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Skull and Facial Muscles - Anatomy & Physiology (view source)
Revision as of 14:05, 30 July 2008
, 14:05, 30 July 2008→Introduction
==Introduction==
==Introduction==
[[Image:Deer Skull with Antlers.jpg|thumb|right|150px|Deer Skull - Copyright nabrown RVC]]
[[Image:Deer Skull with Antlers.jpg|thumb|right|150px|Deer Skull - Copyright nabrown RVC]]
The skull is divided into three components- the neurocranium, the dermatocranium and the viscerocranium. The skull also includes the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]], mandible, ossicles of the middle [[Special Senses - Auditory - Anatomy & Physiology|ear]] and the cartilage of the [[Larynx - Anatomy & Physiology|larynx]], nose and [[Special Senses - Auditory - Anatomy & Physiology|ear]]. The skull protects the brain and head against injury and supports the structures of the face. In some animals the skull is also used for defensive actions, for example in [[Anatomy & Physiology of the Horn|horned]] ungulates such as red deer stags.
The shape and size of the skull varies widely, not only between species but also with age, breed and sex of similar species. The skull is divided into three components- the neurocranium, the dermatocranium and the viscerocranium. The skull also includes the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]], mandible, ossicles of the middle [[Special Senses - Auditory - Anatomy & Physiology|ear]] and the cartilage of the [[Larynx - Anatomy & Physiology|larynx]], nose and [[Special Senses - Auditory - Anatomy & Physiology|ear]]. The skull protects the brain and head against injury and supports the structures of the face. In some animals the skull is also used for defensive actions, for example in [[Anatomy & Physiology of the Horn|horned]] ungulates such as red deer stags.
The neurocranium develops from the neural crest and mesoderm and undergoes endochondral ossification. It lies ventral to the brain.
The neurocranium develops from the neural crest and mesoderm and undergoes endochondral ossification. It lies ventral to the brain.
The viscerocranium is the pharyngeal skeleton. It is derived only from the neural crest and undergoes endochondral and intramembranous ossification.
The viscerocranium is the pharyngeal skeleton. It is derived only from the neural crest and undergoes endochondral and intramembranous ossification.
The shape and size of the skull varies widely, not only between species but also with age, breed and sex of similar species.
The various facial muscles attach onto the skull in different places depending on their function. Movement of the external apendages, mastication and facial expressions all rely on the movement of the facial muscles.
==Structure==
==Structure==