Blood Pressure

Blood pressure is the presssure that blood exerts against the walls of blood vessels. It is the main force that transports blood from the heart to the body parts.

***The pressure is highest in the arteries as they are nearest the heart. The force is greater when more blood flows through the vessel and when it is narrower.

Blood Pressure

Two measurements are taken for blood pressure:

Systolic pressure Diastolic pressure

- it is the maximum pressure - it is the minimum pressure during contraction of left during the relaxation of the left ventricle ventricle

Average: 120 mmHg (men) Average: 80 mmHg (men)

110 mmHg (women) 70 mmHg (women)

High Blood Pressure

High Blood Pressure

-Physical exercise *bp high to transport materials more

-Anxiety – stress rapidly to more active cells

-Hypertension *atherosclerosis cholesterol & fats accumulate

(medical problem of in the walls of arteries narrower arteries high blood pressure ) *salty food may increase blood volume

*nicotine, caffeine constricts arteries

Low Blood Pressure

*weakened heart can’t pump enough blood (defect in muscles or valves)

Hypotension *blocked coronary artery, heart infection, aging

*malnutrition –low protein diet (water lost from

capillaries)

The Vessels of a Capillary Bed

Starling Hypothesis

Starling Hypothesis

Starling Hypothesis

Pathways of Human Circulation

Pulmonary Circulation Systemic Circulation

Coronary Hepatic Portal Renal Circulation Circulation Circulation

carries blood between lungs and heart

adds oxygen and removes CO2 from the blood

begins in right ventricle and finishes in left atrium

Pulmonary Circulation

Pulmonary Circulation

Right ventricle

Left pulmonary arteriesPulmonary

arteries Right pulmonary arteries

Left lung

Right lung

Left atrium

Pulmonary veins

Left pulmonary capillaries

Right pulmonary capillaries

Left pulmonary veins

Right pulmonary veins

AortaRight Pulmonary Artery

Left Pulmonary Artery

Right Pulmonar

y Vein

Left Pulmonar

y Vein

Superior Vena Cava

Inferior Vena Cava

CO2

O2

Gas Exchange

CO2

O2

Gas Exchange

Systemic Circulation

- carries blood between heart and the rest of the body

- begins from the left ventricle, ends in the right atrium

Systemic Circulation

Left ventricle

Arteries Aorta Arterioles

Right atrium

Vena cava

Body capillaries

Venules Veins

CO2 O2

CO2 O2

CO2

O2

Gas Exchange

CO2

O2

Gas Exchange

CO2 O2

CO2 O2

Pulmonary circulation adds _____________ and removes _____________ from the blood. Blood returning to the heart from the body tissues is low in oxygen and high in carbon dioxide. This blood enters the _____________ and flows into the _____________. This chamber of the heart pumps it through the _____________ arteries to the lungs. These are the only _____________ that carry _____________ blood. All other _____________ carry _____________ blood. As the blood travels through the capillaries in the lungs, it gains _____________ and gets rid of _____________. The pulmonary capillaries merge into pulmonary veins. These veins carry the _____________ blood to the _____________ of the heart. The _______________ are the only _____________ that carry oxygen-rich blood. All other _____________ carry oxygen-poor blood.

oxygencarbon dioxide

right atriumright ventriclepulmonary

arteries oxygen-poorarteries oxygen-rich

oxygencarbon dioxide

oxygen-richleft atrium pulmonary veins

veinsveins

From the _____________ the blood enters the _____________. Systemic circulation begins in the _____________ of the heart. From here the blood is pumped into the _____________. It branches forming arteries that serve all parts of the body. The arteries divide into arterioles an finally into _____________. These tiny blood vessels are the sites for _____________ and _____________ exchange between the blood and body cells. Capillaries merge to form veins. These veins finally return the blood to the heart. The largest veins of the body are: the _________________ which returns blood from the upper parts of the body, and ________________ which returns blood from the lower parts of the body.

left atriumleft ventricleleft ventricle

aorta

capillariesoxygen carbon dioxide

superior vena cava

inferior vena cava

Coronary Circulation

Right coronary artery

Aorta Right atrium Left coronary

artery

Coronary capillaries

Right coronary veins

Left coronary veins

• Coronary circulation supplies blood to the muscle of the heart.

Hepatic Portal Circulation

Hepatic portal circulation helps to maintain balance of glucose in the blood.

As blood passes through the liver excess glucose molecules are absorbed by liver cells; and converted into glycogen.

If the amount of glucose is less in blood then liver converts glycogen into glucose that diffuse into blood.

Hepatic Portal Circulation

Capillaries in small

intestinePortal vein Venules Hepatic

sinuses

Hepatic veinsInferior vena cava

Right atrium

*Hepatic portal circulation is the only circulation that capillaries (hepatic sinuses) are found between veins.

Renal Circulation

• It is the branch of the systemic circulation that carries blood to and from kidneys.

• blood transports nitrogenous wastes (urea) to the kidneys for excretion