Transcript Adv Bio #13 - Blood PP rev 14

The Cardiovascular
System
Blood
Functions of
Blood
• I. Transportation
–
–
–
–
–
–
Oxygen
Carbon dioxide
Nutrients
Heat
Waste products
Hormones
RBCs are most numerous, white blood
cells are stained purple.
Functions of
Blood
• II. Regulation
– pH using buffers
– Body temperature
– Water content of
cells.
Water content of blood is
regulated by the kidneys
Functions of
Blood
• III. Protection
– Blood loss
– Against microbes
and viruses.
Red Blood Cell Infected With
Malaria
Physical Characteristics
of Blood
• Temperature
– 38 C.
• More viscous than water.
• pH
– 7.35 - 7.45
• Volume
– 5-6 liters (male)
– 4-5 liters (female)
• Percent total body weight
– 8 percent
Components of
Blood
• I. Plasma
• II. Formed
elements
– Red blood cells
– White blood cells
• Granular
• Agranular
III. Platelets
Neutrophil
Platelets
RBC
Plasma
• Straw-colored
liquid
• 91.5% water, 7%
proteins
• Albumins maintain
osmotic pressure
• Antibodies fight
disease
Formation of
Blood cells
• Hemopoiesis
– Occurs in fetus
• Yolk sac, then liver,
spleen and thymus
• Red bone
marrow- after
birth and
throughout
life
Adult hemopoiesis
Proximal ends of
femur and
humerus.
• Flat bones such
as scapula, ribs,
pelvis, sternum.
Originates from
hemopoietic stem
cells that
differentiate into
five types of blood
cells.
Erythrocytes: red blood cells
• Structure:
– Biconcave discs.
– 8 microns in
diameter
– No nucleus or
organelles.
– Contains
hemoglobin.
– 4.5 to 5.5 million
per. mm3.
• Function
– Carries oxygen & carbon dioxide.
– Hemoglobin consists of four proteins attached to
four hemes
– Each heme has iron.
– Iron attaches to oxygen.
– RBCs maintain a
biconcave shape.
– Maximum S.A. for
gas exchange
– 2 million are made
each second!
Recycling of a RBC
– RBCs live from 3 to 120 days.
– Removed by spleen, liver, and red bone marrow.
(Macrophages)
Jaundice
– The non- Iron part of
hemoglobin is usually
converted into bilirubin.
– Liver then excretes it
into the large intestine.
– If the liver fails to
process bilirubin in
newborns, they will turn
a yellow color: jaundice
Erythrocytes
• Production of RBCs
– Erythropoiesis
– Kidneys determine
rate of RBC
production.
– Kidneys produce
erythropoietin.
• Speeds up
erythropoiesis.
Leukocytes
• Structure
– Contains a nucleus.
– Granular
• Neutrophils
• Eosinophils
• Basophils
– Agranular
• Lymphocytes
Leukocytes
Tortora
Pages 326-330
• Functions
– Neutrophils and
monocytes are
phagocytic.
– Monocytes are referred
to as macrophages.
– WBC’s are capable of
emigration (diapedesis).
– Capable of chemotaxis.
Monocyte
Leukocytes
• Life Span
– Most live just a few
days.
– Lymphocytes live
years.
– 5,000 - 7,000/ mm3.
Tortora
Pages 326-330
Leukocytes
Tortora
Pages 326-330
• Number
– 5,000 - 7,000/ mm3.
• Leukocytes are
produced in the red
bone marrow.
Macrophages
Thrombocytes
Tortora
Pages 326-330
• Structure
– Fragment of cytoplasm
surrounded by
membrane.
– Originate from a
megakaryocyte.
– Megakaryocyte
fragments to form
platelets.
Thrombocyte
Thrombocytes
• Function
– Forms a plug to stop
bleeding.
– Initiates clotting
process.
Thrombocytes
• Life Span
– 5 to 9 days.
• Number
• 250,000 to
400,000 mm3.
• Production
– Formed in red bone
marrow.
Hemostasis
• Three
mechanisms
– Vascular spasm
– Platelet plug
formation
– Blood
coagulation
Hemostasis
• Vascular Spasm
– Smooth muscle in wall contracts.
– Initiated by nociceptors.
– Lasts from 20 minutes to several hours.
Hemostasis
• Platelet Plug Formation
– Platelets get ‘sticky’ when they
come in contact with a damaged
blood vessel.
Hemostasis
• Coagulation
– Clotting involves several
coagulation factors.
• Formation of
prothrombinase.
• Prothrombin converted
to thrombin.
• Fibrinogen converted to
fibrin by thrombin.
• Fibrin forms threads of
protein that trap RBC’s
to form clot.
Hemostasis
• Extrinsic pathway
– Initiated from
outside the
circulatory system
– Tissue Factor (TF)
found on surface of
cells cause the
formation of
prothrombinase.
Hemostasis
• Intrinsic pathway
– Initiated from
inside the blood
vessels.
– Slower than
extrinsic.
– Initiated when
blood contacts
damaged
endothelial cells.
Blood Groupings
• ABO
– Based on types of
proteins (antigens) on
surface of the red
blood cells.
– Type A has only A
antigen.
– Type B has only B
antigen.
– Type O has none.
– Type AB has both.
Blood Groupings
• Type O is the
universal donor.
• Type AB is the
universal
recipient
Blood Groupings
• Typing Blood.
– Antisera
– Clumping
means antigen
is present.
Blood Groupings
• Rh
– Separate
system
– Positive
– Negative
Rh Incompatibility