Female Reproductive System

Female Reproductive System Overview

Introduction

  • Detailed description of the female reproductive system focusing on structural components and functions.

Structures of the Female Reproductive System

Urethra and Bladder

  • Urethra: Tube allowing urine to exit the bladder. Female urethra is shorter than male's, increasing UTI risk as bacteria have a shorter distance to travel to the bladder.

  • Bladder: Balloon-shaped organ that stores urine and has a muscular wall for expansion.

Fallopian Tubes, Cervix, and Vagina

  • Fallopian Tubes: Slender tubes that connect ovaries to the uterus, allowing for the transport of ova.

  • Cervix: Connects the uterus to the vagina, facilitating menstrual fluid passage.

  • Vagina: Elastic muscular tube connecting the uterus to the external body.

External Structures

Components

  • Clitoris: Erectile tissue containing a plexus of veins.

  • Labia Majora: Outer skin layer that is hairy.

  • Labia Minora: Inner skin layer that is devoid of hair.

  • Separate openings for urethra and vagina.

Mammary Glands

  • Located in the pectoral fat; the nipple is surrounded by the areola.

  • Lactiferous Ducts: Openings for milk drainage; milk is produced by secretory lobules.

  • Oxytocin: Triggers milk secretion during lactation.

Oogenesis

  • Oogonia: Stem cells in ovaries undergo mitosis to produce oocytes before birth.

  • Meiosis I: Occurs at ovulation, resulting in a secondary oocyte and a polar body.

  • Meiosis II: Finalizes before fertilization, resulting in a mature egg cell and another polar body.

  • Females are born with approximately 1-2 million oocytes, though many degenerate by puberty, leaving about 300,000.

Uterus Layers

  1. Perimetrium: Outer protective layer made of epithelial cells.

  2. Myometrium: Middle muscular layer, expands during pregnancy, aids labor.

  3. Endometrium: Innermost layer, glandular and vascular; sheds during menstruation if no fertilization occurs.

The Ovarian Cycle

  • Phases: Follicular Phase, Ovulation, Luteal Phase.

Follicular Phase

  • Primordial Follicle: Present from birth, contains an oocyte arrested in prophase of meiosis I until ovulation.

  • Primary Follicles: Develop monthly post-puberty, surrounding oocyte with granulosa cells, begin estrogen production.

  • Secondary and Tertiary Follicles: Progressively larger; tertiary follicle has a single large fluid cavity (antrum) and undergoes an estrogen surge prior to ovulation.

Ovulation

  • Triggered by an estrogen surge leading to an LH surge, resulting in the release of the oocyte from the follicle.

Luteal Phase

  • Corpus Luteum: Remnant of the ovulated follicle, secretes progesterone to prepare for potential pregnancy; degenerates into corpus albicans if no fertilization occurs.

Hormonal Regulation

  • FSH: Stimulates follicle maturation.

  • LH: Triggers ovulation and corpus luteum formation.

  • Progesterone: Secreted to maintain the uterine lining for pregnancy.

The Uterine (Menstrual) Cycle

  • Phases: Menses, Proliferative Phase, Secretory Phase.

Overview of the Menstrual Cycle

  • Repetition of changes in the endometrium every 21-35 days, average being 28 days, responding to ovarian hormones.

Phases Breakdown

  • Menses: Occurs when progesterone decreases, leading to shedding of the endometrium.

  • Proliferative Phase: Rebuilding of the endometrium stimulated by estrogen.

  • Secretory Phase: Post-ovulation, progesterone stimulates growth of arteries and glands to nourish potential embryo.

Quiz Questions

  • Example questions from the material focusing on key concepts such as oocyte development, hormone secretion, and structural identification.

  • Key Topics: Timing of oogonia mitosis, hormone control of lactation, external structures with hair, and the layers of the uterine wall.