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Embryology > Introduction > Flashcards

Introduction Flashcards

1
Q

What are the tree subdisciplines of Embryology?

A

Descriptive
Comparative
Experimental

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2
Q

What is descriptive embryology

A

The study of the mechanisms of development

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3
Q

What are the two different periods that embryology can first be divided into?

A

Prenatal - before birth

Post natal- after birth

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4
Q

What are the two subdivisions of the prenatal period and how long are they?

A

Embryonic- 0-8 weeks

Fetal- 8 weeks to birth

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5
Q

The postnatal period can also be further divided into what five groups?

A 
Infancy (neonatal period during the first 4 weeks)
Childhood
Puberty
Adolescence
Adulthood
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6
Q

In the post natal period how long do Infancy, childhood and Puberty last and what is the deciding factor that ends childhood?

A

Infancy- 0-1 year
Childhood- 1-13 years
Puberty 12-15 in girls and 13-16 in boys

Deciding factor in when childhood ends varies depending on when the child begins puberty

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7
Q

A division of the postnatal period, adolescence, is significant because this is where the individual gains what ability

A

The ability to reproduce

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8
Q

What does the term ventral mean?

A

Toward the belly

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9
Q

What does the term dorsal mean?

A

Toward the back

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10
Q

What does the term cranial mean?

A

Toward the head

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11
Q

What does the term caudal mean?

A

Toward the tail

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12
Q

What does the term rostral mean?

A

Toward the nose

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13
Q

What are the 4-5 sections called that can be made to study and embryo and what are their definitions?

A

Midsagittal- equal right and left halves

Sagittal- a section that yields right and left halves

Transverse (cross sectional)- top and bottom sections

Coronal (frontal)- yields front and back sections

Oblique- any section that is not cut on one of the three main planes of the body (X, Y, Z axes)

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14
Q

What is the primary sex organ of the male? And what is its function?

A

Testis

Where the sperm cells are developed and where testosterone is produced ( gamete production and hormone production)

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15
Q

What is are the two functions of the epididymis?

A

Storage of the sperm cells and activation of the sperm cells

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16
Q

What are the functions of the male reproductive system?

A

To produce and deliver the male gametes (sperm cells)

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17
Q

What are the 7 parts that make up the male reproductive system?

A 
Testis
Epididymis 
Ductus deferens 
Ejactulatory duct
Urethra
Prostate gland 
Seminal vesicles
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18
Q

What is the muscular tube that transports the sperm cells from the epididymis to the ejaculatory duct?

A

Ductus defrens

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19
Q

What is the function of the ductus defrens

A

Transports the sperm cells from the epididymis to the ejaculatory duct

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20
Q

What two parts of the male reproductive system run together to form the ejaculatory duct? And what is its function?

A

A short duct that formed from the union of the ductus defrens and the duct of the Seminal vesicle.

Empties into the prostatic urethra

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21
Q

The urethra of the male is divided into 3 sections. What are the three sections and where do they pass through?

A

Prostatic urethra: passes through the prostate gland.

Membranous urethra: passes through he pelvic diaphragm

Penile urethra: final section that passes through the penis

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22
Q

What represents the union of the reproductive and urinary systems in the male?

A

The prostatic urethra

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23
Q

Describe the seminal vesicles and where they are located.

A

Secretory glands that add an alkaline fluid tot he seminal fluid

Located on the posterior aspect of the urinary bladder

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24
Q

What is the function of the prostate gland and where is it located?

A

Located at the base of the urinary bladder

It adds fructose to the seminal fluid

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25
Q

What is the product of mitosis?

A

Two daughter cells identical to the parent cells

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26
Q

What is the product of meiosis?

A

Cells with half of the genetic material of the parents

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27
Q

What is the order of sperm production?

A

Spermatogonia (2n)-> primary spermatocyte (2n)-> secondary spermatocyte (1n)-> spermatid (1n)

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28
Q

What are large cells with a centrally placed nucleus found against the outer wall of the seminiferous tubules?

A

Spermatogonia

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29
Q

What are spermatogonia functions?

A

To make new spermatogonia (mitosis

Develop sperm cells (begin process of meiosis)

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30
Q

________ are mature sperm cells that enter the lumen of the seminiferous tubules

A

Spermatids

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31
Q

What are the stages of maturation from spermatids -> mature sperm?

A

Golgi phase

Acrosomal phase

Maturation phase

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32
Q

What happens in the golgi phase during the transformation of spermatids to mature sperm?

A

Golgi body forms the acrosomal vesicle and centrioles migrate toward the nucleus

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33
Q

What happens during the acrosomal stage during the transformation of spermatids to mature sperm?

A

Acrosomal vescile grows to cover the anterior half of the nucleus

Acrosome is critical for fertilization of egg

Nucleus becomes more condensed and the mitochondria condense around the forming flagellum

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34
Q

What happens during the maturation phase of the transformation of spermatids to mature sperm?

A

The residual cytoplasm is lost and the sperm cell is released into the tubercle

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35
Q

The head of the sperm is made up of the ______ and ______
The middle of the sperm is made up of ______ and ________
The tail of the sperm is made up of _______

A

Acrosome and nucleus

Mitochondria and flagellum

Flagellum

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36
Q

What makes the microtubules that form the flagellum?

A

Centrioles

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37
Q

What cell makes testosterone?

A

Leydig cell

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38
Q

What cell secretes the seminal fluid that supports the cells of sperm?

A

Sertoli cells

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39
Q

What secretes FSH and LH?

A

Anterior pituitary

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40
Q

What is the function of FSH in the male?

A

Stimulates seminiferous tubules to produce sperm cells

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41
Q

What does LH do in the male?

A

Stimulates the cells fo Leydig to produce testosterone

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42
Q

What controls the rate of sperm production to where if there are enough sperm produced, excess is no longer produced?

A

The hormone inhibin

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43
Q

What is the primary sex organ of the female?

A

Ovaries

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44
Q

What hormones are produced by the ovary?

A

Estrogen and progesterone

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45
Q

What are the 3 parts of the uterine tube?

A

Isthmus
Ampulla
Infundibulum

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46
Q

What is the function of the uterine tube?

A

Provides a passageway from ovary to the uterus for the egg cell and contains the site of fertilization

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47
Q

What part of the uterine tube is the site of fertilization?

A

Ampulla

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48
Q

The uterus is a muscular organ divided into what 4 parts?

A

Cervix, isthmus, body, and fundus

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49
Q

What are the layers of the wall of the uterus?

A

Endometrium
Myometrium
Perimetrium

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50
Q

What is the function of the endometrium?

A

Where the baby implants and it is the part that undergoes the monthly cycle

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51
Q

What is the function of the myometrium?

A

Smooth muscle layer that can stretch to accommodate pregnancy

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52
Q

What is the connective tissue covering the uterus called?

A

Perimetrium

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53
Q

The uterus is the site of __________ and where the _________ develops

A

Implantation and where the embryo develops

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54
Q

The endometrium is made up of what 3 layers?

A

Compact layer
Spongy layer
Basal layer

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55
Q

What makes up the functional layer of the endometrium?

A

Spongy and compact layers

These two are shed during the menstrual phase

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56
Q

Explain the menstrual phase of the uterine cycle

A

Day 1-5
Both estrogen and progesterone are at their lowest

Functional layer is lost during this phase

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57
Q

Explain the proliferative phase of the uterine cycle

A

Day 6-15

Estrogen levels increase

Functional layer is rebuilt

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58
Q

Explain the secretory phase

A

Day 15-27

Progesterone levels increase
Glands of the uterus begin to function and produce glycoproteins that coat the endometrium
Implantation occurs on day 21 of the cycle

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59
Q

Explain the ischemic phase of the uterine cycle

A

Day 28
Both progesterone and estrogen levels drop quickly resulting in the smooth muscle spasming in the functional layer
The spasm of the spiral arteries in the spongy layer results in the beginning of menstrual flow

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60
Q

What structure in the ovary are the eggs stored?

A

Egg nest

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61
Q

Explain the egg nest (hormone, make up, amount)

A

Made up of the egg cell and one layer of follicle cells

Under the influence of FSH

About 12 egg nests per month begin to develop primary follicles (marked by the development of 4 layers of follicle cells

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62
Q

The formation of ________ _______ begin via FSH resulting in 4 layers of follicle cells

A

Primary follicles

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63
Q

Explain secondary follicles

A

a fluid filled antrum that appears in about 6 follicles, as they develop more follicles, estrogen secretion increases

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64
Q

What makes up the mature follicle?

A

One large antrum, on day 14 the mature follicle ruptures resulting in ovulation

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65
Q

What is released from the mature follicle rupture?

A

Corona radiata

Egg+ zona pellucida and some layers of follicle cells

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66
Q

What hormone influences ovulation?

A

LH

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67
Q

The remaining cells that stay in the follicle swell and a small blood clot forms called the _______ _________

A

Corpus hemorrhagicans

68
Q

As the follicle cell swells they secrete _______

If pregnancy occurs, they secrete it for 3 months

A

Progesterone

69
Q

_________ cells make and secrete estrogen

A

Thecal cells

70
Q

In the proliferative stage of the uterine cycle what hormones are prominent?

A

Estrogens being secreted from thecal cells

71
Q

Secretory stage of the uterine cycle what hormone is prominent and where is it secreted from?

A

Progesterone and secreted from the follicle cells

72
Q

What must occur in order for fertilization to occur (what must the sperm undergo in order to be able to fertilaize an egg)?

A

Capacitation

73
Q

Only _______ sperm cells can pass through the corona radiata

A

Capacitated

74
Q

Once the sperm cells have passed through the corona radiate, they must pass through the ________ _________

A

Zona pellucidum

75
Q

What is the first stage of the process of penetrating the Zona pellucida (ZP)?

A

Attachment of the sperm to the ZP

76
Q

Where does the attachment of the sperm to the ZP take place?

A

The ZP3 receptors

77
Q

What are ZP3 receptors? And what from the sperm recognizes them?

A

Glycoproteins and recognized by bindin

78
Q

What is bindin

A

A protein in the acrosome and egg binding protein

79
Q

Explain the attachment phase

A

The sperm attaches to the ZP through binding to the ZP-3 receptors by the protein bindin that is located in the sperms acrosome

80
Q

After attachment to the ZP, the sperm cells undergo _________ ______

A

Acrosomal reaction

81
Q

What enzymes are in the acrosome that help penetrate the ZP?

A

Proteinase, glycosidase, phosphatase and phospholipase

82
Q

During the acrosomal reaction, when the acrosomal enzymes are released it causes an influx of Na and Ca ions. What does the influx of these ions result in?

A

An efflux of Hydrogen ions which leads to an increase in the intracellular pH

83
Q

The acrosomal reaction is dependent on what two things being present?

A

Calmodulin and ATP

84
Q

With the release of enzymes plus the movement of ions in the acrosomal reaction, the _______ receptors convert to _______ receptors

A

ZP3

ZP2

85
Q

What does the conversion of the ZP-3 receptors to ZP-2 receptors do?

A

Brings the inner wall of the acrosome to the zona pellucidum
And the release of acrosin enzyme

86
Q

When does the sperm cell move across the ZP?

A

Once the ZP-3 receptor has been changed to ZP-2 and the release of the sperms acrosin

87
Q

the _______ region of the cell fuses with the egg cell membrane

A

Posterior

88
Q

What three events prevents polyspermy

A 
Fast block (large depolarization)
Slow block (cortical reaction)
Zona reaction
89
Q

Describe fast block to polyspermy

A

Depolarization of the membrane within 3 seconds of fertilization.

Na out and K in. The movement of the ions causes an electrical charge that stops all sperm movement for approx 1 min

90
Q

Describe the cortical reaction

A

Cortical granules of the egg cell release hydrolytic enzymes that cause the inactivation of the ZP receptors and the hardening of the zona pellucidum

91
Q

Explain the zona reaction

A

Any other ZP3 receptors on the ZP surface undergo change to become ZP3F receptors and cannot form any new attachements

And any ZP2 receptors undergo change to become ZP2F recprots to prevent any more penetration of sperm cells

92
Q

What are the outcomes of fertilization?

A

Restoration of the 2n chromosome number
The determination of the sex of the individual
The initiation of cleavage division

93
Q

The moment of fertilization when the two membranes fuse, the egg is called a ______

A

Zygote

94
Q

At the 16 cell stage the dividing egg is referred to as a ______

A

Morula

95
Q

At the _______ stage there is a solid ball of cells, the ZP is still intact and at this point diffusion of nutrients to the cell wil not be efficient

A

Morula (16 cell)

96
Q

At what stage in cleavage division does one see differentiation of cells and the cells are no longer multipotential?

A

Blastocyst

97
Q

When during cleavage division does the Zona pellucida disappear?

A

Late blastocyst stage

98
Q

What cells secrete hCG?

A

Trophoblast cells

99
Q

The blastocyst becomes polarized, what are the two poles called and what doe they consist of?

A

Animal pole- consists of the ICM

Vegetative pole- doesnt have the embryo, more of where the trophoblastic cells are

100
Q

What are the three types of implantation?

A

Central
Eccentric
Interstitial

101
Q

_________ implantation is where the zygote just attaches to the uterine wall

A

Central

102
Q

_______ implantation is when the zygote partially enters the endometrium

A

Eccentric

103
Q

What happens during the first phase of implantation?

A

The uterine smooth muscle contracts and slows down the embryo

104
Q

The second stage of implantation is the ________ stage, when the embryo becomes trappe din the secretions of the uterine glands

A

Adhesive stage

105
Q

The _____ phase and final phase of implantation is when the embryo begins to submerge into the endometrium of the uterus

A

Invasion phase

106
Q

At the blastocyst stage its surrounded by a flattened layer of cells called the _______

A

Trophoblast

107
Q

The trophoblast cells eventually form what?

A

The placenta

108
Q

Also at the blastocyst stage the ICM is made up of cuboidal cells called the __________, these cells will form the developing embryo

A

Embryoblast

109
Q

What cells differentiate into the bilaminar disk?

A

Embryoblast cells of the ICM

110
Q

The bilaminar disk has an upper layer of cells called the ________ and a lower layer of cells called the ________

A

Epiblast

Hypoblast

111
Q

During day 8 of devleopment the epiblastic layer undergoes mitosis and forms a fluid filled cavity called the _______

A

Amnion

112
Q

What are the cells that line the amnion referred to as?

A

Amnioblast

113
Q

During day 8 the hypoblast also undergoes mitosis and this mitosis gives rise to the ________ ________ that lines the primitive yolk sac

A

Exoceolomic membrane

114
Q

The primitive yolk sac replaces the ________ as it develops

A

Blastocoel

115
Q

The trophoblastic layer undergoes a mitosis to form two layers. What are they called?

A

The cytotrophoblast and the syncytiotrophoblast

116
Q

What forms the extraembryonic mesoderm?

A

The cells that forms eh wall of the primitive yolk sac undergo mitosis and give rise to the new cells that are considered the extraembryonic mesoderm

117
Q

The _______ _________ cells are found between the cytotrophoblast, the yolk sac and the amnion

A

Extraembryonic mesoderm

118
Q

Syncytiotrophoblast cells conintue to grow and develop small cavities called ________

A

Lacunae

119
Q

What establishes the utero-placental circulation?

A

Syncytiotrophoblast

120
Q

The extraembryonic mesoderm splits into what two layers?

A

The extraembryonic somatopleuric mesoderm

The extraembryonic splanchnopleuric mesoderm

121
Q

The cavity between the extraembryonic somatopleuric mesoderm and extraembryonic splanchnopleuric mesoderm is referred to as the _________

A

Chorion

122
Q

What is the only area where this speration of the extraembryonic mesoderm has not occurred?

A

The connecting stalk

123
Q

What eventually forms the umbilical cord?

A

The connecting stalk

124
Q

What forms the primary villi?

A

The cytotrophoblast undergo mitosis to form the extensions called primary villi

125
Q

The hypoblast undergoes another mitosis and forms a secondary yolk sac that replaces __________

A

The primary yolk sac

126
Q

At the 2 week stage the bilaminar disk begins to change. The epiblast and hypoblast are still present but what changes occur in the hypoblast?

A

The hypoblast at one end of the embryo increases their height and form the prechordal plate

127
Q

What marks the head-end of the embryo?

A

Prechordal plate

128
Q

During ________ 3 germ layers are established

A

Gastrulation

129
Q

What are the three germ layers established on week 3?

A

Endoderm
Ectoderm
Mesoderm

130
Q

The process of gastrulation begins with the formation of the ___________

A

Primitive streak

131
Q

The primitive streak has a _______ ______ at its cephalic end

A

Primitive node

132
Q

the _____ ______ is a slightly raised area with a small primitive pit

A

Primitive node

133
Q

Cells of the _______ layer migrate toward the primitive streak and invaginate

A

Epiblastic

134
Q

The ectoderm is the old ______

The endoderm and mesoderm are the old _______

A

Epiblast

Hypoblast

135
Q

Prenotochordal cells invaginate and move toward the prechordal plate, these cells from the ______ ______

A

Notochordal plate

136
Q

The notochordal plate detaches from the endoderm and forms a solid chord of cells known as the _______

A

Definitive notochord

137
Q

At the point where the primitive pit forms an indentation in the epiblast known as the _________

A

Neurenteric canal

138
Q

The ______ ______ temporarily connects the amniotic and yolk sac cavities

A

Neurenteric canal

139
Q

The ____ ______ is a muscular tube that transports the sperm cells from the epididymis to the ejaculatory duct

A

Ductus defrens

140
Q

Where does the ductus defrens pass through?

A

From the epididymis through the spermatic cord, through the inguinal canal and to the posterior aspect of the urinary bladder. It then joins the duct of the seminal vesicle to form the ejaculaotry duct

141
Q

The ______ ______ passes through the prostate gland to empty into the prostatic urethra

A

Ejaculatory duct

142
Q

The urethra of the male may be divided into three sections. The _______ _______ passes through the prostate gland and represents the union of the reproductive and urinary systems in the male.

A

Prostatic urethra

143
Q

The ________ urethra is the section that passes through the pelvic diaphragm.

A

Membranous

144
Q

The ________ urethra is the final section is that part which passes through the penis.

A

Penile

145
Q

Where are the seminal vesicles located and what is their function?

A

Secrete alkaline fluid to the seminal fluid

Located on the posterior aspect of the urinary bladder

146
Q

Where is the prostate gland at and what is its function?

A

Located at the base of the urinary bladder

Adds fructose to the seminal fluid

147
Q

Where are the sperm cells developed and where the hormone testosterone produced?

A

Testis

148
Q

The ________ is locat4ed on the superior posterior aspect of the testis in the scrotum

A

Epididymis

149
Q

On day 10 the _________ forms the utero-placental circulation with the maternal blood vessels

A

Syncytiotrophoblast

150
Q

The intraembryonic mesoderm develops from the _______

A

Epiblast

151
Q

Bottle cells would be found lining the ______ _____

A

Primitive node

152
Q

The cloacal membrane is made up of what germ layers?

A

Ectoderm and endoderm

153
Q

The process of hatching refers to what?

A

The removal of the zona pellucidum from the blastocyst

154
Q

What does the intraembryonic mesoderm form from and what is it made up of and when is it formed?

A

Forms from the epiblast
Made up of mesenchyme cells
Formed by the process of gastrulation

155
Q

The secondary yolk sac develops from the ________

A

Hypoblast

156
Q

_______ ______ can trace the origin to the inner cell mass, embryoblast, ectoderm

A

Bottle cells

157
Q

Cleavage division occurs in the __________

A

Uterine tube

158
Q

The process of gastrulation is an example of what type of embryology?

A

Descriptive

159
Q

What cells secrete progesterone?

A

Luteal cells

160
Q

Which germ layer is in contact with the yolk sac?

A

Endoderm

161
Q

Cleavage division does what 3 things?

A

Decreases cell size
Increases cell mobility
Divides the cytoplasm

162
Q

What are the cells that directly cover the secondary yolk sac?

A

Extraembryonic splanchnopleuric mesoderm

163
Q

What does the neurenteric canal connect?

A

The amnion and the yolk sac

164
Q

The process of gastrulation describes the formation of the ________

A

Mesoderm

165
Q

Hypoblast is renamed as the ______ in the trilaminar disc

A

Endoderm

Embryology (4 decks)

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