Rules Mnemonics in Anatomy

Discussion in 'MRCP Forum' started by samuel, Oct 25, 2014.

  1. samuel

    samuel New Member

    All are about 45 cms or 18 inches:

    1. Length of Vas deferens or ductus deferens
    2. Length of thoracic duct
    3. Length of Spinal cord
    4. Femur (for 6 feet person)
    5. Length of transverse colon
    6. Distance from the incisor teeth to the cardiac end of the stomach
    7. Umbilical cord at birth
    8. Length of sartorius muscle
  2. samuel

    samuel New Member

    All are about 25 cms or 10 inches:

    1. Length of Esophagus
    2. Length of Ureter
    3. Length of Duodenum
    4. Length of Descending colon
  3. samuel

    samuel New Member

    All are about 10 cms or 4 inches:

    1. Length of Trachea
    2. Length of Fallopian or Uterine tube
    3. Length of Common bile duct
    4. Length of 3rd part of Duodenum (Transverse Duodenum)
    5. Length of Posterior wall of Vagina
  4. samuel

    samuel New Member

    All are about 10 cms or 4 inches:

    1. Length of Trachea
    2. Length of Fallopian or Uterine tube
    3. Length of Common bile duct
    4. Length of 3rd part of Duodenum (Transverse Duodenum)
    5. Length of Posterior wall of Vagina
    6. Anteroposterior measurement of Inlet of Pelvis
    7. Transverse measurement of Outlet of Pelvis
  5. samuel

    samuel New Member

    All are about 4 cms or 1.5 inches:
    1. Length of Auditory tube
    2. Length of Anal canal
    3. Length of Female urethra
    4. Length of Cystic duct
    5. Length of Common hepatic duct
    6. Length of External acoustic/auditory meatus when measured from tragus
    7. Length of Optic nerve
    8. Length of Ovary
    9. Length of Inguinal canal
    10. Length of Femoral sheath
    11. Thickness of Kidney
    12. Width of Pons
  6. samuel

    samuel New Member

    All are about 1 inch or 2.5 cm
    1. Length of Medulla
    2. Length of Midbrain
    3. Length of Pons
    4. Length of 4th part of Duodenum (Ascending Duodenum)
    5. Length of Ducts of Bartholin’s gland (Greater vestibular glands)
    6. Diameter of Trachea
    7. Diameter of Right main bronchus
    8. Distance between Ureteric orifice in Empty bladder
  7. samuel

    samuel New Member

    Structures whose width is greater than length:
    1. Pons varioli
    2. Cecum
    3. Prostate
  8. samuel

    samuel New Member

    Descent of Testis:
    1. 3rd month: Reaches Iliac fossa
    2. 6th month: Rests at Deep Inguinal ring
    3. 7th month: Traverses Inguinal canal
    4. 8th month: Reaches Superficial Inguinal ring
    5. 9th month: Descneds into Scrotum
  9. samuel

    samuel New Member

    Rule of 2s for Meckel’s Diverticulum:
    Meckel’s Diverticulum is a congenital outpouching of the ileum that is a normal variant and is the remnant of omphalomesenteric (vitellointestinal) duct. It is a true diverticulum, that consists of all the layers of the intestinal wall (mucosa, submucosa and muscularis).
    1. Occurs in 2% population
    2. 2 times more common in male
    3. 2 feet proximal to ileocecal valve
    4. 2 inches in length
    5. 2 years of age is typical for onset of symptoms
    6. 2 % are symptomatic
    7. 2 types of mucosa possible (Small intestine and Gastric)
  10. samuel

    samuel New Member

    Rule of 2s: 2nd week of Development (Embryology)
    1. Trophoblast differentiates into 2 layers: Cytotrophoblast and Sycytiotrophoblast
    2. Embryoblast forms 2 layers: Epiblast and Hypoblast
    3. Extraembryonic mesoderm splits in 2 layers: Somatopleure and Splanchnopleure
    4. 2 cavities are formed: Amniotic cavity and Yolk sac cavity
  11. samuel

    samuel New Member

    Rule of 3s: Thoracic spine levelling
    1. T1-3 (and T12) transverse processes are at the level of the corresponding thoracic spine.
    2. T4-6 (and T11) transverse processes lie superiorly between its level’s spine and the spine of the thoracic segment above it.
    3. T7-9 (and T10) transverse processes lie superiorly at the level of the superior segment’s spine.
  12. samuel

    samuel New Member

    Rule of 3s: 3rd week of Development
    1. Bilaminar germ disc changes into trilaminar germ disc with 3 layers ectoderm, mesoderm and endoderm
    2. Formation of 3 important structures: Notochord, Neural plate and Primitive streak
    3. 3 layered chorionic villi
    4. 3 carnegie stages
  13. samuel

    samuel New Member

    Gate’s Rule of 4s: For Detecting Brainstem Lesion
    There are 4 rules in Rules of 4s:
    1. 4 structures in the “M“idline begins with “M“: Motor pathway (Corticospinal Tract), Medial Lemniscus, Medial longitudinal fasciculus, Motor nucleus and nerves (CN 3,4,6,12)
    2. 4 structures to the “S“ide begins with “S“: Spinothalamic, Spinocerebellar tract, Sensory nucleus of CN V, Sympathetic pathway
    3. 4 Cranial nerves in Each of:
    • Medulla: 9,10,11,12
    • Pons: 5,6,7,8
    • Above Pons: 1,2,3,4
    4. The 4 midline motor nuclei can exactly divide 12 (excluding 1 and 2 which are purely sensory) – 3, 4, 6 and12 (Remaining 4 motor nuclei are on sides/laterally i.e 5, 7, 9 and 11).
  14. samuel

    samuel New Member

    Rule of 7s: For Orbit
    There are 7 bones, 7 intraorbital muscles and 7 nerves in orbit
    • 7 Bones: Frontal, Ethmoid, Lacrimal, Sphenoid, Zygomatic, Palatine, Maxilla
    • 7 intraorbital muscles: Levatorpalpebrae, 4 recti (Superior, Inferior, Medial and Lateral), 2 oblique (Superior and Inferior)
    • 7 orbital nerves: Optic (CN II), Occulomotor (CN III), 3 branches of Opthalmic nerve (CN V1) – Frontal, Nasociliary, Lacrimal, Abducens nerve (CN VI)
  15. samuel

    samuel New Member

    Rule of 9s: Surface area of Skin
    Adults:
    • 9 % in head and neck
    • 9% in each upper limb
    • 18% in front of the trunk
    • 18% in back of the trunk (including buttocks)
    • 18% in each lower limb
    • 1% in perineum
    Children:
    • 18% in head and neck
    • 9 % in each limb
    • 18% in front of the trunl
    • 18% in back of the trunk
    • 13.5% in each lower limb
    • 1% in perineum
  16. samuel

    samuel New Member

    Bifurcation Vertebral Landmarks:

    C4 - Bifurcation of Common Carotid Artery
    T4 - Bifurcation of Trachea
    L4 - Bifurcation of Aorta

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