Week 1: Intro to Patho and Cellular Stress and Injury

Pathophysiology

The study of what happens when normal anatomy and physiology are altered, causing disease or abnormal states. It is the "why" behind patient symptoms and nursing care.

Health

The absence of disease, including wellness of the mind, body, and spirit.

Disease

A disorder of structure or function that produces specific signs or symptoms and is not simply a direct result of physical injury.

Acute Disease

A disease with a short duration and rapid onset.

Chronic Disease

A disease with a prolonged duration; may be manageable but not necessarily curable.

Clinical Manifestations

The clinical effects or evidence of a disease (e.g., signs and symptoms).

Etiology

The cause of a disease.

Iatrogenic

An unintended effect resulting from medical treatment.

Idiopathic

A disease of unknown cause.

Homeostasis

The body's state of equilibrium, balance, and stability, maintained through self-regulating compensatory mechanisms.

Negative Feedback

A regulatory mechanism that counteracts a change to return to a set point (e.g., thermostat, blood sugar regulation).

Positive Feedback

A regulatory mechanism that amplifies the original stressor (e.g., childbirth contractions).

Cellular Injury

Occurs when a cell is unable to maintain homeostasis in the face of a stressor. The severity depends on the injury and factors like blood supply.

Atrophy

A cellular adaptation involving a decrease in the size of cells, leading to a smaller organ.

Hypertrophy

A cellular adaptation involving an increase in the size of cells, leading to a larger organ (e.g., heart from increased workload).

Hyperplasia

A cellular adaptation involving an increase in the number of cells in a tissue (e.g., epidermis, glandular tissue).

Dysplasia

A cellular adaptation involving deranged cell growth with varied size, shape, and organization. It is abnormal but can be reversible and is a potential cancer precursor.

Apoptosis

Genetically programmed cell death; a normal, degenerative process (e.g., ovarian changes during menopause).

Necrosis

Irreversible cell death involving membrane disintegration and lysis, which triggers an inflammatory response; not normal.

Inflammation

The body's response to tissue disruption (injury, ischemia, immune reaction), characterized by vascular changes (vasodilation, permeability) and cellular changes (phagocytosis).

Local Effects of Inflammation

Redness, warmth, swelling, pain, and loss of function at the site of injury.

Systemic Effects of Inflammation

Fever, leukocytosis (high white blood cell count), malaise, anorexia, and potentially sepsis.

Cellular Healing: Regeneration

The process of restoring damaged tissue to its original structure and function; depends on the cell type and is facilitated by rapid correction of the injury.

Primary Cause of Muscle Wasting in a Chronically Ill Patient

Cellular Atrophy, due to factors like disuse, poor nutrition, or chronic disease.

Essential Mechanism for Maintaining Homeostasis During Fluid Loss

Increased thirst sensation, which drives fluid intake to correct dehydration.

Physiological Response in a Negative Feedback Loop for High Body Temperature

Sweating to cool the body through evaporation.