Class Notes (807,382)
Canada (492,740)
BIOB33H3 (116)
Lecture 10

Lecture 10 notes.doc

9 Pages
Unlock Document

University of Toronto Scarborough
Biological Sciences
Connie Soros

1 Lecture 10 The Cardiovascular System: Heart and Blood & the Senses Introduction The cardiovascular system functions as a system to transport numerous substances throughout the body such as: nutrients, oxygen and carbon dioxide, hormones and ions Transports metabolic wastes to the kidneys Transports leukocytes to aid in fighting infectious agents Composition of the Blood Whole blood 4-6 liters Plasma - makes up about 55% of the volume of whole blood - liquid matrix of blood Consists of: 92% water 7% proteins (albumin, globulins, fibrinogen, regulatory proteins) 1% other solutes (electrolytes, organic nutrients, organic waste) Plasma proteins: there are three major classes of protein in the blood 60% Albumin contributes to the osmotic pressure, transports fatty acids and steroids, smallest of the proteins 35% Globulins - act as immunoglobulins (antibodies) and act as transport proteins (transport ions and hormones) 4% Fibrinogen - involved in blood clotting, largest of the proteins Formed elements - makes up about 45% of whole blood - blood cells and cell fragments that are suspended in the plasma, and include: Platelets (<0.1% of formed elements) - involved in blood clotting Leukocytes (White Blood Cells WBC) (<0.1% of formed elements) : function in the immune system Neutrophils (5070% of the WBCs) Eosinophils (24% of the WBCs) Basophils (<1% of the WBCs) Lymphocytes (2030% of the WBCs) Monocytes (28% of the WBCs) Erythrocytes (Red Blood Cells RBC) (99.9% of formed elements) - transport oxygen and carbon dioxide Structure of RBCs Biconcave disc Thin central region Measure about 7.7 microns in diameter Lack cell organelles Lack a nucleus (anucleated) RBC Life Span Since RBCs lack a nucleus and all the organelles, have a life span of about 120 days Significance of a lack of a nucleus: Allows the cell to be flexible as it travels through the circulatory system Allows for more room for hemoglobin Significance of a lack of mitochondria: Mitochondria use oxygen to manufacture ATP Without mitochondria, oxygen can be transported to the tissues instead of being used by the mitochondria RBCs and Hemoglobin A developing erythrocyte loses its nucleus and organelles A mature erythrocyte is mainly a cell membrane surrounding water and protein The water accounts for 66% of the RBCs volume 2 The protein accounts for 33% of the RBCs volume of which >95% is hemoglobin Hemoglobin is responsible for transporting oxygen and carbon dioxide (the main function of RBCs) Hemoglobin Consists of four polypeptide subunits Each subunit contains a molecule of heme Heme is a porphyrin ring Each heme consists of an iron ion Iron binds to oxygen The polypeptide units bind to carbon dioxide Oxygen and carbon dioxide do not compete with each other for binding sites Leukocytes or White Blood Cells (WBCs) There are two major classes of leukocytes consisting of a total of five major types of leukocytes Granulocytes: neutrophils, eosinophils, basophils Agranulocytes: monocytes, lymphocytes WBCs have a short life span (usually a few days) When the body is compromised, the white blood cells multiply to combat the invading agent or allergen, etc. Granulocytes Neutrophils (normal range is 5070%) Granules contain chemicals to kill bacteria Typically the first WBC at the bacterial site Very active phagocytic cells Nucleus is multilobed Eosinophils (normal range is 24%) Granules release chemicals that reduce inflammation Attack a foreign substance that has reacted with circulating antibodies (such as an allergic reaction or parasites) Typically have a bilobed nucleus Basophils (normal range less than 1%) Granules release histamine and heparin Histamine dilates blood vessels Heparin prevents abnormal blood clotting Nucleus is usually hidden due to all the granules Agranulocytes Monocytes (normal range is 28%) Large phagocytic cells Release chemicals to attract other phagocytic cells Release chemicals to attract fibroblasts Fibroblasts produce collagen fibers to surround an infected site These collagen fibers can produce scar tissue Nucleus is kidney-shaped or large oval-shaped Lymphocytes (normal range is 2030%) Responsible for specific immunity Can differentiate to form T cells, B cells, and NK cells Nucleus is typically large and round leaving a small halo around the entire nucleus or part of it T cells - attack foreign cells directly B cells - antibodies to attack foreign cells NK cells - Responsible for immune surveillance3 Platelets Derived from megakaryocytes Megakaryocytes will fragment forming bits and pieces of membrane- enclosed packets of chemicals The main chemical is platelet thromboplastin factor About 350,000 per microliter of blood Formerly called thrombocytes Involved in blood clotting (hemostasis) Release chemicals to initiate the clotting process (platelet thromboplastin factor) Clump together to form a platelet plug Contain actin and myosin that function to contract the clot Hemopoiesis (blood formation) Begin with pluripotential stem cells Differentiate to form two cells: myeloid stem cells and lymphoid stem cells The Heart The heart keeps the blood in motion The heart beats about 100,000 times per day The heart pumps about 1.5 million gallons of blood per year The heart pumps between 5 and 30 liters of blood per minute An Overview of the Cardiovascular System The heart is about the size of on
More Less

Related notes for BIOB33H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.