Cellular Biology Presented by Susan L. Maiocco MSN, RN, APN LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 1

Cell Structure Cytoplasm – Surrounds and protects the nucleus Cell Membrane – The border of the cell – Protects the cell and transport material – Maintains the cell’s electrical activities that power cell function LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 2

Cell Structure and Function Mitochondrion – Gives the cell energy Nucleus – The brain of the cell – Responsible for cellular reproduction and division – Stores DNA Ribosome – Protein synthesis Organelles – In the cytoplasm – Principal part – Surrounded by cell membrane Lysosome – The cell’s digestive system – Cytoplasmic digestion Golgi Apparatus – Holds enzyme systems – Assist in cell’s metabolism LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 3

Phases of Mitosis Prophase – Chromosomes coil & shorten – Nuclear membrane dissolves – Chromatids connect to a centromere Metaphase – Centromeres divide pulling chromosomes apart and align the spindle LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 4

Mitosis (con’t) Anaphase – Centromeres separate and pull new replicated chromosomes to the opposite sides of the cell – Result 46 chromosomes on each side of cell Telephase – Final phase – New membrane forms around 46 chromosomes through cytokinesis – Produces 2 identical new cells LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 5

Cell Adaptation Cell faces number of challenges Continue functioning despite challenges Prolonged stress or changes may kill or destroy cells When cell integrity is threatened, cell draws in its reserves to keep functioning – Adaptive changes – Cellular dysfunction Cell will die if reserve is insufficient LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 6

Cell Adaptation Atrophy – Reversible reduction in size of the cell Hypertrophy – Increase in size of a cell due to an increased workload Hyperplasia – Increase in the number of cells Metaplasia – Replacement of one adult cell with another adult cell that can better endure change or stress Dysplasia – Deranged cell growth of specific tissue results in abnormal size, shape, & appearance – May precede cancerous changes LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 7

Types of Cell Injury Toxic injury – Endogenous metabolic errors – Gross malformations – Hypersensitivity reactions – Exogenous Alcohol Lead Carbon monoxide Drugs Infectious injury – Viruses – Fungi – Protozoa – Bacteria Physical injury – Thermal Electrical Radiation Mechanical – trauma – surgery – Deficit injury Lack of basic requirement LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 8

Maintaining Homeostasis Regulators – Medulla – Pituitary gland – Reticular formation Feedback mechanisms that maintain homeostasis – Negative mechanism Senses change and returns it to normal – Positive mechanism Exaggerates change LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 9

Differentiating Disease and Illness Disease Occurs when homeostasis is not maintained Influenced by genetic factors, unhealthy behaviors, personality type, & perception of the disease Manifests in various ways depending on patient’s environment Illness Occurs when a person is no longer in a state of “normal” health Enables a person’s body to adapt to the disease LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 10

Causes of Disease Intrinsic – Heredity traits – Age – Gender Extrinsic – Infectious agents or behaviors Inactivity Smoking Drug use Stressors – Physiologic – Psychological LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 11

Disease Development Signs & symptoms – Increase or decrease in metabolism or cell division – Hypofunction Constipation – Hyperfunction Increased mucous production – Increased mechanical function Seizure LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 12

Disease Stages Exposure/injury Incubation period—organisms growing and multiplying Prodromal stage—person is most infectious, vague and nonspecific signs of disease Full stage of illness—presence of specific signs and symptoms of disease Convalescent period—recovery from the infection Recovery LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW 13