Review of Cardiovascular System

							           Learning Objectives
About organization of cardio vascular system
About Components of cardio vascular system
About location, external and internal
 structure of heart
About different chambers and valve of the
 heart
About two different circulatory circuits; he
 should understands the working of these
 circuits
About the structure of different vessels
  Components of Cardio-vascular System
Different components of are:
1. Heart: pumps the blood
2. Blood Vessels:
 Arteries: carrying the
   oxygenated blood way from
   the heart
 Capillaries: Exchange of
   nutrients
 Veins: carrying the
   deoxygenated blood towards
   heart
3. Lymphatic Vessels: draining
    the interstitial fluid
  Functions of Cardiovascular System
– Circulate blood
throughout entire body for
– Transport of oxygen to
cells
– Transport of CO2 away
from cells
– Transport of nutrients
(glucose) to cells
– Movement of immune
system components (cells,
antibodies)
– Transport of endocrine
gland secretions
                 Organization of CVS
Heart is the central organ for
pumping
The cardiovascular system is
divided into two circuits
Pulmonary circuit:
blood to and from the lungs
Systemic circuit:
blood to and from the rest of the
body
Vessels carry the blood through
the circuits
Arteries carry blood away from
the heart
Veins carry blood to the heart
Capillaries permit exchange
 Over View
  of Heart
Pumping station
of the body
Hollow muscular
organ
About the size of
the fist
                        Location
In middle
mediastinum
Within pericardial
cavity
Between lungs
Posterior to sternum
Anterior to vertebral
column
Pointed apex
directed to left
               Structure of Heart
 Covered by pericardium
 Has 3 layers in wall
 Has 4 chambers
 Has four valves
 Supplied by coronary
  arteries
 Connected to pulmonary
  and systemic circuit by
  large vessels
 Has specialized,
  autonomous conducting
  system
           Over View of Pericardium
A double-walled sac around the
   heart composed of:
A superficial fibrous
   pericardium
A deep two-layer serous
   pericardium
The parietal layer lines the
   internal surface of the
   fibrous pericardium
The visceral layer or epicardium
   lines the surface of the heart
They are separated by the fluid-
   filled pericardial cavity
           Over View of Heart Wall
   Three layers
Epicardium
   Outside layer
   This layer is the
     parietal pericardium
   Connective tissue
     layer
Myocardium
   Middle layer
   Mostly cardiac muscle
Endocardium
   Inner layer
        Over View of Heart Chambers
Right and left side act as
   separate pumps
Four chambers
Atria
Receiving and upper chambers
   Right atrium
   Left atrium
Ventricles
Discharging and lower
chambers
   Right ventricle
   Left ventricle
                     Over View of Atria
 Receiving chambers of the
  heart
 Each atrium has a protruding
  auricle
 Pectinate muscles mark
  atrial walls
 Collect blood
Right atria from systemic
  circuit through
   Superior and inferior venae
     cavae
   Coronary sinus
Left atria from pulmonary
  circuit through
   Pulmonary veins
             Over View of Ventricles
 Discharging chambers of
  the heart
 Papillary muscles and
  trabeculae carneae
  muscles mark ventricular
  walls
 Pumps blood
   o Right ventricle into the
     pulmonary trunk
   o Left ventricle into the aorta
           Over View of Heart Valves
 Allow blood to flow in only
  One direction
 Four valves
Atrioventricular valves
Between atria and ventricles
   – Bicuspid valve (left)
   – Tricuspid valve (right)
Semilunar valves
Between ventricle and artery
   – Pulmonary between right
     ventricle and pulmonary
     trunk
   – Aortic between left ventricle
     and aorta
  The Heart: Associated Great Vessels
• Aorta
   – Leaves left ventricle
• Pulmonary arteries
   – Leave right ventricle
• Vena cava
   – Enters right atrium
• Pulmonary veins (four)
   – Enter left atrium
   Over View of Coronary Circulation
 Blood in the heart
   chambers does not nourish
   the myocardium
 The heart has its own
   nourishing circulatory
   system
– Coronary arteries
– Cardiac veins
– Blood empties into the
right atrium via the coronary
sinus
     Over View of Conducting System
• Intrinsic conduction system
   (nodal system)
    – Heart muscle cells
      contract, without nerve
      impulses, in a
      regular, continuous way
    – Special tissue sets the pace
• Sinoatrial node (right atrium)
» Pacemaker
• Atrioventricular node
– (junction of R & L atria and
ventricles)
• Atrioventricular bundle (Bundle
of His)
• Bundle branches (right and left)
• Purkinje fibers
    Pulmonary Circulation Pathway
Deoxygenated blood
 from body
 vena cava
 Right atrium
tricuspid valve
 right ventricle
 pulmonary
 semilunar valve
pulmonary arteries
 lungs
       Systemic Circulation Pathway
Oxygenated blood from
  lungs
pulmonary veins
 left atrium
bicuspid valve
 left ventricle
aortic semilunar valve
aorta
systemic circulation
       Over View of Vascular System
BLOOD VESSELS
LYMPHATICS
Tubular structures that carry
  blood to and from the
  heart
   – Arteries
   – Arterioles
   – Capillaries
   – Venules
   – Veins
  Over View of Blood Vessels Layers of Vessel Wall

Tunica externa
   Outermost layer
   CT w/elastin and collagen
   Strengthens, Anchors
Tunica media
   Middle layer
   Circular Smooth Muscle
   Vaso-constriction/dilation
Tunica intima
   Innermost layer
   Endothelium
   Minimize friction
Features            Artery        Vein
Dimension           Smaller       Larger
Thickness           More          Less
Tunica Adventitia   Narrow        Wider
Tunica Media        Wider         Narrow
                    More Muscle   Less Muscle Fibers
                    Fibers
Tunica Intima       Wider         Narrow
Lumen               Narrow        Wider
Valves              Absent        Present
 Movement of Blood through Vessels
Most arterial blood
  is pumped by the
  heart
Veins use the
  milking action of
  muscles to help
  move blood
                         Capillaries
• Microscopic--one cell layer
  thick
• Bathed in extracellular matrix
  of areolar tissue
• Capillary beds consist of two
  types of vessels
   – Vascular shunt – directly
      connects an arteriole to a
      venule
   – True capillaries – exchange
      vessels
   • Oxygen and nutrients cross
     to cells
   • Carbon dioxide and
     metabolic waste products
     cross into blood
       Lymphatic Vessels: Anatomy
Lymph- clear fluid from loose
areolar CT around capillaries
Lymphatic capillaries (near
blood capillaries)
Lymph collecting vessels
(small, 3 tunicas, valves)
Lymph nodes (sit along
collecting vessels)-clean
lymph of pathogens, they are
NOT glands
       Lymphatic Vessels: Anatomy
Lymphatic trunks
(convergence large
collecting vessels)
Lumbar, intestinal, bronc
homediastinal, subclavia
n, jugular
Lymphatic ducts empty
into veins of neck
        Lymphatic Vessels: Function
Collect excess tissue fluid
  collecting at arteriole end.
  Return leaked blood
  proteins to blood
  circulation
Lymph moved through
  vessels by
   Pulse of nearby arteries
   Contraction of
     surrounding skeletal
     muscle
   Regular movement of
     body (wiggling legs)
   Muscle in tunica media