Transcript Chapter 19 Blood Lecture

Cardiovascular System
Chapters 19 Blood
Anatomy and Physiology
Liberty Senior High
Mr. Knowles
What’s the purpose of the
cardiovascular system?
Do all organisms have one?
Let’s model!
Why we need a cardiovascular
system!
• Human embryos before 3 weeks are so
small, materials are transported by
simple diffusion.
• At third week (few mms in length),
heart begins beating- first system to
function.
• Supplies nutrients to all 75 trillion
cells in the body.
What is the cardiovascular
system?
Three parts:
• Blood – a circulating fluid.
(Chapter 19).
• Heart – a pump. (Chapter 20).
• Blood vessels – the conducting
pipes (Chapter 21)
Cardiovascular Lymphatic
Systems
• Fluid leaves the vessel and enters the
•
•
•
•
tissues- interstitial fluid.
Eventually returns to the vessels.
Lymphatic system has its own vessels.
Used to transport antibodies, white
blood cells, and monitor for infection and
cancer.
Cardiovascular + Lymphatic =
Circulatory System.
What is blood?
• Specialized connective tissue
with cells in a fluid matrix.
Functions of the Blood
• Transport dissolved gases, nutrients,
hormones, and metabolic wastes.
• Regulation of the pH and
electrolytes of interstitial fluid.
Neutralizes the acids created by
metabolism (lactic acid).
• Restricts fluid losses through
damaged vessels or at injury sitesblood clots.
Functions of the Blood
• Defense against toxins and pathogenstransports white blood cells that migrate
into tissue to fight infection and remove
debris. Also, deliver antibodies.
• Stabilize body temperature- absorbs
heat from active muscles and distributes
to other tissues. Also brings heat to the
surface of the skin to lose heat.
Composition of Blood
• It is a fluid connective tissue
with an extracellular matrixplasma + formed elements
(cells and cell fragments) =
whole blood.
• Plasma + Formed Elements =
Whole Blood.
Whole Blood After Centrifugation
Plasma
Red Blood
Cells
White Blood
Cells “Buffy
Coat”
Whole Blood
37-54%
46-63%
Centrifuge
and
Separate
Formed Elements
Plasma
Plasma
7 % Plasma
Proteins
1 % Electrolytes
and other Solutes
92 % Water
Plasma- The Fluid of Life!
• Plasma = Plasma Proteins + a Ground
Substance (Serum).
• Plasma Proteins:
Albumin- transport fatty acids,
maintain isotonic solution.
Globulin- immunoglobulin
(antibodies).
Fibrinogen- form blood clots; becomes
fibrin- an insoluble protein.
Plasma
Globulin
Serum
Albumin
Fibrinogen
Plasma- The Fluid of Life!
• Plasma that has been
allowed to clot will lose
its fibrin and other salts
+2
like Ca .
• Plasma without its fibrin
– Serum.
Formed Elements
• Formed Elements = Blood Cells + Fragments
suspended in the plasma.
• Erythrocytes (Red Blood Cells) – most
abundant (99.9% of all cells); transport of
oxygen and carbon dioxide.
• Leukocytes (White Blood Cells) – body’s
defense cells. (0.1% of cells).
• Thrombocytes (Platelets) – small, membranebound packets of cytoplasm that contain
enzymes for blood clot formation.
Erythrocyte
A Normal Blood Smear
Collecting and Analysis of Blood
• Blood usually collected at a veinvenipuncture.
• Venipuncture- veins are easy to locate,
walls of vein are thinner, pressure is
lower heals easier.
• Peripheral capillaries- tip of finger,
earlobe; oozing small drop for blood
smear.
• Arterial Puncture- check for efficiency
of gas exchange.
Properties of Blood
• Temperature- 38° C or 100.4° F.
• Viscosity- has a great deal of
dissolved proteins in plasma 
more viscous than water.
• pH – 7.35-7.45; slightly alkaline.
Erythrocytes (RBCs)
• “erythros”- red; “cyte”- cell.
• RBCs are the most abundant blood
cell (99.9%). 25 trillion in average
adult. Takes ~ 1 min. to travel circuit.
• Hematocrit- percentage of formed
elements in a sample of whole blood. #
of cells / microliter of whole blood.
• Has a red pigment-hemoglobin- gives
whole blood its color.
RBCs Structure and Function
• Highly specialized cell to transport
gases.
• Cell structure is a biconcave disc.
EM of RBCs
A Biconcave Disc
RBCs Structure and Function
• Shape provides the RBC with a large
surface area.
• Exchange of O2 with the surrounding
plasma must be quick; larger surface
area faster the exchange.
• Total surface of all RBCs is 3800 m2
2
compared to 1.9 m of the whole
human body.
RBCs Structure and Function
• Biconcave shape allows them to form
stacks (dinner plates) – rouleaux
inside narrow blood vessels.
• Rouleaux permit the cells to pass
through blood vessels without
bumping along the walls.
• Do not form logjams or clogs in the
narrow capillary.
Rouleaux in a Blood Smear
Rouleaux in Bone Marrow
A Rouleaux
RBCs Structure and Function
• Biconcave shape allows the
RBCs to bend and flex when
entering capillaries.
• May pass through capillaries ½
the RBC’s diameter.
RBC’s are Highly Specialized
Cells
• Have lost all organelles- lack nuclei,
mitochondria, and ribosomes.
• Lost these structures to allow more space for
hemoglobin and oxygen transport.
• Downside: RBCs unable to divide or repair
themselves. Made in bone marrow.
• Short lifespan- 120 days and then must be
broken down.
The Destiny of an RBC
Hemoglobin (Hb)
• Accounts for 95% of proteins
inside the RBC.
• 280 million Hbs in each RBC.
• Hb binds to and transports O2
and CO2.
The Structure of Hemoglobin
Hb Molecule
• Each Hb molecule = four protein chains
= 2 alpha chains + 2 beta chains of
polypeptides.
• Each chain is a globular subunit and has
a heme group.
• Heme – a porphyrin which is a ring
compound with an iron in the center.
• Iron has a + charge and can bind to O2
(negative).
Hb Molecule
• When hemoglobin binds to O2 – it
becomes oxyhemoglobin.
• Very weak interaction; easy to
separate.
• Fetus uses a fetal hemoglobin- more
readily binds to O2 for more efficient
uptake from mother’s RBCs.
Hb Molecule
• Alpha and Beta chains bind to CO2
at other sites and transport to
lungs.
• If hematocrit is low or the
amount of Hb in RBCs is low
than normal activity cannot be
sustained in tissue- anemia.
Sickle Cell Anemia
• Mutations in the beta chains of the Hb
molecule.
• When the blood contains abundant O2, the
Hb and RBCs are normal.
• But when the defective Hb loses its O2,
neighboring Hb molecules interact and
change the shape of the cell- curved and
stiff.
• Cannot form rouleaux and may form
clots.
Sickle
Cell
Mutation
Sickle
Cell
Mutation
Sickle Cell Anemia
Iron-Deficiency Anemia
Malaria in an RBC
Leukocytes (WBCs)
• General Properties:
1. Help defend against pathogens,
toxins, and damaged cells.
2. They have nuclei and other
organelles.
3. Are made in bone marrow,
thymus, spleen, and other lymphatic
tissue.
Two Major Groups of WBCs
1. Granulocytes- WBCs with
darkly-staining vesicles and
lysosomes inside.
a. Neutrophils
b. Eosinophils
c. Basophils
Two Major Groups of WBCs
2. Agranulocytes- do not stain
darkly on their interior; have
very small vesicles and
lysosomes.
a. Monocytes
b. Lymphocytes
Leukocytes
• Most WBCs are not in the
circulatory system, but in tissues
or organs of the lymphatic
system.
• Circulate for only a short time in
vessels.
Characteristics of WBCs
• Move along the capillaries by amoeboid
movement.
• Detect chemicals from injured cells.
• Leave the capillary by squeezing through
cells –diapedesis.
• Are positively chemotactic in the tissue.
• Can destroy things by phagocytosis.
Ameboid Movement and
Phagocytosis
Infected Cell
White Blood Cell
Diapedesis
Neutrophils
• Most abundant of WBCs.
• Granules are neutral. Filled with
toxins.
• Have a dense, segmented nucleus of
2 to 5 lobes- Polymorphonulear
(PMNs).
• Very mobile and arrive at site of
infection first.
Neutrophils
• Phagocytize “tagged”
bacteria.
• Breakdown bacteria with
their toxic granules.
• Also, release chemicals to
call WBCs to the siteinterleukins.
Neutrophils
Eosinophiles
•
•
•
•
•
Granules stain with eosin- a red dye.
Only amount 2-4 % of the WBCs.
Have a bilobed nucleus.
Phagocytize bacteria and cell debris.
Use exocytosis to release toxins onto the
surface of large parasites.
• Release chemicals that cause allergic
reactions.
Eosinophil
Neutrophil and Eosinophil
Basophiles
• Stain very darkly. Very small cells.
• Very rare in circulation. Usually in tissue.
• Release granules of histamine and
heparin.
• Histamine = permeability of capillaries.
• Heparin = blood clotting.
• Do not phagocytize.
Basophil
The Last Type of Phil
How’s
that
blood
working
for you?
Monocytes
• Larger cells with oval nuclei.
• Circulate throughout the blood stream.
• Leave the vessel and become
macrophages.
• Macrophages phagocytize bacteria, cell
debris, and other foreign elements.
• Also, release chemical messengers.
Monocyte
Lymphocytes
• Larger than RBCs and lack deeplystained granules. Single, large
nucleus.
• Abundant in blood. Migrate from
blood  to tissue through lymph
return to blood.
• Most are not found in blood at any
one time.
Lymphocyte
3 Kinds of Lymphocytes
• T Cells: cellular immunity against foreign
tissue and cells infected with viruses;
have killer T cells and helper T cells (CD4 and CD-8).
• B cells: humoral immunity, produce
antibodies (globulin proteins).Also
memory cells.
• NK cells: (Natural Killers) large granules
of toxin that destroy cancerous cells and
some virally-infected cells.
Leukemia
A WBC Review
Platelets
• Thrombocytes
(nonmammalian)
• Circulates for 9-12 days
• Cell fragments
Platelet Function
• Transport of chemicals
important to the clotting
process.
Show me platelet activation!
Platelet Function
• Active contraction after clot
formation has occurred
–Contain actin & myosin
–After clot forms contraction shrinks
clot & reduces size of break in vessel
wall
Platelet Function
• Formation of a temporary patch
in the walls of damaged blood
vessels
–Forms a platelet plug: slows the
rate of blood loss while clotting
continues
Blood Clot
Platelet Production
• Thrombocytopoiesis occurs in
the bone marrow
• Bone marrow contains:
Megakaryocytes: enormous
w/ large nuclei
Platelet Production
• Megakaryocytes make proteins,
enzymes, & membranes.
• Shed cytoplasm in small
membrane-enclosed packets:
Platelets that enter circulation
• Mature megakaryocyte produces
4000 platelets.
Megakaryocyte
What happens when we
have an allergic reaction?
Can allergies kill?
An Application
Video: Discovery-Body
Story- Allergies