Reproductive System Flashcards
1
Q
What is the term used to describe the avian reproductive system?
A
Heterosexual.
2
Q
What does the male contribute?
A
Sperm in semen.
3
Q
What does the female contribute?
A
An ovum in the egg yolk.
4
Q
What is the ovum referred to as?
A
Blastoderm, blastodisc, or germ disc.
5
Q
Where does the yolk move to after it is released from the follicle?
A
Into the oviduct.
6
Q
What happens to the yolk in the oviduct?
A
- Fertilization.
- Addition of albumen.
- Addition of the shell membrane.
- Addition of the shell.
7
Q
What does the male reproductive system in fowl consist of?
A
- Two testes.
- Two deferent ducts.
8
Q
What structure do male fowls lack that is found in other male animals?
A
A penis.
9
Q
Where are the testes located?
A
Against the backbone, at the front of the kidneys.
10
Q
What happens to the testes when the cock is mating?
A
They enlarge.
*The left is larger than the right.
11
Q
What is the small, flattened area on each testis thought to correspond to?
A
The epididymis in mammals.
*Deferent ducts start here.
12
Q
What is the function of the deferent duct?
A
To transport sperm from the testes to the cloaca.
13
Q
What type of structure do the deferent ducts lead into in the cloaca?
A
A small pimple-like structure that is analogous to the penis in other animals.
14
Q
What are the tubes inside the testes called?
A
Seminiferous tubules.
15
Q
What two processes occur in the seminiferous tubules?
A
Meiosis and the early steps of spermatogenesis.
16
Q
How many sperm are found in one cubic mm of semen?
A
3-5 million.
17
Q
How is avian sperm described?
A
- Long pointed head.
- Long tail.
18
Q
What type of hormones do the testes produce?
A
Androgens.
19
Q
Why is the volume of the seminal fluid very low?
A
Due to lacking seminal vesicles and a prostate gland.
20
Q
How much semen do chickens produce per ejaculate?
A
1 ml.
*Whitish
21
Q
How much semen do turkeys produce per ejaculate?
A
0.5 ml, but 2x as concentrated as that of a chicken.
*Yellowish or brownish.
22
Q
What does the female reproductive system consist of?
A
Ovary and oviduct.
*Have two sets, but only the left side is functional.
23
Q
Where is the ovary located?
A
Just in front of the kidney, attached firmly to the peritoneum by the meso-ovarian ligament.
24
Q
Why is the ovary well-vascularized?
A
To be able to transport nutrients to the developing yolk.
25
What does the ovary consist of?
A mass of yellowish, round follicles.
*Only a small number of follicles reach maturity.
26
What does each follicle contain?
An ovum/yolk.
27
What is the size of a normal egg yolk?
40 millimeters in diameter.
28
What is the first stage of follicular development?
Primary follicle.
*Not yet commenced growth.
29
What is the second stage of follicular development?
Growing follicle.
30
What is the third stage of follicular development?
Mature follicle.
*Ready or near ready for ovulation.
31
What is the fourth stage of follicular development?
Discharged follicle.
*Ovulation has occurred.
32
What is the fifth stage of follicular development?
Atretic follicle.
*Yolk was released some time ago.
33
How long does it take the yolk to develop?
10 days.
*Happens in the follicle.
34
What is the stigma?
An elongated, virtually blood vessel free area on the distal surface of a mature follicle that splits to release the yolk.
*If it splits elsewhere, blood spots appear in the yolk.
35
What is the function of the oviduct?
To produce albumen, the shell membrane, and the shell around the yolk.
*Why many glands are located within its walls.
36
How is the oviduct of a non-layer described?
1. Short.
2. Small in diameter.
37
How is the oviduct described when the hen is actively laying?
70-80 cm with variable diameter (depending on section function).
38
What are the 5 sections of the oviduct in order from innermost to outermost?
1. Infundibulum/Funnel.
2. Ampulla/Magnum.
3. Isthmus.
4. Uterus/Shell gland.
5. Vagina.
39
How is the infundibulum described?
1. Thin-walled.
2. 6-9 cm long.
3. Adjacent to the ovary w/ long segment enclosing the ovary.
40
What are the 2 functions of the infundibulum?
1. Collects and directs the yolk into the oviduct.
2. Site of fertilization.
41
What happens if the infundibulum is unable to collect a yolk?
It is absorbed within three days.
*If this occurs frequently enough, the hen's abdomen will become distended as the yolks accumulate faster than they can be absorbed.
42
How long is the yolk in the infundibulum?
15 minutes.
43
How is the magnum described?
40 cm long.
44
What is the function of the magnum?
Secretes more than 40% of the albumen.
45
What are the 4 layers of albumen?
1. Chalazae and chalaziferous layer.
2. Liquid inner layer.
3. Dense layer.
4. Outer liquid layer.
46
What % of the albumen layer is the chalazae and chalaziferous layer?
2.7.
47
What % of the albumen layer is the liquid inner layer?
17.3.
48
What % of the albumen layer is the dense layer?
57.0.
49
What % of the albumen layer is the outer liquid layer?
23.0.
50
What are the chalazae?
Two twisted chords of albumen extending from opposite sides of the yolk into the remaining albumen.
51
What is the function of the chalazae?
To keep the yolk centrally located as it passes through the oviduct, to ensure embryo survival.
*Part of a special thin albumen envelope that surrounds the yolk to hold it in position.
52
How are the liquid inner and outer liquid layers formed?
Dense albumen produced by the bird is mixed with water, the egg is repeatedly rotated and the inner liquid and dense layers are formed, more water added in the uterus/shell gland causes the outer liquid layer to form.
53
What does the dense layer contain a significant amount of and what does this cause the texture of the dense layer to be?
Mucin, which causes it to be jelly-like.
54
What happens to the level of dense albumen as an egg stales?
It decreases and becomes more liquid.
55
How long is the developing egg in the magnum?
3 hours.
56
How is the isthmus described?
12 cm long.
57
What are the 2 functions of the isthmus?
1. Secrete some albumen.
2. Secrete the shell membrane.
58
What are the two shell membranes?
1. Inner shell membrane.
2. Outer shell membrane.
*Are so closely associated when in the oviduct that they appear to be one.
59
Which shell membrane is laid down first, the inner or the outer shell membrane?
Inner shell membrane.
60
How many times thicker is the outer shell membrane than the inner shell membrane?
3 times thicker.
61
How long is the developing egg in the isthmus?
75 minutes.
62
What happens when the membranes separate as the egg cools following laying?
The air cell forms.
63
What is the diameter and depth of the air cell of a newly laid egg?
1.5 cm and 0.5 cm respectively.
64
What happens as the egg ages?
1. The interior content loses water.
2. Air cell increase in size.
65
What do the shell glands consist of?
A fibrous protein material.
66
What are the 4 functions of the shell membrane?
1. Prevents fungi penetration into the egg.
2. Prevents bacteria penetration into the egg.
3. Reduces the rate of evaporation of water from the egg, slowing the rate of deterioration.
4. Forms the first crystals of calcium carbonate on the outer shell membrane, laying down the foundation for the shell.
67
How is the shell gland described?
12 cm long.
68
How long is the developing egg in the shell gland?
18-20 hours.
69
What are the 2 functions of the shell gland?
1. Secrete the egg's outer cuticle.
2. Possibly secrete the shell pigment.
70
What functions does the cuticle serve?
1. Acts as a lubricant during oviposition.
2. Closes off the pores once it dries out to prevent bacterial and fungal entry.
71
What two factors is the number of calcium carbonate crystals deposited controlled by?
1. Genetics.
2. The number of grains deposited in the isthmus (controls shell thickness).
72
What are the two layers of the egg shell?
1. Mammillary layer.
2. Palisade layer.
72
What is the palisade layer?
The outer layer of the shell formed from columns of hard calcite crystals.
*The longer the columns, the stronger the egg.
73
What is the mammillary layer?
The inner layer formed from soft calcite crystals. Sponge-like.
74
What types of hormones does the female reproductive system produce?
1. Androgen.
2. Estrogen.
*P4 as well.
75
What are the functions of androgen in females?
1. Comb growth and condition.
2. Albumen formation.
76
What are the functions of estrogen in females?
1. Mating behavior.
2. Nesting behavior.
3. Growth of female plumage.
4. Oviduct development.
77
What are the functions of progesterone in females?
1. Albumen production.
2. Signals the anterior pituitary gland to release LH.
78
What is the first sign of developing maturity in hens?
Changes in comb development. It takes on a vivid red hue.
79
What are the 4 parts of a normal egg?
1. Yolk carrying the ovum.
2. Albumen/white.
3. Shell membranes.
4. Shell.
80
How many ova are contained on one follicle?
2000-12000.
81
How many ova reach maturity?
200-350.
82
What % of an eggs weight is the yolk?
31%.
83
What % of the egg is water?
48.0.
84
What % of the egg is protein?
17.5.
85
What % of the egg is fat?
32.5.
86
What % of the egg is carbs?
1.0.
87
What % of the egg is other compounds?
1.0.
88
What causes the pigmentation in the yolk material?
Xanthophylls (yellow/orange/red).
*Found in plants.
89
How is the yolk laid down?
In concentric rings of darker and lighter pigmented material.
90
What is the bulk of the yolk material used for?
Providing food for the embryo.
91
Where does the embryo originate from?
The fertilized germ disc on the upper surface of the yolk.
92
What hormone initiates yolk development?
FSH.
*From anterior pituitary gland.
93
What is the major controlling factor influencing the subsequent steps in the formation and laying of the egg?
The release of the yolk/ovulation.
94
What does the presence of a mature yolk in the follicle cause the stimulation of the release of what hormone?
LH.
*From the anterior pituitary gland.
95
What does LH cause to occur?
The follicle to split along the stigma.
96
When do hens reach sexual maturity?
When they lay their first egg.
97
What is sexually maturity generally controlled by?
Genetics, but the environment plays a large role.
98
What environmental factors impact when a hen reaches sexual maturity?
1. Feed practices.
2. Light intensity.
3. Day length management.
4. Other management practices.
99
What is the age range for a hen reaching sexual maturity?
18-24 weeks.
100
What are subsequent ovulations largely controlled by?
The time the previous egg passed through the vent.
101
Approximately how many minutes after an egg is laid is the yolk for the next egg released?
40-60 minutes.
102
What is a clutch?
All of the eggs laid on successive days.
103
What is the range on clutch size?
2-100 eggs.
*Individual characteristic.
104
What is a normal clutch size?
3-8 eggs.
105
What is smaller clutch size associated with?
Long breaks in between clutches.
106
What is the range of time for egg formation?
24-26 hours.
*Longer than 24 hours will push the egg progressively later in the day for each successive egg in the clutch.
107
When does egg formation start and end?
From when the yolk is ovulated to when the egg passes through the vent.
108
What happens when eggs are laid at a late hour?
An ovulation is missed and the start of the new clutch will be earlier in the next laying day.
109
When do hens that produce large clutches ovulate?
Shortly after first exposure to light (natural or artificial).
110
Why do new layers lay eggs in a haphazard sequence?
Their hormonal, nervous, and other controlling systems are not in a state of balance yet.
*Takes 7-10 days.
111
When is peak ovulation reached?
3-5 weeks after the first egg.
112
From what 3 places does calcium for eggshell formation come from?
1. The diet.
2. Medullary bone.
3. The skeleton.
113
How many grams of calcium are used to form one normal egg shell?
2.5.
114
How many grams of calcium can a hen absorb from the diet every day?
2.0, requiring 0.5g to be pulled from other sources.
115
What time of day is mobilization of calcium from the skeleton at its highest?
At night, when most of the shell is being formed and the hen is not eating.
116
In addition to calcite, what 3 other minerals are found in small quantities in the shell?
1. Magnesium.
2. Sodium.
3. Potassium.
117
What two locations in the body do the carbonate ions used to form calcium carbonate originate from?
1. Shell gland.
2. Blood.
118
What happens to the egg shell if the carbonate supply is interrupted?
The egg shell is thin.
119
Why does hot weather interrupt the flow of carbonate ions?
1. The hen pants because it is hot.
2. The increased respiratory rate decreases the levels of carbonate ions in the blood by decreasing the levels of carbon dioxide in the blood.
3. Therefore, less carbonate ions are available for eggshell formation.
120
What enzyme catalyzes the conversion of carbon dioxide and water to carbonate ions?
Carbonic anhydrase.
121
What mineral is a co-factor of carbonic anhydrase?
Zinc.
*Deficiency will lead to egg shell formation problems.
122
What are the 7 factors that influence eggshell quality?
1. Length of time in lay.
2. Drugs.
3. Increased environmental temperatures.
4. Disease.
5. Egg laying time.
6. Body checked and misshapen eggs.
7. Stress.
123
What impact does length of time in lay have on eggshell quality?
The longer the bird is in lay, the weaker the eggshell will be due to the hen's inability to obtain enough calcium.
124
What impact do drugs have on eggshell quality?
Certain drugs impact formation and deposition of the eggshell.
125
What impact does environmental temperature have on eggshell quality?
Increased temp. leads to reduced food and calcium consumption. Also, increased panting leads to a reduction in carbonate ion availability.
126
What impact does disease have on eggshell quality?
Certain diseases can weaken shells and misshapen eggs.
127
What impact does egg laying time have on eggshell quality?
Eggs laid early in the morning are more likely to have thinner shells than those laid by the same bird later in the day. This is due to the shell being made with calcium pulled strictly from the skeleton.
128
What impact does stress have on eggshell quality?
Stressed birds lay thinner shelled eggs.
129
What impact do body checked and misshapen eggs have on eggshell quality?
Happens when bird is startled shortly after egg has entered shell gland/uterus and first layer of calcium carbonate has been deposited. The contraction of all muscles in the body due to startling causes the newly formed shell to crack.
130
How many pores does the shell of a normal egg contain?
8,000.
131
What is the function of the pores in the eggshell?
To provide for gaseous exchange during incubation and embryonic development.
*Developing embryo requires O2 and gives off CO2.
132
What causes the pores on the egg to pop open?
The egg aging.
133
How long is the vagina?
12 cm.
134
What is the function of the vagina?
Adding pigment to the outer shell.*
*Speculative.
135
Where is the egg held immediately before being laid?
In the cloaca.
*May be there for several hours, usually shorter.
136
What way does the egg enter the cloaca?
Small end first, but rotates to be laid large end first.
*If startled, the hen may lay the egg small end first.
