Term
| Changes in hormones, ovaries, and uterus during menstrual cycle |
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Definition
Ovarian cycle
Primary follicles contain oocyte and begin producing the sex hormone estrogen.
Secondary follicles contain secondary oocyte and produce estrogen and some progesterone. They thicken lining (endometrium) of uterus.
Vesicular (Graafian) follicle develops.
Ovulation: The secondary oocyte is released.
Corpus luteum produces female sex hormones. (lasts about 2 weeks, continues to produce estrogen and progesterone until it degenerates).
Corpus luteum degenerates (if no signal saying pregnant, corpus luteum breaks down, becomes white and is called corpus albicans). Menstruation begins. |
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Term
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Definition
| Estrogen: supports secretory endometrium |
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Term
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Definition
| Progesterone: supports secretory endometrium, inhibits contractility of uterine muscle, firms cervix and inhibits dilation. |
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Term
| Function of human chorionic gonadotropin (hCG) |
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Definition
Hormones produced by pituitary gland (in brain). Both for pituitary gonadotropins (target the gonads). Both have levels that increase around middle of process
LH: Luteinizing hormone. Largest amount around day 14. Induces ovulation.
FSH: follicle stimulating hormone.
hCG: Human chorionic gonadotripin. After fertilization, sends signal to corpus luteum, lets it know not to slough endometrium. |
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Term
| how are monozygotic and dizygotic twins produced? |
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Definition
monozygotic twins:
if cells split at the 2-stage, develop with separate placentas
if complete split of inner cell mass: two amnions
split of inner cell mass late in development: 1 placenta, 1 amnion
Dizygotic (Fraternal twins)
2 separate oocytes are fertilized, develop separately |
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Term
| Process of development/major events in development of a multicellular animal |
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Definition
1. Gamete formation (sperm and eggs develop, mature)
2. Fertilization (egg and sperm fuse)
3. Cleavage (zygote subdivides, determinants partitioned in blastomeres)
4. Gastrulation (germ layers form)
5. Organogenesis (Body organs form, cells interact and differentiate)
6. Growth (Organs increase in size, adult body form is attained) |
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Term
| Define radial and spiral cleavage. |
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Definition
Radial cleavage: cleavage planes are parallel or perpendicular to axis of cell. Examples: sea stars, humans
Spiral cleavage: cleavage planes of cells are any angle besides parallel or perpendicular to axis of cell. Examples: Many invertebrates. |
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Term
| How does the formation of a true coelem differ between organisms with radial versus spiral cleavage? |
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Definition
blastula begins to differentiate into the gastrula, an invagination (in-pocketing) forms. The invagination is called the blastopore.
If does radial cleavage: Blastopore becomes anus first.
If does spiral cleavage: blastopore becomes mouth first. |
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Term
| What is the difference between regulative and mosaic development? |
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Definition
Regulative development: if something happens and early blastula is split, forms normal larvae. Examples: sea urchin, humans (why we can have identical twins)
Mosaic development: If blastula is split up, result is defective larvae (example: molluscs) |
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Term
| Major developmental differences between protostomes and deuterostomes |
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Definition
Protostome
1. Radial cleavage
2. Blastophore becomes mouth first, anus second
3. Indeterminate (regulative) development.
4. Coelom forms by splitting (schizocoelus)
Examples: annelids, platyhelminthes, nemertea, mollusca, arthropoda
Deuterostome:
Blastopore becomes anus first, mouth second.
Radial cleavage.
Determinate/mosaic
Coelem forms by outpocketing (enterocoelus)
Examples: Echidnodermata, hemichordata, chordata. |
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Term
| Developmental origin of specific vertebrate tissues. |
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Definition
In humans:
Germ cells (for reproduction) are sequestered before gastrulation
2. Ectoderm becomes: outer epithelium of body and derivatives, neural tube (brain, spinal cord, nerves), neural crest.
3. Mesoderm: notochord, lining of thoracic and abdominal cavities, circulatory system, somites (skeletal muscle, bone, cartilage except skull, etc), organs of urogenital system
4. Endoderm: epithelium of respiratory tract, pharynx, liver, pancreas, epithelium of urogenital system |
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