Glandular Epithelia and Skin Derivatives - PPT

MEDI11-102 Week 6 Title Forum: Glandular epithelia, thick and thin skin, cells of skin and epithelial derivatives of skin Presenter Assistant Professor Joan Roehl...

MEDI11-102 Week 6 Title Forum: Glandular epithelia, thick and thin skin, cells of skin and epithelial derivatives of skin Presenter Assistant Professor Joan Roehl Lining epithelia were studied in MEDI11-101. We now complete the histology of epithelial tissue by studying glandular epithelia (exocrine only), with special emphasis on the glands associated with skin. Building on MEDI11-101 Scenario week 5, skin is studied as an organ system in two scenarios in MEDI11-102 (weeks 6 and 9). At the end of this week, you should be able to identify and describe the structure and function, as appropriate, of the: Why you should attend this session Exocrine glands of the body, including the pancreas (an exocrine and endocrine gland) Exocrine glands of skin (i.e., sebaceous glands, merocrine and apocrine sweat glands) The contribution of the various layers of skin to skin’s functions (e.g., as part of the innate immune system, desiccation-tolerance, in temperature regulation) What you will need to do in preparation Refresh your knowledge about primary tissues, particularly epithelial tissues, and skin (MEDI11-101). What you will need to bring Bring a digital or printed copy of the worksheet. 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 1  ATTENDANCE Have you checked in? Please remember to check into the session via Osler! 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 2  Acknowledgement of Country Bond University acknowledges the Kombumerri people, the traditional Owners and Custodians of the land on which the University now stands. We pay respect to Elders past, present and emerging. Copyright Warning. This material has been reproduced and communicated to you by or on behalf of Bond University in accordance with section 113P of the Copyright Act 1968 (Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 3  Glandular epithelia and epithelial derivates Assistant Professor Joan Roehl 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 4  Week Learning outcomes Week 6 – Science and Scholarship During this session you will learn about  1. Describe the structure, function and formation of glandular epithelia (exocrine only as endocrine done elsewhere) including the different modes of secretion of glandular tissue (merocrine, apocrine, holocrine, paracrine) (Forum, practical)  2. Identify and describe skin appendages (hairs and sweat glands, both epithelial derivatives) (Forum, practical)  3. Describe how skin structure and function changes with age and with some common skin presentations/conditions (e.g., keratoses, blisters, carcinoma, psoriasis, acne (workshop) 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 6  Session Learning outcomes During this session you will learn about  Complete the study of epithelial tissue: Glandular epithelial tissue (lining epithelia was done in MEDI11-101)  Study the different types of exocrine glands from different body locations  Discuss modes of secretion (merocrine, apocrine, holocrine)  Pay special attention to the glands and other epithelial derivatives of skin (Scenario week 6) 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 7  Epithelial tissue – Review Epithelial tissues consist of sheet of closely adhering cells, one or more cells thick. MEDI11-101 1. Provide lining of internal and external surfaces (e.g. skin, GI tract, blood vessels, body cavities, airways, kidney tubules, uterus, bladder, ducts, cornea…). Nick Sherman, Flickr, CC BY-NC-ND 2.0 DEED 2. Form glands that secrete products (e.g. mucus, sweat, hormones…) MEDI11-102 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 8 Thinkaliker, DeviantArt, CC BY-NC-SA 3.0 DEED  Epithelial tissue – Glandular epithelia - Review Exocrine glands Endocrine glands keep their connection lose their connection with the surface (duct) with the surface 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Junqueira's basic histology : text and atlas 9 Copyright © 2006 by The McGraw-Hill Companies, Inc.  Epithelial tissue – Glandular epithelia - Review A gland is a single cell, or a mass of epithelial cells adapted for secretion Endocrine (into circulation, i.e., blood) vs. Exocrine glands (into ducts or onto surface) Endocrine: Exocrine: Goblet Pituitary, thyroid, cells, sweat glands, parathyroids, islets salivary glands, of Langerhans, lacrimal glands, adrenals, gonads, pancreas, prostate, etc. etc. 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 10 Tortora, G. J., Derrickson, B. H., Burkett, B., Dye, D., Cooke, J., DiPiero, F., Diversi, T., McKean, M., & Peoples, G. (2022). Principles of anatomy and physiology (3rd Asia-Pacific edition.). John Wiley & Sons, Incorporated.  Epithelial tissue – Glandular epithelia - Review Exocrine glands Unicellular: 1 cell (Goblet cells) - Mucus-producing cells in the epithelium of the GIT, respiratory tract and other locations Mucus secretion: Apical, generally poorly stained, unless specific stains used Nucleus wedge-shaped and basal Image source unknown https://biology4isc.weebly.com/animal-tissues.html 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 11  Epithelial tissue – Glandular epithelia - Review Exocrine glands Unicellular: Multicellular: 1 cell (Goblet cells) > than 1 cell (e.g. Salivary glands) https://biology4isc.weebly.com/animal-tissues.html Image source unknown 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 12  Glandular epithelia: Multicellular exocrine glands 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 13  Multicellular glands Modes of secretion Gartner, Leslie P.. Textbook of Histology E-Book : Textbook of Histology E-Book, Elsevier, 2020. ProQuest Ebook Central, https://ebookcentral.proquest.com/lib/bond/detail.action?docID=6031953. Cells in the secretion Secreted by exocytosis Part of the cell is released Sebaceous, testis Most glands Mammary 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 14  Multicellular glands Nature of secretion Pancreas, Parotid Brunner’s, Sublingual Submandibular Serous: watery secretion Mucous: viscous Mixed: serous and mucus (usually enzymes/proteins) (glycoprotein mixture) 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 15 Source: Textbook of Histology. Gartner, Leslie P., PhD. Published January 1, 2021. Pages 79-102.e2. © 2021.  Multicellular glands Morphology of the gland https://histology.siu.edu/intro/glands.htm Classified according to the branching (or not) of the duct and the shape of the secretory unit https://histology.siu.edu/intro/glands.htm Branching of duct Simple - unbranched Compound - branched Blue Histology, University of Western Australia Shape of secretory unit Tubular - long and narrow Acinar or alveolar - round, like a berry 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 16  Multicellular glands Morphology of the gland 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 17  Multicellular glands Straight Goblet cells and Simple tubular gland Large intestine (colonic gland) Columnar cells Single, straight tubular lumen 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Longitudinal section Source: Wheater's Functional Histology. © 2023. Transverse section 18  Multicellular glands Coiled Simple tubular gland Sweat gland S: Secretory portion (simple cuboidal) D: excretory duct Single tube, (stratified cuboidal) coiled in three dimensions 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 19 Source: Wheater's Functional Histology. © 2023.  Multicellular glands Simple branched tubular gland Gastric glands several tubular secretory portions, Body of the stomach converge onto a single unbranched duct Source: Wheater's Functional Histology. © 2023. 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072  Multicellular glands Simple acinar gland penile urethra secretory cells are pale stained compared to the non-secretory cells lining the urethra U 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Source: Wheater's Functional Histology. © 2023.  Multicellular glands Simple branched acinar gland Source: Wheater's Functional Histology. Published January 1, 2023. Pages 159-179.e5. © 2023. Source: Gray's Anatomy. Published January 1, 2021. Pages 145-165.e1. © 2021. Source: Wheater's Functional Histology. © 2023. Sebaceous glands (thin skin) 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072  duct system D is branched, secretory portions S have a tubular form Multicellular glands which is branched and coiled Compound tubular gland Brunner’s glands (duodenum) 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Source: Wheater's Functional Histology. © 2023.  Multicellular glands Compound acinar gland minute ducts D, drain into excretory ducts E exocrine lined by simple cuboidal epithelium. Pancreas Source: Wheater's Functional Histology. © 2023. 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 endocrine Source: Integrated Physiology and Pathophysiology. Published January 1, 2022. Pages 402-414. © 2022.  Multicellular glands Compound tubulo-acinar gland Submandibular salivary gland Tubular components T (mucous), Acinar components A (serous), Tubular + acinar demilunes D 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Source: Wheater's Functional Histology. © 2023.  Multicellular glands Overview 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 28 Source: Textbook of Histology. Published January 1, 2021. Pages 79-102.e2. © 2021.  Multicellular glands Ducts (branched glands) Intercalated Secretory (Striated) Intralobular Interlobular Excretory Lobar 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 30  Multicellular glands Secretory ducts Pancreas - exocrine (serous acini) Source: Michelle McLean Intercalated duct Intralobular duct 11/10/2024 (small duct; joins acinus to intralobular duct)(intra = within the lobule) CRICOS Provider Code: 00017B TEQSA: PRV12072  In salivary glands, intercalated ducts lead to striated ducts, which are lined by a simple cuboidal/columnar epithelium Multicellular glands with fine striations visible in the cytoplasm. Striated ducts Parotid gland Striated duct 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Hill, M.A. (2024, February 14) Embryology Parotid gland histology 06.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Parotid_gland_histology_06.jpg Source: Blue Histology Multicellular glands Excretory ducts Interlobular septa (singular = septum) Submandibular gland Interlobular duct (inter = between lobules, within CT septa) CRICOS Provider Code: 00017B TEQSA: PRV12072 Source: Michelle McLean  Skin appendages: Epithelial derivates 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 34  Skin appendages: Epithelial derivates Overview The skin appendages include: Hair follicles Exocrine glands Sebaceous glands Sweat glands Apocrine Eccrine Nails Source: Michelle McLean 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 36  Skin appendages: Overview Skin appendages first develop in the second trimester of intrauterine development as simple down-growths of the surface epithelium (epidermis) into the developing subepithelial layers of mesoderm which will eventually become dermis and subcutis. Hair follicles are tubular invaginations lined by stratified squamous epithelium like the epidermis. Toward the bottom of each follicle, processes of cell division, growth, and maturation like those in the epidermis yield a cylindrical column of dead, keratinized cells (the hair shaft) which gradually extrudes from the follicle. 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 37 11/10/2024 Overview CRICOS Provider Code: 00017B TEQSA: PRV12072 Pilo-sebaceous unit Skin appendages: A memory dependent analysis on permeation of non-Gaussian laser pulse through human skin - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Layers-of-Skin-The-skin-is-composed-of-two-main- layers-the-epidermis-made-of-closely_fig1_374936597 [accessed 14 Feb, 2024] 38  Skin appendages: Overview 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 39  Skin appendages: Epithelial derivates Hair follicle Hairs are long, thin, cylindrical shafts composed of keratin; hair shafts have a surface cuticle composed of a single layer of flattened keratin scales. This covers a cortex of keratin forming the bulk of the hair. Large hairs may have a central medulla. 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Source: Michelle McLean 40  Skin appendages: Epithelial derivates Pilo-sebaceous unit Source: Wheater's Functional Histology. © 2023. Source: Wheater's Functional Histology. © 2023. Sebum: oily, waxy substance made Source: Sobotta Atlas of Anatomy, Volume 1. Published January 1, 2023. from CRICOS triglyceride 11/10/2024 oils, wax, squalene Provider Code: 00017B TEQSA: PRV12072 Pages 1-80. © 2023. 41  Skin appendages: Epithelial derivates Sebaceous follicles Sebaceous follicles not associated with hair follicles open directly onto the skin surface in the following locations: Eyelids Glans penis Labia minora Areolar region Source: Wheater's Functional Histology. © 2023. keratinising stratified squamous epidermis and scattered 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 sebaceous glands S which open directly onto the skin surface 43  Skin appendages: Epithelial derivates Sebaceous glands Source: Histology SIU © 2022 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 45  Skin appendages: Epithelial derivates Sweat glands vital for thermoregulation; influence water and ion balance Source: Pearson Education © 2015 larger ordinary Apocrine sweat gland Eccrine sweat gland Simple coiled tubular gland The secretory portion of the gland lies deep in the Source: Histology SIU © 2022 11/10/2024 (cuboidal epithelium) CRICOS Provider Code: 00017B TEQSA: PRV12072 dermis, where the tubule is twisted into a tangle. 46  Skin appendages: Epithelial derivates Sweat glands ordinary larger 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 Axilla, genitalia Most of the body 47  Skin appendages: Epithelial derivates Sweat glands stratified cuboidal epithelium Source: Front. Cell Dev. Biol., 28 July 2021. Sec. Stem Cell Research Volume 9 - 2021 | https://doi.org/10.3389/fcell.2021.667765 Source: Michelle McLean Source: Blue Histology simple cuboidal epithelium 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 with myoepithelial cells 51  Skin appendages: Epithelial derivates Sweat glands Myoepithelial cells are contractile epithelial cells which forcibly express the contents of a gland Source: Michelle McLean Source: Front. Cell Dev. Biol., 28 July 2021. Sec. Stem Cell Research Volume 9 - 2021 | https://doi.org/10.3389/fcell.2021.667765 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 52 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 54 Terminology checklist  Exocrine vs. endocrine  Holocrine, merocrine, apocrine  Acinus (sing. L. = any juicy berry with seeds like a grape; pl. = acini)  Alveolus (L. = a belly)  Tubulo-alveolar, alveolar, acinar  Lobe, lobule  Intralobular duct, e.g. striated duct  Interlobular duct, e.g. excretory duct  Myo-epithelial cell CRICOS Provider Code: 00017B TEQSA: PRV12072 E-Resources Virtual Histology: http://www.histologyguide.org/slidebox/12- exocrine-glands.html (Slidebox, Chapter 12, Exocrine) https://histology.siu.edu/intro/glands.htm Virtual Histology: http://www.histologyguide.org/slidebox/11- skin.html (Slidebox, Chapter 11, Skin) CRICOS Provider Code: 00017B TEQSA: PRV12072  bond.edu.au Assistant Professor Joan Roehl Faculty of Health Sciences and Medicine Bond University, Gold Coast, Australia 11/10/2024 CRICOS Provider Code: 00017B TEQSA: PRV12072 61