Fissure
Encyclopedia
In anatomy
, a fissure (Latin
fissura, plural
fissurae) is a groove, natural division, deep furrow, elongated cleft, or tear in various parts of the body.
and called an anal fissure
.
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
, a fissure (Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
fissura, plural
Plural
In linguistics, plurality or [a] plural is a concept of quantity representing a value of more-than-one. Typically applied to nouns, a plural word or marker is used to distinguish a value other than the default quantity of a noun, which is typically one...
fissurae) is a groove, natural division, deep furrow, elongated cleft, or tear in various parts of the body.
Brain
- Medial longitudinal fissureMedial longitudinal fissureThe great longitudinal fissure is the deep groove which separates the two hemispheres of the vertebrate brain....
or Longitudinal fissure: which divides the cerebrum into the two hemispheres. - Fissure of Bichat: found below the corpus callosumCorpus callosumThe corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...
in the cerebellumCerebellumThe cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
of the brainBrainThe brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
. - Broca's fissure: found in the third left frontal fold of the brain.
- Burdach's fissure: connects the brain's insula and the inner surface of the operculumOperculum (brain)Operculum, derived from Latin, meaning "little lid", refers to the cerebral cortex on the outside surface of the brain bordering the lateral sulcus, and the roof and floor of the lateral sulcus. Neuroscience divides the operculum into orbital, frontal, parietal and temporal regions, after the...
. - Calcarin's fissure: extends from the occipital of the cerebrumTelencephalonThe cerebrum or telencephalon, together with the diencephalon, constitutes the forebrain. The cerebrum is the most anterior region of the vertebrate central nervous system. Telencephalon refers to the embryonic structure, from which the mature cerebrum develops...
to the occipital fissure. - Callosomarginal fissure: found in the mesial surface of the cerebrum.
- Central fissure or Rolando's fissure: separates the brain's frontal and parietal lobeParietal lobeThe parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the...
s. - Clevenger's fissure: found in the inferior temporal lobe of the brain
- Collateral fissureCollateral fissureThe collateral fissure is on the tentorial surface of the hemisphere and extends from near the occipital pole to within a short distance of the temporal pole....
: found in the inferior surface of the cerebrum. - Hippocampal fissure: a fissure that extends from the brain's corpus callosum to the tip of the temporal lobe.
- Horizontal fissure or Transverse fissure: found between the cerebrum and the cerebellum. Note that a "transverse fissure" can also be found in the liverLiverThe liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
and lungLungThe lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
s. - Occipitoparietal fissure: found between the occipital and parietal lobes of the brain.
- Fissure of Sylvius: separates the frontal and parietal lobes of the brain from the temporal lobe.
- Wernicke's fissure: separates the brain's temporal and parietal lobes from the occipital lobe by means of a fissure
- Zygal fissure: found in the cerebrum.
Skull
- Auricular fissure: found in the temporal boneTemporal boneThe temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebrum.The temporal bone supports that part of the face known as the temple.-Parts:The temporal bone consists of four parts:* Squama temporalis...
- Pterygomaxillary fissurePterygomaxillary fissureThe pterygomaxillary fissure is a fissure of the human skull. It is vertical, and descends at right angles from the medial end of the inferior orbital fissure; it is a triangular interval, formed by the divergence of the maxilla from the pterygoid process of the sphenoid.It connects the...
- Petrotympanic fissurePetrotympanic fissureThe petrotympanic fissure is a fissure in the temporal bone that runs from the temporomandibular joint to the tympanic cavity....
- Sphenoidal fissure: separates the wings and the body of the sphenoidSphenoid boneThe sphenoid bone is an unpaired bone situated at the base of the skull in front of the temporal bone and basilar part of the occipital bone.The sphenoid bone is one of the seven bones that articulate to form the orbit...
boneBoneBones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
. - Superior orbital fissure
Liver
- Longitudinal fissure: found in the lower surface of the liverLiverThe liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
, also a fissure that separates the right and left hemispheres of the cerebrum. - Portal fissure: found in the under-surface of the liver.
- Umbilical fissure: found in front of the liver.
Other
- Henle's fissure: the connective tissue between the muscle fibers of the heartHeartThe heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
. - Palpebral fissurePalpebral fissurePalpebral fissure is the anatomic name for the separation between the upper and lower eyelids. In adults, this measures about 10mm vertically and 30mm horizontally.It can be reduced in horizontal size by fetal alcohol syndrome and in Williams Syndrome...
: separates the upper and lower eyelidEyelidAn eyelid is a thin fold of skin that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily...
s.
Abnormal fissure
Fissure can also refer to an unnatural tract or ulcer, most commonly found in the anusAnus
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,...
and called an anal fissure
Anal fissure
An anal fissure is a break or tear in the skin of the anal canal. Anal fissures may be noticed by bright red anal bleeding on the toilet paper, sometimes in the toilet. If acute they may cause severe periodic pain after defecation but with chronic fissures pain intensity is often less...
.