1. The document outlines different types of glands found in the skin, including simple and compound tubular and saccular glands. 2. Examples of simple tubular glands given are sweat glands and ceruminous glands, while mammary glands are identified as compound tubular glands. 3. The skin of mammals is described as the most complex, with two main layers - the epidermis and dermis, along with associated structures like hair, claws/nails, and glands.

2. OUTLINE

15. TYPES CHARACTERISTICS EXAMPLES
1. Simple Tubular - Short blind tubes located in
the epidermis
-Thumb pads( male anurans)
-Ceruminous
glands(mammals)
2. Simple coiled tubular - Long, narrow tube, coiled
distal end located in
epidermis
- Sweat glands of mammals
3. Simple branched tubular - Divides at its distal end to
two or more
- Terminal portions may or
may not be coiled
- Large sweat glands of
axillae or armpit
4. Compound tubular - Consist of varying number of
simple tubular glands
-Mammary glands of
monotremes

16. TYPES CHARACTERSTICS EXAMPLES
1. Simple saccular - With only one
expanded bulb or acinus
at the end of the duct
- Mucous and poison
glands in skin of
amphibians
2. Simple branched
saccular
- With several acini
arranged along single
excretory duct
- With single acinus
divided by partitions into
smaller acini
- Meibomian glands of
eyelid
- Sebaceous gland of
skin
3. Compound saccular - Consist of several
simple saccular glands
(lobules)
- Mammary glands of
matatherian and
eutherian mammals

21. Mucous gland - Frog skin

22. Serves as exoskeleton
of vertebrates for
protection of the body

27. Modified reptilian
scales formed from
the beta keratin
layer of the
epidermis

29. - Found in ALL MAMMALS and is composed
primarily of alpha keratin of epidermis
- Consists of a base or root and a shaft or the
remaining length of the stand.

43. Skin in Mammals
• most complex system
• relatively thick
• have hair
• layer of insulation (fat) – hypodermis
• Composed of two other layers of cells,
epidermis and dermis

44. The epidermis made up of cell types:
• Keratinocytes – most prominent cell type
• Langerhans cells – participate in immune
response
• Merkel cells – connected with sensory nerves
(mechanoreceptors)
• Chromatophores – secrete pigment melanin
- In humans, melanophores protect us
against Uv rays

45. Dermis
• composed of irregularly arranged fibrous CT
• blood vessels, nerves and smooth muscles
• produces dermal bones
• With rich blood supply
• Many hair follicles, sweat and sebaceous glands
• divided into two sub layers, outer papillary
layer(dermal papillae) and the deeper reticular
layer
• separated by a superficial fascia

48. Claws, Nails, and Hooves
• Most tetrapods (+) claws
• Primates have nails – flattened version of
claws
• Hooves- UNGULATES

49. Hooves-homologous to fingernails in
amniotes

50. • Since the dermis may have a potential to form bones…

51. Antlers vs.Horns
• Antlers – made of bone ( family CERVIDAE)
• Horns – have an outer keratinized layer
(family BOVIDAE)

52. Fishes Amphibians Reptiles Mammals Birds
Epidermis -very thin w/
2 types of
cell:
● epidermal
cells
●unicellular
glands
-mucous
cuticle on
surface.
-with thin
stratum
corneum
and very
little
keratin;
Leydig cells
- epidermal
scale, with
thick outer
layer of
keratin
Epidermis
with 5
layers :
-corneum
-lucidum
-granolosum
-spinosum
-basale
-thin and
bilayered
Comprises
of:
-corneum
-basale

53. Fishes Amphibians Reptiles Mammals Birds
Dermis - contains
chromato
phores.
-organized
into
regular
layers of
fibrous
connective
tissue.
-with
chromatopho
res, poison
glands and
mucous
glands.
- composed
of fibrous
connective
tissues.
- With
chromatop
hores in
many. May
possess
Osteoderms
- fibrous
connectve
tissues.
well-vasculari
zed and
innervated
- Outer
papillary
layer
- Deeper
reticular
layer
well-vasculari
zed and
innervated
-richly
supplied by
blood
vessels,
sensory
nerves and
smooth
muscles.