Anatomy Circulatory system

Males: 5-6 Liters, Female: 4-5 Liters

How many liters of blood?

8%

Blood accounts for ~ \____ body mass

5x viscosity of water, sticky, opaque fluid with metallic taste

Physical characteristics of blood

Color varies with O2 content: High O2 - scarlet; Low O2 - dark red

Color of blood

Slightly alkaline - pH 7.35 - 7.45

pH of blood

Transportation( Gases, Nutrients, Metabolic Waste, Hormones and neurohormones, Immune cells), Temperature regulation, pH regulation, Hemostasis (prevention of blood loss and infection)

blood functions

plasma, Erythrocytes, leukocytes, thrombocytes

Blood is made of (4)

connective

blood is a fluid \_________ tissue

Plasma

nonliving fluid matrix

water, ions, proteins, nutrients, wastes, gases

What does plasma contain

Formed Elements

living blood "cells" suspended in plasma

Erythrocytes

(red blood cells or RBCs)

Leukocytes

(white blood cells or WBCs)

Plasma on top (~55%)
Erythrocytes on bottom (~45%)
WBCs and platelets in Buffy Coat (

Spun tube of blood yields 3 layers:

Leukocytes and platelets

What does the Buffy coat consist of

Hematocrit

% of blood volume that is RBCs

47%

Hematocrit for men

42%

Hematocrit for women

Women tend to have a smaller body size
AND Female hormones inhibit erythropoietin the hormone responsible for activating the production of RBCs in the bone marrow and testosterone is believed to activate it.

Why do women have a lower hematocrit

Most numerous of formed elements (99%)
Anucleate, biconcave disc, absent organelles
Shape can change - why is this important (viscosity), flexible cell membrane.
Primary component is hemoglobin
Life span: 100-120 days

Erythrocytes (RBCs) description

Globin composed of 4 polypeptide chains
Heme pigment bonded to each globin chain (Gives blood red color)
Heme's central iron atom binds one O2
Each Hb molecule can transport four O2
Each RBC contains 250 million Hb molecules

Hemoglobin Structure

Hematopoiesis

Give rise to all formed elements (all blood cells)

Hormones and growth factors push cell toward specific pathway of blood cell development

red bone marrow

Hematopoiesis occurs in

Erythropoiesis

RBC Production
Rate: 2-3 million RBCs per second, produced in bone marrow (RED)
Degraded in the liver and spleen

Hormone control
Adequate supplies (iron, amino acids, and B vitamin)

Balance between RBC production & destruction depends on:

Erythropoietin (EPO)

Hormone that is a direct stimulus for erythropoiesis, released by the kidney in response to hypoxia

Hypoxia

Hemorrhage, iron deficiency, reduced O2 availability (high altitudes)

1. Stimulus: Hypoxia\-- low blood O2 carrying ability due to decreased RBC count, decreased amount of hemoglobin, and decreased availability of O2
2. Kidney and liver to a smaller extent release EPO.
3. Eryhtropoetin stimulates bone marrow.
4. Enhanced erythropoiesis increases RBC count.
5. O2- carrying ability of the blood increases.

Homeostasis to hypoxia imbalance steps

Life span: 100-120 days
Old RBCs become fragile; Hb begins to degenerate
Get trapped in smaller circulatory channels especially in spleen.
Macrophages engulf dying RBCs in spleen.

Fate and Life Span of RBCs

diapedesis

the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation.

Granulocytes

Contain granules in cytoplasm

neutrophils, eosinophils, basophils

List granulocytes

Neutrophils

Destroy bacteria by phagocytosis

Eosinophils

Turn off allergic responses and kill parasites

Basophils

release histamine and other mediators of inflammation

Agranulocytes

Do not contain granules

Lymphocytes, Monocytes

List agranulocytes

Lymphocytes

Mount immune response by direct attack or antibodies

Monocytes

Phagocytosis- develop into macrophages

neutrophils, lymphocytes, monocytes, eosinophils, basophils

List the leukocytes from most abundant to least abundant

Destroy bacteria by phagocytosis
Active phagocytes
60% of WBC
Present in the pus of wounds
Nucleus has several lobes

neutrophils

Mainly attack parasites
2% WBC

eosinophil

Produces
Heparin \= blood thinner
Histamines \= Important in Inflammatory Reaction
1% WBC

Basophil

larger cell, horseshoe shaped nucleus
Become macrophages
6% of wbc's

macrophages

nucleus is dark and takes up almost whole cell; almost no cytoplasm seen
Main defense (immune system)
Produce Antibodies
30% WBC

lymphocytes

Platelets (thrombocytes)

Blood clots and vessel repair

The liquid portion of blood is 92% water
Also contains nutrients, gases, vitamins (etc) and plasma proteins

Plasma components

albumins, globulins, fibrinogen

plasma proteins

Albumins

Transport fatty acids and steroids, help regulate osmotic pressure of the blood.

Globulins

transport lipids and antibodies for immunity

fibrinogen

important for blood clotting

hemostasis

The process of stopping bleeding
Involves the coagulation and clotting of the blood to seal the site of damage

therapeutic plasma exchange

This machine removes the plasma from the blood and returns the RBC's to the donor.

1. Blood spasm, Serotonin = vasoconstrictor
2. Platelet plug formation = plugs opening
3. Blood coagulation
conversion of fibrinogen to fibrin

THREE EVENTS IN HEMOSTASIS

thrombin

is an enzyme that causes the conversion in hemostasis

Coagulation

the thickening of blood to form a clot (hematoma)

thrombus

blood clot (abnormal) stationary

embolus

when the clot moves to another place.

Cerebral Embolism

when a blood clot goes to the brain

Pulmonary Embolism

when a blood clot goes to the lungs

Cytoplasmic fragments
Important role in hemostasis and blood clotting
1-5 min after damage to vessel, platelet plug forms and initiate clotting cascade
Also secrete chemicals that affect local blood flow and platelet aggregation

Thrombocytes/Platelets description

90% water
Over 100 dissolved solutes
Nutrients, gases, hormones, waste, proteins, etc.
Plasma proteins most abundant solutes - remain in blood

blood plasma

blood types

Refers to the types of ANTIGENS ("antibody generating" protein) on the RBCs

Agglutinins

antibodies in plasma

Agglutinogens

antigens on RBCs

Transfusion reaction

fatal accident

indicate paternity, incriminate, and prevent fatalities.

Blood-typing

produced by lymphocytes, acts as a critical part of the immune response by specifically recognizing and binding to particular antigens, such as bacteria or viruses, and aiding in their destruction.

Antibody (immunoglobulin)

Blood doesn't normally have anti-Rh antibodies
Blood transfusion can produce antibodies

Rhesus System (RH)

Rh- mom exposed to Rh+ blood of fetus during delivery of first baby - baby healthy
Mother synthesizes anti-Rh antibodies
Second pregnancy - Mom's anti-Rh antibodies cross placenta and destroy RBCs of Rh+ baby

RH system and Women during pregnancy

Anemia

A condition in which the blood is deficient in red blood cells, in hemoglobin, or in total volume.
inability to carry oxygen
Low RBCs or deficiency of hemoglobin

Leukopenia

Abnormally low white blood cell count (AIDS)

Mononucleosis

infectious disease marked by increased numbers of mononuclear leukocytes and enlarged cervical lymph nodes

Leukemia

cancer of white blood cells

Hemophilia

A hereditary disease where blood does not coagulate to stop bleeding
failure to produce clotting protein

depressed (lower)

Anemia \_____ hematocrit

elevated (higher)

Polycythemia \____ hematocrit

higher average hematocrit

healthy people living at high altitude have \____________ levels than people living at sea level

size of a fist

Heart size

On superior surface of diaphragm
Two-thirds of heart to left of midsternal line
Anterior to vertebral column, posterior to sternum

Location of heart

fibrous pericardium, serous pericardium (parietal, visceral/epicardium), myocardium, endocardium

covering of heart

Superficial fibrous pericardium

Protects, anchors to surrounding structures, and prevents overfilling

parietal layer of serous pericardium

lines internal surface of fibrous pericardium

visceral layer of serous pericardium

epicardium, on the surface of the heart, most external layer of heart tissue

fluid-filled pericardial cavity (decreases friction)

Two layers of serous pericardium are separated by \_______-

Epicardium

Visceral layer of serous pericardium

Myocardium

Spiral bundles of contractile cardiac muscle cells

Endocardium

Lines heart chambers
epithelial and connective tissue... very smooth
NO Nutrient exchange

figure 8 and start at apex

muscle fascicle arrangement of heart

Four chambers: Two superior atria, Two inferior ventricles

chambers of the heart

Interatrial septum

separates atria

Interventricular septum

separates ventricles

Small, thin-walled
Contribute little to propulsion of blood

atria

Most of the volume of heart
Thicker walls than atria
Actual pumps of heart

Ventricles

ensure unidirectional blood flow through the heart.
Open and close in response to pressure changes

valves function

atrioventricular (AV) valves

Prevent backflow into atria when ventricles contract

Tricuspid valve

right AV valve

mitral valve (bicuspid valve)

left av valve

Chordae tendineae

thin bands of fibrous tissue that attach to the valves in the heart and prevent them from inverting

papillary muscles

responsible for pulling the atrioventricular valves closed by means of the chordae tendineae