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 functions1. 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 bloodPlasma > 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 Componentsof Blood

Red Blood Cells

The Cellular Componentsof Blood

plasma

cells,platelets

Components Relative Amounts Functions

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

1. water

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

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

91%–92% ofplasma volume

7%–8%

1%–2%

Solvent

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

Roles in extracellular fluid volume, pH, etc.

Cellular Portion (40%–50% of total volume):

1. Red blood cells

2. White blood cells:NeutrophilsLymphocytesMonocytes (macrophages)EosinophilsBasophils

3. Platelets

4,800,000–5,400,000per microliter

3,000–6,7501,000–2,700150–720100–36025–90

250,000–300,000

Oxygen, carbon dioxide transport

Phagocytosis during inflammationImmune responsesPhagocytosis in all defense responsesDefense against parasitic wormsSecrete substances for inflammatoryresponse and for fat removal from blood

Roles in clotting

blood

Bone Marrow

Aging

Human circulatory system

I. FunctionsII. Blood VesselsIII. The HeartIV. Heart SoundsV. Blood PressureVI. Human Blood types

Human circulatory system

Human circulatory systemFunctions

1. Transport of O2 and CO22. Distribution of nutrients3. Transport of waste ( liver kidney excretion)4. Distribution of hormones5. Regulation of body temperature6. Protection of the body against

blood loss and disease

Human circulatory system (Blood Vessels)

Arteries and Arteriolesa. Thick walls, smooth muscle with elastic tissue to

withstand high pressureb. Carry blood away from the heart

Capillariesa. Tiniest vessels; thin, single-cell thick for easy diffusionb. Exchange of materials between blood and body cells

Venules and Veinsa. 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

VeinsLarge diameter

Low resistance

Valves

One-way flow

Blood Reservoir

50-60% or total

blood volume

Human circulatory system (The Heart)

1. Two types of chambersA. Atria (Atrium) – receiving chambersB. 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 circuitsPulmonary

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 nodePacemaker

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 areaBlood pressure (B. P.) = pressure of blood on

walls of vessels.Young adult: Systolic B. P. 120 mmHgYoung 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 kg165 lb = 75 kg x 8% = 6 l blood

Blood Pressure

Systolic

Diastolic

Blood Pressure

Systolic

Diastolic

Fig. 39.21, p. 682

narrowedlumen ofartery

cholesteroland fatdeposits

endothelium

lumen of artery

Blood TypingHuman 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) anti B antibodies

2. B (BB, Bo) anti A antibodies

3. AB (AB) none

4. O (oo) anti A and anti B antibodies

Lymphatic SystemLymphatic System - supplement to vertebrate circulatory

system. It runs parallel to venous half of circulatory system.

1. Structurea. complex network of thin-walled vessels and two

organs (thymus and spleen both produce lymphocytes)

b. in proximity to the capillary networkc. composed of cells with openings between them that

act as one-way valves2. Components of lymphatic fluid (lymph):

a. water b. white blood cells c. foreign matter

Lymphatic System3. Lymph flow comes from the contraction of

nearby muscles (walking, breathing, etc.)4. Functions

a. Remove of excess body tissue fluidsb. 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. Lymph vessels and capillaries

2. Functions1. 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

See you later!