Human Reproductive and Developmental Biology

A comprehensive set of flashcards covering key concepts in human reproductive and developmental biology, including genetic determination of sex, hormone functions, reproductive organs, embryonic development, and immune responses.

Fetus Sex Determination

The sex of a fetus is determined at fertilization when a sperm fuses with an oocyte; sperm can contribute either an X or a Y chromosome.

Diploid Zygote

A fertilized egg that has two sets of chromosomes, one from each parent.

Primary Germ Layers

The three layers (ectoderm, mesoderm, endoderm) from which all tissues and organs develop.

Ectoderm

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

Mesoderm

The middle germ layer that forms muscles, bones, and blood.

Endoderm

The innermost germ layer that develops into internal organs.

Corpus Luteum

Structure formed from the ovarian follicle; produces progesterone and estrogen.

Placenta

The organ that connects the developing fetus to the uterine wall for nutrient and waste exchange.

Ovaries

Gonads that produce oocytes and secrete hormones like estrogen and progesterone.

Testes

Male gonads that produce sperm and testosterone.

Progesterone

Hormone that maintains the endometrium and inhibits uterine contractions.

Estrogen

Hormone that thickens the endometrium and stimulates breast growth.

Inhibin A

Hormone that inhibits FSH and prevents new follicle development.

Relaxin

Hormone that relaxes the uterus and softens the cervix.

hCG

Hormone that maintains the corpus luteum and promotes progesterone production.

hPL

Hormone that alters maternal metabolism to favor fetal nutrition.

CRH

Hormone that regulates labor onset and fetal adrenal development.

Testosterone

Hormone that promotes male sex traits and spermatogenesis.

Anti-Mullerian Hormone

Hormone causing regression of Mullerian ducts in male fetuses.

Prostaglandins

Substances that promote uterine contractions during menstruation and labor.

GnRH

Gonadotropin-releasing hormone that stimulates LH and FSH release.

LH

Luteinizing hormone that triggers ovulation and stimulates progesterone and testosterone production.

FSH

Follicle-stimulating hormone that stimulates follicle development and sperm production.

X-linked Dominant Traits

Traits expressed in both genders that manifest more severely in males due to lack of a normal recessive allele.

Polygenic Inheritance

Inheritance of traits influenced by multiple genes.

Endometriosis

Condition where endometrial tissue grows outside the uterus, affecting fertility.

IVF

In vitro fertilization, a technique in which an egg is fertilized outside the body.

Testes Function

Primary organs that produce sperm and testosterone.

Seminiferous Tubules

Structures within the testes where sperm cells are formed.

Epididymis

Structure where sperm mature and are stored.

Vas Deferens

Duct that transports sperm from the epididymis to the urethra.

Seminal Vesicles

Glands that produce a nutrient-rich fluid that nourishes sperm.

Prostate Gland

Gland that adds fluid to sperm to enhance motility.

Bulbourethral Glands

Glands that secrete mucus to lubricate the urethra.

Urethra

Duct through which sperm exits the body.

Ovarian Function

Ovaries produce oocytes and hormones regulating the reproductive cycle.

Fallopian Tube

Tube that transports the oocyte from the ovary to the uterus.

Uterus

Muscular organ where implantation and fetal development occur.

Cervix

Narrow lower portion of the uterus that opens into the vagina.

Vagina

Muscular canal that receives sperm and serves as the birth canal.

Hypothalamus

Brain region that regulates puberty and lactation through hormonal control.

Prolactin

Hormone that stimulates milk production in mammary glands.

Oxytocin

Hormone that triggers the milk ejection reflex during breastfeeding.

First Trimester

Stage of pregnancy where rapid organ development occurs.

Second Trimester

Stage where previously formed organs grow and function becomes apparent.

Third Trimester

Final stage of fetal development characterized by rapid growth and organ maturation.

Placenta Function

The organ that facilitates nutrient exchange and hormone production during pregnancy.

Pulmonary Circulation

Movement of blood from the right heart to the lungs and back to the left heart.

Systemic Circulation

Movement of oxygenated blood from the left heart to the body and back to the right heart.

Arteries

Blood vessels that carry oxygenated blood away from the heart.

Veins

Blood vessels that carry deoxygenated blood back to the heart.

Erythrocytes

Red blood cells that transport oxygen in the blood.

Leukocytes

White blood cells that defend against pathogens.

Platelets

Cell fragments that aid in blood clotting.

Plasma

The liquid component of blood that carries cells and proteins.

Lymphatic System

System that returns excess fluid to blood and houses immune cells.

Primary Lymphatic Organs

Bone marrow and thymus, where blood cells are produced and mature.

Secondary Lymphatic Organs

Lymph nodes, spleen, tonsils; involved in filtering and immune response.

Innate Immunity

Non-specific, immediate defense against pathogens present from birth.

Adaptive Immunity

Specific immune response that develops after exposure to pathogens.

Active Immunity

Long-lasting immunity developed by the body after exposure to an antigen.

Passive Immunity

Temporary immunity provided by external antibodies instead of produced by the body.

Respiratory System Functions

Facilitates gas exchange, maintains blood pH, enables speech, and provides a sense of smell.

Epistaxis

Nosebleed, usually caused by irritation or injury.

Hemoptysis

Coughing up blood from the respiratory tract.

Pneumothorax

Air in the pleural cavity leading to lung collapse.

Effusion

Buildup of excess fluid in the pleural cavity.

Digestive Organs

Organs involved in the breakdown and absorption of food.

Stomach Regions

Includes the fundus, body, and pylorus.

Small Intestine

Site of most digestion and nutrient absorption, includes duodenum, jejunum, and ileum.

Large Intestine

Responsible for water absorption and feces formation.