Anatomy Chapter 3 Homeostatic Imbalances
Chapter 3
Homeostatic Imbalances
3.1
Definite changes occur in the glycocalyx of a cell that is becoming cancerous. In fact, a cancer cell's glycocalyx may change almost continuously, allowing it to keep ahead of immune system recognition mechanisms and avoid destruction. (Cancer is discussed on pp. 145-146)
3.2
Selective permeability is a characteristics of healthy, intact cells. When a cell (or its plasma membrane) is severely damaged, the membrane becomes permeable to virtually everything, and substances flow into and out of the cell freely. This phenomenon is evident when someone has been severely burned. Precious fluids, proteins, and ions "weep" from the damaged cells.
3.3
Hypertonic solutions are sometimes infused intravenously into the bloodstream of patients who are edematous (swollen because their tissues retain water). This is done to draw excess water out of the extracellular space and move it into the bloodstream so the kidneys can eliminate it. Hypotonic solutions may be used (with care) to rehydrate the tissues of extremely dehydrated patients. In mild cases of dehydration, drinking hypotonic fluids (such as apple juice and sports drinks) usually does the trick.
3.4
Lysosomes degrade glycogen and certain lipids in the brain at a relatively constant rate. In Tay-Sachs disease, an inherited condition seen mostly in Jews from Central Europe, the lysosomes lack an enzyme needed to breakdown a glycolipid abundant in nerve cell membranes. As a result, the nerve cell lysosomes sweel with undigested lipids, which interfere with nervous system functioning. Affected infants typically have doll-like features and pink translucent skin. At 3 to 6 months of age, the first symptoms progress to mental retardation, seizures, blindness, and ultimately death within 18 months.
Clinical Terms
1. Anaplasia- abnormalities in cell structure and loss of differentiation: for example, cancer cells typically lose the appearance of the parent cells and come to
Homeostatic Imbalances
3.1
Definite changes occur in the glycocalyx of a cell that is becoming cancerous. In fact, a cancer cell's glycocalyx may change almost continuously, allowing it to keep ahead of immune system recognition mechanisms and avoid destruction. (Cancer is discussed on pp. 145-146)
3.2
Selective permeability is a characteristics of healthy, intact cells. When a cell (or its plasma membrane) is severely damaged, the membrane becomes permeable to virtually everything, and substances flow into and out of the cell freely. This phenomenon is evident when someone has been severely burned. Precious fluids, proteins, and ions "weep" from the damaged cells.
3.3
Hypertonic solutions are sometimes infused intravenously into the bloodstream of patients who are edematous (swollen because their tissues retain water). This is done to draw excess water out of the extracellular space and move it into the bloodstream so the kidneys can eliminate it. Hypotonic solutions may be used (with care) to rehydrate the tissues of extremely dehydrated patients. In mild cases of dehydration, drinking hypotonic fluids (such as apple juice and sports drinks) usually does the trick.
3.4
Lysosomes degrade glycogen and certain lipids in the brain at a relatively constant rate. In Tay-Sachs disease, an inherited condition seen mostly in Jews from Central Europe, the lysosomes lack an enzyme needed to breakdown a glycolipid abundant in nerve cell membranes. As a result, the nerve cell lysosomes sweel with undigested lipids, which interfere with nervous system functioning. Affected infants typically have doll-like features and pink translucent skin. At 3 to 6 months of age, the first symptoms progress to mental retardation, seizures, blindness, and ultimately death within 18 months.
Clinical Terms
1. Anaplasia- abnormalities in cell structure and loss of differentiation: for example, cancer cells typically lose the appearance of the parent cells and come to