Animals: Circulation

Blood is the transport medium of the circulatory system

Outline 1. Key Concepts 2. Circulatory system basics 3. Types of circulatory systems 4. Components of blood 5. Human circulatory system 6. Lymphatic system 7. Conclusions

Key Concepts: 1.All cells survive by exchanging substances with their surroundings 2.Blood is the transport medium of the circulatory system 3.There are two types of circulatory systems (open and closed) 4.The lymphatic system has three functions 1. Drainage 2.Absorption 3.Delivery of pathogens

Circulatory, Respiratory, and Digestive Systems

circulatory system basics 1. A fluid-blood: as a medium of transport 2. A system of channels – blood vessels: conduct the blood throughout the body 3. A pump – the heart: keep the blood circulation

Types of circulatory systems 1. Open circulatory systems - blood not always in vessels - insects, spiders

2. Closed circulatory systems - blood always in vessels - earthworm, vertebrates

Flow Through an Open Circulatory System Grasshopper

Flow Through a Closed Circulatory System Earthworm

Closed Circulatory Systems of Vertebrates Fish

Amphibian

Closed Circulatory Systems of Vertebrates Birds and Mammals

Components of blood Plasma > 50% Water 91-92 % Protein 7-8 % Ions, sugars, amino acids, hormones, vitamins, and gases 1-2 %

Cellular portion (Blood Cells) 40-50% Red blood cells

5.4 million/ul

White blood cells

5,000 - 10,000

Platelets

250,000 - 300,000

The Cellular Components of Blood

Red Blood Cells

The Cellular Components of Blood

Components

Relative Amounts

Functions

Plasma Portion (50%–60% of total volume): 1. water

blood

91%–92% of plasma volume

2. Plasma proteins (albumin, globulins, Fibrinogens, etc.)

7%–8%

Solvent Defense, clotting, lipid transport, roles in extracellular fluid volume, etc.

plasma 3. Ions, sugars, lipids, amino acids, hormones, vitamins, dissolved gases

1%–2%

Roles in extracellular fluid volume, pH, etc.

Cellular Portion (40%–50% of total volume): 1. Red blood cells

cells, platelets

2. White blood cells: Neutrophils Lymphocytes Monocytes (macrophages) Eosinophils Basophils 3. Platelets

4,800,000–5,400,000 per microliter 3,000–6,750 1,000–2,700 150–720 100–360 25–90 250,000–300,000

Oxygen, carbon dioxide transport Phagocytosis during inflammation Immune responses Phagocytosis in all defense responses Defense against parasitic worms Secrete substances for inflammatory response and for fat removal from blood Roles in clotting

Bone Marrow

Aging

Human circulatory system I. II. III. IV. V. VI.

Functions Blood Vessels The Heart Heart Sounds Blood Pressure Human Blood types

Human circulatory system

Human circulatory system Functions 1. Transport of O2 and CO2 2. Distribution of nutrients 3. Transport of waste ( liver  kidney  excretion) 4. Distribution of hormones 5. Regulation of body temperature 6. Protection of the body against blood loss and disease

Human circulatory system (Blood Vessels) Arteries and Arterioles a. Thick walls, smooth muscle with elastic tissue to withstand high pressure b. Carry blood away from the heart Capillaries a. Tiniest vessels; thin, single-cell thick for easy diffusion b. Exchange of materials between blood and body cells Venules and Veins a. One-way valves in thin-walled vessels surrounded by thin layer of smooth muscle giving low resistance to blood flow, which is assisted by skeletal muscle b. Returns blood to the heart

Structure of Blood Vessels Arteries

Veins

Veins Veins Large diameter Low resistance Valves One-way flow Blood Reservoir 50-60% or total blood volume

Human circulatory system (The Heart) 1. Two types of chambers A. Atria (Atrium) – receiving chambers B. Ventricles – pumping chambers  arteries 2. Mammals and birds – 2 halves of heart (separated) - each half = atrium + ventricle One circuit (pulmonary circuit) –pick up O2 R V  lungs  L A  L V 2nd circuit (Systemic circuit) – deliver nutrients, O2, etc. L V  body tissue  R A  R V

Human pulmonary circuit

2 circuits Pulmonary Systemic

Systemic Circuit for Blood Flow

Distribution of Blood-Heart Output

Heart Structure and Location

The Human Heart

Human circulatory system (The Heart) Pacemaker – a region of cells that generate electrical signals, heart contracts. = Sinoatrial node (SA node) SA node sends signal to walls of atria (to contract) it also sends signal to another node AV node (atrioventricular node). Then AV node sends signal to ventricle muscles  ventricles contract.

Cardiac Conducting System SA node Pacemaker

AV node AV bundle

Human circulatory system(Heart Sounds) Cardiac output = 5-6 l /min (sports 30-35 l / min) 60-80 contraction/min First sound “Lubb” = closing of valves between atria and ventricles. Second sound “Dubb” = closing of valves between ventricles and arteries. Systole = period of contraction of heart ventricles, begins with “Lubb’ sound. Diastole = period of relaxation of heart ventricles, begins with “Dubb” sound.

Cardiac Cycle Systole Diastole Closure/Opening of valves Contraction of ventricles is the force for blood flow

Human circulatory system(B.P.) Pressure = force/unit area Blood pressure (B. P.) = pressure of blood on walls of vessels. Young adult: Systolic B. P.  120 mmHg Young adult: Diastolic B. P.  80 mmHg (millimeters of mercury) 50,000 miles of human capillaries, only 30-50% capillaries open. No closure of capillaries to brain & heart. wt. in kg x 8% = # l blood, 1 lb = 0.45 kg 165 lb = 75 kg x 8% = 6 l blood

Blood Pressure

Systolic Diastolic

Blood Pressure

Systolic Diastolic

cholesterol and fat deposits

narrowed lumen of artery

endothelium lumen of artery

Fig. 39.21, p. 682

Blood Typing Human Blood types a single gene located on chromosome 9 (4 types: A, B, AB, O) Based on markers on red blood cells [Blood Type] 1.

A (AA, Ao)

2.

B (BB, Bo)

anti B antibodies anti A antibodies

3.

AB (AB)

none

4.

O (oo)

anti A and anti B antibodies

Lymphatic System Lymphatic System - supplement to vertebrate circulatory system. It runs parallel to venous half of circulatory system. 1. Structure a. complex network of thin-walled vessels and two organs (thymus and spleen both produce lymphocytes) b. in proximity to the capillary network c. composed of cells with openings between them that act as one-way valves 2. Components of lymphatic fluid (lymph): a. water b. white blood cells c. foreign matter

Lymphatic System 3. Lymph flow comes from the contraction of nearby muscles (walking, breathing, etc.) 4. Functions a. Remove of excess body tissue fluids b. Transport of fats from the small intestine to blood (absorption) c. Defense of the body by exposing viruses, bacteria, and cancer cells to white blood cells (sites = lymphatic nodes)

Lymphatic System 1.

2.

Lymph vessels and capillaries Functions 1.

Drainage

2.

Absorption

3.

Delivery of pathogens

Lymphatic System

Lymphatic System

In Conclusion 1. Circulatory systems consist of a heart, blood vessels, and blood 2. Blood helps maintain favorable conditions for cells 3. The human heart is a double pump 4. The heart’s partition separates blood flow into two circuits, the pulmonary and the other systemic

In Conclusion 5. Ventricular contraction drives the blood through both circuits 6. The cardiac conduction system serves as the basis for the heart’s rhythmic, spontaneous contractions 7. The lymphatic system has three functions

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