anthro 3621 unit 1

Pelvic floor

The (term) supports pelvic organs and helps control openings of the urinary, reproductive, and digestive tracts.

Levator ani

A major group of pelvic floor muscles that supports pelvic organs and helps control the pelvic floor.

Perineum

The region of the pelvic floor between the pubic symphysis and coccyx that contains muscles and connective tissue supporting pelvic structures.

Pelvic girdle

The bony structure connecting the lower limbs to the axial skeleton; major structures include the sacrum, ilium, pubic symphysis, and sacroiliac joints.

Sacrum

The triangular bone at the back of the pelvis that connects with the pelvic bones through the sacroiliac joints.

Ilium

The large, upper portion of the hip bone that forms part of the pelvic girdle.

Pubic symphysis

The joint connecting the left and right pubic bones at the front of the pelvis.

Sacroiliac joint

The joint connecting the sacrum to the ilium on each side of the pelvis.

Bladder

A muscular organ that stores urine before urination.

Urethra

The tube that carries urine from the bladder to the outside of the body.

Rectum

The terminal portion of the large intestine that stores feces before elimination.

Puborectalis

A pelvic floor muscle that forms a sling around the rectum and helps maintain the anorectal angle.

Stress urinary incontinence

Involuntary urine leakage caused by increased pressure on the bladder, such as during coughing, sneezing, or physical activity.

Uterus

A muscular reproductive organ where implantation occurs and pregnancy develops.

Fundus

The upper portion of the uterus above the openings of the fallopian tubes.

Cervix

The lower portion of the uterus that connects the uterine cavity to the vagina.

Endocervix

The inner portion of the cervix containing the cervical canal.

Ectocervix

The portion of the cervix that projects into the vagina.

Vagina

A muscular canal connecting the cervix to the external genital tract.

Vulva

The external genital structures surrounding the openings of the vagina and urethra.

Broad ligament

A fold of peritoneum extending from the uterus toward the lateral pelvic wall that contains uterine tubes, ovarian vessels, uterine vessels, and associated ligaments.

Ovary

A paired reproductive organ containing ovarian follicles and producing eggs and ovarian hormones.

Ovarian cortex

The outer region of the ovary containing connective tissue and numerous ovarian follicles.

Ovarian medulla

The inner region of the ovary containing loose connective tissue and a rich neurovascular network.

Ovarian follicle

A structure in the ovarian cortex containing an oocyte surrounded by follicular cells.

Mesovarium

A portion of the broad ligament that attaches the ovary to its posterior layer.

Uterine (fallopian) tubes

Tubes extending from the uterus toward the ovaries through which the egg travels; fertilization normally occurs within a uterine tube.

Spiral arteries

Specialized arteries supplying the functional layer of the uterine endometrium; they change during the menstrual cycle and pregnancy.

Uterine arteries

Major blood vessels supplying the uterus.

Ovarian arteries

Blood vessels supplying the ovaries.

Uterine wall layers

The major layers of the uterine wall are the endometrium, myometrium, and perimetrium.

Endometrium

The inner lining of the uterus that changes throughout the menstrual cycle and provides the site for implantation.

Myometrium

The thick muscular layer of the uterus that contracts during menstruation and childbirth.

Perimetrium

The outer serous covering of the uterus.

Four endometrial layers listed in lecture

The four layers are epithelium, lamina propria, muscularis, and adventice.

Epithelium of the endometrium

The epithelial lining forming the innermost cellular surface of the uterine lining.

Lamina propria

Connective tissue underlying the epithelial layer of the endometrium.

Muscularis

The muscular component listed as one of the four endometrial layers in the course material.

Adventice

The outer connective-tissue layer listed among the four layers in the course material.

Anteverted uterus

A uterus tilted forward relative to the vagina and pelvis.

Retroverted uterus

A uterus tilted backward relative to the vagina.

Anteflexed uterus

A uterus in which the body is bent forward relative to the cervix.

Retroflexed uterus

A uterus in which the body is bent backward relative to the cervix.

Labial diversity

Labia vary substantially in size, shape, color, symmetry, and appearance; there is no single normal appearance.

Ovarian cycle

The cycle of follicle development, ovulation, and corpus luteum formation occurring in the ovary.

Uterine cycle

Cyclic changes in the uterine endometrium, including menstruation, proliferation, and secretion.

Ovarian and uterine cycle relationship

Ovarian hormones coordinate cyclic changes in the uterine endometrium so it can potentially support implantation.

Menstrual cycle

The recurring ovarian and uterine changes that prepare for possible pregnancy and, when pregnancy does not occur, lead to menstruation.

Menstrual versus estrous cycle

Humans have a menstrual cycle in which the endometrium is shed; many other mammals have an estrous cycle in which the uterine lining is largely reabsorbed.

Typical menstrual cycle length

A commonly cited cycle is about 28 days, although normal cycle length varies among individuals.

Ovulation

Release of a mature oocyte from an ovarian follicle, triggered by the mid-cycle LH surge.

Egg lifespan after ovulation

The ovulated egg remains viable for a relatively short period, approximately 12–24 hours.

Sperm survival in the reproductive tract

Sperm can survive for several days, allowing conception from intercourse occurring before ovulation.

FSH

(term) promotes ovarian follicle development and contributes to estrogen production.

LH

Luteinizing hormone triggers ovulation and supports corpus luteum formation.

Estrogen

An ovarian hormone that promotes endometrial proliferation and contributes to reproductive-cycle regulation.

Progesterone

A hormone produced mainly by the corpus luteum after ovulation that supports the secretory endometrium and pregnancy.

Corpus luteum

The structure remaining after ovulation that produces progesterone and other hormones.

Corpus albicans

The scar-like remnant formed when the corpus luteum degenerates.

Basal body temperature

Body temperature measured at rest; it typically rises slightly after ovulation because of progesterone.

Functional endometrium

The portion of the endometrium that undergoes major cyclic changes and is shed during menstruation.

Basal endometrium

The deeper portion of the endometrium that remains after menstruation and helps regenerate the functional layer.

Proliferative phase

The uterine phase after menstruation when estrogen stimulates regrowth and thickening of the endometrium.

Secretory phase

The post-ovulation uterine phase when progesterone makes the endometrium more receptive to implantation.

Decidualization

Transformation of endometrial tissue into specialized tissue that supports implantation and early pregnancy.

Decidua

The specialized endometrial tissue present during pregnancy after decidualization

Menstruation

Shedding of the functional endometrial layer when pregnancy and implantation have not occurred.

Endometriosis

A condition in which tissue resembling endometrium occurs outside the uterus and can cause pain and other symptoms.

Concealed ovulation

The evolutionary phenomenon in humans in which ovulation is not accompanied by obvious external signs of fertility.

Concealed ovulation hypotheses

Proposed explanations include strengthening pair bonds, reducing certainty of paternity, reducing male competition, and other reproductive or social benefits.

Endometrial maintenance hypothesis

One evolutionary explanation proposes that menstruation results partly from maintaining an endometrium capable of supporting highly invasive implantation.

Expensive-maintenance hypothesis

A hypothesis proposing that menstruation may be a byproduct of maintaining a costly, hormonally prepared uterine lining.

Simple-byproduct hypothesis

A hypothesis proposing that menstruation may result from other reproductive processes rather than being directly selected for itself.

Menstruation and pathogen-control hypothesis

A proposed explanation that menstruation may reduce pathogens associated with reproductive tissues, although evidence and applicability across species are debated.

Vascularization of the uterus

The uterus receives blood primarily through the uterine arteries, which give rise to vessels supplying the endometrium, including spiral arteries.

Vascularization of the ovary

The ovaries receive blood from ovarian arteries, with additional connections to the uterine arterial circulation.

Endometrial role in pregnancy

The endometrium thickens and becomes secretory and decidualized to provide a receptive environment for implantation and early embryonic support.

Conception

The sequence beginning with fertilization and continuing through early embryonic development toward implantation.

Spermatogenesis

Continuous production of sperm beginning at puberty, producing large numbers of sperm throughout reproductive life.

Oogenesis

Egg production in which the number of oocytes is established largely before birth and mature oocytes are released over the reproductive lifespan.

Sperm versus egg production

Sperm are produced continuously in large numbers, whereas oocytes are formed before birth and released individually through ovulation.

Acrosome

A cap-like structure on the sperm head containing enzymes that help the sperm penetrate the egg's surrounding layers.

Zona pellucida

A glycoprotein-rich layer surrounding the egg that sperm must penetrate during fertilization.

Polyspermy

Fertilization of an egg by multiple sperm, which prevents normal development.

Polyspermy block

Changes to the egg and zona pellucida after fertilization prevent additional sperm from entering.

Fertilization

Fusion of sperm and egg genetic material to form a zygote.

Zygote

The single cell produced by fertilization before subsequent embryonic cell divisions.

First embryonic mitosis

The (term) occurs about 30 hours after fertilization.

Early cleavage

Rapid cell divisions after fertilization increase cell number without initially producing a proportionate increase in overall embryo size.

4-cell stage

Around days 2–3, the developing embryo contains approximately four cells.

Morula

An early solid ball of approximately 16 cells formed after repeated cleavage divisions.

Blastocyst

A later embryonic structure containing an inner cell mass and surrounding trophoblast cells, with a fluid-filled cavity.

Zona hatching

The process by which the blastocyst emerges from the zona pellucida before implantation.

Implantation

Attachment and embedding of the developing blastocyst into the uterine endometrium, generally beginning around days 7–15.

Syncytiotrophoblast

An invasive trophoblast layer that contributes to implantation and produces signals important for maintaining pregnancy.

Endometrial changes during implantation

The endometrium becomes decidualized and develops a supportive environment for the implanting embryo.

Immune resistance to implantation

The maternal immune system must be regulated so that it tolerates the developing embryo while still maintaining immune protection.

T regulatory cells

Regulatory immune cells that help suppress immune responses and contribute to tolerance during pregnancy.

Natural killer cells in implantation

Uterine NK cells are regulated during implantation and contribute to placental development and vascular changes rather than simply attacking the embryo.

Hormonal immune signaling

Pregnancy-associated hormones influence immune receptors and help downregulate potentially damaging immune activity toward the developing conceptus.