Hair, Footpads..& Skin & Integumentary System Flashcards
Term “COMMON INTEGUMENT” means?
Role of Skin?
Layers of skin include ? and ?
Skin rests on a ? named ?
label the pic
Common integument: ordinary skin w its covering of hair and variety of skin glands as well as more specialized parts such as claws, hoofs and horns
Role of skin:
1. covers the body and protects it against injury
2. temperature control
3. enables the animal to respond to various external stimuli
Layers of skin include the epidermis and dermis
Skin rests on a looser connective tissue named subcutis, hypodermis and superficial fascia
HAIR
- Diagnostic of the class
- Thick haircoat is spread over the body (in most or some species?)
- except about the ? and ? and on the ? of the feet
- Domestic pig: the covering is ?
Only three types of hair need to be distinguished:
- straight, rather stiff **? provide a “?”;
- fine, ? hairs provide an “undercoat”;
- stout ? of restricted distribution are associated with touch receptors.
label the pic
HAIR
- Diagnostic of the class
- Thick haircoat is spread over the body (in most species)
- except about the mouth and other openings and on the surfaces of the feet
- Domestic pig: the covering is sparse
Only three types of hair need to be distinguished:
- straight, rather stiff guard hairs provide a “topcoat”;
- fine, wavy wool hairs provide an “undercoat”;
- stout tactile hairs of restricted distribution are associated with touch receptors (e.g. whiskers, in ears, at root have neuron endings for mechanical touch)
HAIR
Responsible for the colour is:
- ? => it is a pigment which is produced in a ? known as ?.
- Also gives ? to the skin
FYI - Absence of melanin: Albinism
“congenital absence of any pigmentation or coloration in a person, animal or plant, resulting in white hair, feathers, scales and skin and pink eyes in mammals, birds, reptiles, amphibians and fish and other small invertebrates as well.”
Guard hairs
- Lie close against the skin and sweep uniformly in broad tracts;
- provides the coat w a ? appearance distrubed only by the ?, ?
- it promotes the runoff of rain, preventing the ? that would occur if water were allowed to ? the pile to reach the skin.
- occasionally, animals are born w/ a ? coat pattern, which may seriously impair ?
- each hair grows from a ? that protrudes above the ?
Guard hairs
- Lie close against the skin and sweep uniformly in broad tracts;
- provides the coat w a smooth appearance distrubed only by the whorls, crests;
- it promotes the runoff of rain, preventing the chilling that would occur if water were allowed to penetrate the pile to reach the skin.
- occasionally, animals are born w/ a disturbed coat pattern, which may seriously impair their ability to withstand severe weather.
- each hair grows from a tiny pit called follicle that protrudes above the skin
Guard hairs
The follicle develops from an ectodermal bud;
The distal end of the bud forms a bulbous enlargement, which is then indented by a mesenchymal (dermal) papilla to form a primitive hair follicle.
HAIR
Guard Hairs
LOCAL VARIATIONS in the ? and ? of guard hairs:
- in pigs: stiff, ? scattered ? of pigs
- in horses: the ? hair of the mane and tail of horses
- the long ? hairs of cattle
- the ? of horses
- the ? of the tail and limbs of certain breeds of dogs
LOCAL VARIATIONS of guard hair are:
- are *? dependent
- evident in the ? species
Lives:
- Hairs have ? lives and are discarded sooner or later
- Although hair shedding in humans is a ? process involving a ? hairs at a time, most other species, especially wild species, shed ? hairs at a time in a seasonal fashion.
HAIR
Guard Hairs
LOCAL VARIATIONS in the form and development of guard hairs:
- in pigs: stiff, bristle scattered bristles of pigs
- in horses: the coarse hair of the mane and tail of horses
- the long tail hairs of cattle
- the fetlock tufts of horses
- the featherings of the tail and limbs of certain breeds of dogs
LOCAL VARIATIONS of guard hair are:
- are *hormone-dependent
- evident in the human species
Lives:
- Hairs have restricted lives and are discarded sooner or later
- Although hair shedding in humans is a contrinual process involving a few hairs at a time, most other species, especially wild species, shed a lot of hairs at a time in a seasonal fashion.
Domesticated animals shedding:
- Show a ? pattern with peaks in the which seasons? spring shedding lasts about ? in dogs
- More obvious in animals not regularly groomed to ?
- Cats also molt most heavily in ?, with less substantial loss through which seasons? followed by attaining prime condition in ?
Wool hairs:
- Provide the ?
- Thick or thin?
- straight, curly or wavy?
- ? and more ? then the guard hair
- Concealed between the guard hair
Wool hairs
- In many species, including mature dogs and cats, several hairs share a ?
- The ? hair is the longest and of the guard type
- The ? hairs are shorter and ?
- They provide the ? and may be designated wool hairs because they have little medulla.
In the image which one is
- a simple follicle = A, B or C
- follicle present during the first few
months after birth
- complex adult follicle
Domesticated animals shedding:
- Show a recurrent pattern with peaks in the which spring and fall. spring shedding lasts about 5 weeks in dogs
- More obvious in animals not regularly groomed to dead hair.
- Cats also molt most heavily in spring, with less substantial loss through which summer and fall followed by attaining prime condition in winter.
Wool hairs:
- Provide the soft undercoat
- Thick or thin? Thin
- straight, curly or wavy? - wavy
- shorter and more numerous than the guard hair
- Concealed between the guard hair
Wool hairs
- In many species, including mature dogs and cats, several hairs share a single opening
- The central (primary) hair is the longest and of the guard type
- The surrounding (secondary) hairs are shorter and softer
- They provide the undercoat and may be designated wool hairs because they have little medulla
HAIR
TACTILE HAIR
substantially ?
generally protrude beyond the neighboring ? hairs
reach deep into the ? or even the ? muscles
characterized by the presence of a ? filled with ? and located between inner and outer layers of the ?
nerve endings responsive contained within the which sheath ?
Topography:
on ?,
principally on the ? and near the ?,
although others are scattered (in species-variable fashion) on the ?, the ?, and elsewhere on the head.
Functionality:
? responsive to mechanical stimulation
the stimulus provided by disturbance of the hair is ? by ? in the blood
**Development:
follicles of tactile hairs start appearing first when ?
HAIR
TACTILE HAIR
substantially thicker
generally protrude beyond the neighboring guard hairs
reach deep into the subcutis or even the superficial muscles
characterized by the presence of a venouos sinus filled with blood and located between inner and outer layers of the dermal sheath
nerve endings responsive contained within the dermal sheath
Topography:
on face
principally on the upper lip and near the eyes,
although others are scattered (in species-variable fashion) on the lower lip, the chin, and elsewhere on the head.
Functionality:
nerve endings responsive to mechanical stimulation
the stimulus provided by disturbance of the hair is amplified by wave motion in the blood
**Development:
follicles of tactile hairs appear early in development, before those of the coat hairs.
FOOTPADS
? = A bulging or rounded projection or swelling
The term Torus - used in connection with the common integument, denotes a ?.
It includes the ? covering, the ?, and the ?
Structure:
- naked, ? epidermis
- dermis is ? (not particularly interesting)
- thick, resilient ?
- admixture of ? and ? interspersed with adipose tissue (fat)
The footpads are the ? on which animals walk
PLANTIGRADE
- Footpads of a bear, forelimb (left) and hindlimb (right). label the #s
DIGITIGRADE
- Footpads of canine (A) forelimbs and (A′) hindlimbs and of (B) feline forelimb. label the #s (in answer)
Torus/Tori = A bulging or rounded projection or swelling
The term Torus - used in connection with the common integument, denotes a pad.
It includes the thick epidermal covering, the dermis, and the subcutaneous cushion, or Pulvinus.
Structure:
- naked, densely cornified epidermis
- dermis is unremarkable (not particularly interesting)
- thick, resilient subcutis
- an admixture of collagenous and elastic fibers interspersed with adipose tissue (fat)
The footpads are the digital cushions on which animals walk
PLANTIGRADE (pic in Q.)
Footpads of a bear, forelimb (left) and hindlimb (right). 1, Digital pads; 2, metacarpal pad; 3, metatarsal pad; 4, carpal pads; 5, tarsal pad, fused with the metatarsal pad.
DIGITIGRADE (pic in A.)
Footpads of canine (A) forelimbs and (A′) hindlimbs and of (B) feline forelimb. 1, Digital pads; 2, metacarpal pad; 3, metatarsal pad; 4, carpal pad; 5, carpal gland and associated tactile hairs.
FOOTPADS
Ruminants and pigs:
- only digital pads called ? located in the hoof
Horse
- only digital pads called ? located in the hoof
functional and in contact with the ?
FOOTPADS
Ruminants and pigs:
- only digital pads called bulb located in the hoof
Horse
- only digital pads called frog located in the hoof
functional and in contact with the ground
chestnuts above carpus = vestigial carpal pads
chestnuts below hock = vestigial tarsal pads
Nails, Claws, and Hoofs
Similar structures enclosing the ? appear strikingly different
? modifications of skin
Serve primarily to protect the ?
Used for list 4 things?: -
Equine Hoof
** reduces ? on ? **
Presents three parts: what are they?
THE WALL
- strongly ?
- the sides are sharply inflected to form the so-called ?
white line in the image in ans. is white as it is ?
Equine Hoof
space between the bars is occupied by the *? which is the part of the footpad that makes contact with the ground
Nails, Claws, and Hoofs
Similar structures enclosing the distal phalanx appear strikingly different
local modifications of skin
Serve primarily to protect the underlying tissues
Used for list 4 things?: -
1. weapon
2. scratching
3. digging
4. grabbing food
Equine Hoof
** reduces concussion on foot pad**
Presents three parts: what are they?
1. wall
2. sole
3. Associated pad (horny structure; it corresponds with the digital bulb of primates and the digital pad of carnivores)
THE WALL
- strongly curved
- the sides are sharply inflected to form the so-called “bars”
white line in the image is white as it is avascular so no blood vessels
Equine Hoof
space between the bars is occupied by the “FROG” which is the part of the footpad that makes contact with the ground
Equine Hoof
the sole horn that fills the ground surface between wall and frog meets the wall at a junction known as the ?
Equine Hoof
Periople
* band of ?
* lies over the ? of the wall near its junction with the ?
* it descends with the wall and dries to a ?
* widens at the back of the hoof, where it covers the ? of the heels and part of
the frog.
CLAWS IN CARNIVORES
Compared with a nail that has been laterally compressed. (image in ans)
Characteristics:
* sharp ? border
* epidermis is ? productive
* the dermis that covers the unguicular process fuses with the ?
* longitudinal interdigitations between dermal and epidermal laminae strongly bond the ? to the dorsal border of the bone
Equine Hoof
the sole horn that fills the ground surface between wall and frog meets the wall at a junction known as the “white line”
Equine Hoof
Periople
* band of soft horn
* lies over the external surface of the wall near its junction with the skin
* it descends with the wall and dries to a protective glossy layer
* widens at the back of the hoof, where it covers the bulbs of the heels and part of
the frog.
CLAWS IN CARNIVORES
Compared with a nail that has been laterally compressed. (image in ans)
Characteristics:
* sharp dorsal border
* epidermis is minimally productive
* the dermis that covers the unguicular process fuses with the periosteum
* longitudinal interdigitations between dermal and epidermal laminae strongly bond the claw to the dorsal border of the bone
HORNS
Horns of domestic ruminants:
* have ? bases provided by the ? processes of the frontal bones
* are permanent and grow ? after their first appearance soon after ?.
HORNS
1. ? frontal ? extending into horn (look at image for further understanding);
2. ? process of the frontal bone
PRACTICE QUESTIONS
1. The cornual process in cattle is invaded by the ? sinus.
2. look at image. Label.
- Which one of the following statements is correct statement regarding wavy wool hairs?
A. Are associated with touch receptors
B. Are longer and less numerous than the guard hair
C. Have cortex
D. Provide a ‘topcoat’
E. Provide an ‘undercoat’
HORNS
Horns of domestic ruminants:
* have osseous bases provided by the cornual processes of the frontal bones
* are permanent and grow continuously after their first appearance soon after birth.
HORNS
1. caudal frontal sinus extending into horn (look at image for further understanding and also to see what cornual process is (top left in pic);
2. cornual process of the frontal bone
PRACTICE QUESTIONS
1. The cornual process in cattle is invaded by the “frontal” sinus.
- Which one of the following statements is correct statement regarding wavy wool hairs?
E. Provide an ‘undercoat’ - CORRECT - wall of claw option correct
The Skin and the Integumentary System
Skin:
* ? sensory organ in the body
* Covers the body thereby protecting ? and ?
* Very important for ? in animals
- ? in localized parts of the skin functions as
visual signals
The skin helps animals recognize the structure of ?, their ? and ?.
In humans, the skin is an essential component of our affective ?.
Functions of Skin
Protection of the body against ? and ? injury by 3 mechanisms
** 1. ? - Hair and keratinized surface which protect against ?, ?, and ? & ? of superficial cells and hair helps regulate number of microorganisms and debris on skin surface
2. ? - Antibacterial and antifungal properties
3. ? (aka skin microbiome) - Prevents invasion by pathogenic bacteria by occupying microbial niches and producing compounds that inhibit the growth of other microorganisms **
Other Functions of Skin
? barrier
?
? (pressure, temperature, pain)
Transmission of ? and ? signals
? storage
Synthesis of ?, which is converted to vitamin D3 by ultraviolet light
The Skin and the Integumentary System
Skin:
* Largest sensory organ in the body
* Covers the body thereby protecting cells and tissues
* Very important for communication in animals
- Piloerection in localized parts of the skin functions as visual signals
The skin helps animals recognize the structure of surfaces, their composition, and temperature.
In humans, the skin is an essential component of our affective behaviour.
Functions of Skin
Protection of the body against chemical and mechanical injury by 3 mechanisms
- physical structure of skin - Hair and keratinized surface which protect against loss of water, electrolytes, and other constituents & turnover (shedding) of superficial cells and hair helps regulate number of microorganisms and debris on skin surface
- secretory products - Antibacterial and antifungal properties
- Normal bacterial flora (aka skin microbiome) - Prevents invasion by pathogenic bacteria by occupying microbial niches and producing compounds that inhibit the growth of other microorganisms
Other Functions of Skin
immunologic barrier
thermoregulation
sensory information provision (pressure, temperature, pain)
Transmission of emotional and chemical signals
fat storage
Synthesis of 7-dehydrocholestrol, which is converted to vitamin D3 by ultraviolet light
Skin structure:
Use the weblink on the previous slide and the figure on the right to help you fill in the blanks:
Three main components of the skin:
1.The ?, the outermost layer of skin, a multilayered epithelium
2.The ________, an underlying layer of dermis
vascularized connective tissue
3. The subcutis or hypodermis, also known as the ** ? ** layer.
4. ** ? **, such as hair, feathers, and glands
The epidermis
The epidermis is made up of four cell layers: (image in ans.)
- ? (layers of keratinized, dead cells still connected by desmosomes)
- ? (flattening of cells, high keratin content)
- ? (cells joined by Desmosomes providing mechanical strength)
- Desmosomes = prominent ? junctions
- ? (stem cells)
for hairless skin dogs, is the skin thick or thin relative to the skin in haired skin?
Skin structure:
Use the weblink on the previous slide and the figure on the right to help you fill in the blanks:
Three main components of the skin:
* The epidermis, the outermost layer of skin, a multilayered epithelium
* The dermis, an underlying layer of dermis
vascularized connective tissue
* The subcutis or hypodermis also known as the subcutaneous layer.
* Accessory structures such as hair, feathers, and glands
The EPIDERMIS
The EPIDERMIS is made up of four cell layers: CGSB (image in ans.)
- stratum corneum (layers of keratinized, dead cells still connected by desmosomes)
- stratum granulosum (flattening of cells, high keratin content)
- stratum spinosum (cells joined by Desmosomes providing mechanical strength)
- Desmosomes = prominent ? junctions
- stratum basale (stem cells)
for hairless skin dogs, is the skin thick or thin relative to the skin in haired skin? - THICK because no hair
The Skin and the Integumentary System
The four cells of the epidermis are?
1) Keratinocytes:
* Produce ?, the major ? protein in the epidermis
* Contribute to the formation of the ?
* Makes up the majority of the structure of the ?, ?, and ?
Keratin synthesis and the formation of the epidermal water barrier:
Cell division occurs in the stratum basale (basal layer) - > These cells synthesize ? (intermediate keratin filaments).
Cells are pushed into the stratum ?; As it enters, tonofilaments synthesis continues and the cell begins to produce: * ? * that contain proteins (aid in aggregation of keratin filaments), helps convert granular cells to 1. cornified cells (process known as ?) & 2. glycolipids-containing?
- Cells are pushed into the stratum ? and continue to stratum ?.
- ? are discharged by exocytosis into the spaces between stratum granulosum and stratum corneum
- Lamellar bodies + ? -> epidermal water barrier
- The epidermal water barrier prevents entry of ? and ? as well as ? from the body
The four cells of the epidermis are: (KMLM - girl whos stays inside - wifey type)
Keratinocytes (the most predominant ones)
Melanocytes
Langerhans’ cells
Merkel’s cells
1) Keratinocytes:
* Produce keratin, the major structural protein in the epidermis
* Contribute to the formation of the epidermal water barrier
* Makes up the majority of the structure of the skin, hair, and nails
Keratin synthesis and the formation of the epidermal water barrier:
- Cell division occurs in the stratum basale (basal layer) - > These cells synthesize tonocytes (intermediate keratin filaments).
Cells are pushed into the stratum spinosum; As it enters, tonofilaments synthesis continues and the cell begins to produce: * keratohyalin granules * that contain proteins (aid in aggregation of keratin filaments), helps convert granular cells to 1. cornified cells (process known as keratinization) & 2. glycolipids-containing lamellar bodies.
- Cells are pushed into the stratum granulosum and continue to the stratum corneum.
- lamellar bodies are discharged by exocytosis into the spaces between stratum granulosum and stratum corneum
- Lamellar bodies + lipid envelope -> epidermal water barrier
- The epidermal water barrier prevents entry of microbials and fluids as well as fluid loss from the body
The Skin and the Integumentary System
2) Melanocytes:
Melanocyte precursor cells originate in the ? crest
Melanocytes are in close association with a number of ? in the epidermis
Normally located in stratum ? are easily recognized by the presence of IMP inside “dendritic” processes
Melanin protects the skin against?
Synthesis starts in pre-melanosomes from the amino acid ?
As more melanin is produced, melanosomes become more visible at the ? being then transferred to neighboring ? (known as ** ? **)
- Light skin vs dark skin melanin degradation
Lysosomal activity degradation of melanin is faster in individuals with ? skin than in individuals with ? skin and melanosomes are distributed only in ?
Two forms of melanin pigments (genetically determined):
? -> brownish black
? -> reddish yellow
Exposure to UV light accelerates the rate of ? as a way to protect the skin
The Skin and the Integumentary System
2) Melanocytes:
Melanocyte precursor cells originate in the neural crest
Melanocytes are in close association with a number of keratinocytes in the epidermis
Normally located in stratum basale are easily recognized by the presence of melanin granules inside “dendritic” processes
Melanin protects the skin against nonionizing UV radiation
Synthesis starts in pre-melanosomes from the amino acid tyrosine
As more melanin is produced, melanosomes become more visible at the tip of the dendritic process being then transferred to neighboring keratinocytes (known as ** pigment donation **)
- Light skin vs dark skin melanin degradation
Lysosomal activity degradation of melanin is faster in individuals with light skin than in individuals with dark skin and melanosomes are distributed only in stratum basale
Two forms of melanin pigments (genetically determined):
eumelanin -> brownish black
pheomelanin -> reddish yellow
Exposure to UV light accelerates the rate of melanin production as a way to protect the skin
3) Langerhans’ cell:
Can be seen in the stratum ?
* First line defenders, play a role in ?
* Aka ? are antigen-presenting
cells
4) Merkel’s cells:
? epidermal cells found in stratum
?
* Most abundant in skin where sensor perception is ?, such as ?
Merkel’s cells are associated with a terminal disk of an ? nerve fiber (? -> mechanoreceptor)
The dermis
Strong and ? connective tissue composed by cells and ? fibers
Cells of the dermis:
* ? (primary cells)
list.3 more
Tissue derived from the epidermis extend into the dermis and gives rise to ?, ? and ? that form hair and feathers
3) Langerhans’ cell:
Can be seen in the stratum spinosum
* First line defenders, play a role in antigen presenting cell
* Aka dendritic cells are antigen-presenting
cells
4) Merkel’s cells:
modified epidermal cells found in stratum
basale
* Most abundant in skin where sensor perception is acute, such as fingertips
Merkel’s cells are associated with a terminal disk of an afferent nerve fiber (merkel’s corpuscle -> mechanoreceptor)
The dermis
Strong and flexible connective tissue composed by cells and collagen fibers
Cells of the dermis: FMLM (KMLM = cells of the epidermis)
* fibroblasts (primary cells), macrophages, leukocytes, mast cells
Tissue derived from the epidermis extend into the dermis and gives rise to sweat glands,
sebaceous glands, and the papillae that form hair and feathers
Other nerve endings in the skin
Meissner: In ** IMP ? ** skin only; ?receptors
Merkel
Pacini (P P in pacini and pressure): deep pressure receptors for ? and ? pressure
Hair folicle sensor: only in ?; mechanoreceptors (tactile hairs)
Ruffini: respond to mechanical ? of adjacent collagen fibers
The Skin and the Integumentary System
Hairs
* Hair follicles are formed by invaginations of the ? into the ?
* After a skin injury, cells in ? are
capable of forming new hair follicles
* At the deep end, each follicle is expanded into a hair root or ** ? ** that surrounds a portion of dermis, the ?
* The ? region of the hair bulb produces new daughter cells that are pushed towards the ?
The hair shaft consists of ? epithelial cells that are pushed from the hair root outwards the root canal
- ** ?: single layer of dead, scale-like keratinocytes
- ** ?: several layers of dead keratinocytes
containing hard keratin - ** ?: dead loosely keratinized cells
** ?? ** (aka arrector pili m.): a smooth muscle associated to hair bulb and anchored to the outer layer of the dermis (sympathetic innervated)
Hair follicules have cycles of activity:
? (Growth) -> ? (regression) -> ? (resting) -> ? (shedding)
Other nerve endings in the skin
Meissner: In ** hairless ** skin only; touchreceptors
Merkel
Pacini (P P in pacini and pressure): deep pressure receptors for mechanical and vibratory pressure
Hair folicle sensor: only in haired skin; mechanoreceptors (tactile hairs)
Ruffini: respond to mechanical displacement of adjacent collagen fibers
The Skin and the Integumentary System
Hairs
* Hair follicles are formed by invaginations of the epidermis into the dermis
* After a skin injury, cells in stratum basale are
capable of forming new hair follicles
* At the deep end, each follicle is expanded into a hair root or ** hair bulb ** that surrounds a portion of dermis, the hair papilla
* The matrix region of the hair bulb produces new daughter cells that are pushed towards the surface
The hair shaft consists of keratinized epithelial cells that are pushed from the hair root outwards the root canal
- ** cuticle : single layer of dead, scale-like keratinocytes
- ** cortex: several layers of dead keratinocytes
containing hard keratin - ** medulla: dead loosely keratinized cells
** Piloerecter muscle ** (aka arrector pili m.): a smooth muscle associated to hair bulb and anchored to the outer layer of the dermis (sympathetic innervated)
Hair follicules have cycles of activity:
anogen (Growth) catogen ? (regression) -> telogen (resting) -> exogen (shedding)
Feather Types
- ? feathers
- ? feathers (? feathers)
The ? is the flat part of the feather
It consists of ** ? ** that are at angles of about 45 °
The ** ? **, which are present only on the * ? * on one side of the barb, hook onto the smooth barbule from the adjacent barb
- The barbules of down feathers lack ?
Feathers from the same feather follicle can have different ?
Thermoregulation
Heat transport to the skin. Heat passes through layers with good insulation properties, the subcutaneous adipose tissue and fur or plumage.
Mechanisms of heat exchange ->
a. radiation: solar radiation (short waved); radiation from body surface (long waved)
b. convection and conduction (wind goes to body and heated air goes out of body dorsally known as convection and some of it also goes down into the ground known as conduction
c. evaporation: exhaled water vapor goes out of cranial aspect of body and evaporation from skin to outside
Feather Types
- flight feathers
- cover feathers (down feathers)
The vane is the flat part of the feather
It consists of ** bards ** that are at angles of about 45 °
The ** hooklets **, which are present only on the * barbules * on one side of the barb, hook onto the smooth barbule from the adjacent barb
- The barbules of down feathers lack hooklets
Feathers from the same feather follicle can have different pigmentation
Thermoregulation
Heat transport to the skin. Heat passes through layers with good insulation properties, the subcutaneous adipose tissue and fur or plummage.
Mechanisms of heat exchange ->
a. radiation: solar radiation (short waved); radiation from body surface (long waved)
b. convection and conduction (wind goes to body and heated air goes out of body dorsally known as convection and some of it also goes down into the ground known as conduction
c. evaporation: exhaled water vapor goes out of cranial aspect of body and evaporation from skin to outside
Sweat glands
* Eccrine glands:
- Very common in ?
- Open in ? at the skin surface
- Ionic composition is similar to the ?. In the duct, ?and ? are reabsorbed
- Degree of reabsorption depends on the ? rate
- Apocrine glands:
- Very common in ?
- Open into/attched to hair ?
- Odoriferous secretion composed of ? and ?
Mammary gland
Glands + teats = The udder
? (?): milk-producing units
?: clusters of alveoli
?: clusters of lobuli
? required for milk production diffuse from blood capillaries and enter into the ?
? cells are involved in milk ejection
Cornified epidermal structures
* ?, ?, and ? in mammals
* ? in reptiles and birds
* ? in turtles and birds
* ? and ? in reptiles
* ? in fish
Hooves
Horny hoof wall is formed by ? of the cells in the coronary band. Recently produced horn is pushed ? as new horn is being formed
At the coronary band the dermis of the ? is continuous with the dermis of the hoof.
In equine eosinophilic granuloma, eosinophils and macrophages are the primarily inflammatory cells. They are found in what skin layer and cell layer if they stimulate the maturation of Langerhans cells and dendritic cells?
What is a concern if corticosteroids are used when thinking about the hoof? (Hint look up condition in Merck Vet Manual)
Sweat glands
* Eccrine glands:
- Very common in primates
- Open in pores at the skin surface
- Ionic composition is similar to the plasma. In the duct, Na and Cl- are reabsorbed
- Degree of reabsorption depends on the secretion rate
- Apocrine glands:
- Very common in domestic animals
- Open into/attched to hair follicle
- Odoriferous secretion composed of fatty acids and proteins
LOBI > Lobuli > alveoli
Mammary gland
Glands + teats = The udder
alveoli (acini): milk-producing units
lobuli: clusters of alveoli
lobi: clusters of lobuli
nutrients and water required for milk production diffuse from blood capillaries and enter into the epithelial cells
myoepithelial cells are involved in milk ejection
Cornified epidermal structures
* hoofs, claws, and horns in mammals
* claws in reptiles and birds
* beaks in turtles and birds
* shells and scales in reptiles
* scales in fish
Hooves
Horny hoof wall is formed by keratinization of the cells in the coronary band. Recently produced horn is pushed downward as new horn is being formed
At the coronary band, the dermis of the skin is continuous with the dermis of the hoof.
skin layer: epidermis
cell layer: stratum spinosum
What is a concern if corticosteroids are used when thinking about the hoof? equine laminitus
