In order to cope with their environment, cells undergo structural and functional changes. These cellular adaptations are reversible responses that allow cells to survive and continue to adequately function. Adaptive processes consist of increased cellular size and function (hypertrophy), increase in cell number (hyperplasia), decrease in cell size and metabolic activity (atrophy), or a change in the phenotype Phenotype The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics of the cells (metaplasia). If the stress or stimulus is removed, the cell can return to its original state. However, when the limits of the adaptive responses are exceeded, cellular function is adversely affected, leading to cellular injury.
Last updated: 10 Feb, 2021
Adaptation:
Cross-section of a heart with left ventricular hypertrophy Ventricular Hypertrophy Tetralogy of Fallot: Note the thickened ventricular walls and associated reduced ventricular cavity.
Image: “Heart left ventricular hypertrophy Ventricular Hypertrophy Tetralogy of Fallot short axis Axis The second cervical vertebra. Vertebral Column: Anatomy view” by Patrick J. Lynch, medical illustrator. License: CC BY 2.5Illustration of the difference between hypertrophy (increase in size of cells) and hyperplasia (increase in number of cells)
Image by Lecturio.Normal prostate Prostate The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. Prostate, Seminal, and Bulbourethral Glands: Anatomy (left) and an enlarged prostate Prostate The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. Prostate, Seminal, and Bulbourethral Glands: Anatomy or benign Benign Fibroadenoma prostatic hyperplasia (right), which is associated with bladder Bladder A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination. Pyelonephritis and Perinephric Abscess outlet obstruction
Image: “ Benign Benign Fibroadenoma Prostatic Hyperplasia” by National Cancer Institute. License: Public DomainHistopathology of complex hyperplasia with atypia Atypia Fibrocystic Change: closely packed endometrial glands with sparse intervening stroma and stratification of the lining epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology. Epithelial cells show cytological atypia Atypia Fibrocystic Change with high nucleocytoplasmic ratio, irregular clumping of nuclear chromatin Chromatin The material of chromosomes. It is a complex of dna; histones; and nonhistone proteins found within the nucleus of a cell. DNA Types and Structure, and mitotic figures (hematoxylin and eosin stain, × 200).
Image: “Histopathology of complex hyperplasia with atypia Atypia Fibrocystic Change” by Shalinee Rao. License: CC BY 2.0Photos showing the hands and legs of
patients
Patients
Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.
Clinician–Patient Relationship with axonal sensorimotor
polyneuropathy
Polyneuropathy
Polyneuropathy is any disease process affecting the function of or causing damage to multiple nerves of the peripheral nervous system. There are numerous etiologies of polyneuropathy, most of which are systemic and the most common of which is diabetic neuropathy.
Polyneuropathy:
Hands, patient 1 (a) and 2 (b). Right
hand
Hand
The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves.
Hand: Anatomy shows severe, atrophied, intrinsic muscle and
flexion
Flexion
Examination of the Upper Limbs deformities of
interphalangeal joints
Interphalangeal joints
Hand: Anatomy.
Lower extremities, patient 1 (c) and 2 (d). Severe bilateral distal muscle atrophies with
ankle joint
Ankle joint
The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot.
deformities are observed in both
patients
Patients
Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.
Clinician–Patient Relationship.
Hematoxylin and eosin staining of the histopathology of Barrett’s
esophagus
Esophagus
The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part.
Esophagus: Anatomy, dysplasia, and adenocarcinoma
A. Non-dysplastic Barrett’s mucosa (columnar cells) characterized by uniform, bland nuclei arranged in a surface monolayer
B. Low-grade dysplasia (nuclear hyperchromasia,
elongation
Elongation
Polymerase Chain Reaction (PCR), and stratification extending up to the
surface epithelium
Surface epithelium
Epithelium is classified according to the cells (squamous, cuboidal, columnar), the number of layers, and other unique characteristics either due to function (transitional epithelium allowing distention) or appearance (pseudostratified epithelium giving a false impression of multiple layers). Surface epithelium has multiple functions, which include protection, secretion, filtration, and sensory reception.
Surface Epithelium: Histology)
C. High-grade dysplasia (increased architectural and cytologic complexity)
D. Intramucosal adenocarcinoma (severe architectural
distortion
Distortion
Defense Mechanisms, including angulated glands).