Difference between revisions of "Muscles Developmental - Pathology"

From WikiVet English
Jump to navigation Jump to search
(New page: {{toplink |backcolour =CDE472 |linkpage =Musculoskeletal System - Pathology |linktext =Musculoskeletal System |maplink = Musculoskeletal System (Content Map) - Pathology |pagetype =Patholo...)
 
Line 9: Line 9:
 
}}
 
}}
 
<br>
 
<br>
 +
===Congenital diaphragmatic defects===
 +
 +
*Clefts may lead to [[Peritoneal cavity - developmental#Pleuroperitoneal diaphragmatic hernia|herniation]] of abdominal organs into thoracic cavity in any species
 +
 +
 +
===Myofibrillar hypoplasia===
 +
 +
*In piglets
 +
* = '''Splayleg'''
 +
*May spontaneously resolve
 +
*Unknown cause
 +
*Responsible for significant deaths
 +
 +
 +
===Hyperplasia of muscle fibres===
 +
 +
*In calves and lambs
 +
*'''“Double muscling”'''
 +
**Increased number of myofibres in affected muscle (thighs, rump, loin)
 +
**Predisposes to dystocia
 +
 +
 +
===Muscular dystrophies===
 +
 +
*Inherited group of degenerative muscular diseases
 +
*Progressive muscle weakness and wasting
 +
*Usually due to a genetic fault -> muscular protein deficiency
 +
**Duchenne MD in humans due to dystrophin deficiency also present in some animals
 +
**Dystrophin gene mutations reported in the Golden Retriever, Rottweiler, German shorthaired pointer and Irish terrier ''etc.''
 +
*Inadequate [[Muscles - normal#Regeneration|regeneration]], [[Muscles - hyperplastic and neoplastic#Hypertrophy|compensatory hypertrophy]]
 +
*More about [[Muscular dystrophy]]
 +
 +
 +
===Glycogen storage diseases===
 +
 +
*Caused by a deficiency of an enzyme
 +
*See [[General Pathology - Degenerations and Infiltrations#Glycogen infiltration|general pathology]]
 +
*Type II glycogenosis
 +
**Deficiency of acid maltase
 +
**In Shorthorn cattle
 +
**Muscular weakness and incoordination
 +
**Glycogen stored in skeletal muscle, heart and CNS
 +
**Type I and II muscle fibres contain glycogen vacuoles
 +
*Type III glycogenosis
 +
**Deficiency of debranching enzyme
 +
**In dogs
 +
**Causes [[Myocardial - Pathology#Hypertrophic cardiomyopathy|hypertrophic cardiomyopathy]] and hepatomegaly
 +
**Glycogen in skeletal and cardiac muscle, neurons nad hepatocytes
 +
 +
 +
===Steatosis===
 +
 +
*Also called '''lipomatosis'''
 +
*In cattle, sheep and pigs
 +
*Fat replaces lost muscle fibres
 +
*Pale muscle, bilaterally symmetrical
 +
*No clinical significance
 +
*Noticed at slaughter or necropsy
 +
 +
 +
===Myasthenia gravis (MG)===
 +
 +
*'''Acquired'''
 +
**Autoimmune disease
 +
***Antibodies directed against acetyl choline receptors
 +
**Associated with [[Lymphoreticular/Haemotopoietic system - general pathology#Tumours of the Thymus|thymomas]], [[Oesophagus#Congenital Achalasia - Megaoesophagus|megaoesophagus]] and dysphagia
 +
**In adult dogs
 +
*'''Congenital'''
 +
**Inherited deficiency in acetyl choline receptors
 +
**Rare
 +
**Newfoundland, Jack Russel Terrier, Springer Spaniels – genetic predisposition
 +
**In dogs – 4 DLA genes recognized: DLA-12, DLA-88, DLA-79 and DLA-64
 +
**Associated with HLA gene in humans
 +
**No antibodies against acetyl choline receptors in serum
 +
**Non-specific muscle [[Muscles - degenerative#Atrophy|disuse atrophy]] and fibrosis or no changes on histology
 +
*Both forms manifest as weakness which worsens on exercise
 +
 +
 +
===Canine dermatomyositis===
 +
 +
*Hereditary in Collies and Shetland sheepdgs
 +
*Lesions resemble [[Muscles - inflammatory#Canine polymyositis|canine polymyositis]]
 +
*Also degeneration of blood vessels -> muscle [[Muscles - degenerative#Ischaemia|microinfarcts]]
 +
*Usually generalised but temporalis may be involved the most
 +
*Also involves [[Skin Immunologic - Pathology#Dermatomyositis|skin]]
 +
 +
===[[Muscles - degenerative#Porcine stress syndrome|Porcine stress syndrome]]===

Revision as of 20:07, 18 August 2008

WikiPathWikiPath Banner.png
()Map MUSCULOSKELETAL SYSTEM (Map)
MUSCLES



Congenital diaphragmatic defects

  • Clefts may lead to herniation of abdominal organs into thoracic cavity in any species


Myofibrillar hypoplasia

  • In piglets
  • = Splayleg
  • May spontaneously resolve
  • Unknown cause
  • Responsible for significant deaths


Hyperplasia of muscle fibres

  • In calves and lambs
  • “Double muscling”
    • Increased number of myofibres in affected muscle (thighs, rump, loin)
    • Predisposes to dystocia


Muscular dystrophies

  • Inherited group of degenerative muscular diseases
  • Progressive muscle weakness and wasting
  • Usually due to a genetic fault -> muscular protein deficiency
    • Duchenne MD in humans due to dystrophin deficiency also present in some animals
    • Dystrophin gene mutations reported in the Golden Retriever, Rottweiler, German shorthaired pointer and Irish terrier etc.
  • Inadequate regeneration, compensatory hypertrophy
  • More about Muscular dystrophy


Glycogen storage diseases

  • Caused by a deficiency of an enzyme
  • See general pathology
  • Type II glycogenosis
    • Deficiency of acid maltase
    • In Shorthorn cattle
    • Muscular weakness and incoordination
    • Glycogen stored in skeletal muscle, heart and CNS
    • Type I and II muscle fibres contain glycogen vacuoles
  • Type III glycogenosis
    • Deficiency of debranching enzyme
    • In dogs
    • Causes hypertrophic cardiomyopathy and hepatomegaly
    • Glycogen in skeletal and cardiac muscle, neurons nad hepatocytes


Steatosis

  • Also called lipomatosis
  • In cattle, sheep and pigs
  • Fat replaces lost muscle fibres
  • Pale muscle, bilaterally symmetrical
  • No clinical significance
  • Noticed at slaughter or necropsy


Myasthenia gravis (MG)

  • Acquired
    • Autoimmune disease
      • Antibodies directed against acetyl choline receptors
    • Associated with thymomas, megaoesophagus and dysphagia
    • In adult dogs
  • Congenital
    • Inherited deficiency in acetyl choline receptors
    • Rare
    • Newfoundland, Jack Russel Terrier, Springer Spaniels – genetic predisposition
    • In dogs – 4 DLA genes recognized: DLA-12, DLA-88, DLA-79 and DLA-64
    • Associated with HLA gene in humans
    • No antibodies against acetyl choline receptors in serum
    • Non-specific muscle disuse atrophy and fibrosis or no changes on histology
  • Both forms manifest as weakness which worsens on exercise


Canine dermatomyositis

  • Hereditary in Collies and Shetland sheepdgs
  • Lesions resemble canine polymyositis
  • Also degeneration of blood vessels -> muscle microinfarcts
  • Usually generalised but temporalis may be involved the most
  • Also involves skin

Porcine stress syndrome

Retrieved from "https://en.wikivet.net/index.php?title=Muscles_Developmental_-_Pathology&oldid=28886"