Exoskeletal Structures Flashcards
derived from dermis and are therefore mesoderm in origin
scales of sihes
the dermal embedded, flat, bony base of the scale
basal plate or root
shiny curved dermal outgrowth directed caudad and erupts from the epidermis
spine
Consist of dentine that is covered with a hard layer of virodentine (both are mesodermal origin)
spine
spine consists of what
dentine
what covers dentine
virodentine
cavity found at the center of the basal plate and spine
pulp cavity
scales found in cartilaginous fishes
placoid scales
a fish of a large group that comprises all ray-finned fishes apart from the primitive bichirs, sturgeons, paddlefishes, freshwater garfishes, and bowfins.
teleost fishes
lobe-finned fish
sacopterygii
ray-finned fish
actinopterygii
label the different scales
grade yourself accordingly
roughly circular, fluted, thin, and flexible scale
cycloid
scale that is made up of concentric ridges
cycloid scales
Expected free half is smooth and cleft
cycloid scales
Embedded portion of the scale constitutes the other half if fluted
cycloid scales
also thin with ridges, but the basal embedded portion is scalloped
ctenoid scale
Free edge hears numerous comb-like or tooth-like
projections called ctenidia or
teeth
ctenoid scale
tooth-like projections in ctenoid scale
ctenidia
Both ____ and _____ scaleconsist of a thin layer of cellular lamellar bone
cycloid
ctenoid
scale is rhomboidal in shaped and covered by a hard, shiny, translucent material
ganoid scale
ganoid scale is covered by a hard, shiny, translucent material called what
ganoin
ganoid scale is what in origin
mesodermal
Edges are darkly stained due to the presence of ganoin
ganoid scale
athickenedbonyplate on a turtle’s shell or on the back of acrocodile
scite
– mark the boundaries of the large, thin horny, epidermal scutes of the surface of the carapace
grooves
label the scutes in the dorsal side of the carapace
grade yourself accordingly
median row of five scutes
central scutes
circular row of 25 scutes consisting of nuchal scute
costal scute
an anterior smaller, median unpaired scutes
nuchal scute
two median posterior scute
supracaudal scute
can be removed from the carapace but its boundaries are not the same as that of underlying plates
scutes
scute is what in origin ____
epidermal
since scutes are epidermal in origin, where is it originate in embryonic origin
ectodermal
label the ventral side of the carapace
grade yourself accordingly
continuation or extension of marginal scutes covering the margin of the underside of the carapace
inframarginal scute
made up of heavy bony plates, which are dermal and mesodermal in origin (which side of carapace)
ventral side
plates are fused to the vertebrae or ribs and are bounded by what
jagged sutures
made up of bony dermal plates covered by horny epidermal scutes bounded by sutures (what side of plastron)
dorsal
label the ventral and dorsal side of plastron
grade yourself accordingly
most anterior small of plates
epiplastra
unpaired median plate posterior to the epiplastra and provided with a posteriorly projecting point
entoplastron
pair of squarish plates immediately posterior to the entoplastron
hyoplastra
pair of squarish plates immediately posterior to the hyoplastra
hypoplastra
pair of squarish plates immediately posterior to the hypoplastra
xiphiplastra
the most anterior and smallest par of scutes
gular scutes
label the ventral side of the plastron
grade yourself accordingly
label the scales on the snake
grade yourself accordingly
this has epidermal scales
snake scales
central and unpaired scale in snake
frontal plate
two large plates posterior to the frontal in the snake
parietals
paired plates, somewhat oblongated and situated between the frontal plates and eyes of the snake
supraorbitals
paired plates anterior to the frontal scale of the snake
prefrontals
paired, anterior to the prefrontals and between the nasals of the snake
internasals
in some species, this is separated by a small median plate known as
azygos
internasals
small median plate that separates internasals
azygos
unpaired plate, covering the extremity of the snout
rostral
plates surrounding the paired nostrils
nasals
small plates surrounding each eye, the number depends on the kind of species
orbitals
situated on the edge of the upper and lower lips, respectively
superior and inferior labials
situated posterior to the orbitals and above the superior labials
temporals
entirely covered with epidermal scales
body and tail of the snake
scale of the ventral surface are short and wide slightly overlapping
gastrosteges
two rows, more or less united, scale on the underside of the tail of a snake
urostege
last gastrostegite in a snake
anal plate
part of birds covered with epidermal scales and provided with claws
hindlimb
mouth of the bird is modified to this
horny beaks
where feathers are found in these areas of skin
pterylae
featherless areas found in between in chickens
apterylae
three general types of feathers
filoplume/hair feather
plumule/down feather
contour feather
fine hair that can only be seen in the young and plucked bird
filoplume or hair feather
long slender shaft that is embedded in the skin and surrounded at its
base by the feather follicle or root
main axis
soft rays that are borne at the distal end of the main axis, provided with side rays (barbules), without hooklets
terminal barbs
fluffy covering found in the young birds between the bases of the contour feather in adult birds
plumule or down feather
basal short hollow stem, which is embedded into the integument
quill or calamus
numerous soft rays that arise in a circle from the free end of the quill
barbs
minute of tiny side rays arising from each side of the barbs
barbule
covers and gives an outline to the body. Arises from the feather tracts or pterylae
contour feather
feather used for flying
flight feather
the central axis which bears on each side a web-like, flat expansion called the vane.
quill
the lower bare and hollow part of the quill.
calamus
the opening on the proximal end of the quill and is inserted into the feather follicle
inferior umbilicus
a ventral opening at the beginning of the vane and serves as a point where the afterfeather, a less-developed tuft of accessory feather arises.
superior umbilicus
solid part of the quill that supports the vane
shaft/rachis
expanded portion of the quill which is divided into:
vane
narrower side of the feather
outer vane
wider side of the feather.
inner vane
parallel, obliquely placed rays that adhere to each other and arise from the rachis.
barbs
- side rays originating from each side of the barb.
barbules
tiny hooks situated on the lower part of each distal barbules, resulting in the barbs being hooked together
hooklets
a median ventral groove that extends from the superior umbilicus to the tip of the rachis
umbilical groove
primarily used to cover the body, covers the bases of flight feathers
covert feather
body of mammals is almost entirely covered with this
hair
exposed part of the hair
shaft
embedded part of the hair
root
forms the surface layer of the hair
cuticle
median innermost layer of the hair, often absent, especially in smaller hair
medulla
between the cuticle and medulla
cortex
label the diagrams
grade yourself accordingly
