BIOL 204 Study Guide - Final Guide: Dermal Bone, Am General, Desiccation
General Information
Epidermis
Derived from epidermal ectoderm
○
Outermost layer of the body
○
Gives rise to the Glands of the skin and keratinized structure
○
Stratum Germinativum
Location of formation of new epidermal cells
-
Located in the innermost layer of the epidermis
-
New cells pushed to the outer surface of the epidermis to
replace old cells that are worn away by environment
-
○
Stratum Corneum
Composed of dead keratinized epidermal cells
-
Dead because or regulated self-destruction to produce Keratin
-
Keratin -Special Class of Protein
-
Function?
Prevent dessication
□
Protect against friction and mechanical damage
□
-
○
-
Dermis
Derived from dermatome epimere mesoderm
○
Beneath the epidermis linked via the basement membrane
○
Composition
Usually much thicker then the epidermis
-
Made of fibrous mass of collagen
-
Contain fatty deposits, smooth muscle, blood vessels, and
nerves
-
○
Function
May directly form dermal bone
From mesenchyme of the dermis
□
-
Insulation in Endotherms
-
Sometimes contain Pigments
-
○
-
Endotherms
Animals that actively regulate body temperature by producing heat
from metabolic processes
○
-
Pigments - Colouration of the Skin
-
Basement Membrane
Made of basal lamina and recticular lamina
○
-
Functions of the Skin?
Protect invasion of microorganism
○
Flexibility in Motion
○
Minimize water loss to the environment
○
-
Keratinized Structures:
Epidermal Scales
Continuous Layer of Repetitious thickening
○
Cannot dissect, will be lost in small flakes or shed via moulting
○
Claws and Talons
Curved and laterally compressed projections from the tips of digits
○
Nails
Keratinized epithelial cells
○
Produced at nail base but push existing nail forward
○
Function?
Provide protection from mechanical injury
-
Provide strong grip when grasping
-
○
Hooves
Enlarged keratinized plates found on ends of ungulate digits
○
Function?
Support the weight of the animal
-
Dissipate energy when impacting the ground
-
Protect tissue and bone in the hoof capsule
-
Traction for the animal
-
○
Baleen
Series of keratinized plates that hang from upper jaw along its
length
○
Arise from oral epithelium
○
Function?
Allow filter feeding to occur
-
○
Horn Sheath
Tough keratinized layer with a dermal bone core
○
Retained year-round and continue to grow throughout animal's life
○
Beaks
Keratinized sheath covering the jaws
○
Secondarily lost teeth
○
Feathers
Growth of projection of the skin or a keratinized epidermal sheath
with inner keratinized feather shaft
○
Believed to have evolved from epidermal Scales
○
Columns of epidermal cells project into the dermis to form an
invagination called the feather follicle
○
Feathers grow via the dermal Papillae
○
Dermal Papillae die in the grown feather to form the pulp
○
Types of Feathers
Flight Feathers
Barbules interlock to form strong connections between
barbs
□
asymmetrical□
-
Down Feathers
Soft and fluffy feathers for insulation □
Barbules do not interlock□
-
Contour Feathers
Have some interlocking barbules on distal end but not
the proximal end
□
May help with flight□
Make the colours of the bird□
-
○
Parts of a Feather
Rachis
Central Shaft of the feather□
-
Barb
On both sides of the Rachis □
Can be asymmetrical or symmetrical depending on
relative length of barb to each other
□
-
Interlocking Barbule
Amount of interlocking determines the function of
feathers
□
Determines how interlocked feathers are to determine
how aerodynamic it is
□
-
○
Hair
Initial invagination of epidermal cells into the dermis to form the
hair follicle
○
Hair shaft is formed by outward growth of keratinized epidermal
cells
○
Arrector Pili
Muscle attached to the hair follicle
-
Used to pull hair upright
-
○
Similarities between Hair and Feathers
Dermal papillae
○
Shaft
○
Columns of specialized keratinized cells
○
Glands
Produce and secrete specific products
Mucus, oil, sweat, or milk
○
-
Mucous Cuticle
Layer of mucous that coats epidermis
○
-
Unicellular Gland
Single cell that secretes a product
○
Located in the epidermis
Interspersed between other living cells
-
○
-
Multicellular Gland
Many cells that secrete a product together through a common duct
○
Infolding of the epidermis into the dermis
Composed of epidermal cells located in the dermis
-
○
Duct allows secretions to be released on the outside of the body
○
-
Types of Glands
Sweat Gland
○
Sebaceous Gland
○
Mucus Gland
○
Poison (granular) gland
○
Mammary Gland
○
-
Dermal bone
Shell -thick layer of the dermal bone, outer layer of epidermal scale
Gastralia -Dermal bones located in the body wall of ventral abdomen
Protection
-
Sites for Muscle Attachment in lumbar region because lack of ribs
-
Antlers
Often found in males and shed anually
-
Covered by Velvet -shapes and provide blood to growing dermal
bone; outer layer of living skin
-
Velvet is shed when antlers are fully grown
-
Dermal Scales
Placoid
Teleost
Ctenoid
Cycloid
Enamel
Dentin
Pulp Cavity
Lamellar bone
Trabecular Bone
Tooth
Pelvic fins
Pectoral Fins
Claspers
Lateral Line
Endolymphatic Ducts
Cloaca
Cloacal Vent
Ampullae of Lorenzini
Uropygium
Urogygial Gland
Nares
Auditory Meatus
Scrotum
Testes
Nipples
Lab 5 - Integument (Skin) and its derivatives
DEFINITIONS
February 11, 2018
3:20 AM
General Information
Epidermis
Derived from epidermal ectoderm
○
Outermost layer of the body
○
Gives rise to the Glands of the skin and keratinized structure
○
Stratum Germinativum
Location of formation of new epidermal cells
-
Located in the innermost layer of the epidermis
-
New cells pushed to the outer surface of the epidermis to
replace old cells that are worn away by environment
-
○
Stratum Corneum
Composed of dead keratinized epidermal cells
-
Dead because or regulated self-destruction to produce Keratin
-
Keratin -Special Class of Protein
-
Function?
Prevent dessication□
Protect against friction and mechanical damage□
-
○
-
Dermis
Derived from dermatome epimere mesoderm
○
Beneath the epidermis linked via the basement membrane
○
Composition
Usually much thicker then the epidermis
-
Made of fibrous mass of collagen
-
Contain fatty deposits, smooth muscle, blood vessels, and
nerves
-
○
Function
May directly form dermal bone
From mesenchyme of the dermis□
-
Insulation in Endotherms
-
Sometimes contain Pigments
-
○
-
Endotherms
Animals that actively regulate body temperature by producing heat
from metabolic processes
○
-
Pigments - Colouration of the Skin
-
Basement Membrane
Made of basal lamina and recticular lamina
○
-
Functions of the Skin?
Protect invasion of microorganism
○
Flexibility in Motion
○
Minimize water loss to the environment
○
-
Keratinized Structures:
Epidermal Scales
Continuous Layer of Repetitious thickening
○
Cannot dissect, will be lost in small flakes or shed via moulting
○
Claws and Talons
Curved and laterally compressed projections from the tips of digits
○
Nails
Keratinized epithelial cells
○
Produced at nail base but push existing nail forward
○
Function?
Provide protection from mechanical injury
-
Provide strong grip when grasping
-
○
Hooves
Enlarged keratinized plates found on ends of ungulate digits
○
Function?
Support the weight of the animal
-
Dissipate energy when impacting the ground
-
Protect tissue and bone in the hoof capsule
-
Traction for the animal
-
○
Baleen
Series of keratinized plates that hang from upper jaw along its
length
○
Arise from oral epithelium
○
Function?
Allow filter feeding to occur
-
○
Horn Sheath
Tough keratinized layer with a dermal bone core
○
Retained year-round and continue to grow throughout animal's life
○
Beaks
Keratinized sheath covering the jaws
○
Secondarily lost teeth
○
Feathers
Growth of projection of the skin or a keratinized epidermal sheath
with inner keratinized feather shaft
○
Believed to have evolved from epidermal Scales
○
Columns of epidermal cells project into the dermis to form an
invagination called the feather follicle
○
Feathers grow via the dermal Papillae
○
Dermal Papillae die in the grown feather to form the pulp
○
Types of Feathers
Flight Feathers
Barbules interlock to form strong connections between
barbs
□
asymmetrical□
-
Down Feathers
Soft and fluffy feathers for insulation □
Barbules do not interlock□
-
Contour Feathers
Have some interlocking barbules on distal end but not
the proximal end
□
May help with flight□
Make the colours of the bird□
-
○
Parts of a Feather
Rachis
Central Shaft of the feather□
-
Barb
On both sides of the Rachis □
Can be asymmetrical or symmetrical depending on
relative length of barb to each other
□
-
Interlocking Barbule
Amount of interlocking determines the function of
feathers
□
Determines how interlocked feathers are to determine
how aerodynamic it is
□
-
○
Hair
Initial invagination of epidermal cells into the dermis to form the
hair follicle
○
Hair shaft is formed by outward growth of keratinized epidermal
cells
○
Arrector Pili
Muscle attached to the hair follicle
-
Used to pull hair upright
-
○
Similarities between Hair and Feathers
Dermal papillae
○
Shaft
○
Columns of specialized keratinized cells
○
Glands
Produce and secrete specific products
Mucus, oil, sweat, or milk
○
-
Mucous Cuticle
Layer of mucous that coats epidermis
○
-
Unicellular Gland
Single cell that secretes a product
○
Located in the epidermis
Interspersed between other living cells
-
○
-
Multicellular Gland
Many cells that secrete a product together through a common duct
○
Infolding of the epidermis into the dermis
Composed of epidermal cells located in the dermis
-
○
Duct allows secretions to be released on the outside of the body
○
-
Types of Glands
Sweat Gland
○
Sebaceous Gland
○
Mucus Gland
○
Poison (granular) gland
○
Mammary Gland
○
-
Dermal bone
Shell -thick layer of the dermal bone, outer layer of epidermal scale
Gastralia -Dermal bones located in the body wall of ventral abdomen
Protection
-
Sites for Muscle Attachment in lumbar region because lack of ribs
-
Antlers
Often found in males and shed anually
-
Covered by Velvet -shapes and provide blood to growing dermal
bone; outer layer of living skin
-
Velvet is shed when antlers are fully grown
-
Dermal Scales
Placoid
Teleost
Ctenoid
Cycloid
Enamel
Dentin
Pulp Cavity
Lamellar bone
Trabecular Bone
Tooth
Pelvic fins
Pectoral Fins
Claspers
Lateral Line
Endolymphatic Ducts
Cloaca
Cloacal Vent
Ampullae of Lorenzini
Uropygium
Urogygial Gland
Nares
Auditory Meatus
Scrotum
Testes
Nipples
Lab 5 - Integument (Skin) and its derivatives
DEFINITIONS
February 11, 2018
3:20 AM
Document Summary
Lab 5 - integument (skin) and its derivatives. Gives rise to the glands of the skin and keratinized structure. Located in the innermost layer of the epidermis. New cells pushed to the outer surface of the epidermis to replace old cells that are worn away by environment. Dead because or regulated self-destruction to produce keratin. Beneath the epidermis linked via the basement membrane. Contain fatty deposits, smooth muscle, blood vessels, and nerves. Animals that actively regulate body temperature by producing heat from metabolic processes. Cannot dissect, will be lost in small flakes or shed via moulting. Curved and laterally compressed projections from the tips of digits. Produced at nail base but push existing nail forward. Enlarged keratinized plates found on ends of ungulate digits. Protect tissue and bone in the hoof capsule. Series of keratinized plates that hang from upper jaw along its. Series of keratinized plates that hang from upper jaw along its length.
