Warm-Up 1. (Ch. 41) List the locations where each of the 4 macromolecules are chemically digested. 2. (Ch. 41) Where do vertebrates store excess calories? 3. (Ch. 42) Draw and label the structure of a human heart. 4. (Ch. 42) List the pathway of a single red blood cell through the heart.

Chapter 42 – Part I Circulation

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)

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

Figure 42.10a Endothelium Artery Smooth muscle Connective tissue Capillary Valve Vein Basal lamina Endothelium Smooth muscle Connective tissue Venule Arteriole

Types of Blood Vessels Arteries Blood away from heart High pressure Thick, strong walls Pulse Capillaries Connect arteries/veins Single-cell thick walls Exchange of O 2 /CO 2 Veins Blood back to heart Low pressure Thin-walled, large diameter Valves prevent backflow arteriolesvenules

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

Double circulation pathways in vertebrates

Pathway of blood through heart

Superior vena cava Pulmonary artery Capillaries of right lung Pulmonary vein Aorta Inferior vena cava Right ventricle Capillaries of abdominal organs and hind limbs Right atrium Aorta Left ventricle Left atrium Pulmonary vein Pulmonary artery Capillaries of left lung Capillaries of head and forelimbs Figure 42.6

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

Figure Atrial and ventricular diastole Atrial systole and ventricular diastole Ventricular systole and atrial diastole 0.1 sec 0.4 sec 0.3 sec 2 1 3

Valves Valves: prevent backflow of blood atrioventricular (AV) valves  The atrioventricular (AV) valves (tricuspid, bicuspid) separate each atrium and ventricle semilunar valves  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.

Sinoatrial (SA) node: pacemaker of heart, in right atrium

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

Blood pressure reading: 120/ Sounds stop Sounds audible in stethoscope 120 Artery closed Using a Sphygmomanometer

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

lymph Lymphatic System: returns lost fluid and proteins to blood as lymph  Lymph Nodes:  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 erythrocytes  Red blood cells (erythrocytes): O 2 transport via hemoglobin leukocytes  White blood cells (leukocytes): fight infection  Platelets  Platelets (cell fragments): blood clotting

Figure Plasma 55% ConstituentMajor functions Water Ions (blood electrolytes) Sodium Potassium Calcium Magnesium Chloride Bicarbonate Solvent for carrying other substances Osmotic balance, pH buffering, and regulation of membrane permeablity Plasma proteins Osmotic balance, pH buffering Albumin Fibrinogen Immunoglobulins (antibodies) Clotting Defense Substances transported by blood Nutrients Waste products Respiratory gases Hormones Separated blood elements Basophils Neutrophils Monocytes Lymphocytes Eosinophils Platelets Erythrocytes (red blood cells) 5–6 million 250,000–400,000Blood clotting Transport of O 2 and some CO 2 Defense and immunity Functions Number per  L (mm 3 ) of blood Cell type Cellular elements 45% Leukocytes (white blood cells)5,000–10,000

Figure Collagen fibers 1 23 Platelet plug Fibrin clot Fibrin clot formation Red blood cell 5  m Clotting factors from: Platelets Damaged cells Plasma (factors include calcium, vitamin K) Enzymatic cascade ProthrombinThrombin FibrinogenFibrin 

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.

Lumen of artery Smooth muscle Endothelium Plaque Smooth muscle cell T lymphocyte Extra- cellular matrix Foam cell Macrophage Plaque rupture LDL Cholesterol Fibrous cap Figure 42.20