Integumentary System

• What is the integument of unicellular organisms?

  Plasma membrane
• Pellicle: thick protein coat found on several

  protozoa

  – offers further environmental protection

  – semi-rigid structure that transmits the

  force of cilia or flagella to the entire

  body as the animal moves

  
• The invertebrate epidermis is composed of what kind of epithelial tissue?

  Simple columnar
• some invertebrates have cuticle over the epidermis
• delicate and soft in mollusks and contain mucous glands, some of which secrete calcium carbonate of the shell
• The vertebrate epidermis is composed of what kind of epithelium?

  Stratified squamous
• Vertebrate skin consists of a dermis layer containing blood vessels, collagenous fibers, nerves, pigment cells, fat cells, and fibroblasts
• stratified squamous epithelium, will undergo what?

  Keratinization (cornified cells)
• Label the following.

  A) Epicuticle

  B) Procuticle

  C) Chitin

  D) Calcium salts

  E) Epidermis

  
• The arthropod cuticle may be hardened by what?

  Sclerotization, Calcification
• Sclerotization - protein molecules bond together with stabilizing cross-linkages, within and between adjacent layers of the procuticle and formation of a highly resistant and insoluble protein, sclerotin
• Calcification – deposition of calcium carbonate in the outer

  layers of procuticle (Make up the shell)
• Label the following.

  A) Mucous gland

  B) Epidermis

  C) Dermis

  D) Blood vessels

  
• Label the following.

  A) Sebaceous glands

  B) Sweat glands

  C) Hair follicle

  
• Label the following

  A) Stratum corneum

  B) Basement membrane

  C) Dermis

  
• Epidermis -stratified squamous epithelium devoid of blood vessel and cells of the basal part undergo frequent mitosis
• keratinization - takes place as outer layer of cells are displaced upward by new generations of cells beneath. In some areas, keratin replaces all metabolically active cytoplasm, and the cells die as they become cornified.
• cornified cells - highly resistant to abrasion and water diffusion, comprise the outermost stratum corneum
• Dermis - dense connective tissue layer

  – contains blood vessels,

  collagenous fibers,

  nerves, pigment cells, fat

  cells, and fibroblasts

  – support, cushion, and

  nourish the epidermis

  – macrophages and

  lymphocytes provide the

  first line of defense

  – The dermis may also

  contain true bony

  structures of dermal

  origin
• Label the following.

  A) Claw

  B) Beak

  C) Horn

  
• Antlers - bone derived
• Horns - have a sheath of epidermal covering
• Fishes have bony scales from dermis
• Lizards have keratinized scales from epidermis.
• Hairs - epidermal growths that function in protection and insulation with shaft, root, and follicles.
• matrix - the part of the hair follicle where keratinized cells proliferate to form the hair shaft of growing hair.
• Label the following.

  A) Hair

  B) Hair follicle

  C) Matrix

  
• Nails - protection, scratching, and manipulation and are plates of highly packed, keratinized cells
• Nails are formed by cells in nail bed, also called the nail matrix (in area of lunula)
• Label the following.

  A) Lunula

  B) Nail matrix

  
• Sebaceous glands - usually connected to hair follicles and secretes Sebum (oil), fats, cholesterol, proteins, salts, and cell debris, moistens hair and waterproofs skin
• Eccrine sweat glands - water, salt, wastes, hairless regions, scattered

  all over the body, function is to cool the body
• Apocrine sweat glands - larger, associated with hair follicles, more viscous – fatty acids and proteins, restricted to armpits and pubic region (humans), breasts, prepuce, scrotum, external auditory canals, Secretion is correlated with certain activities of the reproductive cycle
• Apocrine sweat glands are involved in the production of what to attract potential mates?

  Pheromones
• Ceruminous glands - modified sweat glands found along the lining of the external ear canal
• What do the ceruminous glands secrete?

  Cerumen
• Cerumen - protects the skin of the ear canal, assists in cleaning and lubrication, and provides protection from bacteria, fungi and insects
• Mammary glands - Thickening of epidermis, Secretes milk
• The mammary gland is made up of 3 component parts, what are they?

  Skin: consists of the nipple and the areola.

  parenchyma: consists of 15 to 20 secretory lobules (that store and secrete milk).

  Stroma: consists of fibrous and fatty supportive tissue.
• Label the following.

  A) Sebaceous gland

  B) Eccrine sweat gland

  C) Apocrine sweat gland