Warm-Up (Ch. 41) List the locations where each of the 4 macromolecules are chemically digested. (Ch. 41) Where do vertebrates store excess calories? (Ch. 42) Draw and label the structure of a human heart. (Ch. 42) List the pathway of a single red blood cell through the heart.

Circulation Chapter 42 – Part I

What you need to know: Circulatory vessels, heart chambers, route of mammalian circulation Evolution of the heart from 24 chambers How RBC’s demonstrate structure/function Blood pressure Cardiovascular disease (Roles of diet, BP, genetics)

Concept 42.1: Circulatory systems link exchange surfaces with cells throughout the body In small and/or thin animals, In most animals, transport systems connect the organs of exchange with the body cells Most complex animals have internal transport systems that circulate fluid

Transport systems (circulation) linked with gas exchange (respiration) Diffusion of gases only rapid across small distances Basic: Cells in direct contact with environment Ex. sponges Gastrovascular Cavity: For digestion & distribute substances Ex. jellies, flatworms Circulatory System: Moves fluid to tissues & cells for exchange Ex. larger animals

Circulatory System = Blood + Vessels + Heart Open circulatory system: blood bathes organs directly Blood + lymph = hemolymph Heart pumps hemolymph into sinuses Ex. arthropods, mollusks Closed circulatory system: blood contained in vessels & pumped around body Blood and fluid separate Ex. annelids, cephalopods, vertebrates

BLOOD VESSELS

Valve Basal lamina Endothelium Endothelium Smooth Smooth muscle muscle Figure 42.10a Valve Basal lamina Endothelium Endothelium Smooth muscle Smooth muscle Connective tissue Capillary Connective tissue Artery Vein Figure 42.10 The structure of blood vessels. Arteriole Venule

Types of Blood Vessels Arteries Capillaries Veins arterioles venules Blood away from heart High pressure Thick, strong walls Pulse Capillaries Connect arteries/veins Single-cell thick walls Exchange of O2/CO2 Veins Blood back to heart Low pressure Thin-walled, large diameter Valves prevent backflow

Blood enters through an atrium and is pumped out through a ventricle Fish = single circulation pathway, 2 chambers Double circulation: amphibians, reptiles, mammals © 2011 Pearson Education, Inc.

Double circulation pathways in vertebrates

Pathway of blood through heart

Superior vena cava Capillaries of head and forelimbs Pulmonary Figure 42.6 Superior vena cava Capillaries of head and forelimbs Pulmonary artery Pulmonary artery Capillaries of right lung Aorta Capillaries of left lung Pulmonary vein Pulmonary vein Left atrium Figure 42.6 The mammalian cardiovascular system: an overview. Right atrium Left ventricle Right ventricle Aorta Inferior vena cava Capillaries of abdominal organs and hind limbs

Cardiac cycle Systole: contraction or pumping phase Diastole: relaxation or filling phase Heart rate: # beats/minute (72 bpm resting) Stroke volume: amount of blood pumped by L. ventricle during contraction (~70 ml)

Atrial systole and ventricular diastole Figure 42.8-3 Atrial systole and ventricular diastole 2 Atrial and ventricular diastole 1 0.1 sec Figure 42.8 The cardiac cycle. 0.3 sec 0.4 sec Ventricular systole and atrial diastole 3

Valves: prevent backflow of blood The atrioventricular (AV) valves (tricuspid, bicuspid) separate each atrium and ventricle The semilunar valves control blood flow to the aorta and the pulmonary artery “Lub-dup” sound = blood against closed AV valves (lub) / the semilunar (dup) valves Heart murmur: backflow of blood through a defective valve © 2011 Pearson Education, Inc.

Heart Sound Link http://www.med.ucla.edu/wilkes/intro.html Normal Sounds Murmurs Wheezing Crackles

The sympathetic division speeds up the pacemaker The pacemaker is regulated by two portions of the nervous system: the sympathetic and parasympathetic divisions The sympathetic division speeds up the pacemaker The parasympathetic division slows down the pacemaker The pacemaker is also regulated by hormones (epinephrine) and temperature © 2011 Pearson Education, Inc.

Blood Pressure BP = systolic/diastolic pressure Systolic: heart contracts Diastolic: heart relaxed Normal: 120/70 Pulse: rhythmic bulging of artery walls with each heartbeat © 2011 Pearson Education, Inc.

Using a Sphygmomanometer Blood pressure reading: 120/70 1 2 3 120 120 70 Figure 42.12 Measurement of blood pressure. Artery closed Sounds audible in stethoscope Sounds stop

Blood returning to heart through veins and venules Figure 42.13 Direction of blood flow in vein (toward heart) Valve (open) Blood returning to heart through veins and venules Skeletal muscle Figure 42.13 Blood flow in veins. Valve (closed)

VEINS

VEINS FUNCTION – AFTER BLOOD MOVES THROUGH THE ARTERIES IT ENTERS BLOOD VESSELS CALLED VEINS, WHICH CARRY BLOOD BACK TO THE HEART. CHARACTERISTICS THINNER WALLS WITH LESS MUSCLE HAVE VALVES CARRIES DEOXYGENATED BLOOD (1 EXCEPTION) EXAMPLES – VENA CAVA, JUGULAR, LOCATION – NEAR MUSCLES

Vein Valves Allows flow of blood in only ONE DIRECTION

VEINS

SPIDER VEINS

RETICULAR VEINS

VERICOSE VEINS

VERICOSE VEINS

Lymphatic System: returns lost fluid and proteins to blood as lymph Lymph Nodes: filter lymph, house WBC’s Immune system role © 2011 Pearson Education, Inc.

Blood Plasma (55%) – water, ions, proteins, gases, nutrients, wastes, hormones Cells (45%) – RBC, WBC, platelets Develop from stem cells in bone marrow Red blood cells (erythrocytes): O2 transport via hemoglobin White blood cells (leukocytes): fight infection Platelets (cell fragments): blood clotting

Figure 42.17 The composition of mammalian blood. Plasma 55% Cellular elements 45% Constituent Major functions Cell type Number per L (mm3) of blood Functions Water Solvent for carrying other substances Leukocytes (white blood cells) 5,000–10,000 Defense and immunity Ions (blood electrolytes) Osmotic balance, pH buffering, and regulation of membrane permeablity Separated blood elements Lymphocytes Basophils Sodium Potassium Calcium Magnesium Chloride Bicarbonate Eosinophils Plasma proteins Monocytes Neutrophils Albumin Osmotic balance, pH buffering Platelets 250,000–400,000 Blood clotting Fibrinogen Figure 42.17 The composition of mammalian blood. Clotting Immunoglobulins (antibodies) Defense Erythrocytes (red blood cells) 5–6 million Transport of O2 and some CO2 Substances transported by blood Nutrients Waste products Respiratory gases Hormones

 Collagen fibers Platelet plug Fibrin clot Platelet Red blood cell Figure 42.18 1 2 3 Collagen fibers Platelet plug Fibrin clot Platelet Red blood cell 5 m Clotting factors from: Fibrin clot formation Platelets Damaged cells Plasma (factors include calcium, vitamin K) Figure 42.18 Blood clotting. Enzymatic cascade  Prothrombin Thrombin Fibrinogen Fibrin

Cardiovascular Disease Atherosclerosis: buildup of plaque deposits within arteries Heart attack (myocardial infarction): blockage of one or more coronary arteries Stroke: rupture or blockage of arteries in the head Hypertension: high blood pressure; promotes atherosclerosis and increases the risk of heart attack and stroke © 2011 Pearson Education, Inc.

Atherosclerosis

Lumen of artery Plaque Endothelium Smooth muscle 1 2 Smooth muscle Figure 42.20 Lumen of artery Plaque Endothelium Smooth muscle 1 2 Smooth muscle cell LDL Foam cell Extra- cellular matrix Macrophage T lymphocyte Plaque rupture 3 4 Figure 42.20 Atherosclerosis. Fibrous cap Cholesterol