Integument lecture 2- glands, digital organs, horns

Question 1

what are the 2 main kinds of exocrine glands?

Answer 1

1. simple
2. compound

Question 2

what are the 7 types of simple exocrine glands?

Answer 2

1. simple straight tubular
2. simple coiled tubular
3. simple branched tubular
4. simple acinar
5. simple alveolar
   6, simple branched acinar
6. simple branched alveolar

Question 3

where do simple exocrine glands open to/empty their product?

Answer 3

open to secretory surface

Question 4

where do compound exocrine glands open to/empty their product?

Answer 4

not a secreting surface, so empty product into ducts that transport product to target/secretory surface

Question 5

describe the alveolar gland shape

Answer 5

like a balloon with a large lumen

Question 6

describe the acinar gland shape

Answer 6

like a grape with a small lumen

Question 7

what are the 3 kinds of compound exocrine glands?

Answer 7

1. compound tubuloacinar/tubuloalveolar
2. compound tubular
3. compound acinar/alveolar

Question 8

define the anal sacs

Answer 8

paired cutaneous diverticula that open into the anal canal at the anocuteneous junction

Question 9

what tissue type are the ducts and sacs of the anal glands composed of?

Answer 9

stratified squamous epithelium

Question 10

what kind of glands do cats have in their anal sacs? what about dogs?

Answer 10

cats: apocrine and sebaceous
dogs: apocrine only!

Question 11

what are the circumanal glands? common issue with them? what do they look like on histology?

Answer 11

modified sebaceous glands, different from the actual glands of the anal sacs, located around the anus; frequent site of canine tumors; look like christmas stockings hanging from the mantle (skin surface)

Question 12

what kind of glands are mammary glands?

Answer 12

compound tubuloalveolar glands

Question 13

describe the lobes of mammary glands

Answer 13

the larger structures; number varies with species and between individuals, but possess a considerable amount of CT between lobes

Question 14

describe the lobules of the mammary glands

Answer 14

individual groups of tubuloalveolar secretory units

Question 15

what is the actual secretory unit of the mammary glands? what tissue type?

Answer 15

alveoli; simple cuboidal epithelium

Question 16

how are the lipids of milk secreted by alveoli?

Answer 16

via apocrine secretion

Question 17

how are the proteins of milk secreted by alveoli?

Answer 17

via merocrine secretion

Question 18

what type of secretion is responsible for milk?

Answer 18

BOTH apocrine (lipid) and merocrine (proteins)

Question 19

what forces milk into the duct?

Answer 19

myoepithelial cells contract in response to oxytocin

Question 20

describe the tissue type of the ducts of the mammary glands

Answer 20

very from simple cuboidal epithelium (the smaller ducts) to bistratified cuboidal epithelium; surrounded by increasing amounts of CT as approach the progressively larger ducts

Question 21

describe the structure of the teat; describe teat sinus, teat canal, and teat canal tissue type

Answer 21

comprised of a teat sinus (cistern) which is continuous with the larger ducts; leads to a teat canal which is continuous with the surface of the skin and is lined with stratified squamous keratinized epithelium

Question 22

what are the 6 components of a digital organ?

Answer 22

1. a keratinized portion
2. a dermis portion
3. hypodermis
4. bones
5. associated structures of bones
6. digital pads

Question 23

what is the horn comprised of (relating to hoofs and claws)

Answer 23

horn is comprised of the keratinized portion of hoofs and claws

Question 24

what are the 3 parts of the keratinized portion of the digital organ?

Answer 24

1. wall
2. sole
3. frog

Question 25

what are the 3 layers of the hoof wall of the hoof?

Answer 25

1. stratum externum
2. stratum medium
3. stratum internum

Question 26

describe the stratum externum of the wall of the hoof (3)

Answer 26

1. shiny, thin cornified material covering the walls and bulbs
2. originates from the germinal layers of the perioplic epidermis
3. consists of tubular and intertubular horn

Question 27

describe the stratum medium of the wall of the hoof (5)

Answer 27

1. consists of tubular and intertubular horn
2. provides the main support of the hoof
3. originates from the germinal layers of the coronary epidermis
4. tubular structures formed from the coronary papilla
5. intertubular horn formed from the interpapillary part of the coronary corium

Question 28

how long does it take for the hoof wall to grow from coronary border to ground/toe? what does this mean for disease?

Answer 28

6-9 months; is why diseases like laminitis are so devastating because hoof cannot heal before disease progresses too far

Question 29

what is the function of the tubular and intertubular horn of the hoof?

Answer 29

increases number of basal cells to increase rigidity

Question 30

describe the stratum internum of the hoof (4)

Answer 30

1. approx 600 primary vertically oriented keratinized laminae
2. secondary laminae project from the primary laminae
3. germinal cells of the secondary laminae multiply at a rate to keep up with the downward growth of the horny laminae
4. white line: the junction between the nonpigmented wall laminae and the pigmented tubular and intertubular horn of the sole

Question 31

describe the sole of the hoof

Answer 31

epidermis comprised of tubular and intertubular regions but horn material is softer than the wall

Question 32

describe the frog of the hoof

Answer 32

epidermis comprised of tubular and intertubular regions but horn material is softer than the sole

Question 33

describe claws

Answer 33

specialized structures continuous with the epidermis and dermis

Question 34

what do the claws/hoofs or ruminant consist of? (3)

Answer 34

1. wall
2. sole
3. bulbs (not frogs like equine)

Question 35

what do the claws of carnivores consist of? (2)

Answer 35

1. wall
2. sole