40.4 Blood Flow and Blood Pressure Regulation

The tunica intima is a single layer of cells.

stolic blood pressure is the amount of pressure on vessels when the heart is beating.

The optimal blood pressure is 120mmHg.
The pressure in the vessels between the heartbeats is known as diastolic blood pressure.
The ideal blood pressure is 80mmHg.
hormones, stress, exercise, eating, sitting, and standing are some of the factors that can affect blood pressure.
Blood flow through the body is regulated by the size of blood vessels, the action of smooth muscle, and the fluid pressure of the blood itself.

The pumping heart pushes blood through the body.

Blood is pushed under high pressure and away from the heart by each pump.

The law of continuity states that fluid should travel faster through a narrower tube if the diameter of the arteriole and capillary is less than the diameter of the aorta.

The slow rate of travel through the capillary beds, which reach almost every cell in the body, assists with gas and nutrient exchange and also promotes the dispersal of fluid into the interstitial space.

The rate of flow increases after the blood has passed through the capillary beds, but is still slower than in the aorta.
Blood moves in the veins by the movement of smooth muscle in the vessel wall and by the action of the skeletal muscle as the body moves.
One-way valves prevent blood from flowing backward in the veins because most veins have to move blood against the pull of gravity.
It is important to get up and move frequently after a long period of sitting so that blood won't pool in the limbs.

Nerve and hormone signals are used to regulate blood flow through the capillary beds.

Most of the blood goes to the stomach after a large meal because of the constriction of other vessels.

During exercise, blood is diverted to the muscles of the body through a process called vasodilation.

The muscles allow the body to control capillary beds.

Only a small percentage of our capillary beds have blood flowing through them.

There are veins on the legs.

You can see the blood flow.

There are large solutes that cannot leave the capillaries.

A hyperosmotic solution is created by the loss of the watery plasma.
This causes a lot of the blood to leave the capillaries and go to the venules.
The rest of the blood is taken out of the interstitial fluid into the nearby lymphatic vessels.
The fluid in the lymph is similar to the fluid in the interstitial fluid.
The vena cava is used to return the fluid to the heart.
The white blood cells remove infectious agents from the body before they can return to the bloodstream.
The blood returns to the heart after it is cleaned by the action of smooth muscle pumping, skeletal muscle action, and one-way valves.

The fluid from the capillaries moves into the space through the use of a pressure gradient and Osmosis.

A day's worth of fluid pumped by the average heart is over 1,500 liters.

Different animals may have different amounts of pressure, organ and vessel location, and organ size in their blood circulation.

Animals with longs necks and those that live in cold climates have different blood pressures.

giraffes need to pump blood upward from the heart against gravity.

To reach the height of a giraffe's head, which is 2.5 meters higher than the heart, the left ventricle needs to be pumped with a blood pressure equivalent to 250mm Hg.
The giraffe's brain would be damaged if checks and balances were not in place.
There are valves and feedback mechanisms that reduce the rate of cardiac output.
The sauropods had to pump blood up to ten meters above the heart.
It would have required a blood pressure of more than 600mm Hg, which was achieved by an enormous heart.
There is no evidence for an enormous heart and there are mechanisms to reduce blood pressure.
It is likely that they grazed on the ground.

Living in cold water whales need to keep their temperature in their blood.

The veins and arteries are close together so that heat can be exchanged.
The countercurrent heat exchanger is a mechanism.
Thick layers of blubber protect the blood vessels and the whole body from heat loss.
In land animals that live in cold environments, thick fur and hibernation are used to retain heat and slow metabolism.

The pressure of the blood flow in the body is produced by the pressure of the fluid against the walls of the blood vessels.

The fluid will move from high to low pressures.
The arterioles are narrow and the rate of flow is slowed by the high pressure near the heart.

When new blood enters the arteries, the walls of the arteries stretch to accommodate the increased pressure of the blood; during diastole, the walls return to normal because of their elastic properties.

120/80 indicates a reading of 120mm Hg during the systole and 80mm Hg during the diastole.
The arterioles are empty at a relatively even rate throughout the cardiac cycle.

The blood pressure in the arteries is related to the blood pressure in the arterioles.

The blood pressure is decreasing in the veins but increasing in the capillaries.

The volume of blood pumped by the heart is called cardiac output.

Increasing heart rate can increase cardiac output.

If the heart contracts with greater strength, it can be increased by increasing stroke volume.

Speeding blood circulation through the body can increase stroke volume.

During heavy exertion, the blood vessels relax and increase in diameter, offsetting the increased heart rate and ensuring adequate oxygenated blood gets to the muscles.
Increasing blood pressure is caused by a decrease in the diameter of the blood vessels.
Nerve signals and hormones can cause these changes, and even standing up or lying down can have an effect on blood pressure.

The circulatory system is used in most animals.

90 percent of the blood is in the body.
Some primitive animals use water along with various substances to exchange water, nutrients, and gases.

The circulatory system of the blood is used by complex organisms.

The heart and blood fluid can be separated from the interstitial fluid.

There are significant differences in the structure of the circulatory system between the three divisions of the heart muscle.

Due to adaptions during evolution, there is one heart on the right side and one on the left side.

The function of the fish's two heart is cardiomyocytes.

They have double circulation because of the mixing of the blood.

Non-avian reptiles have a three-chambered heart, but it is located near the wall of the right atrium, which is where most internal pacemaker starts.
They have double circulation and electrical charges little mixing of the blood.

A pause in the 40.2 components of the Blood electric signal allows the atria to empty completely into the ventricles.

The specific components of the blood include red blood cells, blood from the heart is carried through the body by white blood cells, platelets, and the plasma, which contains complex network of blood vessels.
Veins bring blood back to the heart.

It also contains components for blood clotting.

Red blood cells are specialized cells that move through the body by the movement of smooth muscle in the vessel wall and the delivery of oxygen to them.
White blood cells are involved in the movement of the body.
Blood is the immune response to invading organisms that are prevented from flowing backward in the veins by one-waybacteria, viruses, and other foreign organisms.

The arteries return to hormone signals during diastole.

Lymph vessels take fluid that has leaked.
The blood pressure of the systole phase and the out of the blood to the lymph nodes give the two pressure readings for blood before it returns to the heart.

There is blood in the vein.

The left ventricle is separated from the b by the mitral valve.

The inferior vena cava has blood in it.

The blood leaves the bicuspid valve and goes to the left d.

There are veins on the legs.

They use less energy.

The animal is helped to move faster.

The above system is not used by some animals.

90 percent of the heart is called _____.

High blood pressure is a result.