Integumentary System Exam 2 Flashcards
(100 cards)
1
Q
What is the skin beneath the toes and foot specialized to withstand?
A
- Compression from standing.
- Abrasion from contact with rough surfaces.
2
Q
What is the skin on the bottom of the foot described as?
A
Thick but flexible.
3
Q
What are the two parts of the beak?
A
- Internal skeleton of bone.
- Closely attached layer of highly keratinized skin over the bony skeleton.
4
Q
What is the epidermis of the beak called?
A
The rhamphotheca.
5
Q
What is the rhamphotheca described as?
A
Thick and horny.
6
Q
What is the egg tooth made of?
A
Strongly calcified keratin cells.
7
Q
What are the claws made of?
A
Keratinized epidermis.
8
Q
What does the claw root epidermis give rise to?
A
Flattened, keratinized cells that remain firmly stuck together.
9
Q
What are the wattle and the comb referred to as?
A
Accessory sexual epidermal appendages.
10
Q
What do the wattle and comb develop as a result of?
A
Production of sex hormones.
11
Q
Why are the wattle and comb bright red?
A
They are rich with blood vessels.
12
Q
What do chickens do with the wattle and comb when it is hot outside?
A
Dip it in water to aid in cooling.
13
Q
What is the preen gland described as?
A
Two-lobed, pea-sized structure that develops from the epidermis at the base of the tail.
14
Q
What does the preen gland discharge?
A
A fatty secretion.
15
Q
What type of secretory gland is the preen gland?
A
Holocrine.
16
Q
How is the fatty secretion created in the preen gland?
A
Cells get pushed to the middle as new cells form and the old cells break down.
17
Q
What is contained in the preen gland secretion?
A
- Non-saponifiable lipids.
- Saponifiable lipids.
- Lecithin.
- Cell breakdown products.
18
Q
What are lecithins?
A
A special phosphorous compound.
19
Q
What are saponifiable lipids?
A
Special fats that can be broken down by an alkali.
20
Q
In what types of birds are preen glands most important?
A
Aquatic birds.
*They develop earlier in aquatic birds.
21
Q
What are the area that feathers are confined to called?
A
Pteryla.
22
Q
What are areas devoid of feathers called?
A
Apteria.
23
Q
How do feathers increase in volume to trap air to keep warm?
A
Smooth muscles attached to the feather follicle contract, causing the feathers to become erect.
*It also works to release heat.
24
Q
What are the 5 types of feathers?
A
- Contour feathers.
- Plumules.
- Filo-Plumules.
- Down (chicks).
- Bristles.
25
What are the 9 parts of the contour feather?
1. Shaft or rachis.
2. Outer vane and inner vane or vexillum.
3. Parallel barbs.
4. Barbules.
5. Barbicels or hooklets.
6. Calamus or quill.
7. Superior umbilicus.
8. Inferior umbillicus.
9. After shaft or hypo-rachis.
26
How is the rachis described?
1. Four-sided.
2. Tapering.
3. Elastic.
4. Possess a longitudinal groove facing towards the body when the feathers are in the normal position.
27
How is the vexillum described?
Sloped obliquely towards the tip.
28
What does each barb contain?
Two rows of barbules, a proximal row and a distal row.
29
Where is the distal row of barbules growing from?
The side of the barb facing towards the tip of the feather.
*Has microscopic hooklets that hook onto the proximal barbules of the next barb.
30
How are hooklets described?
Hold the barbs together to form the vane.
31
What does the interlocking between barbs allow?
A strong, continuous, smooth surface.
32
How is the quill described?
1. Transparent.
2. Rounded.
3. Hollow.
4. Series of conical scales on the interior.
33
How is the inferior umbilicus described?
Forms a papilla of epidermis during feather formation, leaves hole at proximal end of feather.
34
How is the superior umbilicus described?
Hole in shaft at junction of shaft and vanes.
35
How is the hypo-rachis described?
A small feather-like tuft.
36
What are the main wing feathers called?
Remiges.
37
Which part of the vane of remiges is broader, the anterior portion or posterior portion?
The posterior portion.
38
What are the two types of flight feathers?
1. Primary flight feathers.
2. Secondary flight feathers.
39
Where are primary flight feathers located?
On the trailing edge of the outer part of the wing.
40
Where are secondary flight feathers located?
In the same area as primary feathers, just closer to the body.
41
What are the two types of flight feathers separated by?
Axial feathers.
42
How many primary feathers are found on each wing of adult fowl?
10.
43
What are the large feathers of the tail called?
Reticles.
44
What is the name of the feathers that cover the base of remiges and reticles?
Wing coverts and tail coverts respectively.
45
Where are plumules found?
Beneath contour feathers.
46
What kind of undercoat do plumules form?
A soft, downy.
47
How are plumules described?
1. Short shaft.
2. Radiating, free barbs and barbules.
3. No interlocking barbicels or hooklets.
48
What are the two functions of the plumules?
1. Provide depth to the coat.
2. Trapping and holding air, improving the birds ability to conserve warmth.
49
How are filoplumes described?
1. Very small.
2. Hair-like.
3. Contain rudimentary barbules and barbs which are confined to the apex.
50
Why are filoplumes troublesome during processing?
They are difficult to remove.
*If dark in color, they detract from the value of the bird.
51
How is chick down described?
1. Short, fluffy down.
2. Closely resembles plumules.
3. Has multiple radiating barbs.
52
How long is the chick down present?
Until the first molt.
53
What emerges to replace the chick down?
Juvenile feathers from the same follicle.
*Eventually replaced by final plumage.
54
What does the outermost juvenile feathers resemble?
Adult contour feathers, just softer.
55
Is the number of moults the same or different for each pterylae?
Different.
56
Where are the bristles found?
Around the mouth and eyes.
57
What are the two functions of bristles?
1. Sensory ability of the birds.
2. Protect sensitive areas.
58
What are feathers?
Keratinized epidermal derivatives.
59
What are feathers related to?
Scales.
60
What do feather follicles look like in the embryo?
Dome-shaped projections of the epidermis over a raised dermal papilla or pimple.
*This dome later sinks into the skin so that it lies in a short tube beneath the surface of the skin.
61
What is the base of the feather follicle rim called?
The collar.
62
What does the collar constitute and why?
The germinal region of the follicle due to rapid cell division during feather formation.
63
In what way do the cells that form the feather arrange themselves?
In the structural pattern of the parts of the feather.
64
What portion of the follicle is highly vascularized during feather development?
The dermis.
*Supplying nutrients necessary for feather formation.
65
What happens after the feather is keratinized?
The highly vascular part of the dermis dries up and forms the pulp found inside the calamus.
66
What happens after the feather sheath splits?
The new feather unfurls and no new follicles need to be formed.
67
What causes the black, brown, and reddish-brown colors of the feathers?
The granular pigment, melanin.
68
What cells form melanin?
Melanocytes.
69
What amino acid is used to form melanin?
Tyrosine.
70
When does melanin enter cells?
During embryonic development.
*Congregate beneath the feather follicles.
71
When does melanin move into epidermal cells?
Prior to keratinization.
72
What colors does phaemelanin produce?
Black or reddish.
*Chemical difference between the two is unknown.
73
What color do carotenoids produce?
Yellow to orange.
*Lipid pigment.
74
Where are carotenoid pigments found?
1. Skin.
2. Legs.
3. Beak.
4. Egg yolk.
5. Lucerne leaf.
6. Carrots.
7. Corn.
75
What is color pattern dependent upon?
The distribution of melanin and other pigments.
76
What process results in color bands of light and dark?
Cyclic changes in melanin deposition during feather growth.
*Barred Plymouth Rock.
77
What is an example of a breed that shows sexual dimorphism in colors?
Brown Leghorns.
78
What are two mutant feather types?
1. Wolly.
2. Frizzle.
79
What two gene groups control colors and color patterns?
1. Genes that control the pattern the colors are deposited in.
2. Genes that control melanin formation.
80
What is the cyclic growth period of the feather called? Rest period?
1. Anagen.
2. Telogen.
81
When does anagen occur?
Prior to molting old plumage.
82
When does the telogen phase begin?
When the plumage is complete.
83
What can be done to induce the anagen phase?
Plucking feathers.
84
What kinds of genes control when feather growth is initiated and down replaced?
Sex-linked genes.
85
What are the two descriptors used for when a chicken feathers?
1. Early feathering.
2. Late feathering.
86
Which set of feathers molts first?
Proximal flight feathers.
87
What happens during molting between bilaterally symmetrical pterylae?
They are synchronized.
*Important for flying birds.
88
What is the sequence of pterylae during shedding?
Wing feathers, spreads to the body, ends at head and neck.
89
During what season does the molt typically occur?
Fall/autumn.
*Environmental conditions can alter this.
90
Which sex molts first?
Males.
91
What things does thyroxine play a role in?
1. Growth.
2. Patterning of feathers.
3. Differentiation of feathers.
*Increases metabolic activity of feather forming cells.
92
What feather type is not influenced by thyroxine?
Chick down.
93
What happens if the thyroid gland is removed?
All feather growth in adults ceases.
94
How does thyroxine induce molt?
Induces the anagen phase.
*Females more sensitive than males.
95
What are the functions of estrogen?
Maximizing egg laying.
*Occurs during telogen phase.
96
What do high levels of estrogen hinder?
Feather formation.
97
What kind of feathers do males develop in the absence of androgens?
"Female" type feathers.
98
What happens when the gonads are removed?
The feathers will be replaced continuously rather than annually.
99
What does the light pattern affect?
Feather development and molting via the pituitary gland.
100
What also is released as a result of light patterns?
Gonadotropins and thyroxine.
