32Circulatory system

📚
OPEN & CLOSED VASCULAR SYSTEMS
▢ Blood Vascular System: 2 types → Open / Closed
▢ Types:
  • •
    Open circulatory system
  • •
    Closed circulatory system
📚
CIRCULATORY SYSTEM
▢ Components:
  • •
    Blood
  • •
    Blood grouping
  • •
    Heart
  • •
    Blood vessels
  • •
    Lymphatic system
▢ Blood Grouping:

Table 1: Important Blood Groups

Blood group
Significance
O−
Universal donor
AB
Universal recipient
📚
HEART
▢ Definition: Muscular central pump → blood circulation
▢ Heart in Different Organisms:

Table 1: Comparative Heart

Organism / Group
Heart / Circulation
Blood
Prawn 🦐
Open system
Only oxygenated blood
Fish 🐟
2 chambers → 1 auricle + 1 ventricle
Only deoxygenated blood pumped
Amphibia
2 auricles + 1 unpartitioned ventricle
Mixing in ventricle
Reptilia
2 auricles + incompletely partitioned ventricle
Some mixing
Birds
4 chambers → complete ventricular septum
No mixing
Mammals
4 chambers → complete ventricular septum
No mixing
❖ Auricle Partition:
  • •
    Amphibia + Reptilia → auricle divided by septum
  • •
    Right auricle → deoxygenated blood
  • •
    Left auricle → oxygenated blood
❖ Sinus Venosus:
  • •
    Present → fish / amphibian / reptile
  • •
    Absent → bird / mammal
📚
HUMAN HEART
▢ External Structure:

Table 1: External Features

Feature
Point
Situation
Thoracic cavity → mediastinum → between lungs
Size
Length ≈ 12 cm; width ≈ 9 cm
Weight
≈ 300 g
Apex
Pointed inferior end
Base
Broad superior part opposite apex
Coronary / AV sulcus
Deep transverse groove → between atria & ventricles
Anterior interventricular sulcus
Boundary mark → right & left ventricles
Posterior interventricular sulcus
Boundary mark → right & left ventricles
Coronary arteries
Right + left coronary arteries → interventricular sulci
▢ Wall Layers:

Table 1: Pericardium & Heart Wall

Layer / Space
Structure
Key Points
Pericardium
Membrane around heart
Protective covering
Fibrous pericardium
Outer non-distensible fibrous layer
Tough support
Serous pericardium
Inner serous layer
Smooth serous covering
Pericardial cavity
Between fibrous + serous layers
5–30 mL pericardial fluid
Epicardium
Visceral pericardium
Outer heart wall
Myocardium
Cardiac muscle layer
Striated + involuntary; quick contraction; non-fatiguing
Endocardium
Inner endothelial layer
Lines chambers
❖ Pericarditis: Pericardial inflammation → dry membranes → pain during heartbeat
❖ Cardiac Muscle:
  • •
    Structurally → striated muscle-like
  • •
    Functionally → smooth muscle-like
  • •
    Striated but involuntary
  • •
    Quick contraction
  • •
    No fatigue
▢ Internal Structure:
❖ Chambers:
  • •
    4 chambers
  • •
    Upper thin-walled → 2 atria
  • •
    Lower thick-walled → 2 ventricles
❖ Atria:
  • •
    Auricle → small ear-like extension → ↑ atrial volume
  • •
    Frog-like sinus venosus + truncus arteriosus → absent
  • •
    Embryonic sinus venosus remnant → SA node
  • •
    SA node position → near eustachian valve; inferior to SVC opening
  • •
    Left atrium ← 4 pulmonary veins
  • •
    Each atrium → ventricle via AV aperture
❖ Ventricles:
  • •
    Walls thicker than atria
  • •
    Thickest wall → left ventricle
  • •
    Pulmonary aorta + systemic aorta → arise anteriorly from ventricles
❖ Internal Muscular Features:

Table 1: Heart Internal Muscles / Tendons

Structure
Description
Location / Function
Pectinate muscles
Low myocardial ridges
Right atrial wall + auricles
Papillary muscles / Trabeculae carneae
Raised muscular columns
Ventricular wall
Chordae tendineae
Thread-like tendons
Papillary muscle → tricuspid & bicuspid valve flaps
▢ Foetal Remnants:

Table 1: Foetal vs Adult Remnants

Foetal structure
Function
Adult remnant
Foramen ovale
Interatrial opening → RA ↔ LA communication
Fossa ovalis
Ductus arteriosus
Pulmonary aorta → systemic aorta shunt
Ligamentum arteriosus
📚
VALVES
▢ General:
  • •
    Valve = tough connective tissue sheet
  • •
    Function → prevents backflow
▢ Venous Openings:

Table 1: Right Atrial Venous Openings

Opening
Valve
Precaval / Superior vena cava
No valve
Postcaval / Inferior vena cava
Eustachian valve → rudimentary membrane fold
Coronary sinus
Thebesian valve
▢ Heart Valves:

Table 1: Cardiac Valves

Valve
Position
Flaps / Cusps
Function
Tricuspid
Right AV aperture
3 flaps
Prevents RV → RA backflow
Bicuspid / Mitral
Left AV aperture
2 flaps
Prevents LV → LA backflow
Pulmonary semilunar
Base of pulmonary aorta
3 pocket-shaped cusps
Prevents pulmonary aorta → RV backflow
Aortic semilunar
Base of systemic aorta
3 pocket-shaped cusps
Prevents aorta → LV backflow
❖ Mitral: Miter-like bishop headdress
❖ Bicuspid: Also premolar tooth of mammals
▢ Valve Failure:

Table 1: Valve Lesions

Term
Meaning
Stenosis
Failure to open fully → narrowing
Insufficiency / Incompetence
Failure to close completely → regurgitation
❖ Rheumatic Fever:
  • •
    Acute systemic inflammatory disease
  • •
    May weaken entire heart wall
  • •
    Common valve damage → mitral + aortic valves
📚
PHYSIOLOGY OF CIRCULATION
▢ Neurogenic & Myogenic Heart:

Table 1: Neurogenic vs Myogenic Heart

Feature
Neurogenic heart
Myogenic heart
Initiation
Nerve ganglion near heart
SA node = modified cardiac muscle
Origin of heartbeat
Nervous stimulation
Muscle node automaticity
Examples
Arthropods e.g. cockroach; some annelids e.g. earthworm
Vertebrates; tunicates; molluscs
Nerve cut / heart removed
Beating depends on nerve input
Continues beating
Vagus effect
↓ heart rate
❖ Neurogenic Acetylcholine: ACh from nerve endings → accelerates neurogenic heartbeat
▢ Conduction System:
  • •
    Nodal tissue = specialized cardiac muscle
  • •
    Purkinje fibres = specialized cardiac muscle fibres
  • •
    Autorhythmic fibres → inherent rhythmic electrical activity
  • •
    ≈ 1% cardiac muscle fibres become autorhythmic during embryonic development
▢ Cardiac Cycle:
❖ Definition: 1 heartbeat events = atrial systole + atrial diastole + ventricular systole + ventricular diastole
❖ Terms:
◉ Systole: Contraction phase
◉ Diastole: Relaxation phase
❖ Duration at 75 bpm: \(60/75 = 0.8\;s\)

Table 1: Duration of Cardiac Cycle

Event
Duration
Atrial systole
0.1 s
Ventricular systole
0.3 s
Ventricular diastole
0.5 s
Atrial diastole
0.7 s
Complete cardiac diastole
0.4 s
Complete cardiac cycle
0.8 s
❖ Heart Rate & Body Size: Large animal → slower HR; small rodents / shrews / birds → 800–1000/min
▢ Nodal Rhythm & Arrhythmia:

Table 1: Impulse Abnormalities

Condition
Cause / Feature
Consequence
Nodal rhythm
SA node fails → AV node generates impulse
40–45 bpm; life-sustaining; artificial pacemaker needed
Arrhythmia
Abnormal cardiac rhythm
Heart block / conduction failure
Total heart block
AV node damage
Atrial signals fail to reach ventricles
📚
REGULATION OF HEARTBEAT
▢ Normal Resting HR: ≈ 72–80 bpm
▢ Control:
  • •
    Autonomic nervous system
  • •
    Sympathetic → accelerator
  • •
    Parasympathetic / vagus → inhibitory

Table 1: Factors Affecting Heart Rate

Factor
Effect
Mediator / Note
Sympathetic nerves
↑ HR
Noradrenaline / norepinephrine
Parasympathetic / vagus
↓ HR
Acetylcholine
Thyroid hormone
↑ HR + ↑ contractility
Hypermetabolic effect
↑ \(K^+\) / ↑ \(Na^+\)
↓ HR + ↓ contractility
Electrolyte effect
↑ \(Ca^{2+}\)
↑ HR
Calcium effect
Fever / strenuous exercise
↑ HR
↑ body temperature
Fear / anger / anxiety
↑ HR + ↑ BP
Strong emotion
Depression / grief
↓ HR
Mental state
Adult female
Slightly faster HR
Sex difference
Birth
Fastest HR
≈ 120 bpm newborn
Youth
Moderately fast
Age effect
Adult
Average
Age effect
Senior citizen
May become rapid
Age effect
📚
ELECTROCARDIOGRAM (ECG) & CONDUCTION SYSTEM
▢ Autorhythmic Fibres:
  • •
    Specialized cardiac muscle fibres
  • •
    Repeated action potentials
  • •
    Trigger heart contraction
  • •
    Form conduction system
▢ Contraction Nodes:

Table 1: Nodes in Different Groups

Group
Contraction node
Amphibians
Only SA node
Mammals
SA node + AV node
▢ SA Node:
  • •
    0.3 mm specialized cardiac muscle mass
  • •
    Posterior wall of right atrium
  • •
    Below SVC opening
  • •
    Action potential mainly by \(Ca^{2+}\) channel opening
  • •
    Initiates each cardiac cycle
  • •
    Natural pacemaker
  • •
    Intrinsic rate ≈ every 0.6 s ≈ 100/min
  • •
    Resting vagal tone → slows to ≈ 75/min ≈ every 0.8 s
  • •
    Highest rhythmicity → normal impulse origin
▢ AV Node:
  • •
    Near right AV valve
  • •
    Lower end of interatrial septum
  • •
    Gatekeeper of heart
  • •
    Delay between atrial + ventricular excitation
  • •
    Delay → efficient ventricular filling
▢ Conducting Pathway:
  1. SA node
  2. Atrial myocardium / internodal pathways
  3. AV node
  4. AV bundle / Bundle of His
  5. Right + left bundle branches
  6. Purkinje fibres
  7. Ventricular muscle fibres
▢ ECG Basics:
❖ ECG: Recording of electrical changes during cardiac cycle
❖ Electrocardiograph: Instrument for potential differences of heart muscles
❖ Einthoven: String galvanometer → 1903
▢ ECG Waves:

Table 1: Normal ECG Waves

Wave
Shape / Event
Clinical clue
P wave
Small upward deflection → atrial depolarization
Large P → atrial enlargement
QRS complex
Downward Q + tall R + downward S → ventricular systole / depolarization
Large Q → MI; large R → ventricular enlargement
T wave
Dome-shaped upward deflection → ventricular repolarization
Flat T → myocardial ischemia/CHD; tall T → hyperkalemia
▢ ECG Diagnostic Uses:
  • •
    Conducting pathway abnormality
  • •
    Heart enlargement
  • •
    Myocardial infarction
  • •
    Electrolyte imbalance
  • •
    Hormone imbalance
▢ ECG Intervals & Segments:

Table 1: ECG Time Measurements

Interval / Segment
Extent
Meaning
Abnormality
P-Q interval
Start of P → start of QRS
Atria + AV node + conduction system travel time
Lengthened → CHD / rheumatic fever
S-T segment
End of ventricular impulse spread → repolarization
Ventricular plateau phase representation
Elevated → acute MI; depressed → insufficient O₂
Q-T interval
Start of QRS → end of T
Ventricular depolarization → repolarization
Lengthened → myocardial damage / ischemia / conduction abnormality
📚
HEART SOUNDS
▢ Auscultation: Listening to heart sounds
▢ Instrument: Stethoscope

Table 1: Heart Sounds

Sound
Name
Cause
Timing / Feature
S1
Lubb
Closure of AV valves → tricuspid + bicuspid
Beginning of ventricular systole; long + loud
S2
Dupp
Closure of semilunar valves
End of ventricular systole / beginning of ventricular diastole; short + sharp
S3
Rapid ventricular filling
Usually faint / inaudible
S4
Atrial systole
Usually faint / inaudible
▢ Clinical Value:
  • •
    Valve function assessment
  • •
    Heart murmur = abnormal sound
  • •
    Murmur cause → stenosis / incompetence
📚
CARDIAC OUTPUT
▢ Definition: Blood volume ejected by left ventricle into aorta or right ventricle into pulmonary trunk per minute
▢ Formula: \(CO = SV \times HR\)
▢ Resting Calculation: \(CO = 70\;mL \times 75/min = 5250\;mL/min \approx 5\;L/min\)
▢ Stroke Volume: Main determinant → venous return
▢ Frank-Starling Law: ↑ venous return → ↑ cardiac pumping

Table 1: Cardiac Output Values

Condition
CO
Rest
≈ 5 L/min
Vigorous exercise: good condition
≈ 21 L/min
World-class athletes
≈ 35 L/min
▢ Cardiac Reserve: Maximum CO − resting CO
▢ Severe Heart Disease: ↓/Absent cardiac reserve → poor exercise tolerance
▢ CO Distribution:

Table 1: Distribution of Cardiac Output

Organ / Region
Value
Liver
28%
Kidney
25%
Brain
20%
Heart
10%

Table 2: GRB Data

Organ / Region
Value
Heart muscles
10%
Brain
15%
Digestive system
25%
Kidneys
20%
Other organs
30%
📚
BLOOD PRESSURE
▢ Definition: Ventricular contraction → hydrostatic pressure of blood on vessel wall
▢ Meaning: Usually arterial BP
▢ Instrument: Sphygmomanometer
▢ Usual Site: Left brachial artery
▢ Korotkoff Sounds: BP sounds named after Nikolai Korotkoff, 1905

Table 1: Normal Adult BP

Parameter
Value
Systolic BP
120 mmHg
Diastolic BP
80 mmHg
Average BP
120/80 mmHg
Pulse pressure
120 − 80 = 40 mmHg
Systolic : Diastolic : Pulse pressure
3 : 2 : 1
▢ Pulse Pressure: Systolic BP − Diastolic BP → arterial condition clue
▢ Mean Arterial Pressure:
❖ Formula: \(MAP = DBP + \frac{1}{3}PP\)
❖ Calculation: \(MAP = 80 + \frac{40}{3} \approx 93\;mmHg\)
📚
PULSE
▢ Definition: Alternate expansion + elastic recoil of artery with each systole
▢ Key Points:
  • •
    Strongest → arteries closest to heart
  • •
    Detected in superficial arteries → radial artery / temporal artery
  • •
    Normal pulse rate → 70–90/min
  • •
    Pulse rate = heart rate

Table 1: Pulse Rate Abnormalities

Term
Rate
Causes / Association
Tachycardia
>100 beats/min
Stress, anxiety, drugs, heart disease, fever
Bradycardia
<60 beats/min
Sleep, hypothermia
📚
CIRCULATION
▢ William Harvey:
  • •
    Blood circulation described → 1628
  • •
    Book → De motu cordis
  • •
    First demonstration animal → dissected living snake
▢ Vertebrate Heart Circuits:

Table 1: Single vs Double Circuit

Circuit
Found in
Heart / Feature
Single circuit
Fish
2-chambered / venous heart
Double circuit
Birds + mammals
Complete ventricular division
▢ Double Circulation:
  • •
    Blood passes twice through heart in one complete cycle
  • •
    Pulmonary circuit + systemic circuit
  • •
    Blood must pass through lungs to reach left heart
▢ Systemic Circulation:
  1. Left heart = systemic pump
  2. Left atrium receives oxygenated blood from lungs
  3. Left ventricle → aorta → systemic arteries
  4. Tissues
  5. Deoxygenated blood → right atrium
▢ Pulmonary Circulation:
  1. Right heart = pulmonary pump
  2. Right atrium receives systemic deoxygenated blood
  3. Right ventricle → pulmonary arteries → lungs
  4. Oxygenation
  5. Pulmonary veins → left atrium
▢ Circulatory Territories:

Table 1: Body Region & Circuit

Serves
Circulation
General body
Systemic
Lungs
Pulmonary
Heart
Coronary
📚
BLOOD VESSELS
▢ Wall Layers:

Table 1: Blood Vessel Wall

Layer
Structure
Tunica externa
Loose CT + collagen + elastic fibres + lymph vessels + nerve fibres
Tunica media
Thickest; circular smooth muscle + elastic fibres
Tunica interna
Single-layered squamous endothelium
▢ Main Types:
  • •
    Arteries
  • •
    Arterioles
  • •
    Capillaries
  • •
    Venules
  • •
    Veins
▢ Important Arteries:

Table 1: Arteries & Supply

Artery
Supply
Pulmonary
Lungs
Coronary
Heart wall
Subclavian
Forelimbs
Carotid
Brain / Head
Phrenic
Diaphragm
Hepatic
Liver
Lienogastric
Stomach + spleen
Renal
Kidneys
Iliac
Hindlimbs
▢ Important Veins:

Table 1: Veins & Drainage

Vein
Drains from
Jugular azygous
Head
Lingual
Tongue
Femoral
Hindlimbs
Sciatic
Hindlimbs
Hepatic
Liver
Hepatic portal
Digestive system
Vesicular
Urinary bladder
Caudal
Tail
📚
ARTERIAL SYSTEM
▢ Arteries:
  • •
    Carry blood away from heart
  • •
    Stronger + thicker than veins
  • •
    High-pressure blood flow
  • •
    Aorta = largest artery
  • •
    Pulmonary artery + renal artery → thicker muscular coat than respective veins
▢ Artery Wall:
  • •
    Tunica externa
  • •
    Tunica media → thickest; elasticity + contractility
  • •
    Tunica interna
▢ Arterioles:
  • •
    Small arteries → deliver blood to capillaries
  • •
    Wall smooth muscles
  • •
    Contraction → ↓ diameter → ↓ blood flow
  • •
    Relaxation → ↑ diameter → ↑ blood flow
▢ Capillaries:
❖ Discovery: Marcello Malpighi, 1661
❖ Definition: Smallest microscopic blood vessels
❖ Connection: Arterioles ↔ venules
❖ Metarteriole: Arteriole branch → supplies 10–100 capillaries = capillary bed
❖ Wall: Single flat endothelial cell layer; no muscle
❖ Permeability: Water + small solutes pass; proteins/macromolecules excluded
❖ Name: Exchange vessels
❖ Diameter: 7.5–75 μm
❖ Blood Volume: 5–7% total blood volume
▢ Piercing of Diaphragm:
❖ **table:
    📚
    VENOUS SYSTEM
    ▢ Venules:
    • •
      Continue from capillaries
    • •
      Merge → veins
    • •
      Drain blood from capillaries → veins
    ▢ Veins:
    • •
      Less elastic tissue + less smooth muscle than arteries
    • •
      Thin muscular wall
    • •
      Valves present → prevent backflow
    • •
      Low pressure → valves necessary
    • •
      Weak valves → varicose veins
    • •
      Anal canal varicose veins → haemorrhoids
    • •
      Collapsible wall
    • •
      Wider lumen
    • •
      Usually superficial / close to skin
    ▢ Blood Type Exception: All veins carry deoxygenated blood except pulmonary veins → oxygenated blood from lungs to heart
    ▢ Artery vs Vein:

    Table 1: Artery vs Vein

    Feature
    Artery
    Vein
    Direction
    Away from heart
    Toward heart
    Pressure
    High
    Low
    Wall
    Thick
    Thin
    Lumen
    Narrow
    Wide
    Valves
    Absent
    Present
    Wall collapse
    Non-collapsible
    Collapsible
    Position
    Deep
    Mostly superficial
    Usual blood
    Oxygenated except pulmonary artery
    Deoxygenated except pulmonary vein
    ▢ Vasa Vasorum:
    • •
      Blood vessels of large blood vessels
    • •
      Supply oxygen + nutrients to vessel wall
    • •
      Located within vessel wall
    📚
    PORTAL SYSTEM
    ▢ Portal Vein: Vein carrying blood from one capillary network → another capillary network

    Table 1: Portal Systems

    Portal system
    Presence / Route
    Renal portal
    Present in frog; absent in mammals
    Hepatic portal
    Present in frog + mammals
    Hypophyseal portal
    Hypothalamus → hypophyseal portal vein → anterior pituitary
    ▢ Hepatic Portal Vein: GI organs + spleen → liver sinusoids
    ▢ Longest Blood Vessel: Long saphenous vein
    📚
    LYMPHATIC SYSTEM
    ▢ Presence: All vertebrates
    ▢ Lymph Definition: Blood − RBCs
    ▢ Lymph Nature:
    • •
      Clear
    • •
      Colourless
    • •
      Plasma-like
    • •
      Much less protein
    ▢ Formation Centre: Interstitial space
    ▢ Lymph Vessels:
    1. Small lymph vessels unite
    2. Larger lymph vessels form
    3. Drain into thoracic duct + right lymphatic duct
    ▢ Thoracic Duct:
    • •
      Larger + longer lymph duct
    • •
      Begins as cisterna chyli in abdominal cavity
    ▢ Drainage:

    Table 1: Lymph Drainage

    Region
    Drainage point
    Right portion of body
    Right subclavian vein
    Rest of body
    Left subclavian vein
    ▢ Movement:
    • •
      No heart-like pump
    • •
      Surrounding muscle squeeze → lymph movement
    • •
      Slow + uncertain circulation
    • •
      Exercise → ↑ lymph circulation
    ▢ Lymph Nodes:

    Table 1: Lymph Node

    Feature
    Point
    Shape
    Oval / bean-shaped
    Position
    Along lymphatic vessels
    Length
    1–25 mm
    Capsule
    Dense connective tissue
    Stroma
    Capsule + trabeculae + reticular fibres + fibroblasts
    Function
    Filter lymph; trap foreign substances by reticular fibres
    ▢ Lymphoid Organs:
    • •
      Lymph nodes
    • •
      Spleen
    • •
      Thymus
    • •
      Tonsils
    ▢ Immune Function: Produce lymphocytes → antibodies → destroy bacteria / viruses / foreign cells
    ▢ Fat Absorption: Digested fat from small intestine → lacteals → chylomicron droplets → general circulation
    ▢ Oedema / Dropsy:
    • •
      Normal: lymph formation rate = lymph return rate
    • •
      Formation > return → ↑ intercellular fluid
    • •
      Swelling = oedema / dropsy
    📚
    HIGH-YIELD RECALL
    ▢ **table:
      Q1.
      Immunological function of blood is due to:
      📅MOE 2069
      Q2.
      Blood constitute how much % of body part?
      📅BPKIHS 2012
      Q3.
      Peptic ulcer is most common to people of blood group
      📅BPKIHS 2012
      Q4.
      Immunoglobulin which crosses placenta is
      📅BPKIHS 2012
      Q5.
      Normally cardiac cycle takes………seconds to complete
      📅BPKIHS 2012•10M
      Q6.
      Thickest layer in the heart is
      📅BPKIHS 2012•IOM
      Q7.
      Blood supply to blood vessels is by
      📅IOM
      Q8.
      Chordae tendinae is found in
      📅MOE 2010
      Q9.
      The two major opening of the left ventricle are
      Q10.
      Which of the following is the correct pathway for propagation of cardiac impulse?
      📅KU 2012
      Q11.
      The pacemaker of heart is:
      📅BPKIHS 2012
      Q12.
      Aorta pierces the diaphragm at the level of:
      📅IOM
      Q13.
      Which of the following vitamins has close relationship with blood?
      Q14.
      Diaphragm is supplied by …….artery.
      📅IE 2013•IOM 1993
      Q15.
      The first branch of the human aorta is
      📅IOM 1993
      Q16.
      The innermost layer of the blood vessels is made up of:
      Q17.
      The longest vein in the human body is:
      📅IOM
      Q18.
      The instrument used to measure blood pressure is known as:
      Q19.
      The velocity of flow in blood vessels is determined by:
      📅IOM
      Q20.
      About…………of the total cardiac output goes to the kidney.
      Q21.
      Bradycardia (i.e. Heart rate <60/min) occurs in:
      📅IOM
      Q22.
      CCU stands for
      📅IOM
      Q23.
      Which of the following procedures is used to assess the human blood vessel?
      📅IOM
      Q24.
      Blood pressure is higher in:
      📅IOM
      Q25.
      Which of the following has single layer of endothelial structure?
      📅IOM
      Q26.
      A patient with high fever will most likely demonstrate the sign of:
      📅IOM
      Q27.
      Least blood pressure is at:
      📅IOM 1994
      Q28.
      Venous system of frog differs from that of rabbit in presence of
      📅IOM
      Q29.
      The pacemakers of heart of rabbit are made up of:
      Q30.
      Albumin is one of the plasma proteins synthesized in
      Q31.
      Universal donor blood group of human beings is
      Q32.
      Arteries are:
      📅BPKIHS
      Q33.
      The blood in the mammalian heart pumped by the right ventricle pass out of orifice, which is guarded by:
      📅BPKIHS
      Q34.
      Blood clot inside a blood vessel is known as:
      📅BPKIHS
      Q35.
      Hepatic portal system originates from:
      📅BPKIHS
      Q36.
      A person has blood group A means he/she has:
      📅BPKIHS
      Q37.
      Blood capillaries are made up of:
      📅IE
      Q38.
      Tunica adventitia is a part of
      📅IOM
      Q39.
      The function of spleen in adults is
      📅IOM 1998
      Q40.
      In an adult human being spleen is necessary for:
      📅IOM 1996•IOM 1997
      Q41.
      The full form of MI, an acute and very serious disease is
      📅IOM 2004
      Q42.
      Anticoagulant used to store blood in the blood bank
      📅IOM 2002
      Q43.
      Blood grouping is important for
      📅IOM 1998
      Q44.
      Following substance are the buffering agents of human body except:
      📅IOM 1998
      Q45.
      For blood clotting fibrinogen is changed into fibrin with the help of:
      📅IOM 1998
      Q46.
      What is the function of blood platelets?
      📅MOE 2057
      Q47.
      Blood is red in colour due to presence of
      📅MOE 2056
      Q48.
      The rate of heart beat in a new born baby is about
      📅IOM 1992
      Q49.
      Extracellular fluid is rich in the following except
      📅IOM 1996
      Q50.
      Bleeding can be due to all of the following causes except
      📅IOM 1997
      Q51.
      Hemostasis means
      📅IOM 2002
      Q52.
      Carbonic Anhydrase is active in:
      📅BPKIHS 2013
      Q53.
      Insufficient supply of blood to organ is:
      📅BPKIHS 2013
      Q54.
      During ventricular systole:
      📅BPKIHS 2013
      Q55.
      In man, the valve present in between right auricle and right ventricle is:
      📅BPKIHS 2014
      Q56.
      Antigen is present in:
      📅BPKIHS 2014
      Q57.
      Which artery supplies blood to head?
      📅MOE 2014
      Q58.
      Find the correct match among the following pair of words.
      📅MOE 2014
      Q59.
      The heart sound 'dup' produced when:
      📅KU 2015
      Q60.
      Carbonic anhydrase is present in:
      📅IOM 2014
      Q61.
      Ligamentum arteriosum connects
      📅IOM 2014
      Q62.
      Antibodies are principally produced by
      📅IOM 2013
      Q63.
      The right auricular-ventricular aperture in rabbit is guarded by
      📅IOM 2013
      Q64.
      Lymphatic fluid in the body is
      📅IOM 2015
      Q65.
      Which organ is considered as the blood bank of the body?
      📅IOM 2015
      Q66.
      The total duration of cardiac cycle is
      📅IOM 2015
      Q67.
      Which of the following is the correct pathway for propagation of cardiac impulse?
      📅KU 2012
      Q68.
      Total no. of oxygen molecules that can bind to a single haemoglobin molecule under normal partial pressure:
      📅KU 2012
      Q69.
      What does pulse measure?
      📅KU 2012