Flashcards
Pathomorphology sem 5
Cards in this deck (73)
- 1Growth - enlargement of an organism - because of what?- proliferation
- enlargement of cells
- differentiation
- accumulation of extracellular material - 2In some tissues proliferating cells are restricted to specialised areas:- Growth plates of bones
- isthmus area of gastric glands
- basal cell layer of epidermis
- bone marrow - 3Stem cells can migrateSome stem cells can migrate to where they are needed, e.g., mesenchymal stem cells, can migrate from the bone marrow to form e.g., muscle, bone or adipose tissue
- 4Type of cells and their proliferation rate?All cells in the body can undergo proliferation.
Some cells divide very intensively (LABILE) during life
- hematologic stem cells in bone marrow
- progenitor cells in crypts of the small intestine
- basal epidermal cells in active hair follicles
Some cells divide only in specific circumstances (STABILE)
- hepatocytes
-cells are renal tubili
Some cells do not effectively replicate (PERMANENT)
- Neurons
- Cardiomyocytes - 5Cellular differentiationThe process by which a cell becomes specialized in order to perform a specific function, as in the case of a liver cell, a blood cell, or a neuron.
its a process where a less specialised cell becomes a more specilaised cell type.
stem cells divide and create fully differentiated daughther cells during tissue repair and during normal cell turnover
due to highly controlled modifications in gene expression without change in the DNA sequence itself
morphologically and functionally different cells - but with the same genome - 6Totipotent cellsable to differentiate into all cell types, including the three germ layers and placental structures
In mammals only zygote and early embryonic cells - 7Pluripotent cellsAble to differentiate into many cell types (stem cells)
- 8Unipotent cellscan only differentiate into one cell type, e.g., Hepatocytes
- 9Growth Factors - cellsNatural substances produced by various cells
- stimulating cellular growth
- controlling proliferation and cellular differentiation
- controlling extent of growth
- controlling cell migration
Examples:
- fibroblast growth factors in embryo
- growth hormone in juvenile animals
- cytokines
- steroid hormones - 10Growth Factors - mechanism of actionINITIATION by binding of GF to specific receptors on the surface of their target cells
Action on signalling pathways inside the cell - signal is TRANSFERED to subsurface proteins
ACTIVATION of specific genes
SYNTHESIS of specific proteins that regulate of growth
The resting cell (called phase G0), go into G1 phase and to proceed through the growth cycle - 11HyperplasiaIncrease in the number of cells in a tissue, which may then have increased volume
it takes place if the cellular population is capable of synthesising DNA, thus permitting mitotic division - 12Hyperplasia - typesPhysiologic hyperplasia
Hormonal hyperplasia: mammary gland hyperplasia during lactation
compensatory hyperplasia: occurs when a portion of organ, especially liver is removed - REGENERATION - 13Compensatory hyperplasiaCompensatory parathyroid glands hyperplasia:
mechanism: decreased serum calcium levels and increased PTH synthesis
Causes:
- impairment of renal function
- chronic malabsorption
Compensatory nodular spleen hyperplasia:
unknown causes - 14Pathologic hyperplasia - prostateIn several animal species (especially in aged dogs) prostate hyperplasia develops in intact males of advanced age
it is produced by testosterone and its metabolites and regress after cessation of hormonal influences (castration) but can be restored by administration of androgens
Epithelial cells increase in size and number and fibromuscular tissue markedly expands the interstitial - 15Pathologic hyperplasia - hormonal pathologic hyperplasiarapid, benign growth of one or more mammary glands can occur in young intact female cats (fibroepithelial hyperplasia - fibroadenomatosis)
Cause: action endo- or exogenous progestins - 16Pathologic hyperplasia - Epithelial hyperplasiaCauses: chronic irritation (mechanical or toxic injury) and chronic inflammation
Mechanism: induction of epithelial cells to proliferate and accumulate and the thickened epithelium forms a protective barrier against the inciting causal agent
Examples:
- callus in the skin
- epithelial hyperplasia in chronic inflammation
- epithelial hyperplasia in parasite infestation - 17Pathologic hyperplasia - viral induced hyperplasiaexample :
- Poxy viruses
- herpes viruses
- papilloma viruses
Mechanism:
Stimulation of increased cell activity, mitosis and proliferation by peptides released by infected cells that act as epidermal growth factors - 18Pathologic hyperplasia - Connective tissue hyperplasiaCauses:
- wound healing - Physiology
- Chronic irritation (mechanical or toxic injury)
- chronic inflammation
Mechanism:
Proliferating fibroblasts and blood vessels due to various growth factors released by inflammatory and other cells - 19HypertrophyCauses:
- wound healing - Physiology
- Chronic irritation (mechanical or toxic injury)
- chronic inflammation
Mechanism:
Proliferating fibroblasts and blood vessels due to various growth factors released by inflammatory and other cells - 20Hypertrophy - mechanismIt may occur in any tissue, it is seen in pure form only in tissues composed of cells that do not reproduce readily
in organs in which cells have the possibility of mitosis, hypertrophy is often associated with hyperplasia
- increased functional demand or workload
- specific hormonal stimulation
- idiopathic - 21Hypertrophy - types- physiologic
- pathologic
- Primary, idiopathic (hyperplasia spontanea)
- Secondary, compensatory (hyperplasia compensatoria)
- Partial (hyperplasia partialis
- total (hyperplasia totalis) - 22Atrophy (atrophia)A decreas e in the size and function of cells or tissue that have gained full development
when a sufficient number of the cells are involved, the entire organ/tissue diminishes in size and becomes atrophic
atrophy represents adaption to a changed cellular environment
although atrophic cells may have diminished function, they are not dead - 23Atrophy - CausesDecrease workload - immobilised limb in a plaster cast (Atrophia ex inactivatate)
Loss of innervations - paralysis of the muscle after loss of innervation (denervation)
diminished blood supply - progressive atrophy of the brain because of atherosclerosis of blood vessels (atrophia ex inanitione)
Loss of endocrine stimulation - prostate atrophy after castration
Compression - brain atrophy because of hydrocephalus (atrophia compresione)
Aging - senile skin atrophy - 24Atrophy - morphology - 6 typesSimple: atrophia simplex
Vacuolar: atrophia oedema s. vacua
Pigmental: atrophia pigmentosa s fusca
Fibrous: atrophia fibrosa
Centripetal: Atrophia concentrica
Centrifugal: atrophia excentrica - 25HypoplasiaIs the failure of organ or tissue to obtain full size
hypoplastic organs are typically discovered in young animals
Causes: events that occur in late stages of the developing fetus and neonate - most of them are undetermined
known causes:
- deletion of critical cell populations by viruses and toxins
- genetic mutations that alter the proper differentiation and migration of cells in the embryo - 26Cerebellar hypoplasiaCongenital cerebellar hypoplasia occurs in young animals
Causes: Viral infections of foetus
- feline panleukopenia
- blue tongue in lambs and calves
- viral bovine diarrhoea in calves
- border disease in lambs and kids
Clinical manifestation: Ataxia - 27MetaplasiaReversible replacement of one type of differentiated cell with another mature differentiated cell type
as an adaptive process it represents a replacement of susceptible cells by cells more resistent an inciting stress.
Mechanism: genetic reprogramming of stem cells that exist in most epithelia, or undifferentiated mesenchymal cells present in connective tissue
The influences that predispose to metaplasia, if persistent, may induce cancer transformation in metastatic epithelium - 28Metaplasia of epithelium - CausesChronic inflammation/irridation
- gallbladder - gallstones
- trachea, bronchioles - smoke/dust
- stomach - parasites
Barret´s esophagus - transformation of esophageal epithelium into gastric epithelium
Vitamin A deficiencies: widespread squamous metaplasia through the body, vitamin A excess surpasses keratinisation
Hormonal disturbances: Prostate epithelium - long standing action of oestrogen's - 29Connective tissue metaplasiaconversion of cells of fibrous connective tissue into osteoblasts or chondroblasts (osseus metaplasia)
- sometimes adaptive mechanism (cartilage or bone more resistant to injury)
- most common cause is unknown
Conversion of connective tissue into myeloid cells (Myeloid metaplasia) - 30DysplasiaAbnormal development
Tissue/structure that consists of normal cells that are improperly arranged
The term is the most commonly used to describe developmental defects in the:
-eye
- skin
- kidney
- brain
- skeletal system - 31Dysplasia example + microscopic charactersIt´s an abnormality in maturation of cells within a tissue - expansion of immature cells
Dysplasia is often indicative of an early neoplastic process
Example:
- epithelial dysplasia of the uterine cervix
- myelodysplastic syndromes of bone marrow
Microscopic characteristics:
- anisocytosis
-plemorphism
- hyperchromasia
- presence of mitotic figures - 32Regeneration - generalAbility to regrowth of damaged tissues in which injured cells are replaced by the same type of cells and thus the original structure and functions are restored.
Regenerative capacity is inversely related to complexity of organism:
- Less complex animal - High regenerative capacity (limb regeneration after amputation e.g., lizard)
- More complex animal - Low regenerative capacity (only few organs posses regenerative capacity - 33Regeneration - LIVERLiver has the ability to regenerate from as little as 25% of its tissue
Unipotency of hepatocytes and pluripotency of other cells
Resection of liver induce the proliferation of the remaining hepatocytes until the lost mass is restored.
Intensity of the liver´s response is directly proportional to the mass resected - 34Regeneration - KIDNEYRegeneration of the tubular component following an acute injury is well known
Regeneration of the glomerulus has also been documented
surviving epithelial cells undergo migration, de-differentiation, proliferation
Kidney stem cell in the tubular regeneration has been shown
bone marrow stem cells have also been shown to participate in regeneration of the proximal tubule - 35Circulatory disturbancesAbnormal amount of blood
- hyperemia, congestion, ischemia, anemia.
hemorrhages
edema
shock
thrombosis
embolism
infarction
abnormal blood vessel structure - 36Changes in blood volumeIncreased volume:
- hyperemia
- congestion
Decreased volume:
- ischemia
- anemia - 37Increased blood volumeHyperemia:
- active hyperemia (hyperemia arteriosa s. activa)
Congestion:
- passive hyperemia (hyperemia venosa s. passiva) - 38Hyperemia - generalAn active process that occurs when arterial dilation produces an increased flow of blood into capillary beds with opening of active capillary network.
Arterial dilatation is a result of vasoactive substances that are released by sympathic neurogenic mechanisms - 39Active hyperemia is usually connected withheat
erythrema
swelling - 40Hyperemia can beSystemic hyperemia
- increase volume of blood, increase of erythrocyte production, erythrocytosis (polycytemia vera)
Local hyperemia
- Regional inflammation, irritation
Physiologic
- working muscle
- GIT after meal
Pathologic
- inflammation
-rash - 41Hyperemia - pathomorphologyHyperemia is difficult to see during postmortem examination
Antemortem organs are:
- enlarged
- more red than normal
- higher temperature
- blood on cut surface
Chronic hyperemia
can be cause of hypertrophy or hyperplasia of tissue - 42Congestion - generalPassive process and occurs as a result of impaired venous drainage. Always pathologic state
in chronic passive congestion, the stasis of poorly oxygenated blood result in chronic hypoxia, that can lead to tissue degeneration or even death of selected group of cells - 43Congestion - typesCongestion may occur as a systemic phenomenon in congestive heart failure
- or may exclusively affect the lungs in left heart failure
- or the body without the lungs in right heart failure
Congestion can be local, when there is blockage of venous drainage because of:
- external compression on venous wall (tumors, enlarged organs).
- internal narrowing of venous lumen (thrombus, parasites, phlebolith) - 44Congestion - PathomorphologyAffected organs are:
- enlarged
- blue-red in color
- bloody cut surface (dark - venous blood)
Cyanosis - congestion leads to an increase of deoxygenated hemoglobin - 45Congestion - Histopathology- Veins and microvessels filled with large amounts of blood
- small hemorrhages from capillary rupture
- hemosiderin accumulation - chronic congestion - 46Decrease in blood volume - ISCHEMIALocalized ischemia - local decrease of blood volume in tissue or organ
Systemic (general) ischema (anemia) - systemic decrease of blood volume connected with decrease of:
- hematocrit
- hemoglobin concentration
- number of erythrocytes - 47Ischemia - local deficiency of blood in tissue due to:- obstruction or constriction of blood vessels
- blood loss - 48Ischemia - induced (by mechanism hypoxia or anoxia) pathologic processes are major causes of death in humans:- myocardial infraction
- cerebral ischemia - 49Localized Ischemia - causes- Severe constriction of blood vessels (nonoclusive ischemia)
- narrowing by pathologic process involving vessel wall
- compression by external masses (tumor, inflammatory focus)
- presence of intraluminal vessel object (thrombus, embolus, parasite) - 50Generalized ischemiaBlood or erythrocyte loss
Hemorrhage - blood loss
Erythrocyte destruction
(hemolytic anemia)
erythrocyte lysis or erythrocytophagia
- AIHA
- congenital defects of erythrocytes
- toxins, viuses, parasites - 51Impairment of erythrocyte production (2)Bone marrow injury - (aplastic anemia) and lack of erythrocyte production (uremia, estrogens, tumors, drugs, toxins)
Abnormal erythrocytes synthesis
- deficiency of vit B12 (macrocytosis)
- Metallic ions deficiency (iron, cobalt, copper) - microcytosis - 52Hemorrhage - generalloss of whole blood usually as a consequence of a blood vessel rupture
blood outside blood vessels
Increased tendency to hemmorhage is known collectively as the hemorrhagic diatheses - 53Hemorrhage - causesTraumatic hemorrhages hemorrhagie traumatica/per diaresis)
are caused by trauma to blood vessels
hemorrhages by erosions (Hemorrhagie per diabrosin/erosionem)
are caused by erosive/destructive processes that take place within or near vessel wall
Hemorrhages by leakage (hemorrhage per diapedesis)
caused by outflow of small amount of blood because of dilatation of small blood vessels (chronic congestion) - 54Hemorrhage - pathomorphology (2)External:
- direct
- indirect (stomach, intestine, uterus, urinary bladder)
Internal:
- hematoma
- focus hemorrhagicus
- petechiae or purpura
- ecchymosis
- bruise
- blood in body cavities - 55Hemorrhage - pathomorphology - petechia or purpuraMinute, very tiny (1-2 mm) hemorrhages into skin, mucus membranes or serosal surfaces
- 56Hemorrhage - pathomorphology - ecchymosisslightly larger (over 1-2 cm in diameter) subcutaneous hemorrhages
- 57Hemorrhage - pathomorphology - suffusive hemorrhagesLarge areas are affected
- 58HematomaBlood is trapped within the tissues of the body, without tissue destruction.
In dogs and cats hematomas are common on the concave surface of the pinna (aural hematoma) as a consequence of trauma (scratching, shaking of head)
Rupture of aorta, for example in a dissecting or atherosclerotic aneurysm, may cause a massive retroperitoneal hematoma with sufficient loss of blood leading to death - 59Intracranial hemorrhageIntra-axial hemmorhage - blood present within the brain tissue
(- intraparenchymal hemorrhage
- Intraventricular hemorrhages)
Extra-axial hemorrhage - Blood present within the skull but outside of the brain tissue
( Epidural, subdural, subarachnoid hematomas)
Cerebral hemorrhage (intra cerebral hemorrhage) is a subtype of intracranial hemorrhage that occurs within the brain tissue itself that damages neural tissue - focus hemorrhagicus. - 60Edema - generalSwelling.
accumulation of abnormal amount of fluid in extravascular space - 61edema - causes- Increased hydrostatic pressure in venous vessels
- diminished oncotic pressure in blood vessels (plasma colloid pressure of proteins)
- increased vascular permeability
- impaired lymphatic drainage - 62edema - increased hydrostatic pressureIncreased hydrostatic pressure in the vascular system moves fluid out of the system
generalized: Heart Failure
Localized:
- venous stasis
- cirrhosis
- vena cava syndrome - 63Edema - loss of plasma colloid protein pressureHydrostatic pressure of plasma proteins (oncotic pressure) holds the fluid within blood vessels
This type of edema is always generalized:
- malnutrition (KWASHIORKOR)
- malabsorption
- diminished synthesis - cirrhosis
- loss of proteins (Kidney - nefropathy, severe burns, protein losing enteropathy - 64Edema - increased vascular permeability- inflammatory reactions
- anaphylactic edema - 65Edema - impaired lymphatic drainage- neoplastic growth
- parasites
- malformations
- strictures, fibrosis
- destruction - 66Edematous fluids - typeTransudate - non inflammatory edematous fluid
- caused by increase of hydrostatic pressure or reduction in oncotic pressure
- low specific gravity and usually low in protein, and only few cells
Exudate - inflammatory edematous fluid
- caused by blood vessels dilatation because of action of inflammatory cytokines
- high specific gravity and usually rich in proteins and rich in cells - 67Edema - morphologyAccumulation of abnormal amount of fluid in:
- intracellular space (interstitial tissue spaces)
- body cavities
- lumen of lung alveoli - 68Edematous tissue, when examined GROSSLYWet
Gelatinous
heavy - 69Fluids - edema - color- slightly yellow
- light pink
- red - 70Edema - histopathologyTissue spaces are distended by eosinophilic (proteinaceous) fluids - empty spaces are present in tissues affected
In many cases edema is accompanied by presence of hyperemic blood vessels - 71Edema - definitions (6)Effusion - Accumulation of fluid within serous cavities (e.g. pleural effusion)
Hydrothorax - Presence of free fluid in thoracic cavity
Hydropericardium - presence of free fluid in pericardial cavity
Hydroperitoneum, ascites - presence of free fluid in abdominal cavity
elephantosis - is a disease that is characterized by the thickening of the skin and underlying tissues due to connective tissue hyperplasia, usually caused by chronic edema - 72Pulmonary edemaIs accumulation of edema fluid in lung tissue and alveoli of the lungs
Cause:
Left-sided heart failure:
- Earliest phase - accumulation in the interstitium
- Next - Perivascularly in the alveolar wall
- Finally - Alveolar lumen
- Long-Standing - Pulmonary edema, collagen is deposited in the alveolar walls - 73Brain Edema (Causes, pathomorphology, histopathology)Fluid accumulation in brain tissue
Causes:
- trauma
- intracranial infections
- neoplasms
Pathomorphology:
- Heavier than normal
- sulci are narrowed
- gyri are swollen and become flattened by contact with the skull
- on the section, white matter is gelatinous and appears softer than normal
- the external layer of the grey matter is widened
Histopathology:
- Expansion of the perivascular spaces, which are seen as clear halo in the neuropil around blood vessels
Information
- Description
- Veterinary Medicine Flashcards on Pathomorphology sem 5, created by Filippa Hertzberg on 31/08/2021.
- Created by
- Filippa Hertzberg
- Views
- 2
- Rating