Anatomy and Physiology II: Exam 3 Study Guide PDF

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Gregory Tinkler
Anatomy and Physiology II
BSCI 21020
Exam 3 Study Guide...

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Chapter 6 1. Functions of the skin a. Resistance to trauma and infection i. Keratin Protein ii. Secretes defensins 1. Fight off bacteria iii. Acid Mantle 1. Makes it difficult for bacteria to grow b. Other Barrier Function i. Keep H2O in or out ii. Barrier to UV light iii. Keep out harmful chemicals c. 1st step in Vitamin D synthesis d. Sensation i. Touch, pressure, temp changes e. Aid in thermal regulation i. Thermo receptors 1. Detect temp change ii. Vascular system restricts/opens f. Non-Verbal Communication i. Facial expressions ii. Self image 2. 3 Major Layers of Tissue a. Epidermis i. Toward the outside ii. Stratified squamous epithelial iii. Avascular: no blood vessels 1. Get nutrients from underlying tissue iv. Dead cells packed b. Dermis i. Connective tissue ii. Blood supply iii. 2 layers: papillary layer, reticular layer c. Hypodermis i. Connective and adipose tissue ii. Help anchor epidermis and dermis to bone and muscle 3. Epidermis a. Keratinized stratified squamous b. Dead cells packed with Keratin c. Lack blood vessels d. Mechanical → electrical energy e. 4-5 Layers of Epidermis i. Stratum Basale

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1. Deepest layer 2. Single layer of cells a. Stem cells of skin 3. Melanocytes a. Produce pigment b. Protect from UV radiation 4. Tactile Cells a. Signal transduction process 5. Keratinocytes a. Produce keratin b. Rests on boundary between epidermis and dermis Stratum Spinosum 1. Multiple cell layers 2. Mostly keratinocytes joined by desmosomes and tight junctions 3. Cells look spiny 4. Dendritic Cells a. Immune cells Stratum Granulosum 1. 3-5 layers thick a. Flattened 2. Granular appearance Stratum Lucidum 1. One cell thick 2. Flattened 3. Pale keratinocytes Surface Layer 1. Dead keratinocytes 2. Up to 30 layers Cells of Epidermis 1. Stem Cells a. Divide and make more keratinocytes 2. Keratinocytes a. Majority of skin b. Synthesize keratin protein c. Found in all layers 3. Melanocytes a. Synthesize melanin pigment b. Shields skins DNA from UV light c. Only in stratum basale d. Branches produces packets of melanin 4. Tactile Cells a. Touch receptors b. Associated with nerve fibers c. Stratum basale

5. Dendritic Cells a. Macrophage i. From bone marrow b. Immune cell i. Break down viruses c. Stratum spinosum and stratum granulosum 4. Dermis a. b. c. d. e. f.

Connective tissue layer beneath epidermis Ranges from 0.2 mm (eyelids) to 4 mm (palms/soles) Composed mainly of collagen Well supplied with blood vessels, sweat glands, sebbaceous glands, and nerve endings Houses hair follicles and nail roots Is the tissue of the facial skin to which skeletal muscles attach and cause facial expressions of emotion g. Has a wavy, conspicuous boundary with the superficial epidermis i. Dermal papillae are upward, finger-like extensions of dermis ii. Epidermal ridges are downward waves of epidermis iii. Prominent waves on fingers produce friction ridges of fingerprints h. Papillary Layer i. Superficial zone of dermis ii. Thin zone of areolar tissue in and near the dermal papillae iii. Allows for mobility of leukocytes and other defense cells iv. Rich in small blood vessels i. Reticular Layer i. Deeper and thicker layer of dermis ii. Consists of dense, irregular connective tissue iii. Stretch marks (striae) 1. Tears in collagen fibers caused by stretching of the skin due to pregnancy or obesity 5. Hypodermis a. Subcutaneous tissue b. Has more areolar and adipose tissue than dermis has c. Pads body and binds skin to underlying tissues d. Common site of drug injection since it has many blood vessels 6. Subcutaneous Fat a. Energy reservoir b. Thermal insulation c. Thicker in women d. Thinner in infant, elderly 7. Skin Color a. Melanin i. Most significant factor in skin color ii. Produced by melanocytes, accumulates in the keratinocytes iii. 2 forms of the pigment

1. Eumelanin a. Brownish blach 2. Pheomelanin a. Reddish yellow b. Sulfur-containing b. People of different skin colors have the same number of melanocytes i. Darker skinned people 1. Produce greater quantities of melanin 2. Melanin breaks down more slowly 3. Melanin granules more spread out in keratinocytes 4. Melanized cells seen throughout the epidermis ii. Lighter skinned people 1. Melanin clumped near keratinocyte nucleus 2. Little melanin seen beyond stratum basale c. Exposure to UV light stimulates melanin and darkens skin i. This color fades as melanin is degraded and old cells are exfoliated d. Other pigments can influence skin color i. Hemoglobin 1. Pigment in red blood cells 2. Adds reddish to pinkish hue to skin ii. Carotene 1. Yellow pigment acquired from egg yolks and yellow/orange vegetables 2. Concentrates in stratum corneum and subcutaneous fat 8. Hair and Nails a. Hair, nails, and cutaneous glands are accessory organs (appendages) of the skin b. Hair and nails are composed of mostly dead, keratinized cells i. Pliable soft keratin makes up stratum corneum of skin ii. Compact hard keratin makes up hair and nails 1. Tougher and more compact due to numerous cross-linkages between keratin molecules c. Hair i. Plius 1. Another name for hair 2. Pili- plural of pilus ii. A slender filament of keratinized cells growing from a tube in the skin called a hair follicle iii. Hair covers most of the body 1. Hair does not cover: palms, soles; palmar, plantar, and lateral surfaces and distal segments of fingers and toes; lips, nipples, and parts of genitals 2. Limbs and trunk have 55 to 70 hairs per cm squared a. Face has about 10 times as many 3. 100,000 hairs on an average person’s scalp 4. Differences in hairiness across individuals is mainly due to differences in texture and pigment of hair

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Hair is divisible into three zones along its length 1. Bulb a. A swelling at the base where hair originates in dermis or hypodermis b. Only living hair cells are in or near bulb 2. Root a. The remainder of the hair in the follicle 3. Shaft a. The portion above the skin surface v. Structure of the Hair and Follicle 1. Dermal Papilla a. Bud of vascular connective tissue encased by bulb i. Only source of nutrition for hair 2. Hair Matrix a. Region of mitotically active cells immediately above papilla i. Hair’s growth center 3. 3 Layers of the hair in cross section a. Medulla i. Core of loosely arranged cells and air spaces b. Cortex i. Constitutes bulk of the hair ii. Consists of several layers of elongated keratinized cells c. Cuticle i. Composed of multiple layers of very thin, scaly cells that overlap each other ii. Free edges directed upward 4. Follicle a. Diagonal tube that extends into dermis and possibly hypodermis b. Epithelial Root Sheath i. Extension of the epidermis lying adjacent to hair root ii. Widens at deep end into bulge-source of stem cells for follicle growth c. Connective Tissue Root Sheath i. Derived from dermis but a bit denser ii. Surrounds epithelial root sheath 5. Hair Receptors a. Sensory nerve fibers entwining follicles 6. Piloerector Muscle (arrector pili) a. Smooth muscle attaching follicle to dermis b. Contracts to make hair stand on end (goose bumps) 9. Cutaneous Glands a. The skin has 5 types of glands i. Merocrine sweat glands ii. Apocrine sweat glands

iii. Sebaceous glands iv. Ceruminous glands v. Mammary glands b. Sweat Glands i. Apocrine sweat glands 1. Locations: groin, anal region, axilla, areola, beard area in men a. Inactive until puberty 2. Ducts lead to nearby hair follicles 3. Produce sweat that is milky and contains fatty acids 4. Respond to stress and sexual stimulation a. Believed to secrete pheromones-chemicals that can influence behavior of others 5. Bromhidrosis: disagreeable body odor produced by bacterial action on sweat from apocrine glands ii. Merocrine sweat glands 1. Most numerous skin glands-3 to 4 million in adult skin a. Especially dense on palms, soles, and forehead 2. Simple tubular glands 3. Watery perspiration that helps cool the body iii. Myoepithelial Cells 1. Contract in response to stimulation by sympathetic nervous system and squeeze perspiration up the duct a. Found in both apocrine and merocrine glands iv. Sweat 1. Begins as a protein-free filtrate of blood plasma produced by deep secretory portion of gland 2. Some sodium chloride and other small solutes remain in the sweat a. Some sodium chloride reabsorbed by duct 3. Some drugs are excreted in sweat 4. On average, 99% water, with pH range of 4 to 6 a. Acid Mantle-inhibits bacterial growth 5. Insensible Perspiration-500 mL/day a. Does not produce wetness of skin 6. Diaphoresis-sweating with wetness of the skin a. Exercise-may loses 1 L sweat per hour c. Sebaceous Glands i. Sebaceous glands are flask-shaped and have short ducts opening into hair follicles ii. Holocrine secretion style iii. Sebum-oily secretion of sebaceous glands 1. Keeps skin and hair from becoming dry, brittle, and cracked 2. Lanolin-sheep sebum 10. Skin Cancer a. Most cases caused by UV rays of the sun damaging skin cell DNA

i. Most oft3en on the head, neck and hands ii. Most common in fair-skinned people and the elderly iii. One of the most common, easily treated cancers iv. Has one of the highest survival rates if detected and treated early b. Three types of skin cancer named for epidermal cells in which they originate i. Basal cell carcinoma 1. Most common type 2. Least dangerous because it seldom metastasizes 3. Forms from cells in stratum basale 4. Lesion is small, shiny bump with central depression and beaded edges ii. Squamous cell carcinoma 1. Arises from keratinocytes of stratum spinosum 2. Lesions usually on scalp, ears, lower lips, or back of the hand 3. Have raised, reddened, scaly appearance later forming a concave ulcer 4. Chance of recovery good with early detection and surgical removal 5. Tends to metastasize to lymph nodes and may become lethal iii. Malignant melanoma 1. Skin cancer that arises from melanocytes 2. Less than 5% of skin cancers, but most deadly form 3. Can be successfully removed if caught early, but if it metastasizes it is usually fatal 4. Greatest risk factor: familial history of malignant melanoma 5. Highest incidence in men, redheads, and people who had severe sunburn as a child 11. Burns a. Leading cause of accidental death i. Fires, kitchen spills, sunlight, ionizing radiation, strong acids or bases, or electrical shock ii. Deaths result primarily from fluid loss, infection, and toxic effects of eschar (burned, dead tissue) iii. Debridement: removal of eschar b. Classified according to depth of tissue involvement i. First-degree burn 1. Involves only the epidermis 2. Redness, slight edema, and pain 3. Heals in days ii. Second-degree burn 1. Partial-thickness burn; involves part of dermis 2. May appear red, tan, or white; blistered and painful 3. Two weeks to several months to heal and may leave scars iii. Third-degree burn 1. Full-thickness burn; involves epidermis, all of dermis, and often some deeper tissues 2. Often requires skin grafts

3. Needs fluid replacement, infection control, supplemental nutrition c. UV Rays and Sunscreen i. UVA and UVB are improperly called “tanning rays” and “burning rays” 1. Both though to initiate skin cancer 2. No such thing as a “healthy tan” ii. Sunscreens protect you from sunburn but unsure if they provide protection against cancer 1. High SPF numbers can give false sense of security 2. Chemical in sunscreen damage DNA and generate harmful free radicals d. Skin Grafts and Artificial Skin i. Third-degree burns often require skin grafts ii. Graft options 1. Autograft: tissue taken from another location on the same person’s body a. Split-skin graft- taking epidermis and part of the dermis from and undamaged ar4ead such as the thigh or buttocks and grafting it into the burned area b. Isograft- skin from identical twin 2. Temporary grafts (immune system rejection) a. Homograft (allograft): from unrelated person b. Heterograft (xenograft): from another species c. Amnion: from afterbirth d. Artificial skin: from silicone and collagen

Chapter 7 1. Functions of the Skeleton a. Support i. Limb bones and vertebrae support body; jaw bones support teeth; some bones support viscera b. Protection i. Of brain, spinal cord, heart, lungs, and more

c. Movement i. Limb movements, breathing, and other movements depend on bone d. Electrolyte balance i. Calcium and phosphate levels e. Acid-base balance i. Buffers blood against large pH changes by altering phosphate and carbonate salt levels f. Blood formation i. Red bone marrow is the chief producer of blood cells 2. General Features of Bones a. Flat bones i. Thin, curved plates ii. Protect soft organs b. Long bones i. Longer than wide ii. Rigid levers acted upon by muscles; crucial for movement iii. Diaphysis 1. Shaft that provides leverage 2. Medullary Cavity a. Contains bone marrow iv. Epiphyses 1. Enlarged ends of a long bone 2. Strengthen joint and anchor ligaments and tendons c. Short bones i. Approximately equal in length and width ii. Glide across one another in multiple directions d. Irregular bones i. Elaborate shapes that do not fit into other categories e. Compact bone i. Dense outer shell of bone f. Spongy (cancellous) bone i. Loosely organized bone tissue ii. Found in center of ends and center of shafts of long bones and in middle of nearly all others iii. Covered by more durable compact bone g. Skeleton ¾ compact and ¼ spongy bone by weight h. Articular cartilage i. Layer of hyaline cartilage that covers joint surface ii. Allows joint to move more freely i. Nutrient foramina i. Minute holes in bone surface that allows blood vessels to penetrate j. Periosteum-external sheath covering most of bone i. Outer fibrous layer of collagen 1. Some fibers continuous with tendons

2. Perforating fibers a. Penetrate into bone matrix ii. Inner osteogenic layer of bone-forming cells 1. Important to bone growth and healing of fractures k. Endosteum i. Thin layer of reticular connective tissue lining marrow cavity ii. Has cells that dissolve osseous tissue and others that deposit it l. Epiphyseal plate (growth plate) i. Area of hyaline cartilage that separates epiphyses and diaphyses of children’s bones ii. Enables growth in length iii. Epiphyseal line 1. In adults, a bony scar that marks where growth plate used to be m. Dipole i. Spongy middle layer ii. Absorbs shock iii. Marrow spaces lined with endosteum 3. Bone Cells a. Osteogenic cells i. Stem cells ii. Found in endosteum and inner layer of periosteum iii. Arise from embryonic mesenchymal cells iv. Multiply continuously and give rise to most other bone cell types b. Osteoblasts i. Bone-forming cells ii. Form single layer of cells under endosteum and periosteum iii. Nonmitotic iv. Synthesize soft organic matter of matrix which then hardens by mineral deposition v. Stress stimulates osteogenic cells to multiply rapidly and increase the number of osteoblasts which reinforce bone vi. Secrete hormone osteocalcin 1. Stimulates insulin secretion of pancreas 2. Increases insulin sensitivity in adipocytes which limits the growth of adipose tissue c. Osteocytes i. Former osteoblasts that have become trapped in the matrix they deposited ii. Lacunae 1. Tiny cavities where osteocytes reside iii. Canaliculi 1. Little channels that connect lacunae iv. Cytoplasmic processes of osteocytes reach into canaliculi and contact processes of neighboring cells 1. Gap junctions allow for passage of nutrients, wastes, signals

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Some osteocytes reabsorb bone matrix while other deposit it Act as strain sensors 1. When stressed, produce biochemical signals that regulate bone remodeling (shape and density changes that are adaptive) d. Osteoclasts i. Bone dissolving cells ii. Found on bone surface iii. Develop from bone marrow stem cells that give rise to blood cells iv. Very large cells formed from fusion of several stem cells 1. Have multiple nuclei in each cell v. Ruffled border (large surface area) faces bone vi. Cells often reside in resorption bays (pits in bone surface) vii. Dissolving bone is part of bone remodeling Compact Bone a. Histology of compact bone reveals osteons i. Concentric lamellae surround a central canal ii. Perforating canals 1. Transverse or diagonal passages iii. Circumferential lamellae 1. Fill outer region of dense bone iv. Interstitial lamellae 1. Fill irregular regions between osteons Spongy Bone a. Lattice of bone covered with endosteum i. Slivers of bone called spicules ii. Thin plates of bone called trabeculae b. Spaces filled with red bone marrow c. Few osteons and no central canals i. All osteocytes close to bone marrow d. Provides strength with minimal weight i. Trabeculae develop along bone’s lines of stress Bone Marrow a. Soft tissue occupying marrow cavities of long bones and small spaces of spongy bone b. Red marrow (myeloid tissue) i. Contains hemopoietic tissue 1. Produces blood cells ii. In nearly every bone in a child iii. In adults, found in skull, vertebrae, ribs, sternum, part of pelvic girdle, and proximal heads of humerus and femur c. Yellow marrow i. Found in adults ii. Fatty marrow that does not produce blood iii. Can transform back to red marrow in the event of chronic anemia Bone development

a. Ossification or Osteogenesis i. Formation of bone b. Bone develops by two methods in the human fetus i. Intramembranous ossification 1. Produces flat bones of skull and clavicle(fetus) 2. Thickens long bones throughout life ii. Endochondral ossification 1. During infancy and childhood, epiphyses fill with spongy bone 2. Cartilage limited to the articular cartilage covering each joint surface, and to the epiphyseal plate a. A thin wall of cartilage separating the primary and secondary marrow cavities (articular cartilage) b. Epiphyseal plate persists through childhood and adolescence c. Serves as a growth zone for bone elongation 3. By late teens to early 20s, all remaining cartilage in the epiphyseal plate is generally consumed a. Gap between epiphyses and diaphysis closes b. Primary and secondary marrow cavities unite into a single cavity c. Bone can no longer grow in length c. Ossification continues throughout life with the growth and remodeling of bones d. Bones grow in length and width 8. Bone elongation a. Epiphyseal plate i. Cartilage transitions to bone ii. Functions as growth zone where bone elongates iii. Has typical hyaline cartilage in the middle with transition zones on each side iv. Metaphysis is zone of transition facing the marrow cavity b. Interstitial growth i. Growth from within ii. Bone elongation is a result of cartilage growth within the epiphyseal plate iii. Epiphyses close when cartilage is gone-epiphyseal line of spongy bone marks site of former epiphyseal plate 1. Lengthwise growth is finished 2. Occurs at different ages in different bones 9. Bone Remodeling a. Absorption and deposition b. Occurs throughout life-10% of skeleton per year c. Repairs microfractures, releases minerals into blood, reshapes bones in response to use and disuse d. Wolff’s law of bone i. Architecture of bone determined by mechanical stresses placed on it ii. Remodeling is a collaborative and precise action of osteoblasts and osteoclasts iii. Bony processes grow larger in response to mechanical stress 10. Physiology of Osseous Tissue

a. Mature bone remains a metabolically active organ i. Involved in its own maintenance of growth and remodeling ii. Exerts a profound influence over the rest of the body by exchanging minerals with tissue fluid 1. Disturbance of calcium homeostasis in skeleton disrupts function of other organ systems a. Especially nervous and muscular 11. Mineral Deposition and Resorption a. Mineral deposition (mineralization) i. Process in which calcium, phosphate, and other ions are taken from blood and deposited in bone 1. Osteoblasts produce collagen fibers that spiral the length of the osteon 2. Fibers become encrusted with minerals a. Hydroxyapatite crystals form at solubility product- critical level of calcium times phosphate concentration b. First few crystals act as seed crystals that attract more calcium and phosphate from solution 3. Abnormal calcification (ectopic ossification) a. Formation of a calculus i. ...