NRTI 2000
Chapter 3 Notes
The Body’s Cells:
● Body is composed of trillions of cells
● Body needs nutrients
● Cells - the smallest units in which independent life can exist
○ Depend on one another
○ Basic needs (energy, oxygen, and water)
● Cells die at varying rates
Genes Control Functions:
● Direct production of proteins such as enzymes and structural proteins.
● Provide instruction for strictional components of cells
● Affects the way the body handles nutrients
● Gene variations
○ Inborn error of metabolism: genetic variation present from birth that can
result in disease.
● Phenylketonuria (PKU) - inborn error of metabolism that interferes the digestion
of proteins.
Cells, Tissues, Organs, and Systems:
● Cells are organized into tissues that perform specialized tasks.
● Tissues are grouped together to form organs.
, ● Organs work together as part of a body system.
Body Fluids and Circulatory Systems:
● Body fluids
○ Supply energy, oxygen, nutrients, and water to tissues.
● Circulating fluids
○ Blood
○ Travels within arteries, veins, capillaries
○ Plasma - cell free
● Lymph
○ Fluid that moves from the bloodstream into tissue and then into the
vessels.
○ Think Fat.
● Aorta
○ Channels blood from the heart to tissue
● Lungs
○ Oxygenate blood, remove co2 from blood, and return to the heart.
● Heart
○ Right side pumps blood to the lungs and the left side pumps oxygenated
blood to the body.
● Liver
○ Filters toxins from blood, stores, transforms, and mobilizes nutrients.
● Intestines
○ Absorbs nutrients