Applied Animal Reproduction - Introduction to General Reproduction

These flashcards provide essential vocabulary and concepts from the introductory lectures on female and male animal reproduction, covering anatomy, hormonal regulation, oestrous cycles, fertilisation, and parturition.

Sexual Reproduction

The union of male and female gametes, specifically sperm and egg, to create a new individual.

Precocial species

Species where the offspring are relatively mature at birth, meaning they are well-developed and able to stand or walk within hours, such as calves or lambs.

Viviparous

A type of development where the foetus grows inside the mother's body, receiving protection and nourishment in the uterus.

Cortex (Ovary)

The outer layer of the paired ovaries where the eggs develop.

Oogenesis

The process of egg formation; females are born with a finite number of eggs that they will have for their entire life.

Folliculogenesis

The process of development for follicles, which are the structures that contain and nurture developing eggs.

Corpus Luteum

A temporary endocrine gland formed from an empty follicle after ovulation that produces progesterone to maintain pregnancy.

Progesterone ($P4$)

The hormone produced by the corpus luteum that is essential for maintaining pregnancy and preparing the uterine lining for an embryo.

Infundibulum

The funnel-shaped end of the oviduct that contains hair-like structures called fimbriae to collect the ovulated egg.

Ampulla

The widest section of the oviduct and the critical site where fertilisation between sperm and egg occurs.

Isthmus

The narrower section of the oviduct that transports the developing embryo toward the uterus.

Endometrium

The uterine lining that provides the maternal contribution to the placenta.

Parturition

The act of giving birth, specifically the muscular contractions of the uterus to expel the foetus and the placenta.

Cervix

A gateway between the uterus and vagina containing complex folds that acts as a filter for abnormal sperm.

Polyoestrous

Animals with regular oestrous cyclicity throughout the entire year, such as cattle, pigs, and rodents.

Seasonally Polyoestrous

Animals that have regular oestrous cyclicity only during specific seasons of the year, such as sheep, goats, and horses.

Monooestrous

Animals that experience only one period of oestrous per annum, such as dogs, wolves, and foxes.

Spontaneous Ovulation

A process where ovulation occurs on a regular schedule based on hormonal signals, regardless of whether copulation occurs.

Induced Ovulation

A process where the physical stimuli of copulation are required to trigger hormonal signals that cause the release of the egg, seen in cats and camels.

Oestrus

The noun form used to describe the heat period itself during which the animal is sexually receptive.

GnRH

Gonadotropin-Releasing Hormone, released from the brain to stimulate the pituitary to release $FSH$ and $LH$.

Luteolysis

The programmed degradation and destruction of the corpus luteum that occurs during proestrus if pregnancy has not happened.

Inhibin

A hormone produced by dominant follicles that suppresses $FSH$ secretion to prevent other follicles from developing.

Corpus Hemorrhagicum

Commonly called a 'bleeding body,' this structure forms right after ovulation when bleeding occurs into the empty follicle.

Capacitation

The essential process where proteins and the seminal plasma coating are removed from the sperm by fluids in the female reproductive tract to activate the sperm.

Acrosomal Reaction

The release of enzymes from the sperm head that digests a path through the zona pellucida, enabling the sperm to penetrate and fuse with the egg.

Blastocyst

A hollow ball of cells with a fluid-filled centre that reaches the uterus and signals the maternal system to recognize the pregnancy.

Interferon-tau

A specific protein produced by the blastocyst in cattle and sheep to signal pregnancy and prevent the breakdown of the corpus luteum.

Amnion

The fluid-filled protective sac surrounding the developing foetus that protects it from physical trauma and allows movement.

Chorion

The outermost extraembryonic membrane and the foetal contribution to the placenta which develops chorionic villi for attachment.

Allantois

An extraembryonic membrane involved in placental attachment, nutrient and gas exchange, and the removal of foetal waste products.

Placentomes

Discrete button-like attachment points for the placenta in ruminants, composed of foetal cotyledons and maternal caruncles.

Diffuse Placenta

A placental type with uniform distribution of chorionic villi over the entire surface, found in pigs and horses.

Zonary Placenta

A placental type where villi are concentrated in a banded zone around the middle, found in carnivores like cats and dogs.

Discoid Placenta

A regionalised, disc-shaped placenta found in rodents, humans, and primates.

Dystocia

A clinical term for the occurrence of a difficult birth.

Spermatogenesis

The continuous process of sperm production in the seminiferous tubules, which takes approximately $60$ days from start to finish.

Epididymis

A long, coiled tube consisting of a head, body, and tail, where sperm mature, develop motility, and are stored.

Seminal Vesicles

Accessory sex glands that produce seminal plasma and contribute fructose as an energy source for sperm.

Sertoli Cells

Cells in the seminiferous tubules that are acted upon by $FSH$ to stimulate the production of sperm.

Leydig Cells

Cells in the testis that are stimulated by $LH$ to produce testosterone.

Progressive Motility

The characteristic of sperm swimming forward in a straight line, which is essential for reaching the egg.