Anatomical Landmarks: Skull, Foot, Skin, and Limb Regions

Posted on Feb 21, 2025 in Biology

Anatomical Landmarks

Skull Features

  • Trigeminal Impression: Shallow depression near the apex.
  • Arcuate Eminence: Resides posterior to the trigeminal impression; raised by the anterior semicircular canal of the labyrinth.
  • Tegmen Tympani: A thin plate located between the walls of the tympanic cavity. A purulent process can melt the bony plate and spread from the middle ear onto the brain meninges.
  • Petrosquamous Fissure: Separates the anterior surface of the petrous part from the cerebral surface of the squamous part.
  • Hiatus of Greater Petrosal Nerve: A small opening situated laterally from the trigeminal impression.
  • Groove for Greater Petrosal Nerve: Lies in front of the opening.
  • Hiatus for Lesser Petrosal Nerve: A small opening, which resides lateral from the previous hiatus.
  • Sulcus for Lesser Petrosal Nerve: Runs in front of its opening.
  • Groove for Superior Petrosal Sinus: Extends along the upper margin of the pyramid.

Foot Anatomy

  • Talus Trochlea: Upper portion of the bone with articulation with the shin bone.
  • Head of Talus: Anterior convex portion of the bone with the articular surface of the navicular.
  • Lateral / Medial / Posterior Process
  • Anterior, Medial, and Posterior Faces for Calcaneus
  • Calcaneal Tuberosity: Relatively large projection back and downward.
  • Sustentaculum Tali: A process medially.
  • Anterior, Middle, and Posterior Talar Articular Surfaces
  • Articular Surface for Cuboid
  • Navicular: Situated between the talus and cuneiform bones.
  • Medial Cuneiform: Sits in front and medially from the navicular and articulates with the first metatarsal bone.
  • Intermediate Cuneiform: Sits in front of the navicular and lateral to the former bone.
  • Cuboid: Lies on the lateral side of the foot.


Skin Layers

  • Stratum Basale (Stratum Germinativum): Deepest layer; single layer of columnar or cuboidal cells; rapid and repeat mitotic division. Contains Merkel cells, Langerhans cells, melanocytes, and few lymphocytes.
  • Stratum Spinosum: Several layers of keratinocytes attached to each other.
  • Stratum Granulosum: Few layers of flattened & degenerative keratinocyte cells.
  • Stratum Lucidum: Transparent band/layer; appears homogenous, cell boundaries are extremely indistinct; dead keratinocyte layer; traces of flattened nuclei can be seen; present in thick skin.
  • Stratum Corneum: Superficial layer; made up of dead keratinocytes devoid of nuclei and cell organelles; desquamation occurs.

Cubital Fossa

  • Lateral Border: Medial border of the brachioradialis.
  • Medial Border: Lateral border of the pronator teres.
  • Superior Border: Horizontal line between epicondyles.
  • Roof: Bicipital aponeurosis, fascia, subcutaneous fat, and skin.
  • Floor: Brachialis.
  • Radial Nerve: Along the lateral border.
  • Biceps Tendon: Centrally.
  • Brachial Artery: Apex of cubital fossa.
  • Median Nerve: Medially through cubital fossa.

Femoral Triangle

  • Base: Inguinal ligament.
  • Medial Border: Medial border of adductor longus.
  • Lateral Border: Medial border of sartorius.
  • Apex: Meeting of two muscles.
  • Floor: Adductor longus, pectineus, psoas major, and iliacus.
  • Roof: Fascia lata with saphenous opening and cribriform fascia.
  • Contents: Femoral nerve & branches, artery & branches, vein & tributaries, lateral cutaneous nerve of thigh, deep inguinal lymph nodes, femoral branch of genitofemoral nerve.