Reproductive System Flashcards
1
Q
Sexual Reproduction
A
- the genetic material of two organisms
- combines and results in a genetically unique offspring
- occurs via the fusion of two gametes, specialized sex cells produced by each parent
2
Q
Gonads
A
- this is where gametes are produced
- the male gonads are testes - produce sperm in the tightly coiled seminiferous tubules
- the female gonads are the ovaries - produce oocytes (eggs)
3
Q
Gametogenesis
A
- this is the production of functional cells
- in males, it is called spermatogenesis
- in females, it is called oogenesis
4
Q
Fertilization
A
the union of the egg and sperm nuclei to form a zygote with a diploid number of chromosomes
5
Q
Male Reproductive System
A
- the testes are located in the scrotum
- sperm passes from the testes through the vas deferens and the ejaculatory duct and then to the urethra
- the testes are also the sites of production of testosterone
6
Q
Spermatogenesis
A
- occurs in the seminiferous tubules
- spermatogonia differentiate into diploid cells called primary spermatocytes, which undergo a meiotic division to yield two haploid secondary spermatocytes
- a second meiotic division produces four haploid spermatids of equal size
- after meiosis the spermatids undergo a final series of changes that increase their inability resulting in mature sperm - spermatoza
7
Q
Female Reproductive System
A
- ovaries are found in the abdominal cavity below the digestive system
- ovaries consists of follicles
- approx once a month, an immature ovum is released from the ovary to the fallopian tubes
- each fallopian tube opens into the upper end of the uterus
- the lower narrow end of the uterus is called the cervix
- the cervix connects with the vaginal canal
8
Q
Oogenesis
A
- the production of female gametes, occurs in the ovarian follicles
- primary oocytes - at birth all that a female will produce in her lifetime
- secondary oocytes - a small cell known as a polar body. It is expelled from the follicle during ovulation
- the oocytes cell membrane is surrounded by two layers of cells, Inner layer: zona pellucida layer. Outer layer: Corona Radiata layer
- Meiosis II is triggered when these two layers are penetrated by a sperm cell
- the mature ovum is a large cell containing cytoplasm, RNA, organelles, and nutrients needed by the developing embryo
9
Q
Female Sex Hormones
A
- ovaries synthesize to secrete female hormones
- the secretion of both estrogens and progesterone is regulated by leutinizing hormone (LH) and follicle stimulating hormone (FSH), which are regulated by gonadotriptin-releasing hormone (GnRH)
10
Q
Estrogen
A
- steroid hormones necessary for female maturation
- stimulate the development of the female reproductive tract
- responsible for the thickening of the endometrium
- secreted by the ovarian follicles and the corpus luteum
11
Q
Progesterone
A
- a steroid hormone secreted by the corpus luteum during the luteal phase of the menstrual cycle
- stimulates the development and maintenance of the endometrium in prep for implantation
12
Q
The Menstrual Cycle
A
- Follicular Phase: begins with the cessation of the menstrual flow from the pervious cycle
- Ovulation: midway through the cycle ovulation occurs - a mature ovarian follicle bursts and releases an ovum
- caused by a surge in LH and a peak in estrogen levels - Luteal Phase: after ovulation, LH maintains the
remnant of the ruptured follicle - corpus luteum
-the corpus luteum secretes estrogen and progesterone
-progesterone causes the glands of the endometrium that prepare it for the implantation of the embryo - Menstruation
- if the ovum is not fertilized, the corpus luteum atrophies
- the drop of progesterone and estrogen level gives rise to the menstrual flow
- if fertilization occurs, the developing placenta produces hcG, maintaining copus leteum - Fertilization
- occurs in the lateral, widest portion of the fallopian tube
- sperm must travel through the vaginal canal, cervix, uterus, and into the fallopian tubes to reach the ovum
- sperm must first penetrate the corona radiata
- the acrosome is responsible for penetrating the zena pellucida
- once in contact with the membrane, the sperm forms a tube-like structure called the acrosomal process, which extends to the cell membrane and penetrates it
- the acrosomal reaction triggers a cortical reaction in the ovum - calcium ions into the cytoplasm - results in the formation of the fertilization membrane - prevents multiple fertilizations
13
Q
Monozygotic (Identical Twins)
A
- results when a single zygote splits into 2 embryos
- same sex, blood type, etc
14
Q
Dizygotic (Fraternal Twins)
A
- result when two ova are released in one ovarian cycle and are fertilized by 2 different sperm
- develops its own placenta, amnion, and chorion
- develop from 2 different zygotes
