Integumentary System Lesson 5-6 PDF

INTEGUMENTARY SYSTEM LESSON 5 EFREIM LOUIE SOMBILLO ILANO, RN, MSN, MD, FIAMS, MHA COMPOSED OF: 1. skin- largest organ in the body 2. skin appendages a. sweat gland b. sebaceous gland c. hairs d. nails SKIN also called integument simply means “coverin...

INTEGUMENTARY SYSTEM LESSON 5 EFREIM LOUIE SOMBILLO ILANO, RN, MSN, MD, FIAMS, MHA COMPOSED OF: 1. skin- largest organ in the body 2. skin appendages a. sweat gland b. sebaceous gland c. hairs d. nails SKIN also called integument simply means “covering” Functions: 1. keeps water and other precious molecules in the body 2. keeps water out (so one can swim for hours without becoming waterlogged) 3. protects the body from external agents 4. insulates and cushions deeper body organs  5. protects body from mechanical damage (bumps & cuts), chemical damage (from acids and bases) , thermal damage (heat & cold) ultraviolet radiation, and bacteria 6. regulates heat loss from body surface 7. acts as a mini-excretory system; urea, salt, water are lost when we sweat 8. manufactures several proteins important to immunity 9. storage of vitamin D precursor 10. contains cutaneous receptors that serve as sensors for touch, pressure, temperature, and pain 2 Principal Layers: 1. Epidermis 2. Dermis EPIDERMIS - superficial protective layer of the skin - composed of Stratified Squamous Keratrinized Epithelium that varies in thickness - all but the deepest layers of epidermis are composed of dead cells - composed of 4-5 layers, depending on its location within the body - palms & soles have five layers because these areas are exposed to most friction LAYERS OF EPIDERMIS 1. Stratum Basale 2. Stratum Spinosum (Spiny layer) 3. Stratum Granulosum (Granular layer) 4. Stratum Lucidum (Clear layer) 5. Stratum Corneum (Hornlike layer) 1. STRATUM BASALE - Composed of single layer of cells in contact with the dermis - 4 types of cells in the stratum basale: a.) keratinocytes -produce keratin which toughens & waterproofs skin b.) melanocytes - synthesize the pigment melanin providing a protective barrier to UV radiation in sunlight c.) tactile cells (Merkel cells) - aid in tactile (touch) reception d.) non-pigmented granular dendrocytes ( Langerhans cells) - protective macrophagic cells that ingest bacteria & other foreign debris 2. STRATUM SPINOSUM (SPINY LAYER) - Contains several stratified layer of cells - Spiny appearance due to changed shape of keratinocytes - With limited mitosis - This layer plus stratum basale are collectively called Stratum Germinativum 3. STRATUM GRANULOSUM (GRANULAR LAYER) - Consists of only 3-4 flattened rows of cells - Cells here appear granular due to the presence of keratohyaline granules 4. STRATUM LUCIDUM (CLEAR LAYER) - Nuclei, organelles, and cell membranes are no longer visible so this layer appears clear - Exists only in the lips & the thickened skin of soles& palms - Contains a transluscent substance called eleidin 5. STRATUM CORNEUM (HORNLIKE LAYER) - Composed of 25-30 layers of flattened, scale-like anucleated cells, which are continuously shed as flake-like residues of cells - This surface layer is cornified and is the real protective layer of the skin - Cornification is brought on by keratinization and the hardening, flattening process that takes places as the cells die and are pushed to the surface - Friction at the surface of skin stimulates additional mitotic activity of stratum basale, resulting in the formation of a callus for additional protection COLORATION OF SKIN - Caused by expression of a combination of 3 pigments: 1. melanin 2. carotene 3. hemoglobin MELANIN - brown-black pigment produced by the melanocytes of stratum basale - guards skin against damaging effect of ultraviolet rays of sunlight - gradual exposure to sunlight promotes increased production of melanin; hence tanning of skin - in albino, there is a normal number of melanocytes but lacks enzyme tyrosinase, that converts the amino acid thyrosine to melanin - “freckles” - caused by aggregated patch of melanin - “vitiligo”- lack of melanocytes in localized areas of the skin causing distinct white spot CAROTENE - a yellowish pigment found in epidermal cells & fatty parts of dermis - abundant in skin of Asians - together with melanin, accounts for the yellowish-tan color in Asians HEMOGLOBIN - not a pigment of the skin, rather it is the oxygen-binding pigment found in RBC - oxygenated blood flowing through the dermis gives the skin its pinkish tones SURFACE PATTERNS 1. Congenital Patterns: + fingerprints or friction ridges - present on palms and soles - formed by the pull of elastic fibers within the dermis - function to prevent slippage when grasping objects 2. Acquired Lines: Deep Flexion Creases - found on the palms Shallow Flexion Lines - seen on knuckles and surface of other joints  Furrows in the forehead and face (wrinkles) - acquired from continual contraction of facial muscles, such as from smiling or squinting in bright light or against the wind; facial lines become more strongly delineated as person ages LANGER LINES - lines of tension in the skin produced by the orientation of collagen and elastic fi bers in nonrandom pattern of arrangement - surgical incision should be made parallel to Langer lines to promote better wound healing DERMIS - deeper and thicker than the epidermis - a strong and stretchy envelope that helps to hold the body together - blood vessels within the dermis nourish the living portion of the epidermis - with numerous collagenous, elastic, and reticular fibers that gives support to the skin - highly vascular and glandular - contains many nerve endings and hair follicles LAYERS OF THE DERMIS 1. Papillary Layer - In contact with the epidermis - Accounts for about 1/5 of the entire dermis - With numerous projections called Dermal Papillae, that extend from the upper portion of the dermis into the epidermis - Dermal papillae contain capillary loops, which furnish nutrients to the epidermis - Some papillae house pain receptors (free nerve endings) and touch receptors (Meissner’s Corpuscles) - Dermal papillae form the base for the friction ridges on the fingers and toes  2. Reticular Layer - deepest skin layer - contains blood vessels, sweat & oil glands, and deep pressure receptors (Pacinian corpuscles) - many phagocytes are found here; they engulf bacteria that have managed to get through the epidermi  Cutaneous Glands - all enxocrine glands (they release secretions to skin surface via ducts) 1. Sebaceous Glands 2. Sweat Glands SEBACEOUS (OIL) GLANDS - found all over the skin, except on palms and soles - ducts usually empty into a hair follicle but some open directly onto skin surface - secretion is called sebum, a mixture of oily substance and fragmented cells that keeps skin soft and moist and prevents hair from becoming brittle - if the drainage pathway for sebaceous glands becomes blocked for some reason, the glands may become infected, resulting in acne - sebum also contains chemicals that kill bacteria - become very active when sex hormones are produced in increased amounts during adolescence, thus skin is oilier during this period of life SWEAT GLANDS - also called sudoriferous glands - widely distributed in the skin; numerous in palms, sole , axillary & pubic regions - secretion evaporates and cools the body  2 types: 1. Merocrine 2. Apocrine  1. Merocrine Sweat Gland - more numerous and found all over the body especially in forehead, back, palms, and soles - secretion reaches skin surface via a duct that opens directly on surface of skin through sweat pores - secretion is mostly water with few salts 2. Apocrine Sweat Glands - much larger, localized gland found in axillary and pubic regions where they secrete into hair follicles - not functional until puberty - secretion is thick and rich in organic substances which is odorless when released but quickly broken down by bacteria into substances responsible for body odor  Mammary Gland - found within the breasts - specialized sudoriferous or sweat gland that secrete milk during lactation - under the stimulus of pituitary gland HAIR - characteristic of all mammals, but its distribution, function, density and texture varies across mammalian species - humans are relatively hairless , with only the scalp, face, pubis & axilla being densely haired - men with more obvious hair because of the male hormone - certain regions of body are hairless, like the palms, soles, lips, nipples, penis, labia minora - lifespan 3-4 months for an eyelash, 3-4 years in scalp hair  Primary Function of hair: Protection e.g. scalp hair, eyebrows are protection from the sunlight Parts of Hair 1. Shaft – the visible but dead portion of hair projecting above surface of the skin 2. Root – enclosed in the follicle 3. hair bulb matrix – the growth zone; contains melanocytes that give color to the hair  3 Layers of Hair in Cross Section 1. Medulla – inner part 2. Cortex – thick middle part 3. Cuticle – covers cortex and forms toughened outer portion 3 DISTINCT KINDS OF HAIR IN HUMANS: 1. Lanugo - Fine, silky fetal hair that appears during the last trimester of development - Usually not evident on a baby at birth unless it has been born prematurely 2. Angora - grows continuously in length, as on scalp, and on face of males  3. Definitive - grows to a certain length and then ceases to grow - most dominant type of hair e.g. eyelashes, eyebrow, pubic, and axillary hair * a sebaceous gland and an arrector pili muscle are attached to the hair follicle * when the muscle involuntarily contracts due to thermal or psychological stimuli, the hair follicle is pulled into an upright position, causing the hair to “stand on its end” and producing goosebumps NAILS - found on distal dorsum of each fingers and toes - forms from a hardened, transparent , stratum corneum of epidermis  Consists of: Nail Body – visible attached portion Nail Root – part of the nail covered by skin Nail Bed – where nail root and nail body are attached Free Edge – the distal exposed border attached to undersurface of hyponychium  Hyponychium – beneath the free edge Eponychium (cuticle) – covers the nail root - frequently splits causing a hangnail Nail Matrix – proximal part of the nail bed - the growth area of nail  Lunula – whitish crescent (half-moon) shaped area at the proximal aspect of nail - finger nails grow at approximately 1 mm per week - growth of toe nails is slower - nails are transparent and nearly colorless but they look pink because of the rich blood supply in the underlying dermis SKELETAL AND ARTICULAR SYSTEM LESSON 6 EFREIM LOUIE SOMBILLO ILANO,MSN, MD SKELETAL AND ARTICULAR SYSTEM - Composed of bones and cartilages forming framework of body. FUNCTIONS 1. supports surrounding structures 2. It protects vital visceral organs 3. Gives attachment to the muscles and provides leverage so assisting in body movements. 4. It produces blood cells. This occurs in the red bone marrow. 5. For storage of mineral salts, especially phosphorus and calcium, to supply body needs. HISTOLOGY AND PHYSIOLOGY OF BONE - Bone is a connective tissue consisting of cells and a matrix made up of: 1. collagenous fibers( organic components ) - responsible for its resilience 2. calcified ground substance ( inorganic components ) - responsible for its hardness - mainly made up of calcium phospate (caHPO+) which will convert into hydroxyapatite - small amounts of calcium carbonate (CaCO3) are present too.  BONES CELLS 1. osteoblasts (active in bone formation) 2. osteoclasts (active in bone resorption) 3. osteocytes (principal cells of mature bone BONE DEPOSITION AND RESORPTION Bones develop from cells -osteoblasts. This occurs not only in initial formation of bones but also during repair. Osteoblasts secrete the organic components of the matrix. Large cell called osteoclasts are present in almost all cavities of bone and they function to cause resorption. Osteocytes- are osteoblasts that are now surrounded by the bone matrixas the bone is formed.  Hormonal regulation of the release of calcium from bone matrix - one of the important homeostatic regulatory mechanism for maintaining normal blood calcium. 1. Parathyroid hormone (secreted by parathyroid gland) - released when there is decreased blood calcium level. Hormone increases: bone resorption resulting to increased blood calcium 2. Calcitonin (secreted by thyroid gland) - released when there is increased blood calcium level. Hormone inhibits bone resorption thus resulting to decreased blood calcium  TYPES OF BONE TISSUE 1. Compact - dense and strong e.g. outer surfaces of bones 2. Cancellous (spongy) - with many spaces, red bone marrow where hemopoiesis takes place. Blood cells like red blood cells and granular leucocytes and megakaryocytes becoming platelet are produced here. e.g. inside fl at bones like in skull, sternum, ribs. CLASSIFICATION OF BONES A. According to Shape 1. Long bones - consist of a shaft, or diaphysis, and two extremities, each called epiphysis e.g - humerus, radius, tibia and fi bula 2. Short bones - typified by the carpal bones of the wrist and the tarsal bones of the ankle, with a somewhat irregular shape. 3. Flat bones - These bones consist of two fl at plates of compact tissue enclosing a layer of spongy bone. e.g. - The ribs, the scapula, parts of the hip bone, and the bones of the skull are all examples of fl at bones  4. Irregular bones - comprises bones of peculiar and differing shapes, such as the vertebrae and the ossicles of the ear. 5. Sesamoid bone - sesamoid bones are enclosed in tendon and fascial tissue and are found adjacent to joints. e.g - patella  B. According to Development 1. Bones formed by intramembranous ossification - Involves the direct mineralization of dense connective tissue membrane forming bones. e.g - flat bones of the cranium 2. Bones formed by endochondral ossification - Most bones in the body are formed by the process of endochondral ossification, the replacement of hyaline cartilage by bone DIVISIONS OF THE SKELETON - there is a total of 206 bones in the skeleton A. AXIAL SKELETON - Consists of 80 bones - The axial part consists of the skull (28 bones) (8 cranial, 14 facial, 6 ear ossicles) the hyoid bone, the vertebrae (26 bones) the ribs (24 bones) and the sternum B. APPENDICULAR SKELETON - consists of 126 bones 1. Bones of Upper extremities (64 bones, including the shoulder girdle) 2. Bones of Lower extremities (62 bones including pelvic girdle) JOINTS (ARTHROSES) area of union between 2 or more bones Types of joints: These joints are classified on the basis of material between the bones and also according to degree of movement allowed. 1. Fibrous joints - fibrous connective tissue holds the bones together e.g.suture - this is immovable and is called Synarthroses 2. Cartilagenous joints - cartilage holds the bones together e.g. symphysis pubis intervertebral disk - this is slightly movable is called Amphiarthroses  3. Synovial joints - a cavity (synovial cavity) with fluid is found between bones. e.g. most joints in body like in extremities - this is freely movable and is called Diarthroses Types of Synovial joints - classified according to types of movements allowed or shapes of joining bones 1. Ball and socket joint - allows movement in many directions e.g. shoulder joint (between head of humerus and glenoid fossa of scapula) 2. Hinge joint - allows movement in one direction e.g. elbow and knee joints  3. Pivot joint - allows rotation around length of bone e.g. atlantoaxial joint 4. Condyloid joint - allows movement in 2 directions e.g. wrist joint 5. Saddle joint - like condyloid only with deeper articulating surface e.g. carpometacarpal joint of the thumb 6. Gliding joint - bones slide over one another e.g. carpal joints; tarsal joints CLINICAL CORRELATION 1. FRACTURE - A break in a bone or cartilage. - A fracture can be compound or simple depending on whether or not the skin is broken. - It is described as complete or incomplete depending on whether or not the fracture line extends partially or entirely through the bone. 2. VERTEBRAL COLUMN INJURIES a. Exaggerations of the spinal curvature are termed Kyphosis when the posterior curvature is accentuated in the thoracic area. - Lordosis when the anterior curvature is accentuated in the lumbar region - Scoliosis when there is a lateral curvature and rotation of the vertebrae b. Herniated intervertebral disk when the outer covering (the annulus fibrosus) ruptures owing to trauma and the inner core (the nucleus pulposus) protrudes usually postero-laterally towards the vertebral canal 3. DISORDERS OF JOINTS a. Bursitis is the inflammation of the synovial bursa. It may result from excess stress, local inflammation, or systemic disease. b. Arthritis is the general term for inflammation of joints c. Degenerative joint disease comes from prolonged wear and tear on joints. d. Primary fibrositis (“Rheumatism” or “lumbago”) in the lower back region is an inflammation of the fibrous connective tissue of joints. e. Tenosynovitis: the tendon sheaths become inflammed and may deter movement of the involved joints QUESTIONS