Lab-Female-Reproductive-2018.Pdf
Total Page:16
File Type:pdf, Size:1020Kb
Introduction The slides for this lab are located in the “Female Reproductive” folder on the Virtual Microscope. This guide provides you with a description of the slides that you will be examining and a short conceptual framework for studying them. The female reproductive system consists of internal sex organs and external genital structures. This lab focuses on the histology of the internal sex organs which include the ovaries, uterine tubes, uterus and vagina. These organs undergo regular cyclic changes from puberty to menopause under the influence of a number of different hormones. It is not the purpose of this laboratory to discuss these pathways but it is important that you do start to make these correlations as you study the physiological regulation of the female reproductive system. Learning objectives and activities Using the Virtual Slidebox: A Examine the structures of the ovary and trace the development of follicles from primordial follicle, through ovulation to formation of the corpus albicans. B Identify the different regions of the uterine tube based upon their histological organization. C Observe the uterus and determine the structural and functional changes that occur in the endometrium during the menstrual cycle. D Examine the histological features of the vagina. E Complete the self-quiz to test your understanding and master your learning Examine the structures of the ovary and trace the development of follicles from primordial follicle, through ovulation to formation of the corpus albicans Examine Slide 1 and Slide 2 to identify the basic features of the ovary and find examples of follicles at each stage of folliculogenesis. The ovaries are paired, almond-shaped structures that are attached to the pelvic wall by the suspensory ligament of the ovary (conveys ovarian vessels) and to the uterus by the ovarian ligament. Histologically it is composed of medulla and cortex and contains numerous follicles that are at different stages of maturation depending on the stage of menstrual cycle at the time of fixation and processing. i. General organization a. Cortex - found in peripheral ovary surrounding medulla Identify cortex in - contains most of the ovarian follicles Slide 1a and Slide 2a - loose irregular CT and scattered smooth muscle fibers - boundary between cortex and medulla is indistinct b. Medulla - central portion of ovary Identify medulla in - composed of loose irregular CT Slide 1b and Slide 2a - contains a mass of contorted blood vessels and nerves c. Germinal epithelium Find evidence of the - simple cuboidal epithelium covering the ovary germinal epithelium in - continuous with the mesovarium Slide 1c and 2c d. Tunica albuginea - a region of dense irregular CT Find the tunica - lies between germinal epithelium and cortex albuginea in Slide 1d and 2d ii. Folliculogenesis e. Primordial follicles Find examples of - are located in superficial cortex primordial follicles in - are lined with simple squamous follicular cells Slide 1e and Slide 2e - contain a primary oocyte arrested in prophase I meiosis f. Primary/growing follicles (unilaminar) Find examples of - are often located deeper in the cortex than primordial follicles unilaminar primary - are lined with simple cuboidal-columnar follicular cells follicles in - have developed a zona pellucida Slide 1f and Slide 2f - contain a primary oocyte arrested in prophase I meiosis g. Primary/growing follicles (multilaminar) - are lined with stratified columnar follicular cells Find examples of - the follicular cells are now called stratum granulosum multilaminar primary - have developed a zona pellucida follicles in - contain a primary oocyte arrested in prophase I meiosis Slide 2g - connective tissue around follicle organizes to form theca folliculi h. Secondary/antral follicles - are characterized by development of an antrum within the stratum granulosum that is filled with liquor folliculi Find examples of - contain a primary oocyte arrested in prophase I meiosis secondary follicles in - theca folliculi differentiated to form: Slide 1h and 2h i. theca interna: produce androstenedione ii. theca externa: CT and smooth muscle i. Tertiary/Graafian follicles - are the largest follicles - have a large antrum - on Day 13 of the menstrual cycle the LH surge causes the Find the Graafian primary oocyte in the follicle to resume meiosis follicle and its - this division means the Graafian follicle contains a secondary components in oocyte that is: Slide 1i and 2i i. arrested in metaphase II of meiosis ii. surrounded by cloud of granulosa cells (corona radiata) iii. connected to peripheral granulosa cells by a thin stalk called the cumulus oopherus. j. Atretic follicles - represent the follicles that are lost due to mediated apoptosis of Find example of large stratum granulosum cells and small atretic - are formed durin fetal development and during adulthood follicles in - they may be small (apoptosis of primary and primordial follicles) Slide 1j and 2j - they may be large (apoptosis of a secondary follicle that was not selected to mature to Graafina stage) Following ovulation of the secondary oocyte and its corona radiata, the structures of the Graafian follicle persist in the ovary temporarily where it acts as an endocrine gland capable of supporting the uterine endometrium in case fertilization and implantation take place. This structure is called the corpus luteum. If pregnancy occurs the corpus luteum grows to occupy a large portion of the ovary under the control of human Chorionic Gonadoptrophin (hCG) and assists with the endocrine support of the pregnancy for. After 6mmths of preganancy or if fertilization does not occur within 14 days of ovulation the corpus luteum degenerates to form a corpus albican ‘scar’ Examine Slide 3 to identify features of the corpus luteum and Slide 4 to see a corpus albican a. Corpus luteum Examine the corpus - a large, temporary endocrine organ composed of the remnants luteum in of the Graafian follicle after ovulation has occurred. Slide 3a - these remnant structures reorganize to form specialized regions of endocrine cells b. Granulosa lutein cells - are derived from the stratum granulosum of the Graafian Find the granulosa - form the bulk of the wall lutein cells in - produce progesterone Slide 3b - converts androgens produced by theca lutein cells into estrogen c. Theca lutein cells - are located peripherally Find the theca lutein - are derived from the theca interna of the Graafian cells in - produce progesterone and androgens Slide 3c - converts androgens produced by theca lutein cells into estrogen d. Corpus albicans - the CT scar remnant of a degenerated corpus luteum. Find the corpus albicans in Slide 4 Stratified with developing antrum Stratified columnar Atretic (dying) Secondary Primary follicle Simple cuboidal/columnar follicle follicle Approaching (multilaminar) maturity Simple squamous Primary follicle (unilaminar) Primordial Peripheral; large; follicle well developed antrum Tertiary/mature/ Graafian follicle Primary Secondary oocyte Corpus albicans Ovulated oocyte Corpus luteum Ruptured follicle Corpus hemorrhagicum Identify the different regions of the uterine tube based upon their histological organization. The uterine tubes are paired tubes that extend bilaterally from the uterus toward the ovaries. The transport the ovulated secondary oocyte toward the uterus and are the site of fertilization. i. Infundibulum (and fimbrae) The funnel shaped initial segment of the uterine tube that is fringed with fimbrae. Observe the organization and key features of the infundibulum in Slide 5 a. Fimbrae - extend from the mouth of the infundibulum Identify fimbrae in - sway to assist in acceptance of the ovulated oocyte from the Slide 5a surface of the ovary b. Mucosa Identify the mucosa in - composed of the epithelium and CT lamina propria Slide 5b c. Ciliated epithelial cells Find ciliated - a ciliated simple columnar epithelium epithelium in - cilia sway with metachronal rhythm to assist in drawing the Slide 5c oocyte into the uterine tube d. Muscularis mucosa Identify muscularis - a region of poorly defined smooth muscle mucosa in Slide 5d e. Serosa - a thin layer of connective tissue covered in peritoneum (mesothelium) Identify the serosa in Slide 5e ii. Ampulla The longest segment of the uterine tube also has the most folds in its mucosa surface. It is also the most common site of fertilization. Observe the organization and key features of the ampulla in Slide 6 a. Mucosa Identify mucosa in - composed of the epithelium and CT lamina propria Slide 6a - is very highly folded in the ampulla b. Ciliated epithelial cells Find ciliated - a ciliated simple columnar epithelium epithelium in - cilia sway with metachronal rhythm to assist in transport of Slide 6b oocyte through the uterine tube c. Non-ciliated epithelial cells (Peg cells) - relatively rare cells that lack cilia Find peg cells in - secrete a nutrient rich secretion that nourishes the ova as it Slide 6c waits to be fertilized and is also thought to be involved in capacitation of the spermatozoa - nuclei appear more superficial than surrounding cells d. Muscularis mucosa Identify muscularis - a region of poorly defined smooth muscle mucosa in Slide 6d e. Serosa - a thin layer of connective tissue covered in peritoneum Identify serosa in (mesothelium) Slide 6e ii. Isthmus The narrow segment of the uterine tube that lies adjacent to but does not pass through the uterine wall. Observe the organization and key features of the isthmus in Slide 7 a. Mucosa - composed of the