Circulatory Systems Internal transport

Evolution: Review Most primitive : amoebocytes Most primitive : amoebocytes Then: GVC Then: GVC Then: open circulatory Then: open circulatory Then closed w/ 2 chamber heart Then closed w/ 2 chamber heart Then 3 chambers Then 3 chambers Then 4 chambers Then 4 chambers pulmonary & systemic circuits pulmonary & systemic circuits

Blood Connective Tissue…2 parts Connective Tissue…2 parts 1) Cells: red, white, platelets 1) Cells: red, white, platelets 2) Matrix = plasma 2) Matrix = plasma

Plasma % volume % volume Mostly water Mostly water Transport medium for Transport medium for 1) blood cells 1) blood cells 2) blood proteins, hormones 2) blood proteins, hormones 3) nutrients & oxygen 3) nutrients & oxygen 4) waste & CO 2 4) waste & CO 2 5) thermal energy 5) thermal energy 6) ions (regulate pH) 6) ions (regulate pH)

Blood Cells 1) Erythrocytes 1) Erythrocytes red blood cells red blood cells (RBC) (RBC) 2) Megakaryoctyes (break into fragments called platelets)….role in clotting 2) Megakaryoctyes (break into fragments called platelets)….role in clotting 3) Leukocytes (WBC) white blood cells 3) Leukocytes (WBC) white blood cells

Leukocyte Roles Phagocytosis/inflammation: Phagocytosis/inflammation: –basophils & neutrophils Phagocytosis/immune response: Phagocytosis/immune response: –Macrophages & dendritic cells Kill abnormal body cells: Kill abnormal body cells: –natural killer cells

Erythrocytes No nucleus – only live 120 days No nucleus – only live 120 days Require iron Require iron Transport O 2 via hemoglobin Transport O 2 via hemoglobin Transports CO 2 via hemoglobin Transports CO 2 via hemoglobin Carry ABO blood typing markers Carry ABO blood typing markers Lack of RBC = anemia Lack of RBC = anemia

Agglutination Antibodies (immune proteins) bind foreign cells into clumps that attract phagocytes Antibodies (immune proteins) bind foreign cells into clumps that attract phagocytes Clumps may clog vessels Clumps may clog vessels A & B markers are attacked by antibodies present in all individuals lacking A or B A & B markers are attacked by antibodies present in all individuals lacking A or B Rh marker only attacked the second time an Rh- person is exposed Rh marker only attacked the second time an Rh- person is exposed ….the body needs time to make anitbodies against Rh markers ….the body needs time to make anitbodies against Rh markers

Erythroblastosis fetalis Rh – mom Rh – mom 1 st child is Rh+ so mom develops antibodies against Rh 1 st child is Rh+ so mom develops antibodies against Rh 2 nd child is Rh+ 2 nd child is Rh+ Problem = child may receive some of mom’s antibodies from placenta. Antibodies cause Agglutination in fetus Problem = child may receive some of mom’s antibodies from placenta. Antibodies cause Agglutination in fetus

Heart Structures Pericardium = Pericardium = connecitve tissue sac connecitve tissue sac 2 layers w/ fluid between 2 layers w/ fluid between inner layer fused to wall of heart inner layer fused to wall of heart Myocardium = Myocardium = layer of cardiac muscle layer of cardiac muscle reinforced by elastin & collagen fibers reinforced by elastin & collagen fibers Endothelium – epithelial lining of chambers Endothelium – epithelial lining of chambers (Also called enodcardium) (Also called enodcardium)

Myocardium 1) striated muscle (sarcomeres) 1) striated muscle (sarcomeres) 2) single branching cells 2) single branching cells 3) strong adhering junctions 3) strong adhering junctions 4) many gap junctions 4) many gap junctions 5) many mitochondria 5) many mitochondria 6) can store small amts glycogen 6) can store small amts glycogen

Valves Atrioventricular valve Atrioventricular valve Semilunar valve Semilunar valve

Heart Heart’s Left side = Heart’s Left side = pumps to body pumps to body more muscular more muscular blood enters from pulmonary veins blood enters from pulmonary veins blood leaves through aorta blood leaves through aorta

Heart’s Right Sinoatrial node Sinoatrial nodepacemaker pumps to lungs pumps to lungs less muscular less muscular blood enters from vena cavas blood enters from vena cavas blood leaves through pulmonary arteries blood leaves through pulmonary arteries

Cardiac Cycle: cycle of expansion and contraction Diastole (expansion) Diastole (expansion) Systole (contraction) Systole (contraction) 1) atria relax & fill with blood 1) atria relax & fill with blood 2) fluid pressure opens AV valves 2) fluid pressure opens AV valves 3) blood flows to ventricles / atria contract 3) blood flows to ventricles / atria contract 4) ventricles contract = highest pressure 4) ventricles contract = highest pressure 5) ventricles relax as atria are already filling 5) ventricles relax as atria are already filling

Blood Pressure Highest in contracting ventricles Highest in contracting ventricles Lowest in relaxed atria Lowest in relaxed atria Measured in brachial artery Measured in brachial artery Systolic = peak pressure as V contract Systolic = peak pressure as V contract Diastolic = lowest pressure as V relax Diastolic = lowest pressure as V relax 120/80 120/80 Systolic = start to hear sound Systolic = start to hear sound Diastolic = sounds stop Diastolic = sounds stop

Controlling Blood pressure Based on 1) total blood volume Based on 1) total blood volume 2) cardiac output 2) cardiac output 3) arteriole resistance 3) arteriole resistance Regulated by baroreceptors in walls of arteries ex in carotids. Regulated by baroreceptors in walls of arteries ex in carotids.

Cardiac Conduction System 1) Sinoatrial node = clump of cells in rt atrium. Send action potentials. Atria contract 1) Sinoatrial node = clump of cells in rt atrium. Send action potentials. Atria contract 2) junctional fibers = bundles of long thin cells send AP to Atrioventricular node as atria are contracting 2) junctional fibers = bundles of long thin cells send AP to Atrioventricular node as atria are contracting 3)Atrioventricular node is bridge btwn Atria and ventricles. 3)Atrioventricular node is bridge btwn Atria and ventricles.

4) once AP enters ventricles junction fibers spread AP to both ventricles so both contract at same time 4) once AP enters ventricles junction fibers spread AP to both ventricles so both contract at same time Action Potentials pass Action Potentials pass Directly from one cell to The next through gap junctions

Arteries = away Large diameter = low resistance Large diameter = low resistance Bands of elastic tissue Bands of elastic tissue Elastic walls bulge & recoil Elastic walls bulge & recoil (equalize pressure) (equalize pressure) Artierioles regulate flow Artierioles regulate flow vasodilate & vasodilate & vasoconstrict vasoconstrict

Veins = back to heart Large = low resistance Large = low resistance Smooth muscle contracts to prevent bulging Smooth muscle contracts to prevent bulging Contracting skeletal muscles push against veins Contracting skeletal muscles push against veins Too much bulge= Too much bulge= varicose veins varicose veins Backflow valves Backflow valves

Capillaries RBC fit single file RBC fit single file Wall of cap = 1 cell layer thick Wall of cap = 1 cell layer thick Gaps between cap cells let small mol & WBC slip out into interstitial fluid Gaps between cap cells let small mol & WBC slip out into interstitial fluid Other things exit by diffusion across cell membrane of cap cells or by exocytosis Other things exit by diffusion across cell membrane of cap cells or by exocytosis Blood-brain barrier is the exception….no leaking there! Blood-brain barrier is the exception….no leaking there!

Bulk Flow Movement of water & solutes by pressure Movement of water & solutes by pressure Ultrafiltration – pressure pusses plasma out of cap at start of cap bed Ultrafiltration – pressure pusses plasma out of cap at start of cap bed Capillary reabsorption – interstitial fluid moves into cap near end of bed Capillary reabsorption – interstitial fluid moves into cap near end of bed Normal = slight outward flow into tissues Normal = slight outward flow into tissues

Lymphatic System A) Lymph vascular system – A) Lymph vascular system – 1) vessels collect excess interstital fluid 1) vessels collect excess interstital fluid 2) collected fluid called lymph 2) collected fluid called lymph 3) transports lymph to veins in lower neck 3) transports lymph to veins in lower neck B) Lymphoid organs, tissues B) Lymphoid organs, tissues 1) nodes: lymphocytes filter lymph 1) nodes: lymphocytes filter lymph 2) spleen: filters out old RBC & pathogens 2) spleen: filters out old RBC & pathogens 3) Thymus: T lymphocyte differentiation 3) Thymus: T lymphocyte differentiation

Lymphocytes Stem cells in bone marrow produce leukocytes Stem cells in bone marrow produce leukocytes Leukocytes are generic WBC..can differentiate Leukocytes are generic WBC..can differentiate Some Leukocytes become Lymphocytes Some Leukocytes become Lymphocytes B lymphocytes mature in bone marrow B lymphocytes mature in bone marrow T lymphocytes mature in the thymus T lymphocytes mature in the thymus Both have membrane receptors that bind to antigens (foreign materials, virus, bacteria) Both have membrane receptors that bind to antigens (foreign materials, virus, bacteria) Both are part of bodies immune response Both are part of bodies immune response

Other Leukocytes differentiate into the ________Phils Neutrophils – fast acting phagocyte Neutrophils – fast acting phagocyte - attacks bacteria in inflamed wounds - attacks bacteria in inflamed wounds Eosinophils – secrete enzymes to attack worms Eosinophils – secrete enzymes to attack worms Basophils – secrete histamines other Basophils – secrete histamines other inflammatory substances inflammatory substances

Some Leukocytes turn into Mast cells Mast cells are embedded in connective tissues Mast cells are embedded in connective tissues Cause allergic reactions Cause allergic reactions First exposure to the allergen (antigen) : First exposure to the allergen (antigen) : 1) body makes a glycoprotein called an antibody 1) body makes a glycoprotein called an antibody 2) the antibody is specific to the allergen 2) the antibody is specific to the allergen 3) if the allergen enters the body again it binds to the antibody 3) if the allergen enters the body again it binds to the antibody 4) antibody triggers mast cells to make histamines 4) antibody triggers mast cells to make histamines

Histamines & inflammation Histamines cause inflammation by: Histamines cause inflammation by: 1) dilation of arterioles 1) dilation of arterioles 2) increased permeability of capillaries 2) increased permeability of capillaries Results : swelling, redness, heat, runny nose & eyes Results : swelling, redness, heat, runny nose & eyes Acute allergic response – anaphylactic shock…whole body response causes drop in blood pressure and smooth muscle contractions block airways Acute allergic response – anaphylactic shock…whole body response causes drop in blood pressure and smooth muscle contractions block airways

Inflammatory response to injury Injured mast cells also release histamine Injured mast cells also release histamine Increased blood flow causes redness, swelling and heat AND brings in… Increased blood flow causes redness, swelling and heat AND brings in… 1) platelets to clot & block flow of antigens 1) platelets to clot & block flow of antigens 2) antimicrobial proteins 2) antimicrobial proteins 3) Phagocytes to engulf bacteria 3) Phagocytes to engulf bacteria a. neutrophils a. neutrophils b. dendritic cells b. dendritic cells c. macrophages c. macrophages

Macrophages and dendritic cells also come from leukocytes Leukocytes differentiate into monocytes Leukocytes differentiate into monocytes Monocytes differentiate into either Monocytes differentiate into either dendritic cells or macrophages dendritic cells or macrophages Both can engulf bacteria AND stimulate immune response by binding helper T cells Both can engulf bacteria AND stimulate immune response by binding helper T cells