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Oostegite

An oostegite is a large, flexible plate-like flap extending medially from the coxae of the pereiopods in some female crustaceans. It forms part of the marsupium or brood pouch of members of the superorder Peracarida, from the class Malacostraca.

Gingival fibers

The gingival fibers are the connective tissue fibers that inhabit the gingival tissue adjacent to teeth and help hold the tissue firmly against the teeth. They are primarily composed of type I collagen, although type III fibers are also involved. ...

Palate

The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly separated. T ...

Secondary palate

The secondary palate is an anatomical structure that divides the nasal cavity from the oral cavity in many vertebrates. In human embryology, it refers to that part of the hard palate that is formed by the growth of the two Palatine shelves medial ...

Velopharyngeal insufficiency

Velopharyngeal insufficiency is a disorder of structure that causes a failure of the velum to close against the posterior pharyngeal wall during speech in order to close off the nose during oral speech production. This is important because speech ...

Genitourinary system

The genitourinary system, or urogenital system, are the organs of the reproductive system and the urinary system. These are grouped together because of their proximity to each other, their common embryological origin and the use of common pathway ...

Blennorrhoea

Blennorrhoea aka blennorrhagia or myxorrhoea, is a medical term denoting an excessive discharge of watery mucus, especially from the urethra or the vagina, and also used in ophthalmology for an abnormal discharge from the eye, but now regarded as ...

Genitourinary tract injury

The kidney is the most commonly injured urinary tract organ. Injuries occur commonly after automobile- or sports-related accidents. A blunt force is involved in 80-85% of injuries to the kidney. Major decelerations can result in major vascular in ...

Nervous system

The nervous system is a highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, ...

Current of injury

The current of injury – also known as the demarcation current or hermanns demarcation current – is the electric current from the central part of the body to an injured nerve or muscle, or to another injured excitable tissue. The injured tissue ha ...

Motor nerve

A motor nerve is a nerve located in the central nervous system, usually the spinal cord, that sends motor signals from the CNS to the muscles of the body. This is different from the motor neuron, which includes a cell body and branching of dendri ...

Ventral nervous system defective

The ventral nervous system defective gene present in fruit flies of the genus Drosophila functions during embryonic brain development and is necessary for the formation and specification of neural cell lineages. This transcription factor is expre ...

Bronchus

A bronchus is a passage or airway in the respiratory system that conducts air into the lungs. The first bronchi to branch from the trachea are the right main bronchus and the left main bronchus, also known as the primary bronchi. These are the wi ...

Reid index

The Reid Index is a mathematical relationship that exists in a human bronchus section observed under the microscope. It is defined as ratio between the thickness of the submucosal mucus secreting glands and the thickness between the epithelium an ...

Respiratory system

The respiratory system is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the en ...

Spiracle (vertebrates)

Spiracles are openings on the surface of some animals, which usually lead to respiratory systems. The spiracle is a small hole behind each eye that opens his mouth in some fish. In the primitive jawless fish the first Gill openings immediately be ...

Peristomium

The peristomium is the first true body segment in an annelid worms body in the anterior end. It is directly behind the prostomium and contains the mouth, tentacular cirri, and sometimes feeding palps, which may instead occur on the prostomium. If ...

Prostomium

The prostomium is the first body segment in an annelid worms body in the anterior end. It is in front of the mouth, being usually a small shelf- or lip-like extension over the dorsal side of the mouth.

Radiole

A radiole is a heavily ciliated feather-like tentacle found in highly organized clusters on the crowns of Canalipalpata. Canalipalpata is an order of sessile marine polychaete worms consisting of 31 families. These benthic annelid tube worms empl ...

Aesthete (chiton)

Aesthetes are organs in chitons, derived from the mantle of the organism. They are generally believed to be tiny eyes, too small to be seen unaided, embedded in the organisms shell, acting in unison to function as a large, dispersed, compound eye ...

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where the head-foot part of the body of the animal emerges for locomotion, feeding, etc. The term aperture is used for the main opening in gastrop ...

Dystenoid

A dystenoid nervous system is an arrangement of ganglia in the anterior region of some molluscs in which the cerebral and pleural ganglia are situated closer to each other than they are in those molluscs with the more archaic hypoathroid nervous ...

Girdle (chiton)

A girdle is part of the anatomy of a chiton, one class of marine mollusks, the class Polyplacophora. The shell of a chiton consists of eight valves which articulate with one another. The girdle is a strong but flexible structure that in most case ...

Hyaline shield

The hyaline shield is a part of the radula in many kinds of molluscs. It serves as an attachment point for the muscles that retract the radula, and is thus located on the upper surface of the radula, arching backwards into the mouth. This retract ...

Hypoathroid

The term hypoathroid is used to describe the arrangement of ganglia in the nervous system of molluscs. In the hypoathroid state, the pleural ganglia of the "chest" and the pedal ganglia of the "feet" lie close to each other more or less underneat ...

Hypobranchial gland

The hypobranchial gland is a glandular structure which is part of the anatomy of many mollusks, including several different families of gastropods, and also many protobranch bivalves. This gland produces mucus as well as biologically active compo ...

Mantle (mollusc)

The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself. In many species of molluscs the epidermis of t ...

Notum

The notum is the dorsal portion of an insects thoracic segment, or the dorsal surface of the body of nudibranch gastropods. The word "notum" is always applied to dorsal structures, in other words structures that are part of the back of an animal, ...

Odontophore

The odontophore is part of the feeding mechanism in molluscs. It is the cartilage which underlies and supports the radula, a ribbon of teeth. The radula is found in every class of molluscs except for the bivalves. The feeder can be extended from ...

Oesophageal pouch

The oesophageal pouches are a pair of pouches connected to the oesophagus of all molluscs, and represent a synapomorphy of the phylum.

Organ of Valenciennes

The organ of Valenciennes, named after the French naturalist Achille Valenciennes, is one of two secondary sexual organs of the female of the genus Nautilus. The other is Owens laminated organ. Its exact function is unknown.

Owens laminated organ

Owens laminated organ, named after the 19th century English biologist Richard Owen, is one of two secondary sexual organs of the female of the genus Nautilus. The other is the organ of Valenciennes. Its exact function is unknown.

Pallial line

The pallial line is a mark on the interior of each valve of the shell of a bivalve mollusk. This line shows where all of the mantle muscles were attached in life. In clams with two adductor muscles the pallial line usually joins the marks known a ...

Pallial sinus

The pallial sinus is an indentation or inward bending in the pallial line on the interior of a bivalve mollusk shells valves that corresponds to the position of the siphons in those types of clams which have siphons. The position of the pallial s ...

Van der Hoevens organ

Van der Hoevens organ is the infrabuccal lamellar organ in the adult male of genus Nautilus. It consists of a pair of fleshy narrow parallel lobes each containing 15-19 lamellae. It is analogous to Owens laminated organ of the females, which is a ...

Alae (nematode anatomy)

The alae is a protruding ridge that forms longitudinally on many nematodes. In the Caenorhabditis elegans nematode they are present in the L1, dauer and adult stages. The alae are most pronounced during the dauer larval stage and not present in t ...

Amphid

Amphids are innervated invaginations of cuticle in nematodes. They are usually found in the anterior region of the animal, at the base of the lips. Amphids are the principal olfactosensory organs of nematodes. Each amphid is made up of 12 sensory ...

Anchor cell

The anchor cell is a cell in nematodes such as Caenorhabditis elegans. It is important in the development of the reproductive system, as it is required for the production of the tube of cells that allows embryos to pass from the uterus through th ...

Phasmid (nematode anatomy)

Phasmids are unicellular sensilia in the lateral tail region of certain species of nematodes. They are similar in their structure to amphid sensilla, but smaller. Phasmid neurons were recently shown to function in modulation of chemorepulsion beh ...

Bothrium

Bothria are elongate, dorsal or ventral longitudinal grooves on the scolex of cestoda. They have weak muscles but are capable of some sucking action. Bothria occur as a single or two pair and are typical of the order Pseudophyllidea. Batra muscul ...

Clamp (zoology)

Clamps are the main attachment structure of the Polyopisthocotylean monogeneans. These ectoparasitic worms have a variable number of clamps on their haptor, each clamp is attached to the host fish, generally to its gill. Clamps include sclerotise ...

Mehlis gland

Mehlis gland also called Shell gland, is primarily present surrounding the ootype of Platyhelminthes, and it is a part of the female reproductive organ of Platyhelminthes.

Microtriches

Microtriches are the highly specialized microvilli covering the entire surface of the tegument of cestodes. They are fine hair-like filaments distributed throughout the surface of the body, both unique to and ubiquitous among cestodes, giving the ...

Tegument (helminth)

Tegument is a term in helminthology for the outer body covering of members of the phylum Platyhelminthes. The name is derived from a Latin word tegumentum or tegere, meaning "to cover". It is characteristic of flatworms including the broad groups ...

Cephalopod eye

Cephalopods, as active marine predators, possess sensory organs specialized for use in aquatic conditions. They have a camera-type eye which consists of an iris, a circular lens, vitreous cavity, pigment cells, and photoreceptor cells that transl ...

Adipose eyelid

An adipose eyelid is a transparent eyelid found in fish, that covers some or all of the eye. They are most commonly found on deep sea fish, but can also be seen on non-benthic fish. Some fish that this feature is found on include: milkfish, herri ...

Mammalian eye

Mammals normally have a pair of eyes. Although mammalian vision is not so excellent as bird vision, it is at least dichromatic for most of mammalian species, with certain families possessing a trichromatic color perception. The size of the pupil ...

Urethral sponge

The urethral sponge is a spongy cushion of tissue, found in the lower genital area of females, that sits against both the pubic bone and vaginal wall, and surrounds the urethra.

Collophore

A collophore is a tube-like structure on the ventral side of the first abdominal segment of the body of springtails. It used to be believed that it served to stabilise the animal when it jumped by sticking to the surface on which it moved. Howeve ...

Hypostome (tick)

The hypostome is a calcified harpoon-like structure near the mouth area of certain parasitic arthropods including ticks, that allows them to anchor themselves firmly in place on a host mammal while sucking blood. This mechanism is normally so str ...