Lamellae on a gecko's foot. In

surface anatomy Surface anatomy (also called superficial anatomy and visual anatomy) is the study of the external features of the body of an animal.Seeley (2003) chap.1 p.2 In Bird anatomy, birds, this is termed ''topography''. Surface anatomy deals with anatomi ...

, a lamella is a thin plate-like structure, often one amongst many lamellae very close to one another, with open space between. Aside from respiratory organs such as

book lungs A book lung is a type of respiration organ used for atmospheric gas-exchange that is present in many arachnids, such as scorpions and spiders. Each of these organs is located inside an open, ventral-abdominal, air-filled cavity (atrium) and co ...

, they appear in other

biological Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distribution of ...

roles including

filter feeding Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a spe ...

and the traction surfaces of

gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates. They range from . Geckos are unique among lizards ...

s. Gecko feet consist of millions of

setae In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae ...

made of

β-keratin Beta-keratin (β-keratin) is a structural protein found in the epidermis of reptiles, birds, and pangolins. Structure Beta-keratins were named due to their composition of stacked beta sheets in the epidermal stratum corneum, distinguishing th ...

arranged into lamellate structures called spatula, which allow adhesion to walls due to creating more

Van der Waals force In molecular physics and chemistry, the van der Waals force (sometimes van der Waals' force) is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds, these attractions do not result from a chemical elec ...

between the gecko's feet and the wall. In

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, gill lamellae are used to increase the surface area in contact with the environment to maximize gas exchange (both to attain oxygen and to expel carbon dioxide) between the water and the

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ...

. In fish

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

s, there are two types of lamellae, primary and secondary. The primary gill lamellae (also called gill filament) extends from the gill arch, and the secondary gill lamellae extends from the primary gill lamellae. Gas exchange primarily occurs at the secondary gill lamellae, where the tissue is notably only one cell layer thick. Furthermore, countercurrent gas exchange at the secondary gill lamellae further maximizes oxygen uptake and carbon dioxide release. These gill lamellae are larger and have smaller pores in faster-swimming fish compared to slower-swimming fish. In

insects Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...

, some species feature antennae with a lamellate structure such as the members of the

Scarabaeidae The family Scarabaeidae, as currently defined, consists of over 35,000 species of beetles worldwide; they are often called scarabs or scarab beetles. The classification of this family has undergone significant change. Several groups formerly tre ...

family. These antennae, covered in fine hairs (

), are used to detect female pheromones, temperature, humidity, and to touch nearby objects. Ten Lined June Beetle

References

{{Reflist Animal anatomy

See also

References