Pathway of Circulation14

9

11

10

8

6

13

12

6

5

4

3

2

1

1

16

15

14

7

And so on…It takes about 1 min. for blood to make 1 complete cycle

Pulmonary Circuit

Systemic Circuit

Lung

Pulmonaryvein

Aorta

Left atrium

Leftventricle

Pulmonaryartery

Rightatrium

Rightventricle

Venacava

oxygen-poor blood

oxygen-rich blood

CardiovascularCircuits

Pulmonary Circulation Takes place on the right side of the heart. Pumps

blood low in oxygento the lungs to pick up oxygen and return to heart

Systemic Circulation Takes place on left side of heart Oxygenated blood is pumped to

the body cells thruthe aortaand otherarteries

Blood lowin oxygenreturns to the heart

Coronary Circulation

Although blood fills the chambersof the heart, the muscle tissue of the heart is so thick that it requires coronary blood vessels to deliver blood deepinto the myocardium.

The coronary circulation consists of the blood vessels that supply blood to, and remove blood from the heart muscle itself.

Coronary Circulation

The vessels that supply blood high in oxygen to the myocardium are known as coronary arteries.

Blood Vessels Form a closed circuit

of tubes that carry blood throughout the body

Laid end to end, the blood vessels in an average human body will stretch approximately 62,000 miles……2.5 times around the earth

Blood Vessels Have

characteristic features

Are distinguished by size, tissue layers and direction of blood flow

Blood Vessels Arteries

• Receive blood from ventricles

• Take blood away from the heart

• Usually carry oxygenated blood

• Thickest vessel walls• Withstand greater blood pressure• Are very elastic• Connect to capillaries• Aorta is the largest artery

Blood Vessels Veins

• Transport blood away from capillaries• Carry blood

toward heart• Take blood to atria• Have valves• Thinner vessel

walls with lesssmooth muscles

than arteries• Can stretch a great deal• Have larger diameters• Usually carry de-oxygenated blood• Vena cava is the largest vein

Blood Vessels The contraction of muscles

compressing veins helps push blood up through the leg veins back to the heart. The valves allow the blood to flow towards the heart only.

Calf musclerelaxed

Calf musclecontracts

Musclesqueezes veins

Veins constrict;blood moves;valves open

Veins dialated;blood still;valves closed

Valves OPEN

Valves CLOSED

Blood Vessels Capillaries

• Smallest of blood vessels• Only one cell thick (epithelial cell)• Connect arteries to veins• Bring oxygen

and nutrients to cells

• Removes CO2, urea, and other wastes from cells

• Where blood is under low pressure and moving slowly

Blood Vessels A network of capillaries runs

close to the cells in every part of the body. The capillaries have very thin walls which allows nutrients to diffuse through into the tissues and waste products to filter back into the capillaries.

Arteriole Venule

Tissue cells VeinArtery capillaries

Capillaries

C B O L M O P

O A D R I V S

E O S N S

E O L F

S

Blood PressureBlood pressure refers to the force

exerted by circulating blood on the walls of blood vessels

The pressure of the circulating blood decreases as blood moves through arteries, arterioles, capillaries, venules, and veins

Blood Pressure Blood pressure is most commonly

measured via a sphygmomanometer(blood pressure cuff)

It uses the height of a column of mercury to reflect the circulating pressure

Average blood pressure for an adult is 120/80

Blood Pressure

Systolic pressure is defined as the maximum pressure in the arteries exerted during ventricular contraction (which occurs near the beginning of the cardiac cycle)

Diastolic pressure is the minimum pressure exerted when ventricles relax and fill (at the resting phase or end of the cardiac cycle)

Blood pressure readings = S/D

Blood Pressure Pressure waves move through

the blood vessels A person's pulse is the throbbing

of their arteries as an effect of the pressure waves (heart beat)

Pulse is used to denote the frequency of the heart beat

It can be felt at neck, wrist, and other places

Pulse is usually measured in beats per minute.

In most people, the pulse is an accurate measure of heart rate..

Blood Pressure

Vasoconstriction is narrowing of a blood vessel. When a blood vessel constricts, the flow of

blood is restricted or slowed. Blood pressure will increase Vasodilatation is where blood vessels in the

body become wider following relaxation of smooth muscle in vessel wall. This will reduce blood pressure - since there is more room for the blood.

and

Blood

The life stream of the body, affecting every cell and system we have.

The blood is an accumulation of many different elements, each working in a specific way to keep us alive.

Blood

A circulating connective tissue consisting of several types of cells suspended in a fluid medium known as plasma.

Blood

Functions of blood:• Supply oxygen to tissues • Supply nutrients such as glucose, amino acids

and fatty acids to tissues

• Removal of wastes such as CO2

, urea and lactic acid from tissues

• Immunological functions, including circulation of white cells, and detection of foreign material by antibodies

Blood

Functions of blood continued:• Messenger functions, including transport of

hormones and signaling of tissue• Coagulation,

part of body's self-repair mechanism

• Regulation ofcore body temperature

• Regulation of body pH and ion concentrations

Blood What percent of your body is blood? How much blood do we contain?

• On average 4-6 liters• We contain about a pint of

blood for every 15 pounds of body weight

Composition of Blood:• What percent of your blood is

cellular? • What percent of your blood is

plasma?

8%

45%

55%

Blood What is plasma?

• A clear, straw colored fluid

• What percent of plasma is water?

• What’s in plasma? Dissolved gasses Vitamins Minerals Salts Nutrients

Enzymes Hormones Waste products Plasma proteins

90%Buffy coat leukocytesand platelets(<1% of whole blood)

Erythrocytes(45% of whole blood)

Plasma(55% of whole blood)

Formedelements

Layering of blood components in a centrifuged blood sample

Blood

The cellular components are:• red blood cells

(erythrocytes)• white blood cells

(leukocytes) • platelets

(thrombocytes) Blood cells are

formed in bonemarrow

Blood

BBLLOOOOD D

CCEELLLL

FFOORRMMA A TT IIOONN

Blood

Red Blood Cell CharacteristicsRed Blood Cell Characteristics• (RBC)- Erythrocyte(RBC)- Erythrocyte• Biconcave disksBiconcave disks• No nucleusNo nucleus• Contain the iron based pigment Contain the iron based pigment

hemoglobinhemoglobinwhich binds with oxygen to transport itwhich binds with oxygen to transport it

• Life span about 120 daysLife span about 120 days• 5 billion/1mL of blood = most numerous 5 billion/1mL of blood = most numerous • Are very smallAre very small

Blood

To the right is an artist's drawing showing the biconcave shape of the red blood cell.

To the right is a Wright's stained peripheral blood smear under 1000 X magnification.

The average size of a red blood cell is 7.2 micrometers in diameter.

Blood

How RBC’s transport oxygen....Hemoglobin .…the iron containing pigment

Hemoglobin makes red blood cells red

Blood

White Blood Cell Characteristics• (WBC)- Leukocyte• No definite shape• Have nucleus• Protect body against infection• Life span varies (3 days-a few

months)• 7,000/1mL of blood• Numbers increase if

infection is present• Larger than RBC’s

Blood

Types of white blood cells:• Monocytes are the

largest• Neutrophils are

the most numerous

• Lymphocytes are produced by the lymph tissue

• Basophils releasehistamines

Blood

Types of white blood cells:When a cell undergoes apoptosis, programmed cell death, white blood cells called macrophages consume cell debris.

The role of a macrophage is to phagocytize (engulf and then digest) cellular debris and pathogens.