Cellular Regulation

Question 1

Water percentages

Answer 1

Adult bodies: 50-65% water
Child bodies: 75%
*Children are most susceptible to dehydration

Question 2

Cell membrane

Answer 2

Protects, serves as a boundary, regulates material coming in and out of the cell

Question 3

Ribosomes

Answer 3

Made of RNA and assist in the production of enzymes and other proteins needed for cell repair and reproduction

Question 4

Cytoplasm

Answer 4

The internal environment of the cell that is a watery soup of proteins, nucleic acids, gasses, salts, etc.; surrounds and protects the cell

Question 5

Nucleus

Answer 5

The control center or “brain” of the cell; contains the DNA of the cell

Question 6

Nucleolus

Answer 6

Found within the nucleus; synthesizes RNA that forms ribosomes

Question 7

Endoplasmic Reticulum

Answer 7

“Transport system”: series of channels in the cytoplasm
Rough ER: has ribosomes; responsible for synthesis of proteins
Smooth ER: no ribosomes, synthesizes lipids and steroids

Question 8

Mitochondria

Answer 8

Creates energy from food into ATP molecules; supplies 95% of the body’s energy needed for cell repair, movement, and reproduction

Question 9

Golgi Apparatus

Answer 9

Sorts and correctly ships the proteins produced in the ER; “packaging and sorting system”

Question 10

Lysosomes

Answer 10

“Digestive system” of the cell: breaks down large molecules into smaller pieces that the cell can use, clean up intracellular waste, and destroy unwanted bacteria through phagocytosis

Question 11

Atrophy

Answer 11

Reduction in the size of the cell

Question 12

Hypertrophy

Answer 12

Enlargement of the cell to an increased workload

Question 13

Hyperplasia

Answer 13

Increase in cell number due to an increased rate of cellular division

Question 14

Metaplasia

Answer 14

Replacement of one mature cell with another less mature cell type

Question 15

Ex causes of atrophy

Answer 15

Happens from disuse, nutritional deprivation, decreased hormonal stimulation, aging, denervation pressure

Question 16

Ex causes of hypertrophy

Answer 16

Mechanical signals: stretch

Trophic signals: growth factors, hormones, and vasoactive agents (eg uterine growth)

Question 17

Ex causes of hyperplasia

Answer 17

Hormonal: occurs in estrogen-dependent organs (eg uterus and breast)
Compensatory: mechanism that allows certain organs to regenerate (eg liver hepatocytes)

Question 18

Dysplasia

Answer 18

Deranged cell growth of specific tissue results in abnormal size, shape, and appearance (eg cervical precancer and cancer r/t HPV)

Question 19

When does cellular injury occur?

Answer 19

When the cell is unable to maintain homeostasis

Question 20

How do all forms of disease begin?

Answer 20

With alterations to cell

Question 21

Cellular injury causes

Answer 21

Physical injury: trauma, UV radiation
Toxic injury: external (eg smog) or internal
Infectious injury: bacteria, fungi, viruses, parasites
Hypoxic Injury: anemia, decreased perfusion, hypoxia, ischemia
Deficiency injury: nutrition and hydration

Question 22

How long can skeletal muscles vs the heart tolerate ischemia?

Answer 22

Skeletal muscles: 2-3 hrs

Heart: 20 mins

Question 23

What are liver cells susceptible to?

Answer 23

Chemical injury (eg tylenol and OTC cold meds)

Question 24

Free Radicals

Answer 24

AKA Reactive Oxygen Species
Unpaired electron; highly unstable and reactive; will try to steal an electron from another molecule, thereby causing a chain reaction (another molecule becomes a free radical)

Question 25

Initiation of free radicals

Answer 25

1) Absorption of extreme energy sources (eg UV light) 2) Endogenous reactions when oxygen is reduced to water (eg cell growth and proliferation) 3) Enzymatic metabolism (eg cigarette smoke and alcohol)

Question 26

Ex of free radical damage

Answer 26

Lipid peroxidation: destruction of polyunsaturated lipids leading to membrane damage and increased permeability Protein alterations: causing fragmentation of poly peptide chains DNA fragmentation: causing decreased protein synthesis Mitochondrial damage: causing liberation of calcium into the cytosol

Question 27

Ways of terminating free radicals

Answer 27

Antioxidant enzymes: block synthesis of free radicals Endogenous: Catalaste, superoxide dismutase (SOD) Exogenous: vitamin E

Question 28

Necrosis

Answer 28

Sum of cellular changes after local cell death and the process of cellular self-digestion

Question 29

Fat necrosis

Answer 29

Cellular dissolution caused by powerful enzymes (called lipases) that occur in the breast, pancreas, and other abdominal structures

Question 30

Coagulative necrosis

Answer 30

Occurs primarily in the kidneys, heart, and adrenal glands; commonly results from hypoxia caused by severe ischemia or hypoxia from chemical injury; Coagulation is caused by protein denaturation, which causes the protein albumin to change from a gelatinous, transparent state to a firm, opaque state

Question 31

Liquefactive necrosis

Answer 31

Commonly results from ischemic injury to neurons and glial cells in the brain; cells are digested by their own hydrolases, so the tissue becomes soft, liquefies, and segregates from healthy tissue, forming cysts

Question 32

Caseous necrosis

Answer 32

Usually results from tuberculous pulmonary infection; tissue resemble clumped cheese in that they are soft and granular; a granulomatous inflammatory wall encloses areas of caseous necrosis

Question 33

Necrosis: gangrene

Answer 33

Results from severe hypoxic injury, commonly occurring because of arteriosclerosis, or blockage, of major arteries, in particular those of the lower extremities (PVD)

Question 34

Gaseous gangrene

Answer 34

Caused by infection of injured tissue by one of many species of Clostridium; produces hydrolytic enzymes and toxins that destroy connective tissue and cellular membranes; leads to gas bubbles to form in muscles cells

Question 35

Wet gangrene

Answer 35

Develops when neutrophils invade the site, causing liquefactive necrosis (diabetic ulcer)

Question 36

Dry gangrene

Answer 36

Usually the result of coagulative necrosis; the skin becomes very dry and shrinks, resulting in wrinkles, and its color changes to dark brown or black

Question 37

Apoptosis

Answer 37

Programmed cell death and is implicated in both normal and pathologic tissue changes (cells need to die in order for people not to became huge; the avg adult creates 10 billion new cells every day—and destroy the same number)

Question 38

Final step of apoptosis

Answer 38

WBC eats apoptic bodies (phagocytosis)