Cellular Biology Presented by Susan L. Maiocco MSN, RN, APN LWW. (2009). Pathophysiology made...

LWW. (2009). Pathophysiology made incredibly easy. 4th ed. Philadelphia,PA:LWW

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Cellular Biology

Presented by Susan L. MaioccoMSN, RN, APN


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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


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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


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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


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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


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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


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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


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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


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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


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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


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Causes of Disease

• Intrinsic– Heredity traits– Age– Gender

• Extrinsic– Infectious agents or

behaviors• Inactivity• Smoking• Drug use

• Stressors– Physiologic– Psychological


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Disease Development

• Signs & symptoms– Increase or decrease in metabolism or cell division– Hypofunction• Constipation

– Hyperfunction• Increased mucous production

– Increased mechanical function• Seizure


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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

Cellular Biology Presented by Susan L. Maiocco MSN, RN, APN LWW. (2009). Pathophysiology made...

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