human biology: circulatory system
DESCRIPTION
Human Biology: Circulatory System. Lesson 2: Blood and the Lymphati c System (Inquiry into Life pg. 226-230, 240-251). Today’s Objectives. Describe the components of blood, including: Describe the shape, function, and origin of red blood cells, white blood cells, and platelets - PowerPoint PPT PresentationTRANSCRIPT
Human Biology: Circulatory System
Lesson 2: Blood and the Lymphatic System
(Inquiry into Life pg. 226-230, 240-251)
Today’s Objectives Describe the components of blood,
including: Describe the shape, function, and origin of red
blood cells, white blood cells, and platelets List the major components of plasma Explain the roles of antigens and antibodies
Describe the inter-relationships of the structures of the lymphatic system, including: Describe the functions of the lymphatic system Identify and give functions of lymph capillaries,
veins, and nodes
Components of Blood A) Plasma: 55% of blood B) Formed Elements: 45% of blood
Erythrocytes (Red Blood Cells) Leukocytes (White Blood Cells) Thrombocytes (Platelets)
FEATURE RED BLOOD CELLS WHITE BLOOD CELLS PLATELETS
SHAPE Biconcave disc Variable, Amoeboid Tiny, Cell fragments
FUNCTION Transport O2 and CO2 Combat infection Blood clotting
ORIGIN Bone marrow Bone marrowLymphoid Tissue
Bone Marrow
ALSO CALLED Erythrocytes Leukocytes Thrombocytes
Constituents of Plasma NAME FUNCTION
A. Water (90%) Blood Volume Transport of cells and materials B. Plasma Proteins Helps maintain Osmotic pressure in blood. a) Albumen -Transports b) Fibrinogen -Blood Clotting c) Globulins -Infection fighting C. Gases a) Oxygen -For respiration b) Carbon Dioxide -Waste D. Nutrients Energy source - Raw materials for the a) A.A. Glucose, body Fatty acids, Glycerol E. Salts Osmotic Pressure Helps in Metabolism F. Wastes Waste production of Cellular Reactions.
Shape, Function, and Origin of RBC Red Blood Cells
(Erythrocytes) Video Live about 120 days Produced in Red Bone
Marrow (in skull, ribs, vertebrae, and long bones)
Myeloid stem cells form RBC These stem cells are called
Erythroblasts, which will differentiate into Erythrocytes
Produce about 5 million/second RBC contain a protein called
hemoglobin Old RBC destroyed in the
liver and spleen
Hemoglobin Hemoglobin contains iron (gives its red color) Picks up oxygen in the lungs then releases is it in the
tissues Approximately 200,000,000 hemoglobin molecules in
one RBC If hemoglobin was not packaged in RBC, oxygen would
leak out of the circulatory system
Shape, Function, and Origin of WBC White Blood Cells (Leukocytes)Video
Larger than RBC Have a nucleus (RBC do not) Less numerous than RBC (700:1) Do not have a definite shape
Function: Fights against infection in two ways:
Phagocytosis Produce Antibodies
Types of White Blood Cells Granular Leukocytes (Granulocytes)
Have grains, or granules in their cytoplasm which are filled with enzymes and proteins to fight against microbes
Formed in the bone marrow 60-70% of Leukocytes Example: Neutrophil – phagocytize and digest bacteria
Agranular Leukocytes (Agranulocytes) No granules in cytoplasm Produced by lymphatic tissue 25-30% of Leukocytes Example: Monocytes (phagocytize pathogens and
cellular debris) and Lymphocytes (responsible for specific immunity)
Agranulocytes Monocytes:
Largest WBC Take up residence in tissues Differentiate into larger ``macrophages`` which
phagocytize microbes and stimulate other WBC Lymphocytes:
B-Lymphocytes – produced in bone and lymphoid tissue
T-Lymphocytes – produced in the thymus and give rise to plasma cells
Platelets (Thrombocytes) 2 billion produced/day Broken fragments of larger cells Very important in blood clotting
Blood Clotting: Need three things in blood:
- Platelets - Prothrombin - Fibrinogen
1) Platelets clump at the site of the “leak” and partially close it
2) Platelets and the injured tissue together release an enzyme called Thromboplastin
Blood Clotting 3) Thromboplastin converts a blood protein
(Prothrombin) into a new substance called Thrombin
4) Thrombin acts as an enzyme that breaks the ends off another blood protein called Fibrinogen
5) Fibrinogen is then converted into Fibrin 6) Fibrin has sticky ends and forms a lattice or
network over the leak where blood cells get trapped, forming a clot
7) Fibrin clot is only temporary – as soon as the blood vessel repair is initiated, and enzyme called Plasmin destroys the network
RBC trapped in the FIBRIN network
Lymphatic System (see video) Functions:
1) Takes excess tissue fluid and sends it to the circulatory system (lymphatic system joins the circulatory system at the subclavian veins)
2) Products of fat digestion are absorbed into Lacteals which lead to the Lymph vessels and Nodes
3) Lymph nodes produce Lymphocytes (a type of WBC) and help the body defend against disease
4) Lymph nodes act as filters and trap bacteria and other debris (helps to purify the body fluids)
Lymphatic Structures Spleen: Largest Lymphatic Tissue Produces lymphocytes and stores excess blood
If your blood pressure is high, stores blood so blood pressure lowers
If your blood pressure is low, it contracts and squeezes out blood, sending it back to the system so that blood pressure rises
Thymus Gland: Bi-lobed structure which is important In the maturing of lymphocytes Gets smaller as you age
Lymphatic Structures Tonsils and Appendix:
Contain lymphoid tissue Thought to help remove invading
organisms and viruses Lymphatic Tissue:
Produce lymphocytes and stores excess blood
Lymph Vessels: Similar to veins, but fluid only travels in
one direction (lymph veins and capillaries, but no lymph arteries)
Lymph Nodes: Small oval or round tissues which filter
fluids and produce lymphocytes Lacteals:
Sacs in villi of digestive system which absorb products of fat digestion
Infection Fighting – Inflammatory Response Foreign Substances (bacteria or viruses)
attack Monocytes and Neutrophils engulf the
bacteria or viruses in amoeboid fashion (phagocytosis)
These WBC are able to travel to the site of the infection through capillary network
Dead tissue, cells, bacteria, dead and living neutrophils all together make up Pus
Lymphocytes Produce antibodies One antibody fights a specific antigen (foreign
protein) Antigen + Antibody inactive complex Antigens:
A protein found in the outer membrane of RBCs Stimulate an immune response (production of antibodies) The type of protein determines the blood type Can also be a foreign protein introduced to the body
Antibodies: A protein found in the plasma Attack unwanted proteins (bacteria or viruses) End result is agglutination
ABO Blood System (see video)
Blood Group Proteins on Red Blood
Cells(Antigen)
Clumping Chemicals in
Plasma(Antibody)
Can Accept Transfusions
from Group(s)
A A Anti B A, O
B B Anti A B, O
AB A and B None A, B, AB, O(universal
recipient)
O None Anti A Anti B(universal donor)
O
Rhesus Factor Red blood cells may have another antigen
called antigen D, known as the Rhesus Factor.
This distinguishes blood as being RH+ or RH-.
Therefore there are 8 possible blood types.