(59-6-7) What is a regulatory function of blood and Know the functions of the blood and Know the elements of the blood 18.1 Functions and General Composition of Blood & 18.1a Functions of Blood

What is characterized as a protective function of blood?

- Bloodloss prevention

Capillaries

- are permeable, microscopic vessels between arteries and veins. - serve as the sites of exchange between the blood and body tissues; it is from our capillaries that oxygen and nutrients exit the blood, and carbon dioxide and cellular wastes enter the blood.

Leukocytes

- contribute to defending the body against pathogens

Erythrocytes

- function to transport respiratory gases in the blood.

platelets

- help clot the blood and prevent blood loss from damaged vessels.

Blood

- is composed of *formed elements (erythrocytes, leukocytes, and platelets) and plasma* - Fluid connective tissue - Regenerated continuously - Losing too much, fatal - Responsible for transporting gases, nutrients, and hormones - Ever changing composition

Plasma

- is the fluid portion of blood containing plasma proteins and dissolved solutes.

Arteries

- transport blood away from the heart,

Veins

- transport blood toward the heart.

cardiovascular system

- which is composed of the heart (cardio) and blood vessels (vascular).

platelets and plasma proteins

Components of blood, including ____________, also protects the body against blood loss

Protection

One of the 3 function of blood - Blood contains leukocytes, plasma proteins, and various molecules that help protect the body against potentially harmful substances. - These substances are part of the immune system that is described in detail in chapter 22. Components of blood, including platelets and plasma proteins, also protect the body against blood loss, as described later in this chapter.

Transportation

One of the 3 function of blood - Blood transports formed elements and dissolved molecules and ions throughout the body. - Consider that as blood is transported through the blood vessels it carries oxygen from and carbon dioxide to the lungs, nutrients absorbed from the gastrointestinal tract, hormones released by endocrine glands, and heat and waste products from the systemic cells. - Even when you take a medication, it is the blood that delivers it to the cells of your body. Thus, it is the blood that serves as the "delivery system" for the body.

Regulation

One of the 3 function of blood Blood participates in the regulation of body temperature, body pH, and fluid balance: - *Regulates body temperature* • absorbs heat from body cells • released from blood at body surface - as blood transported through vessels of the skin - *Regulates body pH* • absorbs acids and base from body cells • contains chemical buffers that bind and release hydrogen ions) - *Regulates fluid balance* • water added to blood from GI tract • water lost in urine, skin • exchange of fluid between blood plasma and interstitial fluid • contains proteins and ions - exert osmotic pressure - pulls fluid back into capillaries