Human head

In human anatomy, the head is the uppermost part of the body, attached to the torso by the neck. It houses the brain, forming the cranial cavity for protection and support through the skull, which also forms the orbits and nasal cavity. The sensory organs and the mouth are part of the head. The face, except for the exposed sensory organs, is wrapped by tegument (skin, hair on the majority of the surface). Numerous skeletal muscles, as well as mobile articulations in the neck, grant the head mobility.

In human anatomy, the head is the uppermost part of the body, attached to the torso by the neck. It houses the brain, forming the cranial cavity for protection and support through the skull, which also forms the orbits and nasal cavity. The sensory organs and the mouth are part of the head. The face, except for the exposed sensory organs, is wrapped by tegument (skin, hair on the majority of the surface). Numerous skeletal muscles, as well as mobile articulations in the neck, grant the head mobility.

Blood supply

The head receives blood supply through the internal and external carotid arteries. These supply the area outside of the skull (external carotid artery) and inside of the skull (internal carotid artery). The area inside the skull also receives blood supply from the vertebral arteries, which travel up through the transverse foramina of cervical vertebrae.

Nerve supply

The twelve pairs of cranial nerves provide the majority of nervous control to the head. Innervation to the muscles of the face, which allow one to do actions like smile or grimace, is primarily provided by the facial nerve, the seventh cranial nerve. The sensation to the face is provided by the branches of the trigeminal nerve, the fifth cranial nerve. Sensation to other portions of the head is provided by the cervical nerves. Modern texts are in agreement about which areas of the skin are served by which nerves, but there are minor variations in some of the details. The borders designated by diagrams in the 1918 edition of Gray's Anatomy are similar but not identical to those generally accepted today. The cutaneous innervation of the head is as follows: Ophthalmic nerve (green) Maxillary nerve (pink) Mandibular nerve (yellow) Cervical plexus (purple) Dorsal rami of cervical nerves (blue) and others are in picture which show following in upper column

Society and culture

For humans, the front of the head (the face) is the main distinguishing feature between different people due to its easily discernible features, such as eye and hair colors, shapes of the sensory organs, and the wrinkles. Humans easily differentiate between faces because of the brain's predisposition toward facial recognition. When observing a relatively unfamiliar species, all faces seem nearly identical. Human infants are biologically programmed to recognize subtle differences in anthropomorphic facial features. were feared for their headhunting practices]] People who have greater than average intelligence are sometimes depicted in cartoons as having bigger heads as a way of notionally indicating that they have a "larger head". Additionally, in science fiction, an extraterrestrial having a big head is often symbolic of high intelligence. Despite this depiction, advances in neurobiology have shown that the functional diversity of the brain means that a difference in overall brain size is only slightly to moderately correlated to differences in overall intelligence between two humans. The head is a source for many metaphors and metonymies in human language, including referring to things typically near the human head ( "the head of the bed"), things physically similar to the way a head is arranged spatially to a body ("the head of the table"), metaphorically ("the head of the class"), and things that represent some characteristics associated with the head, such as intelligence ("there are a lot of good heads in this company"). Ancient Greeks had a method for evaluating sexual attractiveness based on the Golden ratio, part of which included measurements of the head. Headhunting is the practice of taking and preserving a person's head after killing the person. Headhunting has been practiced across the Americas, Europe, Asia, and Oceania for millennia.

Clothing

]] Headpieces can signify status, origin, religious/spiritual beliefs, social grouping, team affiliation, occupation, or fashion choices. In many cultures, covering the head is seen as a sign of respect. Often, some or all of the head must be covered and veiled when entering holy places or places of prayer. For many centuries, women in Europe, the Middle East, and South Asia have covered their head hair as a sign of modesty. This trend has changed drastically in Europe in the 20th century, although is still observed in other parts of the world. In addition, a number of religions require men to wear specific head clothing—such as the Islamic taqiyah, Jewish yarmulke, or the Sikh turban. The same goes for women with the Muslim hijab or Christian nun's habit. A hat is a head covering that can serve a variety of purposes. Hats may be worn as part of a uniform or used as a protective device, such as a hard hat, a covering for warmth, a covering that meets sensory needs in some neurodivergent people, or a fashion accessory. Hats can also be indicative of social status in some areas of the world.

Anthropometry

While numerous charts detailing head sizes in infants and children exist, most do not measure average head circumference past the age of 21. Reference charts for adult head circumference also generally feature homogeneous samples and fail to take height and weight into account. One study in the United States estimated the average human head circumference to be in males and in females. A British study by Newcastle University showed an average size of 57.2 cm for males and 55.2 cm for females with average size varying proportionally with height Macrocephaly can be an indicator of increased risk for some types of cancer in individuals who carry the genetic mutation that causes Cowden syndrome. For adults, this refers to head sizes greater than 58 centimeters in men or greater than 57 centimeters in women.

Text derived from https://en.wikipedia.org/w/index.php?oldid=1378360682 under CC BY-SA 4.0; modifications have been made.