Exam One Study Guide

Primary function of the Circulatory system

Deliver life supporting material, deliver regulating signal such as hormones, collect waste product, distribute heat throughout the body. Protect: Special components of the blood fight against invaded microorganism and cancerous cells.

What is blood made out of?

55% Plasma, 1% leukocytes and platelets, 45% Erthrocytes

Blood Properties

8% fraction of body weight, Temperture 38C or 100.4F. Ph 7.35-7.45

What is hematocrit?

A test to measure the percentage of RBC in blood. Female: 37%-48% Male: 45%-52%

RBC count

Female 4.8million/ul. Male: 5.4million/ul

Platelet Counts

130,000-360000/ul

Erthrocytes (RBC) appearance?

Biconcave disc

What is the circulatory system composed of?

1) the blood (the circulating material)

2) the heart (pump)

3) blood vessels (conduit)

Composition of the Blood

1) plasma

2) the formed elements (blood cells/cell fragments)

Hemoglobin

Female: 12-16g/100 ml

Male: 13-18g/100ml

Total WBC counts

4,000-11,000/ul

Composition of Plasma

Water

Proteins

Glucose

Cholesterol

Fatty acids

Iron

Vitamins (A,B,C,D,E,K)

Electrolytes

Nitrogenous Wastes

Respiratory gases

Erythrocytes

Red blood cells, RBCs

Platelets

Cellular fragments

Leukocytes

White blood cells, WBCs

Granulocytes

Neutrophils

Eosinophils

Basophils

Agranulocytes

Lymphocytes

Monocytes

Erythrocytes are smaller than…

Leukocytes

What are the structures of erythrocytes? (Red Blood Cells, RBCs)

Structure:

• Primary cell content is hemoglobin, the protein that binds oxygen and carbon dioxide

• No nucleus nor mitochondria

Hemoglobin consists of:

Globin and heme pigment

2 alpha group

2 beta group

Globin

• Consists of to a and two B subunits

• Each subunit binds to a heme group

Hemoglobin Structure

Carry four molecules of oxygen

Carbon monoxide competes with oxygen for heme binding with a much higher affinity, what is the problem and treatment?

Problem: deoxygenate hemoglobin

Treatment: hyperbaric oxygen chamber

Oxyhemoglobin

• Bound with oxygen

• Red

Deoxyhemoglobin

• Free of oxygen

• Dark red

Carbaminohemoglobin

20% of carbon dioxide in the blood binds to the globin part of hemoglobin, which is called carbaminohemoglobin.

Functions of Erythrocytes

1) Primary Function: transport oxygen from the lung to tissue cells and carbon dioxide from tissue cells to the lungs.

2) Buffer blood pH

Hematopoiesis

Refers to whole blood cell production

Erythropoiesis

• Refers specifically to red blood cell production

• Erythrocytes are produced throughout whole life to replace dead cells

All blood cells, including red and white, are produced in…

Red bone marrow

On average, how many blood cells are made each day?

One ounce or 100 billion blood cells each day

The red bone marrow is a network of reticular connective tissue that borders on idle blood capillaries called…

Blood sinusoids

As hemocytoblasts mature, they migrate through the thin walls of the […] to enter the blood.

Sinusoids

All of blood cells including red and white arise from the same type of stem cell, known as the…

Hematopoietic stem cell or hemocytoblast

Erythoblast, normoblast…(continue the pattern)

Reticulocyte, erythrocyte

Feedback Regulation of Erytropoiesis

Regulated by renal oxygen content

Erythropoietin

• A glycoprotein hormone, is produced by renal cells in response to a decreased renal blood O2 content

• Erythropoietin stimulates erythrocyte production in the red bone marrow

A drop in renal blood oxygen level can result from:

1) reduced numbers of red blood cells due to hemorrhage or excess RBC destruction

2) reduced availability of oxygen to the blood, as might occur at high altitudes or during pneumonia

3) increased demands for oxygen (common in those ho are engaged in aerobic exercise)

Legal

Raise RBC count by training athletes at high altitude

Illegal

Use erythropoietin, androgen, or their analogs

Dietary Requirements for Erythropoiesis

• Iron

• Vitamin B12

• Folic acid

(More important to women due to the loss of blood during menstruation)

The average life span of erythrocytes is…

120 days

Anemia

Condition in which the blood has an abnormally low oxygen-carrying capacity

Common causes of anemia:

1) an insufficient number of red blood cells

2) decreased hemoglobin content

3) abnormal hemoglobin

(Two such examples are Thalassemias and Sickle-cell anemia, which are caused by genetic defects)

Polycythemia

An abnormal excess of erythrocytes that increases the viscosity of the blood, causing it to sludge or flow sluggishly (Blood thickens)

Common causes of polycythemia include:

1) bone marrow cancer

2) a response to reduced availability of oxygen as at high altitudes

By who and when were ABO blood types identified?

ABO blood types were identified in 1900 by Karl Landstein (1930 Nobel laureate)

Blood type is determined by…

Agglutinogens

Agglutinogens

• Are specific glycoproteins on red blood cell membranes

• All RBCs in an individual carry the same specific type of Agglutinogen’s

Blood groups: Type A

RBCs carry agglutinogen A

Blood groups: Type B

RBCs carry agglutinogen B

Blood groups: Type O

RBCs carry no A nor B agglutinogens

Blood groups: Type AB

RBCs carry both A and B agglutinogens

Type A blood

• RBCs carry type A agglutinogens

• Plasma contain preformed antibodies, agglutinin B, against B agglutinogens

Agglutinins

• Are preformed antibodies in plasma

• Bind to agglutinogens that are not carried by host RBCs

• Cause agglutination—aggregation and lysis of incompatible RBCs

Type B blood

• RBCs carry type B agglutinogens

• Plasma contain agglutinin against A agglutinogens

Type O blood

• RBCs carry neither type A nor type B agglutinogens

• Plasma contain agglutinin against both A and B agglutinogens

• The person can accept only type O blood transfusion

Classify blood groups based on…

Rh agglutinogens other than A/B agglutinogens

Rh negative

• The RBCs contain no Rh agglutinogens

• Agglutinins against Rh-positive RBCs are produced after Rh-negative blood sees Rh-positive RBCs

The problem with a Rh-negative mother and her Rh-positive…

Fetus

Hemolytic Disease of Newborn—Second Pregnancy

Usually born with…

Severe anemia

Leukocytes are grouped into how many major categories?

Two

Granulocytes

• Contain specialized membrane-bound cytoplasmic granules

• Include neutrophils, eosinophils, and basophils

Agranulocytes

• Lack obvious granules

• Include lymphocytes and monocytes

Function of Leukocytes:

Defense against diseases

Leukocytes form a mobile army that helps protect the body from damage by?

Bacteria, viruses, parasites, toxins and tumor cells

Leukocytes circulate in the blood for various…

Lengths of time

Life span

• Several hours to several days for the majority

• Many years for a few memory cells

Neutrophils

• 40%-70%

• Life Span: 6 hours to a few days

• Function: phagocytize bacteria

Eosinophils

• 1%-4% WBCs

• Life Span: 8-12 days

• Function:

1) kill parasitic worms

2) destroy antigen-antibody complexes

3) inactive some inflammatory chemical of allergy

Basophils

• 0.5% WBCs

• Life Span: a few hours to a fe days

• Function:

  1) release histamine and other mediators of inflammation

  2) contain heparin, an anticoagulant

Lymphocytes

• T cells and B cells

• 20%-45% WBCs

• Life Span: hours to years

• Function: mount immune response by direct cell attack (T cells) or via antibodies (B cells)

Monocytes

• 4%-8% WBCs

• Life Span: months

• Function: Phagocytosis develop into macrophages in tissues

Leukocytes are deployed in the infected areas outside blood vessels via 3 steps. What are the 3 steps?

1) margination

2) diapedesis

3) chemo taxis

Margination

Slow down by cell adhesion molecules secreted by endothelial cells

Diapedesis

Leukocytes slip out of the capillary blood vessels

Chemotaxis

Gather in large numbers at areas of tissue damage and infection by following the chemical trail of molecules released by damaged cells or other leukocytes.

Phagocytosis

Destroy foreign substances or dead cells

Leukocytes Disorders

Normal Leukocyte Count:

4,000-11,000/ul

Leukopenia (Leukocyte Count)

<4,000/ul normal leukocytes

Leukocytosis (Leukocyte Count)

> 11,000/ul normal leukocytes

What is one major side effect of chemotherapy?

Leukopenia

Why Leukopenia during chemotherapy?

• Cancerous cells grow fast, which distinguish themselves from most of normal cells

• Chemotherapy is designed to kill fast-growing cells by interrupting mitosis cell division

• Chemotherapy also kills a fe normal fast-growing cells including:

  1) leukocytes

  2) hair

  3) intestinal epithelial cells

Leukemia

• Leukemia refers to a group of cancerous conditions of white blood cells

• Descendants of a single stem cell in red bone marrow

• Extraordinarily high number of abnormal leukocytes

Hemostasis refers to the…

Stoppage of bleeding

Hemostasis means…

Maintaining balance

Three phases occur in rapid sequence, what are they?

1) vascular spasms

2) platelets plug formation

3) blood clotting/coagulation

Platelets are not cells but cytoplasmic fragments of extraordinarily large (up to 60 um in diameter) cells called…

Megakaryocytes

Normal Platelet Count:

130,000-400,000/ul

Function of Platelets

1) secrete vasoconstrictors that cause vascular spasms in broken vessels

2) form temporary platelet plugs to stop bleeding

3) secrete chemicals that attract neutrophils and monocytes to sites of inflammation

4) secrete growth factors that stimulate mitosis in fibroblasts and smooth muscle and help maintain the linings of blood vessels

5) dissolve blood clots that have outlast their ???

Coagulation

• Many clotting factors in plasma are involved in clotting

Coagulation

They are activated when:

Blood vessel is broken or blood flow slows don

The sequential activation (reaction cascade) of the clotting factors finally leads to the formation of…

Fibrin meshwork

Blood cells are trapped in fibrin meshork to form a…

Hard clot

Coagulation Disorders

Thrombosis:

Is the abnormal clotting of blood in the unbroken vessel

Coagulation Disorders

Thrombus:

Is a clot that attaches to the wall of blood vessel

Coagulation Disorders

Embolus:

Is a clot that comes off the wall of blood vessel and travel in the blood stream

Coagulation Disorders

Embolism:

Is the blockage of blood flow by an embolus that lodges in a small blood vessel

Coagulation Disorders

*Infarction:

• Refers to cell death that results from embolism

• Infarction is responsible for most strokes and heart attacks

Bleeding Disorders

Thrombocytopenia:

• The number of circulating platelets is deficient (<50,000/ul)

• Causes spontaneous bleeding from small blood vessels all over the body