Fetal Circulation

Question 1

Placenta

Answer 1

Where exchange of oxygen and other substances between the separate maternal and fetal blood occurs

Question 2

Umilical arteries (2)

Answer 2

Extensions of the internal iliac arteries that carry fetal blood to the placenta

Question 3

Umbilical vein

Answer 3

returns oxygenated blood from the placenta to the fetus; enters body through the umbilicus and goes to the undersurface of the liver, where it gives off two or three branches and then continues as the DUCTUS VENOSUS

Question 4

Ductus venosus

Answer 4

Continuation of the umbilical vein, drains into inferior vena cava

Question 5

Foramen ovale

Answer 5

Opening in septum between the right and left atria bypass lungs

Question 6

Ductus arteriosus

Answer 6

Small vessel connecting the pulmonary artery with the descending thoracic aorta

bypass lungs

Question 7

Fetal circulation after birth

Umbilical vein

Answer 7

Becomes the round ligament of the liver

Question 8

Ductus venosus

Answer 8

Becomes the ligamentum venosum of the liver

Question 9

Foramen ovale

Answer 9

Functionally closed shortly after a newborn’s first breath, structural closure takes approximately 9 months, becomes Fossa Ovalis

Question 10

Ductus arteriosus

Answer 10

Contracts with establishment of respiration, becomes Ligamentum arteriosum

Question 11

Blood

Answer 11

Composed of plasma and formed elements (blood cells, platelets)

Pick up and delivery service for the body

heat regulation

young adult male has approximately 5 L of blood

Question 12

Leukocytes

Different types and their normal percentages in the blood

Answer 12

1. Neutrophils - 60-70%
2. Lymphocytes - 20-25%
3. Monocytes - 3- 8%
4. Eosinophils- 2- 4%
5. Basophils - 0.5-1%

Question 13

Formed elements in the blood

Red blood cells also called erythrocytes

Answer 13

1. No nucleus, shaped like biconcave discs
2. volume % of RBC’s in whole blood is called hematocrit Normal is 45% for males and 40% for females
3. Primary component is hemoglobin

Question 14

What is the function of Red blood Cells?

Answer 14

1. Critical role in the transport of oxygen and carbon dioxide, depends on hemoglobin

Question 15

How are Red blood cells formed?

Answer 15

1. Erythropoiesis - begins in the red bone marrow as hematopoietic stem cells ( hemocytoblast)
2. Goes through several stages of development to become erythrocytes, maturation process requires 4 days
3. RBC’s are created and destroyed at approximately 100 million per minute in an adult

Question 16

Formed elements in blood

Answer 16

Macrophage cells phagocytose the aged, abnormal or fragmented RBC’s

RBC life span is 105-120 days

Hemoglobin is broken down and amino acids, iron, and bilirubin are released

Question 17

Hemoglobin

Answer 17

1. composed of 4 globin chains, each attached to a heme group which contains one iron atom
2. able to unite with 4 oxygen molecules to form oxyhemoglobin
3. Anemia is a decrease in number or volume of functional RBC’s in a given unit of whole blood.

Question 18

Neutrophils

Answer 18

Phagocytic cells capable of diapedesis

Question 19

Eosinophils

Answer 19

++ in digestive and respiratory tracts, weak phagocytes

associated with antigen- antibody reaction complexes

provide protection against infections caused by parasitic worms and allergic reactions

Question 20

Basophils

Answer 20

Motile and capable of diapedesis, cytoplasmic granules contain histamine and heparin

Question 21

List the granulocytes 3

Answer 21

1. Neutrophils
2. Eosinophils
3. Basophils

Question 22

Agranulocytes

Answer 22

1. Lymphocytes - smallest of the WBC’s
2. T lymphocytes, B lymphocytes have important role in immunity.
3. T lymphocytes directly attack an infected or cancerous cell, and B lymphocytes produce antibodies against specific antigens
4. Monocytes - Largest Leukocytes, mobile and highly phagocytic cells

Question 23

WBC numbers

Answer 23

1mm3 of normal blood, usually contains 5000-9000 leukocytes

WBC numbers are clinically significant because they change with certain abnormal conditions

Question 24

Formation of WBC’s

Answer 24

hematopoetic stem cell where all these come from

Neutrophils, eosinophils, basophils and a few lymphocytes and monocytes originate in red bone marrow

Most Lymphcytes and monocytes deelop from hematopoietic stem cells in lymphatic tissue

Question 25

Platelets three important properties are:

Answer 25

1. agglutination 2. adhesiveness 3. aggregation \*\*\*\*\*Platelet counts in adults average 250,000/mm3 of blood; normal range is 150,000-400,000/mm3\*\*\*\*\*\* Know the normals

Question 26

List functions of platelets

Answer 26

Important role in heostasis and blood coagulation;secondary role in defending against bacterial attacks Hemostasis refers to stoppage of blood flow; if injury is extensive, blood clotting mechanism is activated to assist coagulation cascade

Question 27

Where are platelets formed and what is their life span?

Answer 27

Life span is 7-10 days formed in red bone marrow, lungs, and spleen by fragmentation of megakaryocytes

Question 28

What is blood plasma and what is contained in it.

Answer 28

1. Plasma - liquid part of blood, clear, straw colored, composed of 90% water, and 10%solutes 2. Solutes - 6-8% of plasma solutes are proteins consisting of three main compounds. * Albumins - help maintain osmotic balance of the blood * Globulins - essential component of the immunity mechanism * Fibrinogen - key role in blood clotting * Plasma proteins have an essential role in maintaining normal blood circulation

Question 29

Coagulation

Answer 29

1. Blood clotting - goal is to stop bleeding and prevent loss of vital body fluid 4 components critical to coagulation; 1. Prothrombin 2. Thrombin 3. Fibrinogen 4. Fibrin

Question 30

Clot formation, diagram in power point.

Answer 30

Prothrombin activator⇒prothrombin⇒Thrombin⇒Fibrinogen⇒Fibrin⇒ fibrin clot

Question 31

Antithrombins

Answer 31

Substances in the blood that oppose or inactivate thrombin; prevent thrombin from converting fibrinogen to fibrin

Question 32

Conditions that speed up Clotting

Answer 32

1. Rough spot in the endothelium 2. Abnormally slow blood flow

Question 33

Clot dissolution (important to know)

Answer 33

1. Fibrinolysis- removes unwanted clots 2. Plasmin - fibrin digesting enzyme produced when the plasma protein plasminogen is activated by tissue plasminogen activator tPA, Factor iiv and Thrombin

Question 34

Clot dissolution process

Answer 34

Thrombin factor XII, t-PA, lysosomal enzymes⇒plasminogen, plasmin⇒Fibrin.....Clot dissolution