同济大学：《病理学》课程教学资源（教案讲义）Chapter 01 Adaptation and Injury of Cell and Tissue（Adaptation of Cell and Tissue）

PART 1 Adaptation of Cell and Tissue

Adaptation of Cell and Tissue

Homeostasis (normal cells) o The normal cell is a highly complex unit in which the various organelles and enzyme systems continuously carry out the metabolic activities that maintain cell viability and support its normal functions. Normal function is dependent on: Dthe immediate environment of the cell; 2a continuous supply of nutrients such as oxygen, glucose,and amino acids; 3constant removal of the products of metabolism, including CO2

Homeostasis (normal cells)  The normal cell is a highly complex unit in which the various organelles and enzyme systems continuously carry out the metabolic activities that maintain cell viability and support its normal functions.  Normal function is dependent on: ①the immediate environment of the cell; ②a continuous supply of nutrients such as oxygen, glucose, and amino acids; ③constant removal of the products of metabolism, including CO2

NORMAL CELL REVERSIBLE (homeostasis) INJURY Stress Injurious Mild, stimulus transient ADAPTATION CELL INJURY Inability to adapt Severe, progressive IRREVERSIBLE INJURY CELL NE CROSIS DEATH APOPTOSIS

Adaptations of Cell and Tissue Adaptations of cells are reversible changes in number, size,phenotype (morphology),metabolic activities or functions in response to changes in environment o It reflects cell's adjustment to the stress before reaching a new equilibrium (homeostasis) Mainly,include Atrophy,Hypertrophy,Hyperplasia and Metaplasia

Adaptations of Cell and Tissue  Adaptations of cells are reversible changes in number, size, phenotype (morphology), metabolic activities or functions in response to changes in environment  It reflects cell’s adjustment to the stress before reaching a new equilibrium (homeostasis)  Mainly, include Atrophy, Hypertrophy, Hyperplasia and Metaplasia

√Atrophy o Decrease in cell size and/or decrease in cell numbers,resulting in decrease in size and weight of a tissue or organ. Distinct from agenesis,aplasia and hypoplasia. Physiological (developmental)vs pathologic atrophy

 Atrophy  Decrease in cell size and/or decrease in cell numbers, resulting in decrease in size and weight of a tissue or organ.  Distinct from agenesis, aplasia and hypoplasia.  Physiological (developmental) vs pathologic atrophy

Physiologic Atrophy o A good example is that of endometrium and breast which occurs with menopause and the loss of estrogen stimulation. o Uterine involution Thymic atrophy after puberty In the aging process,atrophy may be a normal morphologic changes,e.g.the brain and heart

Physiologic Atrophy  A good example is that of endometrium and breast which occurs with menopause and the loss of estrogen stimulation.  Uterine involution  Thymic atrophy after puberty  In the aging process, atrophy may be a normal morphologic changes, e.g. the brain and heart

Pathologic Atrophy Atrophy of Disuse o Denervation Atrophy Atrophy Due to Loss of Trophic Hormones Atrophy Due to Lack of Nutrients Pressure Atrophy o Ischemic atrophy

Pathologic Atrophy  Atrophy of Disuse  Denervation Atrophy  Atrophy Due to Loss of Trophic Hormones  Atrophy Due to Lack of Nutrients  Pressure Atrophy  Ischemic atrophy

Atrophy of Disuse Metatarsal o Skeletal muscle atrophies rapidly with fracture disuse. 骨质疏松 ⊙ Osteoporosis of disuse. 正常的骨基贸 骨質疏鬆 Normal bone matrix Osteoporosis Give an another example?

Atrophy of Disuse  Skeletal muscle atrophies rapidly with disuse.  Osteoporosis of disuse.  Give an another example? Metatarsal fracture

Denervation Atrophy Damage to the motor neuron in the anterior horn of spinal cord leads to rapid atrophy of the muscle fibers supplied by that nerve in polio patients Give an another example? Poliomyelitis

Denervation Atrophy  Damage to the motor neuron in the anterior horn of spinal cord leads to rapid atrophy of the muscle fibers supplied by that nerve in polio patients.  Give an another example? Poliomyelitis

Atrophy Due to Loss of Trophic Hormones o Pituitary disease associated with decreased secretion of pituitary trophic hormones results in atrophy of the thyroid, adrenals,and gonads.(Simmonds' disease) Give an another example?

Atrophy Due to Loss of Trophic Hormones  Pituitary disease associated with decreased secretion of pituitary trophic hormones results in atrophy of the thyroid, adrenals, and gonads. (Simmonds’ disease)  Give an another example?