Midterm_Laboratory_Act 5 and 6 Flashcards
The integument includes?
skin and its derivatives,
The skin consists of the?
epidermis and dermis.
The dermis is attached to the underlying?
hypodermis or subcutis
is the animal’s first line of defense when various parasites, bacteria, viruses, fungi, toxins, and other potentially harmful agents come in contact with the skin.
Integumentary system
these are circular growths around the focus
circulli or concentric rings
This functions for interlocking with other scales
peg
what is the special feature of the exposed part of the cycloid scale?
smooth margin
Type of scales in sharks
placoid
radii that extend from the focus to margin
primary radii
are radii that begin outward from, not at, the focus
radii
are toothlike structures on the posterior portion of some scales.
Ctenii
Are found in primitive ray-finned fishes such as Polypterus and gar pikes. (type of scale)
Ganoid
The primitive scales are covered with a hard, shiny and translucent material of mesodermal origin called
ganoin
Ganoid scales fit together like tiles and are arranged in what arrangement?
diagonal rows
Ganoid scales are connected by?
peg-and-socket joints.
What skin layer do scales originate from?
dermal
Ganoin scale consists of a what base?, coated by what shining substance? and openings of that are called?.
bony base
ganoin
lateral canal
What scales are found in carps (teleost) and lungfishes (dipnoi)?
Cycloid
Cycloid scales are located where?
dermal pockets
what scales possess concentric line growths?
cycloid and ctenoid
What do you call the cavity inside the cycloid scale?
pulp cavity
What scales cover the lateral line?
Cycloid scales
What feature of ctenoid scales that cover the lateral line allow passage of small connectives to outside?
perforated
Cycloid scales are derived form of?
Ganoid
what is lost in cycloid scales from ganoid?
ganoin, cosmine and bone cells
Cycloid scales arrangement?
lengthwise in diagonal rows
Other name of placoid scales
Odontoid scales
Arrangement of placoid scales
Regular obliqued rows
What scales form the shark’s entire exoskeleton and give the skin a rough appearance.
placoid scales
What is the diamond shaped part of the placoid?
Basal plate
The basal plate is derived from what connective tissue layer?
Dermis
What is the anterior part of the placoid scale?
trident spine
placoid scales are abundantly found in dermis of what animals?
elasmobranch fishes
placoid spine is composed of? covered by?
dentine covered by vitrodentine
Basal plate is formed of what type of tissue
trabecular calcified tissue
What is the space found in the placoid scale spine?
pulp cavity
Pulp cavity contains?
odontoblasts dentine forming cells, blood capillaries, nerves and lymph channels.
Ctenoid scales are found in what fishes?
acanthopterygian fishes.
what fields are exposed in ctenoid scale?
posterior fields
They are thin, soft and dermal translucent plates.
ctenoid scales
Layers of ctenoid scale
fibrous and bone-resembling layer
T or F
Ctenoid scales do not contain ganoin
True
Each ctenoid scales is embedded in a small ?.
dermal pocket
Arrangement of ctenoid scales
obliquely arranged (posterior end ovelaps anterior end of next scale)