biology- chapter 2- Human Reproduction

Testes

The primary male reproductive organs that produce sperms and secrete hormones.

Scrotum

A pouch of skin containing the testes, which helps maintain their temperature.

Seminiferous Tubules

Highly coiled structures in the testes where sperms are produced.

Sertoli Cells

Cells within the seminiferous tubules that provide nutrition to developing sperms.

Leydig Cells

Cells located in the interstitial spaces of the testes that secrete testosterone.

Epididymis

A long, coiled duct on the outside of the testis where sperm mature and are stored.

Vas Deferens

The duct that conveys sperm from the testicle to the urethra.

Seminal Vesicles

Accessory glands that secrete a fluid rich in fructose, which provides energy for the sperm.

Prostate Gland

A gland surrounding the neck of the bladder in males that releases prostatic fluid.

Bulbourethral Glands

Also known as Cowper's glands; they secrete a fluid that lubricates and neutralizes traces of acidic urine in the urethra.

Penis

The external male genital organ that delivers sperm into the female reproductive tract.

Glans Penis

The sensitive bulbous structure at the distal end of the penis, covered by the foreskin.

Ovaries

The primary female reproductive organs that produce ova and secrete hormones.

Fallopian Tubes

Also known as oviducts; tubes through which ova travel from the ovaries to the uterus.

Uterus

The organ in which a fertilized egg implants and develops into a fetus.

Cervix

The lower part of the uterus that opens into the vagina.

Vagina

The muscular tube leading from the external genitals to the cervix of the uterus.

Mons Pubis

A rounded mass of fatty tissue over the pubic bone.

Labia Majora

The outer folds of skin surrounding the external female genitalia.

Labia Minora

The inner folds of skin surrounding the vaginal opening.

Clitoris

A small, sensitive organ located at the anterior part of the vulva.

Hymen

A membrane that partially covers the external vaginal opening.

Mammary Glands

Glands located in the breasts that produce milk.

Spermatogenesis

The process by which sperms are produced in the testes.

Oogenesis

The process by which ova are produced in the ovaries.

Spermatogonia

The diploid germ cells in males that undergo mitosis and meiosis to form sperms.

Primary Spermatocyte

The diploid cells that undergo the first meiotic division to form secondary spermatocytes.

Secondary Spermatocyte

The haploid cells that undergo the second meiotic division to form spermatids.

Spermatids

The haploid cells that are transformed into spermatozoa.

Spermiogenesis

The process by which spermatids are transformed into mature spermatozoa.

Oogonia

The diploid germ cells in females that undergo mitosis to form primary oocytes.

Primary Oocyte

The diploid cells that begin the first meiotic division and are arrested in prophase I until puberty.

Secondary Oocyte

The haploid cells that are arrested in metaphase II and are released during ovulation.

Polar Bodies

The small cells produced during oogenesis that do not develop into ova.

Graafian Follicle

The mature ovarian follicle that releases the ovum during ovulation.

Menarche

The first occurrence of menstruation in a female.

Menopause

The cessation of menstruation, marking the end of a woman's reproductive years.

Follicular Phase

The phase of the menstrual cycle during which follicles in the ovary mature.

Ovulation

The release of an ovum from the ovary.

Luteal Phase

The phase of the menstrual cycle following ovulation, characterized by the presence of the corpus luteum.

Menstrual Phase

The phase of the menstrual cycle during which the endometrial lining is shed.

Estrogen

A hormone produced by the ovaries that regulates the menstrual cycle and supports pregnancy.

Progesterone

A hormone produced by the corpus luteum that maintains the endometrium for pregnancy.

LH Surge

A rapid increase in luteinizing hormone that triggers ovulation.

Corpus Luteum

The structure that forms from the ruptured follicle after ovulation and secretes progesterone.

Endometrium

The inner lining of the uterus that thickens and sheds during the menstrual cycle.

Pituitary Gland

The gland that secretes follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Fertilisation

The fusion of a sperm and an ovum to form a zygote.

Zygote

The diploid cell resulting from the fusion of a sperm and an ovum.

Cleavage

The series of mitotic divisions that a zygote undergoes after fertilisation.

Blastocyst

The stage of development that implants in the uterine wall.

Implantation

The process by which a blastocyst embeds itself in the endometrium.

Trophoblast

The outer layer of cells in the blastocyst that forms the placenta.

Inner Cell Mass

The group of cells in the blastocyst that develops into the embryo.

Placenta

The organ that provides oxygen and nutrients to the developing fetus and removes waste products.

Umbilical Cord

The structure that connects the fetus to the placenta.

Chorionic Villi

The finger-like projections of the trophoblast that extend into the endometrium.

HCG (Human Chorionic Gonadotropin)

A hormone produced by the placenta that maintains the corpus luteum during pregnancy.

Zona Pellucida

The thick outer covering of the ovum that is penetrated by a sperm during fertilisation.

Gestation Period

The duration of pregnancy, typically about 9 months in humans.

Trimesters

The three periods into which pregnancy is divided, each lasting about three months.

Embryo

The early stage of development from fertilisation to the end of the eighth week.

Fetus

The stage of development from the end of the eighth week until birth.

Amniotic Sac

The fluid-filled sac that surrounds and protects the developing fetus.

Amniotic Fluid

The fluid within the amniotic sac that cushions and protects the fetus.

Chorion

The outer membrane that forms the fetal part of the placenta.

Yolk Sac

The structure that provides nutrients to the embryo during early development.

Allantois

The fetal membrane that forms part of the umbilical cord.

Ectoderm

The outer germ layer that develops into the skin and nervous system.

Mesoderm

The middle germ layer that develops into muscles, bones, and the circulatory system.

Endoderm

The inner germ layer that develops into the digestive and respiratory systems.

Parturition

The process of giving birth.

Oxytocin

A hormone that stimulates uterine contractions during childbirth and milk ejection during breastfeeding.

Labour

The series of events that lead to the expulsion of the fetus from the uterus.

Dilation

The widening of the cervix during the first stage of labor.

Placenta

The organ expelled after the birth of the baby, often called the afterbirth.

Lactation

The production and secretion of milk by the mammary glands.

Colostrum

The first form of milk produced after childbirth, rich in antibodies.

Breastfeeding

The act of feeding a baby with milk directly from the mother's breast.

Mammary Glands

Glands located in the breasts that produce milk.

Prolactin

A hormone that stimulates milk production in the mammary glands.

Let-Down Reflex

The reflex that causes milk to be ejected from the alveoli into the ducts of the breast.

Weaning

The process of gradually introducing the infant to solid food while reducing breastfeeding.