Mastoid antrum is present in which pa of temporal bone?
MastoidIt is an air sinus in the petrous temporal bone.Its upper anterior wall has the opening of aditus, while medial wall is related to posterior semicircular canal (SCC).Posteriorly lies the sigmoid sinus.The posterior belly of digastric muscle forms a groove in the base of mastoid bone.The corresponding ridge inside the mastoid lies lateral not only to sigmoid sinus but also to facial nerve and is a useful landmark.The roof is formed by tegmen antri separating it from middle cranial fossa and temporal lobe of brain. o Anteroinferior is the descending pa of facial nerve canal (or fallopian canal).Lateral wall is formed by squamous temporal bone and is easily palpable behind the pinna.
Tympanic
Petrous
Squamous
Mostoid