2. WHAT IS THE INTEGUMENT?
• The Integument is one of the largest and most extensive
organ systems in the body. It is composed of all four tissue
types, it covers and protects underlying structures and forms a
critical barrier between the delicate inner workings of the
body and the harsh elements of the external world.
3. WHERE DO WE FIND IT?
• The skin together with related structures, forms the
integumentary system or common integument.
• This includes hair, hooves, horns, claws, and various skin
related glands.
• Itincludes the mucous membranes that line the mouth,
anus, and nostrils and has a remarkable ability to heal and
regenerate.
4. THE LAYERS OF SKIN
• Skin
forms two distinct layers: The
epidermis and the dermis.
• Only the dermis contains blood Epidermis
vessels.
•A third layer (the hypodermis) is
found below the dermis and is Dermis
composed primarily of adipose
tissues which act as a
thermoinsulator.
6. THE DERMIS
• The dermis makes up the greatest portion of the integument
and is responsible for most of the structural strength of the
skin.
• The dermis is highly fibrous
• The dermis contains two layers:
• The Papillary layer
• The Dermal Papillae
7. COMPLETE THE
TEST YOURSELF
QUESTIONS AS
WELL AS THE FIRST
EXERCISE :)
8. • Pigmentation:
SPECIAL FEATURES
• Pigmentation is caused by the
presence or absence of melanin
granules in the armlike extensions of
the melanocytes.
• Paw Pads:
• The feet of many animals are
padded and quiet. The pad’s outer
surface is the toughest and thickest
skin on the body.
• Ergots or Chestnuts:
• These are dark, horny structures
found on the legs of horses, ponies
and other members of the equine
family.
9. SPECIAL FEATURES
• Planum Nasale:
• The top of the nose in
cats, dogs, pigs, and
sheep is called the
planum nasale.
• In the cow and horse,
the nose is commonly
called the muzzle and is
technically referred to
as the planum
nasolabiale.
10. SPECIAL FEATURES
• Cutaneous Pouches in
Sheep:
• Cutaneous pouches are
infoldings of skin found in
sheep. They are found in front
of the eyes, between the digits
above the hooves, and in the
groin.
• These pouches are technically
called infraorbital, interdigital,
and inguinal pouches.
11. RELATED STRUCTURES OF
THE INTEGUMENT
Hair
Glands of the skin
Claws and Dewclaws
The Hoof
Horns
12. HAIR
• For
most animals hair is essential for survival. Hair helps in
maintaining body temperature.
• Animalspossess a variety of hair types: In general, hair has
been categorized into three broad groups:
• Primary or Guard Hairs
• Straight and thicker
• Secondary or Wool Type Hairs
• Shorter, Wavy and bristled in dogs
• Tactile or Sinus Hairs
• These are used as probes and feelers
14. GLANDS
• Two types of sweat glands are
apocrine glands, with ducts that
connect to hair follicles, and
eccrine glands, which empty
directly onto the skin surface.
• Sweat glands are meant to trap
moisture on the skin surface in
order to prevent drying out.
15. CLAWS AND DEWCLAWS
• Many animals have claws, which are the hard, often pigmented
outer coverings of the distal digits. Claws are important for
maintaining good traction while running, walking and climbing
and serve as a lifesaving tool for defense and for catching prey.
• Dewclaws are the remains of digits that have regressed in the
course of evolution.
• In dogs, the dewclaw is the first digit.
• Incattle, pigs and sheep the medial and lateral dewclaws
are the second and fifth digits.
16. THE HOOF
• Thetechnical name for the
hoof is the Ungula.
• Ruminant animals have four
hooves per foot, however
weight is only carried on two of
them.
• Bothclaws and hooves rest on
underlying sensitive tissue called
the corium.
17. HORNS
• Horns are epidermal in origin
and are structurally similar to hair.
• Hornsgrow continuously
throughout the animals life.
• Many domesticated animals are
dehorned using a variety of
instruments available depending
on the species and the age of the
animal.
• Animals can be genetically bred
to be horn free. These are called
“polled” breeds.
