Body orifice
Encyclopedia

External orifices

In a typical mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

ian body such as the human body
Human body
The human body is the entire structure of a human organism, and consists of a head, neck, torso, two arms and two legs.By the time the human reaches adulthood, the body consists of close to 100 trillion cells, the basic unit of life...

, the external body orifices are:
  • The nostril
    Nostril
    A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...

    s, for breathing and the associated sense of smell
    Olfaction
    Olfaction is the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates...

    .
  • The eye
    Eye
    Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...

    s, for the sense of sight
    Visual perception
    Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...

     and crying
    Crying
    Crying is shedding tears as a response to an emotional state in humans. The act of crying has been defined as "a complex secretomotor phenomenon characterized by the shedding of tears from the lacrimal apparatus, without any irritation of the ocular structures"...

    .
  • The mouth
    Mouth
    The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....

    , for eating
    Eating
    Eating is the ingestion of food to provide for all organisms their nutritional needs, particularly for energy and growth. Animals and other heterotrophs must eat in order to survive: carnivores eat other animals, herbivores eat plants, omnivores consume a mixture of both plant and animal matter,...

    , breathing, and vocalizations such as speech.
  • The ear canal
    Ear canal
    The ear canal , is a tube running from the outer ear to the middle ear. The human ear canal extends from the pinna to the eardrum and is about 35 mm in length and 5 to 10 mm in diameter....

    s, for the sense of hearing
    Hearing (sense)
    Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...

    .
  • The anus
    Anus
    The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...

    , for defecation
    Defecation
    Defecation is the final act of digestion by which organisms eliminate solid, semisolid or liquid waste material from the digestive tract via the anus. Waves of muscular contraction known as peristalsis in the walls of the colon move fecal matter through the digestive tract towards the rectum...

    .
  • The urethra
    Urethra
    In anatomy, the urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids out of the body. In males, the urethra travels through the penis, and carries semen as well as urine...

    , for urination
    Urination
    Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...

     and ejaculation
    Ejaculation
    Ejaculation is the ejecting of semen from the male reproductory tract, and is usually accompanied by orgasm. It is usually the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. In rare cases ejaculation occurs because of prostatic disease...

  • In female
    Female
    Female is the sex of an organism, or a part of an organism, which produces non-mobile ova .- Defining characteristics :The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male...

    s, the vagina
    Vagina
    The vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...

    , for sexual intercourse
    Sexual intercourse
    Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails...

    , masturbation
    Masturbation
    Masturbation refers to sexual stimulation of a person's own genitals, usually to the point of orgasm. The stimulation can be performed manually, by use of objects or tools, or by some combination of these methods. Masturbation is a common form of autoeroticism...

    , menstruation
    Menstruation
    Menstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...

    , and childbirth
    Childbirth
    Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...

    .
  • Orifices of nipple
    Nipple
    In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

    s
  • Orifices of sweat gland
    Sweat gland
    Sweat glands, or sudoriferous glands, are small tubular structures of the skin that produce sweat. There are two kinds of sweat glands:...

    s
  • Navel
    Navel
    The navel is a scar on the abdomen caused when the umbilical cord is removed from a newborn baby...

     or belly button left over from placental mammals after birth.


Other animals may have some other body orifices:
  • cloaca
    Cloaca
    In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...

    , in bird
    Bird
    Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

    s, reptile
    Reptile
    Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...

    s, amphibians, and some other animals
  • siphon
    Hyponome
    A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda. In other words, a siphon is found in some saltwater and freshwater snails, in some clams, and in octopus, squid and relatives.Siphons in molluscs are tube-like...

     in mollusk, arthropods, and some other animals.

Internal orifices

Internal orifices include the orifices of the outflow tracts of the heart, between the heart valve
Heart valve
A heart valve normally allows blood flow in only one direction through the heart. The four valves commonly represented in a mammalian heart determine the pathway of blood flow through the heart...

s.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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