What does the auditory bullae do?

The auditory bulla (pl. bullae) is a hollow bony structure on the ventral, posterior portion of the skull that encloses parts of the middle and inner ear. In most species, it is formed by the tympanic part of the temporal bone.

Are the auditory bullae relatively large or small?

Middle ear cavity structure. The auditory bullae are conspicuous from ventral views of the skulls (Fig. 1). They are relatively largest in Macroscelides, and in both this sengi and in the gerbils the right and left bullae closely converge in the midline (see later).

Where is tympanic bulla?

The tympanic bulla (Bulla tympanica) is placed medially to the styloid process. This rounded prominence belongs to the pars tympanica and in great part, in Cats, to the endotympanic part. It is hollow, pneumatised by diverticules of the ear drum forming the multiple cells generally separated by very thin bony septums.

Do platyrrhines have an Ectotympanic ring or tube?

Some primates (catarrhines and tarsiers) have been described as having an elongate bony ectotympanic tube; others (strepsirrhines and platyrrhines) maintain just a ring of bone.

Is the auditory tube the same as eustachian tube?

Eustachian tube, also called auditory tube, hollow structure that extends from the middle ear to the pharynx (throat). The eustachian tube is about 31–38 mm (1.2–1.5 inches) long in humans and lined with mucous membrane.

Is mastoid part of temporal bone?

The mastoid part of the temporal bone is its posterior component. The inferior conical projection of the mastoid part is called the mastoid process.

What is meatus of ear?

The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about 2.5 centimetres (1 in) in length and 0.7 centimetres (0.3 in) in diameter.

Which animals have biting teeth?

In general, meat-eating carnivores have teeth for tearing and skulls capable of biting with great force, while the plant-eating herbivores have teeth and skulls equipped to grind tough vegetation. Omnivores, which eat both plants and animals, have skulls and dentition suitable for a wide range of foods.

What is inside the tympanic cavity?

Tympanic cavity – located medially to the tympanic membrane. It contains three small bones known as the auditory ossicles: the malleus, incus and stapes. They transmit sound vibrations through the middle ear. Epitympanic recess – a space superior to the tympanic cavity, which lies next to the mastoid air cells.

What parts of stapes do you know?

The stapes or stirrup is a bone in the middle ear of humans and other animals which is involved in the conduction of sound vibrations to the inner ear….

Do lemurs have a bony ear tube?

In lemurs, this ring is unfused (free floating) within the middle ear cavity (Fig. This elongated bony tube extends laterally toward the external ear opening at the side of the skull and forms the outer ear canal.

What is the tympanic ring?

Anatomical Parts The tympanic ring is an incomplete circle, in the concavity of which is a groove, the tympanic sulcus, for the attachment of the circumference of the tympanic membrane. This ring is still open in the newborn and expands laterally to form the tympanic part of temporal bone.

Is the auditory bulla formed by the petrosal bone?

Other animals. In all extant and extinct primates, including humans, the auditory bulla is formed by the petrosal bone (the petrous part of the temporal bone). This is a diagnostic trait that can be used to distinguish primates, including anthropoids, tarsiers, lemurs, and lorises, from all other mammals.

Where is the auditory bulla located in the skull?

The auditory bulla (pl. bullae) is a hollow bony structure on the ventral, posterior portion of the skull that encloses parts of the middle and inner ear. In most species, it is formed by the tympanic part of the temporal bone.

What was the evolution of the auditory system?

Primate auditory morphology and its evolution since the Paleocene epoch received detailed attention through the research efforts of Coleman and Ross ( 2004) and Coleman and Boyer ( 2012 ). The primate cochlear labyrinth and its relationship to hearing abilities were studied by Kirk and Gosselin-Ildari ( 2009) and Armstrong et al. ( 2011 ).

What kind of research is done on peripheral auditory system?

Research on mammalian hearing and the peripheral auditory system is firmly grounded in the work of Rosowski ( 1992, 2013 ). The relationship between the morphological variation of the mammalian ear and hearing characteristics was also studied by Hemilä et al. ( 1995) and by Nummela ( 1995 ).