LESSON 4 & 5: Tissues & Integumentary System PDF

LESSON 4 TISSUES jOHN MARIE FAMOSO UNIVERSITY OF SAN AGUSTIN ILOILO 'Cause I got tissues, but you got 'em too TISSUES a group of specialized cells and the extracellular substances surrounding them. Histology- microscopic study of tissue structure. C-M-E-N 4 Types of Tissues 1. Epitheliu...

LESSON 4 TISSUES jOHN MARIE FAMOSO UNIVERSITY OF SAN AGUSTIN ILOILO 'Cause I got tissues, but you got 'em too TISSUES a group of specialized cells and the extracellular substances surrounding them. Histology- microscopic study of tissue structure. C-M-E-N 4 Types of Tissues 1. Epithelium – covers and protects surfaces, both outside and inside the body. 2. Connective – a diverse primary tissue type that makes up part of every organ in the body. 3. Muscle – makes movement possible by contracting or shortening. 4. Nervous – responsible for coordinating and controlling many body activities In and out Epithelial tissues covers and protects surfaces, both outside and inside the body. Characteristics Mostly composed of cells with very little extracellular matrix between them. Covers body surfaces that include the exterior surface, lining of digestive, urinary, reproductive, & respiratory tracts, heart & blood vessels, and linings of body cavities. Nonvascular. All gases & nutrients carried in the blood reach the epithelium by diffusing from blood vessels across the basement membrane and capable of regeneration. Characteristics Distinct cell surfaces. Free / Apical Surface – exposed & not attached to other cells Lateral Surface – cells attached to other epithelial cells Basal Surface – attached to a basement membrane (a specialized type of extracellular material that helps attach the epithelial cells to the underlying tissues, and plays an important role in supporting & guiding cell migration during tissue repair.) Functions 1. Protecting underlying structures 2. Acting as a barrier 3. Permitting the passage of substances 4. Secreting substances 5. Absorbing substances Classifications based on Cell Layer Based on Number of Cell Layers Shape of Cells Simple – single layer of cells Squamous, Cuboidal, Columnar Stratified – more than one layer of Squamous Nonkeratinized (moist) cells KeratinizedCuboidalColumnar Pseudostratified – special type of simple epithelium; appears to be Columnar stratified but is not Transitional – modification of Roughly cuboidal to columnar when not stratified epithelium that can be stretched and squamous-like when greatly stretched stretched. Shapes 1. Squamous cells are flat or scale-like. 2. Cuboidal cells are cube-shaped – about as wide as they are tall. 3. Columnar cells tend to be taller than they are wide. Simple squamous layer of flat, tile-like cells, often hexagonal cells. Location: blood vessels, heart, lymphatic vessels, alveoli, kidney tubules, serous membranes Simple cuboidal layer of square-shaped cells Location: kidney tubules, glands, choroid plexuses, terminal bronchioles, ovaries Simple columnar layer of narrrow cells Location: bronchioles, auditory tubes, uterus, fallopian tubes, stomach, intestines, gallbladder, bile ducts, ventricles of brain Pseudostratified columnar 1 layer of tall, narrow cells, appears stratified but isn’t, almost always ciliated Location: nasal cavity, nasal sinuses, auditory tubes, pharynx, trachea, bronchi Stratified Squamous many layers of flat, tile-like cells Location: Nonkeratinized – moist, the surface cells retain a nucleus & cytoplasm (esophagus, vagina, pharynx) Keratinized – cytoplasm of cells at the surface is replaced by a protein called keratin, and the cells are dead (inside the mouth). Stratified Cuboidal many layers, cube-shaped; relatively rare Location: sweat glands, ovarian follicular cells, salivary glands Stratified Columnar many layers, but only the surface cells are columnar; deeper layers are irregular or cuboidal in shape; relatively rare Location: mammary gland ducts, larynx, portion of male urethra Transistional special type that changes shape stretched: squamous not stretched: cuboidal Location: urinary bladder, ureters, superior urethra Structural Units 1. Microvilli – increase cell’s surface area (ex: small intestines) 2. Cilia – move materials across cell’s surface (ex: trachea) 3. Goblet Cells – produce mucus (ex: stomach) Cell Connections 1. Tight Junctions – bind adjacent cell together 2. Desmosomes – mechanical links that bind cells 3. Hemidesmosomes – bind cells to basement membrane 4. Gap Junctions – most common; small channels that allow molecules to pass between cells & allow cells to Glands - structures that secrete substances onto a surface, into a cavity, or into blood; primarily composed of epithelium, with a supporting network of connective tissue. 1. Exocrine – with ducts (ex: sweat & oil glands) 2. Endocrine – no ducts (directly into bloodstream); cellular products are called hormones (ex: pituitary glands) Gland Structures Simple Glands single, non-branched duct (ex: glands in stomach & colon) Compound Glands multiple, branched ducts (ex: mucous glands of duodenum) Gland Shape Tubular - shaped as tubules (small tubes); can be straight or coiled Acinar / Alveolar sac-like structure Tubuloacinar / Tubuloalveolar - glands with combination of the tubular and acinar / alveolar Gland Secretion Merocrine Secretion - most common; involves the release of secretory products by exocytosis. ex: water-producing sweat glands, pancreas Apocrine Secretion - release of secretory products as pinched- off fragments of gland cells ex: milk-producing mammary glands. Holocrine Secretion - nvolves the shedding of entire cells. ex: sebaceous glands of skin. Stay connected Connective tissues distinguished by its extracellular matrix which results from the activity of specialized connective tissue cells Specialized connective tissues - blast cells: form the matrix (osteoblasts form bone, chondroblasts form cartilage) - clast cells: break down the matrix (osteoclasts break down bone) - cyte cells: maintain the matrix (osteocytes maintain the bone) Components of Extracellular Matrix 1.Protein Fibers Collagen Fibers – very flexible but resist stretching Reticular Fibers – very fine, short collagen fibers that branch to form a supporting network Elastic Fibers – have the ability to return to their original shape after being stretched Components of Extracellular Matrix 2.Ground Substance – consists of non-fibrous molecules and has the following major components: Hyaluronic Acid – makes fluid slippery Proteoglycan Aggregates – trap water which gives tissues the capacity to recoil when deformed Adhesive Molecules – hold proteoglycans together & to plasma membrane 3.Fluid – the matrix is liquid that enables blood to flow rapidly through the body Connective Tissue Functions Enclosing & separating other tissues (ex: sheets around organs and muscles) Connecting tissues to one another (ex: tendons: bone to muscle, ligaments: bone to bone) Supporting & moving parts of body (ex: bones) Connective Tissue Functions Storing compound (ex: bones store calcium & phosphate) Cushioning & insulating (ex: adipose tissue protects organs & helps conserve heat) Transporting (ex: blood transports gases, nutrients, enzymes, & hormones) Protecting (ex: immune cells) Classifications Loose Connective Tissue – consists of relatively few protein fibers that form a lacy network, with numerous spaces filled with ground substance & fluid. Areolar - Fine network of fibers (mostly collagen with a few elastic fibers) with spaces in between. Adipose - Little extracellular matrix; adipocytes are full of lipid Reticular - Fine network of reticular fibers irregularly arranged Areolar Adipose Reticular Classifications Dense Connective Tissue – has relatively large number of protein fibers that form thick bundles & fill nearly all of the extracellular space Regular Collagenous - Collagen fibers running in same direction Irregular Collagenous - Collagen fibers run in several directions Regular Elastic - Matrix composed of collagen fibers & elastin fibers running the same direction in elastic ligaments Irregular Elastic - same as RE, fibers are in several directions Regular collagenous Regular Elastic Classifications Supporting Connective Tissue Cartilage – is composed of chondrocytes (cartilage cells); resilient, relatively rigid & enables to spring back after being compressed; not penetrated by blood vessels; therefore, heals slowly after an injury. Hyaline - Collagen fibers are small & evenly dispersed making it transparent (growing bones) Fibrocartilage - Fibers are more numerous than in others; arranged in thick bundles (vertebral disks) Elastic - Similar to hyaline, but matrix contains elastic fibers (ears, epiglottis) Hyaline Fibrocartilage Elastic Classifications Supporting Connective Tissue Bone– hard connective tissue that consists of living cells & mineralized matrix; composed of osteocytes (bone cells) which are located within lacunae; the matrix is organized into layers called lamellae. Compact Bone – more solid, with almost no space between thin layers of mineralized matrix Spongy Bone – has spaces between trabeculae of bone Classifications Fluid Connective Tissue Blood – composed of formed elements & a fluid matrix. function? Hemopoietic Tissue – composed of red and yellow marrow I like to move it, move it Muscle tissues main function is to contract, or shorten, making movement possible; length is greater than its diameter. Don't give me mixed signals Nervous tissues specialized to conduct action potentials (electrical signals); located in the brain, spinal cord & ganglia Neurons – transmit information in form of action potentials, store information, & integrate & evaluate data Three Major Parts: 1. Cell Body – site of general cell functions; contains nucleus 2. Dendrites – receive stimuli leading to electrical changes 3. Axon – send action potential to another neuron Glial/Neuroglia (support cells) – surround the neurons; function to protect, nourish & form specialized sheaths around axons Central nervous system (CNS) There are four types of neuroglia found within the central nervous system: Astrocytes – maintain the blood brain barrier and preserve the chemical environment by recycling ions and neurotransmitters Oligodendrocytes – myelinate axons in the central nervous system and provide an overall structural framework Ependymal cells – line ventricles (brain) and central canal (spine) and are involved in the production of cerebrospinal fluid Microglia – remove cell debris, wastes and pathogens via phagocytosis Peripheral nervous system (CNS) There are 2 types of neuroglia found within the peripheral nervous system: Schwann cells – myelinate axons in the peripheral nervous system Satellite cells – regulate nutrient and neurotransmitter levels around neurons in ganglia  FQ TIME!!!! 1. What are the four basic types of Tissues? 2. Give a function of each type of tissue. 3. What are the two types of Glands? 4. Two types of bone? 5. 3 types of muscle tissue? 6. 3 Major parts of a nerve cell? 7. 2 types of tissues found in our NS? LESSON 5 Integumentary System jOHN MARIE FAMOSO UNIVERSITY OF SAN AGUSTIN ILOILO 1st line of defense Integumentary System consists of the skin and its accessory structures (hair, nails, and glands); one of the more familiar systems of the body because it covers the outside of the body and is easily observed. Integument – this means covering. Major, major Functions 1. Protection - water loss, UV Light, abrasion, foreign objects and sweat and for defense 2. Sensation - he skin contains sensory receptors for pain, heat, cold, and pressure. 3. Vitamin D Production -stimulates the small intestine to absorb calcium and phosphate 4. Temp regulation - Body temperature normally is maintained at about 37°C (98.6°F). T 5. Excretion - Skin glands can remove large amounts of sweat, SKIN 1. made up of two major tissue layers: epidermis and dermis. 2. Skin weighs approximately 9 lbs. 3. Skin is usually referred to as “thin skin”. “Thick skin” is found only on the palms of the hands and soles of feet. 4. Is your outer skin dead? Epidermis the most superficial layer of the skin; made up of stratified squamous epithelium. Function: prevents water loss and resists abrasion c a d b Epidermis Stratum Basale / Stratum Germinativum – deepest layer; consists of cuboidal or columnar cells that undergo mitotic divisions about every 19 days. This stratum is a single layer of cells and firmly attached to dermis. Stratum Spinosum –spiny in appearance due to the protruding cell processing that join the cells; composed of 8 to 10 layers of keratinocytes (cells that manufacture & store the protein keratin) Epidermis Stratum Granulosum – has grainy appearance due to further changes to the keratinocytes as they are pushed from the spinosum; generate large amounts of keratin, which is fibrous Stratum Lucidum – a smooth, seemingly translucent layer that is found only on thick skin of palms, soles, & digits. Epidermis Stratum Corneum - outermost layer of epidermis; 20 to 30 layers of dead squamous cells filled with keratin & accounts for 75% of epidermal thickness; joined by desmosomes. This layer is also coated and surrounded by lipid, which acts as waterproofing material. Keratinization – a process in which new cells (with keratin) is pushing old cells to the surface. It takes 40 to 56 days for the new cells to reach the surface. Dermis the 2nd major skin region; composed of dense collagenous connective tissue containing fibroblasts, adipocytes, macrophages, nerves, hair follicles, smooth muscles, glands, and lymphatic vessels. Function: supplies nutrients & removes waste products to the overlying epidermis; helps regulate body temperature Layers of the Dermis Papillary Layer - thin connective tissue layer that contains blood vessels. Dermal Papillae projections that extend up into epidermis blood flow through these vessels supplies the overlying epidermis arranged in parallel, curving ridges that shape into fingerprints, Reticular Layer - deepest layer of dermis; accounts for 80% of dermis Factors affecting skin color Melanocytes – irregularly shaped cells with many long processes that extend between the epithelial cells of the deep part of epidermis; responsible for production of melanin. Melanocytes of darker skinned people produce more and darker melanin than fairer skinned people. All races have the same number of melanocytes. Factors affecting skin color Melanosomes – these are melanin-containing vesicles which move into the cell processes of melanocytes. Melanin – the group of pigments primarily responsible for skin, hair, and eye color. Pigments of most molecules are brown to black, some are yellowish or reddish. Racial variations in skin color are determined by the amount, kind, & distribution of melanin. Function: Provides protection against ultraviolet light from sunlight. Hypoermis (Subcutaneus) attaches the skin to underlying bone and muscle; below the dermis supplies the area with blood vessels and nerves not part of the skin; made up of loose connective tissue, including adipose tissue; contains about ½ of the body’s stored lipids Hypoermis (Subcutaneus) the amount and location of adipose tissue vary with age, sex, and diet. Functions: 1. Serves as padding and insulator 2. Responsible for some of the differences in appearance between men and women 3. Used to estimate total body fat (the thicker the fold, the greater the amount of total body fat) Accessory Structures Hair – is found everywhere on the skin, except on the palms, the soles, lips, nipples, parts of genitalia, and the distal segments of fingers and toes. Accessory Structures Hair – is found everywhere on the skin, except on the palms, the soles, lips, nipples, parts of genitalia, and the distal segments of fingers and toes. Glands - there are two major glands of the skin, the sebaceous and sweat glands. Nail – a thin plate with layers of dead stratum corneum cells with a very hard type of keratin. Hair components Hair Shaft – flexible strands of keratinized cells; protrudes above the surface of the skin. Hair Root – protrudes below the surface. Hair Follicle – an invagination of the epidermis that extends deep into the dermis; a group of cells that surround the root and bulb and responsible for giving different shapes to the hair. Hair components Hair Cortex – a hard covering of hair that is surrounded by the cuticle, a single layer of overlapping cells that holds the hair in the hair follicle. Hair Medulla – the softer center that is surrounded by the cortex. Hair Bulb – base of hair root; where the hair is produced. Hair components Hair Papilla – an extension of the dermis that protrudes into the hair bulb; the blood vessels within supply the hair bulb with the nourishment needed to produce hair. Arrector Pili – made up of smooth muscle that surrounds each hair follicle; its contraction causes the hair to become more perpendicular to the skin’s surface called “goose bumps”. 2 Types of Skin Glands Sebaceous Glands – are simple, branched acinar glands; most are connected by a duct to the hair follicle. Secrete sebum, released by holocrine secretion, an oily substance rich in lipids that lubricates hair and skin to prevent drying. Sweat Glands have two types: Eccrine Apocrine Sweat glands Eccrine Sweat Glands release sweat by merocrine secretion - made mostly of water with a few salts; located in almost every part of the skin but most numerous in palms and soles; open into the sweat pores Apocrine Sweat Glands – a thick secretion rich in organic substances by merocrine secretion, located only in armpits and genitalia; open into the hair follicles and become active during puberty due to sex hormones, causing body odor. Nail Structure Nail Body – the visible part of the nail. Nail Root – the covered part by the skin. Nail Structure Cuticle / Eponychium – a stratum corneum that extends onto the nail body. Nail Structure Nail Matrix – made up of epithelial cells with a stratum basale that gives rise to most of the nail; continuation of nail roots and is thicker than nail bed. Nail Structure Nail Bed – located distally to the nail matrix & attaches to nail; made up of epithelial cells with a stratum basale Nail Structure Lunula – a small part of the nail matrix that can be seen through the nail body as a whitish, crescent-shaped area at the base of the nail. Burns is an injury to a tissue caused by heat, cold, friction, chemicals, electricity, or radiation. Partial-Thickness Burn – the part of the stratum basale remains viable, and regeneration of the epidermis occurs from within the burn area, as well as from the edges of the burn. Full-Thickness Burn / Third-Degree Burn the epidermis & dermis are completely destroyed. usually painless as the sensory receptors have been destroyed. the burned areas appear white, tan, brown, black, or deep cherry red Classifications First-Degree Burn - this involves only the epidermis Second-Degree Burn - damages both the epidermis and dermis. Third-Degree Burn - damage the underlying bones, muscles, and tendons. The burn site appears white or charred.  FQ TIME!!!! 1. Skin cells have the ability to regenerate and divide. 2. The dermis is thicker than epidermis. 3. The skin is composed of epidermis, dermis, and hypodermis. 4. The new cells produced by mitosis occur in most superficial layers of epidermis. 5. Skin is the largest organ of the body. 6. The water can simply move across the skin. 7. The dead epithelial cells are formed in the outer layer of epidermis to act as a barrier.  Fin Thank You John Marie Famoso [email protected]