Chapter 17.1 and 17.2 part 1 Flashcards
Definition blood
Life-sustaining transport vehicle of the cardiovascular system
Functions of blood (3)
- Transport
- Regulation
- Protection
Transport functions
- Delivering O2 and nutrients to body cells
- Transporting metabolic wastes to lungs and kidneys for elimination
- Transporting hormones from endocrine organs to target organs
Regulation functions
- Maintaining body temperature by absorbing and distributing heat
- Mainaining normal pH using buffers; alkaline reserve or bicarbonate ions
- Maintaining adequate fluid volume in circulatory system
Protection functions
- Preventing blood loss
- Preventing infection
What is the composition of blood?
Plasma and formed elements
What is plasma
Matrix of nonliving fluid
What are formed elements?
Living cells in blood;
- Erythrocytes (red blood cells)
- Leukocytes (white blood cells)
- Platelets (thrombocytes)
Where does plasma consist of?
Water, Salts, Proteins, substances transported by blood
What is hematocrit?
percent of blood volume that is RBCs (47% male, 42% female)
Physical characteristics blood
sticky, opaque fluid with metallic taste
High O2 scarlet red, low O2 dark red
8% body weight
pH 7.35-7.45
What is the average volume of blood?
Male: 5-6 L
Female: 4-5 L
What is the function of albumin?
Carrier of other molecules, blood buffer and contributes to plasma osmotic pressure
What are plasma proteins?
Albumin, Globulins (alpha, beta and gamma), fibrinogen
What are nutrients?
Materials absorbed from digestive tract and transported for use throughout body
What are platelets?
Cell fragments for blood clotting
What do RBCs miss?
They have no nuclei or other organelles
How long do formed elements survive in the bloodstream?
only a few days
What are structural characteristics of eythrocytes?
- small diameter (7.5 um), larger than some capillaries
- Biconcave disc shape, anucleate and no organelles
- Filled with hemoglobin
- plasma membrane protein spectrin
What is the use of spectrin?
Provides flexibility to change shape
Where is the biconcave shape for?
Offers huge surface area relative to volume for gas exchange
How works the ATP production in RBCs?
No mitochondria, so anaerobic
What is the function of hemoglobin?
Binds reversibly with oxygen
Where does hemoglobin consists of?
Heme pigment: gives blood red color and eache heme’s central iron atom binds one O2
Globin: four polypeptide chains (two alpha and two beta chains)
