Transcript circulatory system

CIRCULATORY
SYSTEM
• The Cardiovascular system plus the Lymphatic
system are often said to be part of a single
circulatory system.
• The Cardiovascular system provides a
mechanism for the rapid transfer of nutrients,
waste products, respiratory gases, and cells
within the body.
BLOBLOOD
• Blood is a type of specialized connective
tissue.
• Whole Blood is composed of Plasma (46-63%)
and Formed Element (37-54%)-red blood cells,
white blood cells, and platelets.
• Temperature--roughly 100.4 F
PLAPLASMA
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makes up 46% to 63% of whole blood
92% of plasma is water
the plasma proteins are produced in the liver
The primary plasma proteins are: albumins,
globulins, and fibrinogen
PRIMARY PLASMA PROTEINS
• ALBUMINS
• Are important for transport of fatty acids, thyroid
hormones, some steroid hormones, and other
substances
• GLOBULINS
• most important globulins are antibodies(protect against
foreign proteins and pathogens), and transport proteins
(bind ions and other components.)
• FIBROGEN
• these are insoluble strands of fibrin
• they aid in blood clots
FORMED ELEMENTS
• HEMOPOIESIS- the process by which formed
elements are made
• In an embryo the circulating Hemocytoblasts
(stem cells) divide to make the different cells
found in blood
• The stem cells then settle in organs and then
in the marrow of bones, which becomes the
main site for blood cell formation
RED BLOOD CELLS (RBCs)
• Red blood cells (erythrocytes) make up 99.9% of
all formed elements in blood.
• the hematocrit is the percentage of whole blood
occupied by cellular elements
• RBCs are biconcave with a thin central region and
a thicker outer margin
• they only last about 120 days but are constantly
being replaced by new cells
• RBCs lack organelles like the nuclei and the
ribosomes so they can't reproduce or repair
damage
• 95% of each RBC is made up
of hemoglobin
• hemoglobin is a globular
• protein that is made up of
two pairs of polypeptide subunits.
• each subunit contains a single molecule of heme
and can bind to oxygen molecules.
• due to wear and tear, RBCs have to be constantly
replaced
• phagocytic cells of the liver, spleen, and bone
marrow monitor the conditions of the RBCs,
recognize, and recycle the bad ones.
BLOOD TYPES
• Antigens are substances that can trigger an immune system
response, a defense mechanism that protects you from
infection.
• Cell membranes contain surface antigens, that your
immune system recognizes as "normal", and therefore does
not attack.
• Your blood type is a classification determined by the
presence or absence of specific surface antigens in the RBC
cell membranes.
• There are at least 50 types of surface antigens but the 3
most important are classified as A, B, and Rh (or D).
• The RBCs of an individual have (1) either A or B, (2) both A
and B, or (3) neither A nor B.
• Weather the RBCs have Rh or not is also taken into account.
WHITE BLOOD CELLS (WBCs)
• Unlike red blood cells, white blood cells have
nuclei and other organelles, and these lack
hemoglobin.
• WBCs (leukocytes) defend the body against
pathogens and remove toxins, wastes , and
abnormal or damaged cells.
• WBCs only travel in the in vessels for short
distances and exit in damaged areas or settle in
organs.
• The different WBCs are Neutrophils, Eosinophils,
Basophils, Monocytes, and Lymphocytes.
• NEUTROPHILS
• Phagocytic: Engulf pathoges or debrris in tissue, release
cytoxic enzymes and chemiclas
• Neutrophils equals 50-70% of all white cells
• EOSINOPHILS
• Phagocytic: Engulf pathoges or debris in tissue, release
cytoxic enzymes, reduce inflammation
• Eosinophils equals 2-4%
• BASOPHILS
• only less than 1% of white cells are basophils
• these enter damaged tissue and release histamine and
other chemicals to promote inflamation
• MONOCYTES
• 2-8% of white cells are monocytes
• these are very large and enter tissue to become macrophages
and engulf pathogens and debris
• LYMPHOCYTES
• Lymphocytes are cells of the lymphatic system, providing
defense against specific pathogens or toxins
• these make up for 20-30% of white blood cells
• Include:
-T-cells enter peripheral tissues and attack foreign
cells directly or affect the activities of other
lymphocytes)
-B-cells produce antibodies
-NK cells--natural killer cells destroy abnormal
tissue cells (these are important to prevent
cancer)
WB
PLATELETS
• Fragments of special cells called
magakaryocytes, and participate in a vascular
clotting system
• Functions
• transport of chemicals important to the clotting process
• the function of a temporary patch in the walls of
damaged blood vessels
• Active contraction after clot formation has occurred
HOMEOSTASIS
• Homeostasis prevents the loss of blood through the walls of
damaged vessels
• establishes a frame work for tissue repair
• Consists of 3 phases
• The Vascular Phase--a period of local blood vessels constriction, or
vascular spasms, at the injury site.
• The Platelet Phase--follows as platelets are activated, aggregate at the
site, and adhere to the damaged surfaces.
• The Coagulation Phase--occurs as factors released by platelets and
endothelial cells interact with clotting factors to form a blood clot.
• Clot Retraction--during clot retraction, platelets contract
and pull the torn edges of the damaged vessels closer
together.
• Fibrinolysis--during fibrinolysis, the clot gradually dissolves
through the action of plasmin, the activated form of
circulating plasminogen.
THE HEART
• The blood in our body has to keep on flowing
to provide the cells of the body with the
oxygen needed to and remove waste while
transporting white cells to their intended
targets.
• All functions of the circulatory system depend
on the Heart to pump the blood through the
body.
• The blood flows through a network of blood
vessels that can be separated into two different
sections• Pulmonary Circuit--carries blood to and from the gas
exchange surfaces of the lungs.
• Systemic Circuit--transports blood to and from the rest of
the body.
-The Arteries carry blood away from the
heart
-The Veins return blood to the heart
-Capillaries are the thin walled, narrowdiameter vessels that connect the
smallest arteries and veins and allow
the exchange of O2 and CO2
The Heart can be divided into four
parts:
PERICARDIAL CAVITY
• The heart sits in un the pericardial cavity which is
like a sac and is lined by the pericardium.
•
--the inner part of the pericardium
(touches the heart) is the visceral
pericardium
•
--the outer part of the pericardium
(away from the heart) is the
parietal pericardium
•
--the pericardial cavity if filled with
pericardial fluid
SUPERFICIAL ANATOMY
• Myocardium-the
bulk of the heart
wall
• Endocardiumlines the inner
surface of the
heart
• Epicardiumcovers the outer
surface
INTERNAL ANATOMY
THE BLOOD SUPPLY TO THER HEART
• The heart muscles also need oxygen to function
properly, so there are arteries and veins running
around the outside of the heart
• The Coronary Circulation supplies oxygen and nutrients
needed by the cardiac muscle cells.
THE CORONARY ARTERIES
-take oxygen rich blood from the
aorta and take it to the heart’s
muscles.
THE CARDIAC VEINS
-connect with the coronary arteries and
take the blood back to the heart.
THE HEART BEAT
• A heart beat is the coordinated contraction of
the whole heart to make blood flow in the
right direction at the proper time.
• the contractile cells in the heart are much
faster than regular skeletal muscles.
• THE CONDUCTING SYSTEM
-the conducting system includes the
Senatorial (SA) Node, Antrioventricular
(AV) Node, and Conducting cells.
THE HEART BEAT
• The senatorial (SA) Node (pacemaker)- located
at the wall of the right atrium.
• an action potential appears at the SA Node
• this action potential then spreads through the
Conducting cells around the Right Atrium and reaches
the Left Atrium
• the left and right Atrium begin to contract
• the left and right Atrioventricular (AV) Valve close
THE HEART BEAT
• The Antrioventricular (AV) Node-located at the
junction between the atria and ventricles.
• the action potential arrives at the AV Node.
• it then undergoes a delay there
• this delay allows all the blood to be pushed from the Atriums
to the Ventricles
• the stimulus then travels quickly and spreads through the to
Ventricles.
• the ventricles contract
• the Right and Left AV Valve close
• the Aortic and Pulmonary semilunar valves open and let
the blood out through the arteries.
• these valves then close to keep the blood from rushing back
into the heart.
• HEART RATE
-The Cardiovascular center in the medulla oblongata
activates sympathetic neurons
- The Cardiinhibitory center governs the activities of
the parasympathetic neurons.
CARDIOVASCULAR REGULATION
• Homeostasis mechanisms ensure that tissue
perfusion (blood flow) delivers adequate oxygen
and nutrients.
• Local Factors (Autoregulation) change the pattern of blood
flow within capillary beds in response to chemical changes in
interstitial fluids.
• Central Mechanisms (Neural) respond to changes in arterial
pressure or blood gas levels. Ex. Epinephrine and
Norepinephrine create the “Fight or Flight” effect.
• The Endocrine Factors that help homeostasis are hormones,
Which can assist in short term adjustments (change in
cardiac output and peripheral resistance) and long term
adjustments (changes in blood volume that affect cardiac
output and gas transport).
Patterns of the Cardiovascular System
• Exercise- by exercising often, you can train your heart a
bigger output and get improved Cardiovascular
performance
-athletes have larger stroke volumes, slower resting
heart rates, and larger cardiac reserves than do
nonathletes.
• Response to Hemorrhaging (excessive blood loss)
-blood loss lower blood volume and venous return
and decrease cardiac output.
-peripheral vasoconstriction (vessel constriction)
-hormones are released that promote fluid retention
and more erythrocytes (RBCs) are made.
• Shock is acute circulatory crisis marked by hypotension and
inadequate peripheral blood flow
BLOOD VESSELS
THEPULMONARY CIRCUIT
THE SYSTEMIC CIRCUIT
FETAL CIRCUIT
• Embryonic lungs
are collapsed and
nonfunctional, and
the digestive tract
has nothing to
digest.
• The nutritional and
respiratory needs
are provided by
diffusion across the
placenta.
• AGING AND THE CARDIOVASCULAR
• Age-related Changes in Blood-decrease in hematocrit,
blood clotting, pooling of blood
• The Aging Heart-does not work as efficiently, and can’t
repair as well
• Aging Blood Vessels-vessels can rupture more easily
causing blood loss
• INTEGRATION WITH OTHER SYSTEMS
• The cardiovascular system is anatomically and
functionally linked to all other systems.