Unit 4 Concept Part 1

ways blood plays critical role in maintaining homeostasis

transport, regulation, protection

transport

oxygen from lungs and nutrients from digestive tract to body, remove cell waste and endocrine hormones

regulation

body temp, pH, and fluid volume

protection

prevent blood loss; carry antibodies and white blood cells to infected tissues

Components of Blood

red blood cells, white blood cells, platelets, and plasma

Plasma

main component of blood and consists mostly of water, with proteins, ions, nutrients, and wastes mixed in

Platelets

responsible for blood clotting

White blood cells

part of immune system and function in immune response

Red Blood Cell Shape

biconcave discs that maximize surface area for oxygen and carbon dioxide transport

Hematopoiesis

blood cell formation in bone marrow, connected to circulatory and immune systems

Step 1 Hematopoiesis: Vascular Spasms

blood vessels constrict to slow blood loss

Step 2 Hematopoiesis: Platelet plug formation

platelets stick together to plug break

Step 3 Hematopoiesis: Coagulation

enzymatic process requiring clotting factors and Ca2+

Step 4 Hematopoiesis: Clot retraction and repair

platelets pull on fibrin making them contract (makes damaged vessel edges come closer together for healing)

Step 5 Hematopoiesis: Fibrinolysis

after vessel repaired, clot broken down by enzyme called plasmin

Contributes to Dif Blood Types

antigens on RBCs - foreign substances trigger immune response; safe transfusions depend on careful blood typing and cross-matching

Wrong Blood Type During Transfusion

causes immune reaction, potential lead to severe complications or death

Cardiovascular System

transport blood, nutrients, gases, and waste; composed of heart, veins, arteries, and capillaries

Factors: Resistance to Blood Flow

Blood viscosity, Vessel length, Vessel diameter

Blood Pathway

Blood is oxygen-poor in the veins returning from the body and becomes oxygen-rich in the lungs.