Difference between revisions of "Bones Metabolic - Pathology"

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===Pituitary===
+
#REDIRECT[[:Category:Bones - Metabolic Pathology]]
 
 
*Growth hormone
 
**Secreted by the anterior pituitary
 
**Influences the size of the skeleton and soft tissue
 
 
 
====[[Congenital Panhypopituitarism|Pituitary dwarfism]]====
 
 
 
 
 
====Pituitary gigantism ([[Acromegaly]])====
 
 
 
 
 
 
 
===Thyroid===
 
 
 
*Thyroid hormones affect maturation of growth of cartilage
 
 
 
====[[Hypothyroidism]]====
 
 
 
 
 
====[[Hyperthyroidism]]====
 
 
 
 
 
 
 
 
 
===[[Gonadal Effect on Bones]]===
 
 
 
 
 
 
 
===Adrenal glands===
 
 
 
*[[Hyperadrenocorticism]]
 
 
 
 
 
 
 
===[[Hyperparathyroidism|Hyperparathyroidism]]===
 
 
 
 
 
===[[Rickets]]===
 
 
 
 
 
===[[Osteomalacia]]===
 
 
 
 
 
 
 
 
===Hypovitaminosis A===
 
 
 
*Vitamin A is essential for normal bone growth in foetus and neonates 
 
*Hypovitaminosis from dietary deficiency of dam -> teratogenic in pigs and large cats
 
*More commonly, deficiency in neonates (puppies, kittens, calves, piglets) on vitamin-deficient diets
 
*Dietary deficiency -> failure of [[Bones - Anatomy & Physiology|osteoclastic remodelling]] resulting in bone overgrowth and nerve compression
 
*Optic nerves particularly affected
 
 
 
 
 
[[Category:Bones - Metabolic Pathology]]
 
 
 
 
 
 
 
===Hypervitaminosis A===
 
[[Image:Hypervitaminosis A.jpg|right|thumb|100px|<small><center>Hypervitaminosis A (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 
*Main lesions:
 
**Injury to growth cartilage -> [[Bones - Anatomy & Physiology|premature closure of growth plate]]
 
**[[Bones Degenerative - Pathology#Osteoporosis (Atrophy)|Osteoporosis]]
 
**'''Exostoses'''
 
**[[Musculoskeletal Terminology - Pathology|Osteophyte]] formation in prolonged exposure
 
*In cats fed bovine liver for prolonged periods
 
**Rich in vitamin A in grazing animals
 
**Vertebrae fuse with each other due to bone proliferation - '''cervical spondylosis''' ('''ankylosing exostosis''' of the vertebral column), especially in the neck
 
*Can also be teratogenic, especially in pigs ([[Cleft Palate|cleft plate]] and abortions)
 
 
 
[[Category:Bones - Metabolic Pathology]]
 
 
 
 
 
===Hypervitaminosis D===
 
 
 
*May be of dietary or iatrogenic origin (has narrow safety margin)
 
*Key features are hypercalcaemia with metastatic calcification of soft tissues
 
*'''Acute poisoning'''
 
**In dogs and cats often from rodenticides containing cholecalciferol
 
**Grossly:
 
***Gastrointestinal haemorrhage
 
***Foci of [[Myocardial Mineralisation|myocardial discoloration]]
 
**Microscopically:
 
***Mucosal haemorrhage
 
***Necrosis of crypts
 
***Focal myocardial necrosis
 
***Mineralisation of intestinal mucosa, [[Arterial Calcification#Medial calcification|blood vessel walls]], [[Pulmonary Calcification|lungs]] and kidneys
 
*'''Chronic poisoning'''
 
**Grossly:
 
***Intense [[Bones - Anatomy & Physiology|osteoclastic activity]] -> active resorption of bone, especially [[Bones - Anatomy & Physiology|trabecular]]
 
**Microscopically:
 
***Excessive production of [[Bones - Anatomy & Physiology|osteoid]] - appears both eosinophilic and basophilic in different places
 
***Marrow cavity may be obliterated
 
***Mineralisation of soft tissues, especially [[Arterial Calcification|blood vessel walls]]
 
**Due to inhibition of [[Calcium|Parathyroid Hormone (PTH)|PTH]] and increase of [[Calcium#Calcitonin|calcitonin]]
 
 
 
[[Category:Bones - Metabolic Pathology]]
 
 
 
 
 
 
 
===Fluorine poisoning===
 
 
 
*F is widespread in nature
 
*Pastures may be contaminated by industrial processes (e.g. brick manufacture)
 
*'''Acute poisoning''':
 
**Gastroenteritis
 
**Nephrosis
 
*'''Chronic poisoning''':
 
**''Dental abnormalities''
 
***Intoxication during teeth development
 
***Foci of poor enamel formation - yellow, dark brown/black, chalky
 
***Irregular wear of teeth, chip easily
 
**''Osteodystrophy = Fluorosis''
 
***Generalised skeletal disturbance
 
***Most affected are metatarsals and mandibles
 
***Periosteal hyperostosis + endosteal bone resorption -> thickened bones with enlarged marrow cavities
 
 
 
[[Category:Bones - Metabolic Pathology]]
 
 
 
 
 
===Lead poisoning===
 
 
 
*Lead can bind to mineral portion of bone and cartilage
 
*In young animals ingesting large dose at once
 
** -> Lead induced malfunction of osteoclasts
 
** -> Transverse band of increased density on radiographs of metaphysis = "lead line" = [[Retention of Elongated Primary Trabeculae|growth retardation lattice]]
 
 
 
 
 
[[Category:Bones - Metabolic Pathology]]
 
 
 
 
 
 
 
[[Category:Musculoskeletal System - Pathology]]
 

Latest revision as of 19:07, 27 February 2011