sac, kidney, spleen and liver.
- In adults - red bone marrow.
- Destroyed by spleen & liver.
- Iron containing complex protein called haemoglobin
- Hemoglobin has great affinity for oxygen and carbon-
di-oxide.
- 11.5 -16.5 mg/100 ml of blood.
Function:
- transport of respiratory gases
- maintain blood pH as haemoglobin acts as a buffer.
- maintain the viscosity of blood

10. White Blood Corpuscles / Leucocytes
•Structure:
•Colourless, nucleated, amoeboid, phagocytic
cells.
•They can easily pass through the blood vessels.
•This process is called diapedesis.
•WBC count is 4000-11000 per cu mm and size is
about 8μ to 15μ.
•Life span is3-4 days.
•Leukemia is pathological increase in number
and is commonly called blood cancer.
•Formation of WBCs is called leucopoiesis.
•Leucocytes are produced in red bone marrow,
•spleen, lymph nodes, tonsils, thymus, Payer's
Patches.

11. WBC - Granulocytes
 NEUTROPHILS :
 Stained by neutral stain, 60-65% of WBC’s
 Nucleus is multi-lobed.
 They are the chief phagocytic cells and
engulf microorganisms.
 BASOPHILS:
 Basic stains, about 0.5% of total WBC.
 twisted nucleus ,non-phagocytic ,release
heparin in the blood stream
 along with histamine and serotinin.
 EOSINOPHILS (ACIDOPHILS):
 stained by acidic stains (like eosin), about
2-3% of total WBC.
 Nucleus is bi-lobed.
 Non-phagocytic and their number
increases during allergic conditions.
 They show anti-histaminic property.
 Increase of eosinophils is known as
eosinophilia
.

12. WBC -Agranulocytes
MONOCYTES :
 largest , 6-8 % of the total WBC's.
 kidney shaped nucleus.
 At the site of infection, enlarge to
become macrophages and become
phagocytic and engulf microorganisms.
LYMPHOCYTES:
 large rounded nucleus , about 20-30
% of total WBC's.
 produce antibodies and opsonins to
neutralize harmful effect of toxins
 Two major types – ‘B’ and ‘T’ forms.
 Both B and T lymphocytes are
responsible for immune responses in
body.
,

13. BLOOD PLATELETS (THROMBOCYTES)
These are fragments of large cells called megakaryocytes in
the bone marrow.
They are non-nucleated, round and bi-convex.
These are smallest elements of blood of2.5μm to 5μm.
The average count is about 1.5-3.5 lakhs per cubic
millimeter.
Decrease in the number of platelets is called
thrombocytopenia.
while; increase in number of platelets is called
thrombocytosis.
They help in formation of clot over the injury. Thus, loss of
blood is prevented.
A reduction in their number can lead to clotting disorders
which will lead to excessive loss of blood from the body.

14. FUNCTIONS OF BLOOD
oDistribution : supplies digested and absorbed food from alimentary
canal to all parts.
oTransport: It carries hormones , respiratory gases , nitrogenous
wastes
oProduction of antibodies: Antibodies are produced in response to
foreign substances thus help in defense mechanism.
oThermoregulation: It distributes heat and helps in maintaining body
temperature.
oPrevention of water loss: It distributes adequate quantity of water to
all cells and prevents dehydration.
oProtection: It prevents loss of blood by formation of blood clot.
oPhagocytosis by neutrophils and monocytes, which engulf and digest
bacteria. Thus, it gives protection from pathogens.
oOsmotic balance: The proteins and minerals in plasma exert osmotic
pressure and regulate blood pressure.

15. CLOTTING OF BLOOD
BLOOD CLOTTING OR COAGULATION:
- initiated by platelets.
- The injured cells release substances that
attract the platelets.
- They gather at and stick to the injured
surface of the blood vessel.
- The mass of aggregated platelets alone may
physically plug a cut in a very small vessel.
- The contact of platelets with the collagen
fibers exposed by the injury causes them to
disintegrate and release two substances:
serotonin and thromboplastin, which minimize
loss of blood from the injury in two ways.

16. Vasocontraction:
Serotonin causes the blood vessels at the site of
bleeding to contract.
Clot Formation:
Thromboplastin, a lipoprotein,
helps in clot formation CLOTTING OF BLOOD

18. BLOOD GROUPSABO Blood Groups:
- Karl Landsteiner (1900) recognized four types of blood groups in human beings
(commonly known as ABO blood groups).
- The ABO blood groups are determined by the gene I having three alleles(IA, IB,
and IO)
- In human beings, there are present two antigens A and B produced by IA and IB
alleles respectively.
- These antigens are always present on the surface of red blood cells.
- Also are present two antibodies in the plasma a and b.

20. Rh (Rhesus) System:
Human blood possesses another factor antigen
D i.e. Rh factor.
Accordingly, human blood can be categorized
into two groups: Rh-positive and Rh-negative.
Those human beings who had this antigen were
termed as Rh-positive (Rh+), (80% of the
population)
The persons, in whom Rh antigen was absent,
were designated as Rh-negative (Rh-), (20%
of the population)
It is thought that Rh+ is a dominant character
over Rh-which is recessive.

23. HUMAN HEART
DEFINATION: IT is a hollow, thick
fibromuscular ,reddish brown conical
organ present in the mediastinal space
of the thoracic cavity between two
pleura enclosing the lungs.
 POSITION:The upper broader side of
the heart called base is directed
backward and the lower narrow side
called apex is directed forward and
slightly to the left . The apex rests upon
diaphragm.
So position of heart is oblique and not
exactly vertical.

24. Shape & Size:
1. It is conical in shape and approximately of the
size of one's own-fist.
2. It measures about 12 cm in length, 9 cm in
breadth. It weighs about 300 grams in males
and 250 grams in females
•Bony Protection : sternum
ventrally,
•vertebral column dorsally
•rib cage on the sides

25. Immediate protection:
By double walled membrane called pericardium.
1. The Fibrous-Pericardium: outer, tough, fibrous
connective tissue covering.
2. The Serous-Pericardium: inner , double-layered,
vascularized covering around the heart.
A. The Parietal layer: outer,
B. The Visceral layer: inner in contact with the
heart and is called the epicardium.
In between the parietal and visceral folds of pericardium,
there is a fluid present called pericardial fluid (about 50
ml).
Functions:
1. Acts as a shock absorber and protects the heart from
mechanical-shocks.
2. Prevents friction between the two-pericardial
membranes.

26. EXTERNAL STRUCTURE OF HEART
Externally heart is divided into right, left, anterior and
posterior parts by means of GROOVES.
Two grooves:
I. CORONARY SULCUS : It is transverse grove which
devides the heart in anterior smaller thinner and
softer part i.e auricular part and a posterior longer
thicker and harder part i,.e ventricular part.
II. INTER VENTRICULAR GROOVE: It is an oblique
longitudinal groove on the ventral side of ventricular
part which demarcates the two ventricles externally.

28. •Blood-supply of the heart :
Blood vessels are present on the surface of the
ventricles i.e. the coronary arteries and veins.
1. Two coronary arteries arise from the base of the
aorta i.e. the left and right coronary arteries, which
supply oxygenated blood to the muscles of the heart
(seen on ventral-side).
2. The coronary veins collect deoxygenated blood
from the heart muscles, and collect to form the main
coronary vein called coronary sinus and opens into
the right atrium (seen on the dorsal-side).
Embryonic Connection:
The pulmonary trunk and systemic aorta are
connected by ligamentum arteriosum (It is the remnant
of ductus arteriosus a blood vessel, which used to
bypass the blood to the heart in foetus, as the lungs are
not functioning till the child is born.)
After birth once the lungs start functioning, it starts to
close and is completely closed by second month)that
represents remnant of embryonic connection between
the two blood vessels.

29. INTERNAL STRUCTURE OF THE HEART
THE ATRIA:
•upper, thin-walled, small chambers.
•separated from each other by inter-atrial septum.
•The inter atrial septum shows a shallow saucer shaped depression in the lower part
called as fossa ovalis, which is the remnant of the opening foramen ovale of the
foetal stage when the lungs were not functioning.
Right-Atrium:
•openings for the three major-veins:
•Superior vena cava bringing deoxygenated blood from the head-region.
•Inferior-vena-cava bringing deoxygenated blood from the body-region, guarded by
rudimentary valve of the inferior vena cava (Eustachian valve).
•Coronary sinus, the major coronary vein bringing deoxygenated blood from the
heart muscles guarded by the valve of the coronary sinus (Thebesian valve).
Left-Atrium:
•This left upper chamber shows 4 openings,
•two for the right and two for the left pulmonary veins.

30. THE VENTRICLES:
lower, thick-walled and large chambers.
The left ventricle is larger than the right ventricle.
Also, the walls of the left ventricle are thicker than those of the right ventricle. The
left ventricle also forms the apex of the heart.
Both the ventricles are separated from each other by the vertical partition called
interventricular-septum.
The inner surface of both the ventricles is thrown into muscular ridges called
trabeculaecarnae.
Some particular types of these ridges are pillar like and are called papillary-muscles.
They are three and two respectively in the right and left ventricles.
Right-Ventricle:
A pulmonary-trunk arises anteriorly from the right ventricle, and divides into the
right and left pulmonary arteries carrying deoxygenated blood from it to respective
lungs.
Left ventricle:
A systemic-aorta arises anteriorly from the left-ventricle carrying oxygenated blood
from it to all the parts of the body.

33. Atrio-Ventricular (A-V Valves):
The right atrio-ventricular-aperture is guarded by three
thin leaf -like cusps (flaps) called as the tricuspid valve.
The left atrio-ventricular-aperture is guarded by two
thin leaf- like cusps (flaps) called as the bicuspid
valve(mitral valve).
Each valve is connected by delicate cords
(chordaetendinae)to one papillary-muscle each of the
ventricles, which prevent the opening of the valves into
the atria.
Semilunar-valves:
The opening of the systemic aorta into the left ventricle
is guarded by three somewhat half-moon shaped cusps
(flaps) which is called as the aortic-semilunar-valve.
Similarly the opening of the pulmonary aorta into the
right ventricle is guarded by the pulmonary
semilunarvalve.

34. DOUBLE CIRCULATION
Pulmonary Circulation:
- Deoxygenated blood from the right ventricle is
carried to the lungs via the pulmonary arteries.
- Oxygenation of the blood takes place in the lungs and
oxygenated blood is returned from the lungs to the left auricle
through pulmonary veins.
-Thus blood is carried from the heart to the lungs and back to
the heart.
Systemic Circulation:
- The oxygenated blood from the left ventricle of
the heart is sent to the different parts of the
body (except the lungs) via the aorta and its
branches.
- At the same time deoxygenated blood is collected
from all the parts of the body via veins and is
brought back to the right-auricle by the superior
and inferior vena-cavas.
- The blood is carried from the heart to the organs
and back to the heart.

36. MECHANISM OF HEART WORKING
CARDIAC CYCLE• •The blood is kept in a
constant circulation through
blood vessels by the
pumping action or beating
of the heart throughout life.
• •The rhythmic contraction
of the heart is called systole
followed by its dilatation is
called diastole.
• •One complete systole and
diastole of the heart makes
one heartbeat or
cardiaccycle.
• •During each heartbeat, the
chambers of the heart
contract and relax in a
specific sequence and are
repeated in a cyclic manner.
• These movements take
place in a definite 3 phases:
• Phase I: Atrial-systole
(simultaneous contraction
of both the atria) lasting
about 0.1 sec.
• Phase II: Ventricular systole
(simultaneous contraction
of both the ventricles)
lasting about0.3 sec.
• Phase III:Joint-diastole
(simultaneous relaxation of
both, the 2 atria and the 2
ventricles) lasting about 0.4
sec.

37. CARDIAC CYCLE
Phase I:
Both the atria simultaneously
contract(the ventricles are still
relaxing).
As a result of which the A-V valves
completely open and both the
ventricles get filled with blood(flow
increases by 30 %).
The atrial muscles contract and
constrict the openings of the vena-
cavas and pulmonary veins and prevent
the backflow of blood into these
vessels.

38. CARDIAC CYCLE
Phase II:
It is followed immediately by the ventricular systole (contraction), while
the atria start relaxing.
The bicuspid and tricuspid valves now close sharply to prevent the
backflow of blood into the atria.
Their closure produces the first heart sound (lubb) a fairly loud sound.
Due to the increased pressure in the ventricles, the blood tries to push
both the A-V valves in the upward direction.
The papillary muscles contract and there is a pulling of the cusps by the
stretched chordae-tendinae in the downward direction.
Due to these opposite actions, the opening of
the valves into the atria is prevented. Thus the
backflow of blood into the atria is prevented.
The semilunar valves now open as the
pressure in the ventricles increases and the
deoxygenated blood from the right ventricle
enters the pulmonary artery and goes to the
lungs while the oxygenated blood from the left
ventricle enters the aorta and goes to all the
parts of the body.

39. Phase III (joint-diastole):
The ventricles relax now.
As the ventricular pressure decreases the
semilunar valves close to prevent the backflow
of blood from the vessels into the ventricles.
Their closure produces the second heart
sound (dubb). The atria are already relaxing at
this point (hence joint-diastole) and receiving
blood from the venacavas and pulmonary veins.
The pressure of blood in the atria keeps on
increasing.
The ventricles are relaxing as 'closed
chambers' (i.e. without any blood in them and all
the valves closed) and hence the pressure in the
ventricles decreases rapidly. Thus the pressure
in the atria rises more than in the ventricles.
Hence the A-V valves slightly open and blood
trickles from the atria into the ventricles again
and a new cycle is repeated.

42. HEART BEAT
Heart chambers keeps on contracting and
relaxing .
Heart beat consists of contract once and
relax once.
One heart beat is completed during the
same time ,one cardiac cycle is completed
i.e 0.8 sec.
our heart beats 72 times per minute and
this value is called as THE RATE OF HEART
BEAT .

43. CONDUCTING SYSTEM OF THE HEART

44. CONDUCTING SYSTEM OF THE HEART
 Chordates have MYOGENIC HEART.
 MYOGENIC HEART is the one, in which the
mechanism that begins the heart beat is
present within the heart.
 We the humans ,have this type of heart as we
also belongs to the phylum chordata.
 IN our heart we have present some muscles
that have the property of self excitation i.e they
can produce cardiac impulses.
 Now this patch of muscles present within the
walls of our heart having the property of self
excitation is known by the name THE NODAL
TISSUE.

45. CONDUCTING SYSTEM OF THE HEART
Our heart beat is controlled by the muscles present
within the heart but its rate is controlled by some
harmones and nerves:
EPINEPHRINE and NOREPINEPHRINE (hormones
released by Adrenal gland.)- helps in controlling the rate
of heart beat ( epinephrine helps in controlling the rate of
heart beat during the time of emergency i.e during stress
and norepinephrine controls heart beat rate during
normal condition.)
SYMPATHETIC and PARASYMPATHETIC (two sets of
nerves coming from the brain.)-sympathetic nerves try to
speed up the rate of heart beat and parasympathetic
ones helps in slowing down the rate.

46. NODAL TISSUE
THE NODAL TISSUE consists of S.A
NODE(SINUAURICULAR NODE) , A.V NODE
(AURICULO-VENTRICULAR NODE) ,BUNDLE OF
HIS( AURICULO-VENTRICULAR BUNDLE), RIGHT
AND LEFT VENTRICULAR BRANCHES AND
PURKINJE FIBRES.

47. NODAL TISSUE
S.A NODE also known as PACEMAKER is located in the
wall of the right auricle just at the base of superior
vena cava.
A.V NODE lies at the base of right auricle near the
interauricular septum.
THE BUNDLE OF HIS arises from A.V NODE and passes
downwards through interauricular and interventricular
septum and divides into right and left BUNDLE
BRANCHES which enters into the walls of the two
ventricles.
IN the walls of the ventricles these two branches
divide to form PURKINJE FIBRES which get distributed
in the whole wall of ventricles.

48. NODAL TISSUE
 The S.A NODE has a unique property of self excitation and is able
to produce waves of contraction(CARDIAC
IMPULSES),spontaneously. It is also known as pacemaker.
 The waves of contraction spread over both the auricles along the
muscle fibres but can not pass over the ventricles because the
muscles of auricles and ventricles are not continuous and are
separated by a ring of fibrous connective tissue known as
ANNULAR PAD.
 But the waves of contraction produced by S.A NODE stimulates
the A.V NODE. With the result A.V NODE now starts producing
same type of waves of contraction.
 The waves produced by A.V NODE are carried by BUNDLE OF HIS
and its branches.
 The cardiac impulses passes relatively slowly across the A.V
NODE that’s why auricular systole is over before the ventricles
begin to systole , so auricles systole first and ventricles later.
 The amount of blood pumped out by heart per min. is called as
Heart output or Cardiac output. HEART PUMPS OUT ABOUT
70mlof blood during each beat . Thus, 72x70=5040ml of blood is
the cardiac output.

49. BLOOD PRESSURE
Definition:
It is defined as ‘the lateral pressure exerted by a column of blood
against the wall of artery’.
Measurement:
It is usually measured as the blood pressure in the artery of the elbow
region, by an
mercury filled instrument called sphygmomanometer(sphgmos=
pulse, manometer =device to measure pressure).
Hence measurements are in units of mm of Hg.
HYPERTENSION: (I.E. HIGH BLOOD PRESSURE):
Systolic pressure > 140 mm of Hg & Diastolic pressure > 90 mm of Hg.
HYPOTENSION: (I.E. LOW BLOOD PRESSURE):
- Systolic pressure < 110 mm of Hg
- Diastolic pressure < 60 mm of Hg

50. CARDIO-VASCULAR DISEASES
1. ATHEROMA or ATHEROSCLEROSIS.
2. ARTERIOSCLEROSIS.
3. ANGINA PECTORIS.
4. HEART ATTACK(MYOCARDIAL
INFARCTION)
5. CAD( CORONARY ARTERY
DISEASE) OR TVD(TRIPPLE VESSEL
DISEASE)

51. THANK YOU
ANY QUERIES?