A&P Exam 2
Explain the causes of osteomalacia, rickets, and osteoporosis.
-Osteomalacia and Rickets are caused by insufficient calcium in the diet or vitamin D deficiency -Osteoporosis is caused by lack of calcium in diet, etc....
Match each primary germ layer with the type of tissue it gives rise to. (Figure 4.13, page 146).
-Primary germ layers- 3 cell layers formed early in embryonic development: 1. ectoderm- superficial layer 2. mesoderm- middle layer 3. endoderm- deep layer -layers "specialize" to form the 4 primary tissues: 1. ectoderm- nerve tissue 2. mesoderm- muscle and connective tissue 3. endoderm- lining and digestive system 4. all 3 germ layers- epithelial tissue
Differentiate between appositional and interstitial cartilage growth patterns.
-appositional growth- cartilage-forming cells in perichondrium secrete new matrix on the outside of existing cartilage -interstitial growth- chondrocytes in lacunae divide and secrete new matrix, expanding cartilage from the inside
Differentiate between the axial and appendicular skeleton.
-axial (head and trunk)- forms long axis of body; protects, supports, or carries other body parts; includes the skull, vertebral column, and rib cage -appendicular (limbs, etc.)- bones attached to axial skeleton; function- locomotion and manipulation of environment; includes upper/lower limb bones, shoulder bones, and hip bones
Define the terms bone remodeling, bone deposit, and bone resorption.
-bone remodeling- process of bone formation and bone resorption at surfaces of periosteum and edosteum -bone deposit- occurs when: 1. bone is injured or 2. added bone strength is required (^ mechanical stress) a. osteoblasts deposit a seam of osteoid and after about a week, hydroxyapatite crystals form -bone resorption- occurs when: 1. ionized calcium levels drop in the blood or 2. bones are subjected to less mechanical stress or gravity a. osteoclasts (giant multinucleate cells) resorb bone b. osteoclasts secrete lysosomal enzymes that digest the organic matrix and protons (H+) that convert the calcium calls into soluble forms
Differentiate between collagen, elastic, and reticular fibers.
-collagen (white)- extremely tough fibers that provide high tensile strength -elastic (yellow)- long, thin fibers of elastin that form branching networks; allow for stretch; pull connective tissue back to normal length and shape -reticular fibers- short, fine collagenous fibers that branch forming delicate networks; surround small blood vessels and support the soft tissue of organs
Describe the common types of bone fractures.
-comminuted- bone fragments into 3 or more pieces; common in elderly -spiral- ragged break when bone is excessively twisted; common sports injury -depressed- broken bone portion pressed inward; typical skull fracture -compression- bone is crushed; common in porous bones -epiphyseal- epiphysis separates from diaphysis along epiphyseal plate; occurs where cartilage cells are dying -greenstick- incomplete fracture where one side breaks and other side bends; common in children
Explain the causes for alterations in skin color.
-cyanosis- blue color due to poorly oxygenated blood; caused by heart failure and sever respiratory disorders -erythema- redness caused by embarrassment (blushing), fever, hypertension (high blood pressure), inflammation, or allergy -pallor or blanching- paleness caused by fear, anger, and certain other types of emotional distress, anemia (too few red blood cells), low blood pressure -jaundice- yellow skin caused by liver problems -bronzing- bronze, almost metallic hue caused by Addison's disease; inadequate amounts of certain steroid hormones or certain pituitary gland tumors -black and blue marks- bruises; caused by clotted blood under the skin
Describe the relative location and tissue makeup of skin epidermis, dermis, and hypodermis.
-epidermis- superficial region; avascular; keratinized stratified squamous epithelium -dermis- underlying region; vascular; mostly dense irregular connective tissue -hypodermis (superficial fascia)- not part of the skin, but shares of skin's protect function; mostly adipose tissue; thickens when a person gains weight; anchors skin to underlying tissues, mostly muscles; absorbs shock, insulates
Differentiate between merocrine, holocrine, and apocrine glands.
-functional classification- based on modes of secretion -merocrine- products are secreted by exocytosis; most common pancreas, most sweat glands, and salivary glands -holocrine- accumulate products until they rupture; sebacious (oil) glands -apocrine- accumulate products just beneath free surface; apex of cell pinches off from apical surface; controversy whether this type exists in humans
Identify the three main structural elements of connective tissue.
-ground substance -fibers -cells
Differentiate between loose and dense connective tissue.
-loose- more cells, fewer fibers -dense- fewer cells, more fibers; often referred to as fibrous connective tissue
Describe the general structure of the papillary layer and reticular layer of the dermis.
-papillary layer (superficial)- areolar connective tissue; dermal papillae -reticular layer (deep)- dense irregular connective tissue; cutaneous plexus- network of blood vessels that lies between this layer and the hypodermis
Classify (name) glands based on duct types and secretory unit structure. (Figure 4.6, page 125).
-simple- unbranched duct -compound- branched duct -tubular- tubes -alveolar- sacs -tubuloalveolar- both tubes and sacs -branched- refers to secretory unit
Describe the microscopic structure of short, irregular, and flat bones.
-structure- superficial layers- thin plates of periosteum-covered compact bone -deep layer- endosteum-covered spongy bone; spongy bone is called diploe in flat bones
Define the terms tissue and histology.
-tissue- groups of cells that are similar in structure and perform a common or related function -histology- branch of anatomy dealing with the microscopic structure of tissues
Describe the structural and functional characteristics of each of the five epidermal layers.
1. Stratum Basale (Basal Layer)- deepest epidermal layer; firmly attached to dermis wavy boundary with dermis -single row of youngest keratinocytes (stem cells) -cells undergo rapid division -10%-25% of cells are melanocytes -occasional tactile cells 2. Stratum Spinosum (Spiny Layer)- several layers thick; more mature keratinocytes -cells contain web-like system of intermediate filaments (mainly pre-keratin) attached to desmosomes -spiny appearance- artifact of tissue prep; keratinocytes appear to be covered with spines; cells shrink but their desmosomes hold tight -scattered melanin granules and dendritic cells 3. Stratum Granulosum- 3 to 6 cell layers; cells above this layer die because they are too far from capillaries in the dermis (epithelium is nonvascular) -dramatic change in keratinocyte keratinization of cells begins -cells flatten, nuclei and organelles begin to disintegrate, and 2 types of granules accumulate: 1. keratohyaline granules- form keratin 2. lamellar granules- contain glycolipids that coat the external cell surface preventing water loss 4. Stratum Lucidum (Clear Layer)- thin, translucent band superficial to stratum granulosum -eleidin (by-product of keratohyalin) does not stain -2 or 3 rows clear, flat, dead keratinocytes -only visible in thick skin 5. Stratum Corneum (Cornfield Layer)- 20 to 30 layers of keratinized cells; 3/4 of epidermal thickness -Functions of Stratum Corneum 1. waterproofing 2. abrasion and laceration protection 3. barrier (biological, chemical, physical agents) -dandruff and loose skin flakes come from layer
Explain the ABCD rule for melanoma.
A- asymmetry; two sides of pigmented area do not match B- border is irregular and scalloped C- color; pigmented area contains several colors (blacks, browns, tans, and sometimes reds and blues) D- diameter is larger than 6 mm (size of a pencil eraser)
Arrange the five epidermal layers given a starting orientation (e.g., base or surface).
Base to surface; deepest to most superficial 1. Stratum Basale 2. Stratum Spinosum 3. Stratum Granulosum 4. Stratum Lucidum 5. Stratum Corneum
Describe the main functions and distinguishing characteristics of epithelial tissue.
1. Main functions of epithelial tissue: -forms boundaries between different environments -protects underlying tissue from injury -absorbs substances (digestive tract) -filters substances (kidney tubules) -excretes substances (eliminates metabolic waste) -secretes substances (hormones, mucus) -senses stimuli (pressure, heat, etc.) 2. Distinguishing characteristics of epithelial tissue: -polarity- top and bottom surfaces of cell are different 1. apical surface- upper; most have microvilli (called brush order if "fuzzy" appearance); some covered with cilia. 2. basal surface- lower; rests on a thin supporting sheet called the basal lamina (noncellular adhesive sheet) - specialized contacts- cells are held together in continuous sheets by tight junctions and desmosomes (except for glandular epithelium) -supported by connective tissue- basal lamina+reticular lamina= basement membrane -avascular but innervated- no blood vessels; supplied by nerve fibers -regeneration- rapidly replaces lost cells by divison
Classify burns based on degree of epidermal damage and appearance.
1. first-degree burn- only epidermis is damaged; -appearance- localized redness, swelling, pain -heal in 2-3 days without special attention 2. second-degree burn- damaged epidermis and upper epidermis -appearance- like first degree but with blisters -skin regenerates if infection is prevented 3. third-degree burn- full skin thickness damage -appearance- gray-white, cherry red, or blackened -no initial edema or pain (nerve endings are destroyed) -skin grafting is usually necessary
Describe the stages of bone repair (Figure 6.14, page 190).
1. hematoma forms -torn blood vessels hemorrhage -hematoma forms at fracture site -site becomes swollen, painful, and inflamed 2. fibrocartilaginous callus forms -phagocytic cells clear debris -capillaries grow into the hematoma -fibroblasts secrete collagen fibers to connect bone ends -chondroblasts secrete cartilage -osteoblasts begin forming spongy bone -mass repair tissue now called: fibrocartilaginous (soft) callus 3. bony callus forms -new trabeculae form a bony (hard) callus -a firm union occurs in about 2 months -similar to endochondral ossification 4. bone remodeling occurs -excess material on bone shaft exterior and in medullary canal is removed -compact bone is laid down to reconstruct shaft walls -final structure of the remodeled area resembles that of the original unbroken bony region because it responds to the same stressors
Explain the two control loops for bone remodeling.
1. hormonal mechanism- a negative feedback loop that maintains blood Ca2+ homeostasis -calcium- a critical ion necessary for nerve transmission, muscle contraction, and blood coagulation (clotting) -hormonal control loop maintains blood calcium within a very narrow range 2. mechanical mechanism- involves responses to mechanical and gravitational forces acting upon the skeleton, stimulating stronger bone at stressed areas -a bone is "loaded" (stressed) whenever muscles pull on it (mechanical stress) or weight bears down on it (gravity)
Explain the two processes of fetal bony skeleton formation and the main steps in each process (Figure 6.8, page 184 and Figure 6.9, page 185).
1. intramembranous ossification- bone develops from a fibrous membrane; forms most flat bones of skull and clavicles 2. endochondral ossification- bone develops by replacing hyaline cartilage models; all bones below base of skull except clavicles; also occurs during long bone lengthening and fracture repair; complex process- hyaline cartilage must be broken down as ossification proceeds
Differentiate between keratinocytes, melanocytes, dendritic (Langerhans) cells, and tactile (Merkel) cells based upon cellular function and skin layer locations.
1. keratinocytes: -produce fibrous protein called keratin -continuously divide in the deepest epithelial layer -as cells are pushed upwards, they produce keratin which eventually dominates their cell contents -when they reach skin surface they are dead, scale-like structures; keratin-filled plasma membranes 2. melanocytes: -produce the pigment melanin -located in deepest epithelial layer -melanin accumulates in membrane-bound granules then is taken up by nearby keratinocytes -melanin granules accumulate on the apical (sun-exposed) side of the keratinocyte nucleus -melanin granules form a pigment shield protecting the nucleus from damaging UV radiation in sunlight 3. dendritic (Langerhans) cells: -arise from bone marrow and migrate to epidermis -have slender cellular processes that extend among keratinocytes forming a network; ingest foreign substances; key activators of our immune system 4. tactile (Merkel) cells: -function as touch receptors in association with sensory nerve endings; tactile cell+nerve ending=tactile (Merkel) disc; located at the epidermal-dermal junction
Describe the general shape of long bones, short bones, flat bones, and irregular bones. Give examples of each type (Figure 6.2, page 176).
1. long bones- longer than wide with shaft and two ends -examples- humerus, metacarpals, phalanges 2. short bones- roughly cube-shaped -examples- wrist bones, ankle bones -sesamoid bones- special short bones within tendons -example- patella 3. flat bones- thin, flattened, and curved -examples- sternum, scapulae, most skull bones 4. irregular bones- complicated shapes -examples- vertebrae, hip bones
Describe features of the three skin color pigments.
1. melanin- formed in skin -2 forms- range from reddish yellow to brownish black -differences in skin color- due to kind and amount of melanin made and retained -more melanin=darker color=greater sun protection -tanning- when skin is exposed to sunlight, keratinocytes secrete chemicals that stimulate melanocytes to produce more melanin -local melanin accumulation- freckles, pigmented nevi (moles) 2. carotene- yellow to orange pigment from food like carrots -most obvious in palms and soles or feet 3. hemoglobin- reddish in oxygenated red blood cells -responsible for pinkish blue of fair skin
List the organic and inorganic components of bone.
1. organic components of bone: -bone cells- osteogenic cells, osteoblasts, osteocytes, bone-lining cells, and osteoclasts -osteoid- unmineralized, organic bone matrix composed of ground substance and collagen; 1/3 of matrix; made and secreted by osteoblasts 2. inorganic components of bone: -hydroxyapatities (mineral salts) -65% of bone by mass -mainly calcium phosphate crystals -account for bone's hardness and its ability to resist compression
Differentiate between osteogenic (stem) cells, osteoblasts, osteocytes, bone-lining cells, and osteoclasts.
1. osteogenic cells- mitotically active stem cells -some differentiate into osteoblasts or bone lining cells -located in periosteum and endosteum 2. osteoblasts- bone-forming cells that secrete bone matrix -secrete collagen and osteoid (unmineralized bone matrix) -mitotically active -some differentiate into osteocytes or bone cells 3. osteocytes- mature bone cells that occupy lacunae -monitor and maintain surrounding matrix -"sense" stres or strain on bone and communicate this information to the osteoblasts and osteoclasts 4. bone-lining cells- cells found on bone surfaces where bone remodeling (breaking and building) is not occurring -help maintain bone matrix 5. osteoclasts- giant multinucleate cells that resorb (break down) bone
Classify bone fractures according to position of bone ends, completeness, orientation to long axis, and skin penetration.
1. position of the bone ends after fracture -nondisplaced- bone ends retain their normal position -displaced- bone ends are out of normal alignment 2. completeness of the break -incomplete- bone is not broken all the way through -complete- bone is broken all the way through 3. bone orientation to long axis -linear- fracture is parallel to bone long axis -transverse- fracture is perpendicular to bone long axis 4. skin penetration by bones ends -simple (closed)- bone ends do not penetrate skin -compound (open)- bone ends penetrates skin
List the major functions of the integumentary system.
1. protection- forms chemical, physical, and biological barrier -acid mantle- low pH of skin secretions retards bacteria 2. body temp regulation -sweating cools the body through evaporation -dermal blood vessels constrict to warm the body 3. cutaneous sensation- cutaneous sensory receptors sense touch and pain 4. metabolic- synthesizes vitamin D precursor 5. blood reservoir- dermal blood vessels store to 5% of body's blood volume 6. excretion- eliminates small amounts of nitrogenous wastes in sweat
Differentiate between red bone marrow and yellow bone marrow.
1. red marrow- hematopoietic tissue (forms blood cells) -location- within trabecular cavities of spongy bone in long bones and diploe of flat bones -infants- medullary cavity of diaphysis and all spongy bone -adults- heads of femur and humerus, diploe of flat bones, some irregular bones 2. yellow arrow- fat -location- medullary cavity of long bones -can revert to red marrow if person becomes very anemic
List the functional zones of the epiphyseal plate. Explain what occurs in each zone (Figure 6.10, page 186).
1. resisting (quiescent) zone- relatively inactive cartilage on side of epiphyseal plate facing epiphysis 2. proliferation (growth) zone- cartilage cells divide rapidly, pushing epiphysis away from diaphysis; lengthens bone 3. hypertrophic zone- older chondrocytes hypertrophy (enlarge), lacunae erode and engage leaving large interconnecting spaces 4. calcification zone- surrounding cartilage matrix calcifies causing chondrocytes to die and deteriorate 5. osteogenic zone- cartilage spicules are replaced with new bone
Define the terms trabeculae, diploe, periosteum, endosteum, and Sharpey's fibers.
1. trabeculae- a thin plate of bone; a tiny bone "strut" -align along lines of stress, helping bones resist stress -only a few cells thick -no osteons 2. diploe- spongy bone when in flat bones 3. periosteum- 4. endosteum- 5. Sharpey's fibers- tufts of collagen that secure periosteum to bone
Define hematoma.
A bruise
Explain how bones grow in width.
-appositional growth- growth from the outside; causes long bones to widen -unequal processes produce produce thicker, stronger bone; osteoblasts beneath the periosteum secrete bone matrix on external bone surface; osteoclasts remove bone; normally, slightly more building up than breaking down
Describe bone osteon, lamella, central (Haversian) canal, perforating (Volkmann's) canal, lacuna, canaliculus, and trabecula.
-bone osteon- structural unit of compact bone elongated cylinder running parallel to long axis of bone; concentric tubes of bone matrix - lamella- single column-like tube; calcified matrix containing many collagen fibers; arrangement of fibers resists twisting -central (Haversian) canal- channel running down the center of an osteon; contains blood vessels and nerves -perforating (Volkmann's) canal- channels lying at right angles to the long axis of bone; connects blood and neve supply of the periosteum to the central canal and medullary cavity -lacuna- small cavities containing osteocytes -canaliculus- hair-like canals connecting lacunae to each other and central canal; osteocytes' cellular extensions run through canaliculi allowing nutrients and wastes to be relayed from cell to cell through gap junctions -trabecula- a thin plate of bone; a tiny bone "strut"; align along lines of stress, helping bones resist stress; only a few cells thick; no osteons
Differentiate between compact bone and spongy bone.
-compact bone- smooth and solid dense outer layer -spongy bone- internal honeycomb of small needle-like or flat pieces called trabeculae; the open spaces between trabecular are filled with small amounts of red or yellow bone marrow
Describe the four main classes of connective tissue.
-connective tissue proper -cartilage -blood -bone
Name the fundamental cells (mature and immature) of each of the four classes of connective tissue.
-connective tissue proper- immature: fibroblast; mature: fibrocyte -cartilage- immature: chondroblast; mature: chondrocyte -bone- immature: osteoblast; mature: osteocyte -blood- immature: hematopoietic stem cell; mature: erythrocyte, leukocyte, etc.
Classify (name) glands based on where product is released and number of cells making up the gland.
-endocrine gland- internally secreting -exocrine gland- externally secreting -unicellular gland- one celeb; scattered within epithelial sheets -multicellular gland- many cells -endocrine gland- ductless gland that produces hormones; secretes hormones through exocytosis into extracellular space; hormones enter blood or lymphatic fluid and travel to target organs; hormone prompts organ to respond in a characteristic way; example: certain intestinal cells produce hormones that cause the pancreas to release digestive enzymes into the intestinal tract -exocrine gland- gland that secretes product onto body surfaces (skin) or into body cavities; secretes through exocytosis (unicellular) or ducts (multicellular); include mucus, sweat, oil, and salivary glands, the liver, the pancreas, and many others; can be unicellular or multicellular
Differentiate between epiphyseal plate and epiphyseal line.
-epiphyseal plate- plate of hyaline cartilage at the junction of the diaphysis and epiphysis that provides for growth of long bones -epiphyseal line- at the end of adolescence, the bone of the epiphysis and diaphysis fuses forming the epiphyseal line; longitudinal bone growth ends
Describe the four types of tissue and associated functions.
-epithelial tissue- formas covering of all body surfaces; lines body cavities and hollow organs -connective tissue- binds structures together; supportive -muscle tissue- contracts to cause movement -nervous tissue- coordinates and controls many body cavities
Given a type of tissue, match it with its capacity to regenerate.
-extremely well- epithelium, areolar connective tissue, dense irregular connective tissue, blood-forming tissue -moderate- dense regular connective tissue, smooth muscle -weak- carilage, skeletal muscle -virtually none- cardiac muscle, nervous tissue in brain and spinal cord -scar tissue- fibrous tissue that replaces damaged tissue; strong; lacks flexibiility and elasticity of most normal tissues; cannot perform the normal functions of the tissue it replaced
Identify the structural characteristics of a nail (Figure 5.7, page 160).
-free edge -hypoychium- below free edge -nail body- visible attached portion -lunule- white crescents -nail root- part embedded in skin -nail bed- deeper layers of epidermis underneath the nail -nail matrix- thickened proximal portion of nail bed where the nail grows -nail folds- overlapping skin folds -eponychium (cuticle)- proximal nail fold projects onto nail body
Define the terms gland and secretion.
-gland- consists of one or more cells that make and secrete (export) a particular product -secretion- product secreted by a gland; usually aqueous but some are lipid or steroid-rich; or the process of making and releasing that product
Describe ground substance. Explain its composition and function.
-ground substance- unstructured material that fills the space between the cells and contains the fibers -composition of ground substance- 1. interstitial fluid- fluid in spaces between the tissue cells 2. cell adhesion proteins- connective tissue "glue"; attaches cells to matrix 3. proteoglycans- protein core+glycosaminoglycans (GAGs); chondroitin sulfate and hyaluronic acid- GAGs; like bottle brushes that trap water to form fluid or gel -function- holds large amounts of fluid and functions as a molecular sieve through which nutrients diffuse between blood capillaries and cells
Explain the causes of hirsutism, alopecia, and true (frank) baldness.
-hirsutism- excessive hairiness in females; caused by abnormally elevated amounts of androgens (male hormones) secreted by adrenal or ovation tumors -alopecia- hair thinning in both sexes; caused by aging, very high fever, surgery, sever emotional trauma, certain drugs, protein deficient diet, and lactation -true (frank) baldness- most common type is male pattern baldness, a genetically determined and sex-influenced condition; caused by response hair follicles to a metabolite of testosterone
Describe the hormones that affect bone growth.
-infancy and childhood- epiphyseal plate activity is stimulated by growth hormone; GH activity is modulated by thyroid hormone -puberty- testosterone and estrogens take over; promote initial adolescent growth spurt; cause masculinization or feminization of specific skeleton parts; induce epiphyseal plate closure long bone growth ends
Give the description, function, and location of nervous tissue.
-neural tissue- main component of the nervous system -main cells types: 1. neurons- generate and conduct nerve impulses 2. supporting cells- nonconducting cells that support, insulate, and protect neurons -functions- transmit nerve impulses from sensory receptors to the nervous system and from the nervous system to the muscles and glands -locations- brain, spinal cord, nerves
Define the term osteogenesis (ossification).
-ossification- process of bone formation -results in the following processes: embryonic bony skeleton formation, bone growth (until early adulthood), bone modeling and repair
Explain how parathyroid hormone controls bone remodeling.
-parathyroid hormone (PTH)- primary hormone controlling bone remodeling 1. blood Ca2+ levels 2. parathyroid glands release PTH 3. PTH stimulates osteoclasts to resorb bone, releasing Ca2+ 4. ^ blood Ca2+ levels
List the risk factors for osteoporosis. List preventative measures.
-reduced estrogen levels in postmenopausal women -petite body form -insufficient body form -diet poor in calcium and protein -abnormal vitamin D receptors -smoking (reduces estrogen) -some hormone imbalances -Preventative measures: 1. get plenty of calcium while your bones are still increasing in density (through early adulthood) 2. avoid excessive intake of carbonated beverages and alcohol; leach minerals from bone 3. get plenty of weight-bearing exercise (walking, jogging, tennis) throughout life
Classify (name) epithelia using number of cell layers and cell shapes (Figure 4.2, page 118).
-simple- single layer (absorption, secretion, filtration) -stratified- 2 or more layers (protection 1. classified according to shape of ells in apical layer -squamous- flattened, scale-like; wider than tall; disc-shaped nucleus -cuboidal- box-like; approximately as tall as wide; spherical (centrally located) nucleus -columnar- tall, column-shaped; taller than wide; elongated nucleus usually close to cell base
List characteristics of skeletal cartilage. Describe the perichondrium.
-skeletal cartilage- white, semi-opaque connective tissue; lacks nerve fibers and blood vessels (avascular); chondrocytes are typically found in small groups within cavities called lacunae; extracellular matrix contains jellylike ground substance and fibers -perichondrium- layer of dense irregular connective tissue that surrounds all cartilage except fibrocartilage; resists outward expansion of cartilage when compressed; contains blood vessels (nutrient delivery)
Explain the general functions of bones.
-support- provide framework that supports body and soft organs -protection- provide a protective case for brain, spinal cord, and vital organs of the thorax -movement- provide levers for muscles -mineral storage- mineral reservoir, especially calcium and phosphate; released into blood as needed -blood cell formation- hematopoiesis occurs in the red marrow of certain bones -triglyceride (fat) storage- source of stored energy -hormone production- produce osteocalcin which regulate bone formation and protects against glucose intolerance, and diabetes
Differentiate between thick skin and thin skin. List the locations of both.
-thick skin- 5 layers (strata); palms, fingertips, feet soles (areas subject to abrasion) -thin skin- 4 layers (no stratum lucid); other strata are thinner; covers remainder of body
Explain what causes gigantism, dwarfism, and osteogenesis imperfecta.
-too much or too little of these hormones leads to abnormal skeleton development -gigantism- caused by hyper secretion of growth hormone in children -dwarfism- caused by deficits of growth hormone or thyroid hormone in children -osteogenesis imperfecta- genetic disorder characterized by bones that break easily with little or no apparent cause; also called brittle bone disease;bone matrix contains inadequate amounts and/or quality of collagen; initially mistaken for child abuse
Differentiate between vellus and terminal hair.
-vellus hair- pale, fine body hair of children and women -terminal hair- coarse, longer hair of eyebrows, scalp, regions, pubic region; males- face, chest, arms, and legs
Describe the three major types of skin cancer and their characteristics.
1. Basal cell carcinoma: -most common, least malignant skin cancer -stratum basal cells proliferate then invade dermis and hypodermic -shiny, dome-shaped nodules that later develop a central ulcer with a pearly, beaded edge -occurs mostly on sun-exposed areas of the face -slow growing and do not metastasize often -99% of cases can be cured by surgical removal 2. Squamous cell carcinoma: -second most common skin cancer -develops from stratum spinosum keratinocytes -scaly reddened papule (small, round elevation) most often seen on scalp, ears, lower lip, or hands -grows rapidly and metastasizes if not removed -good prognosis if treated by radiation therapy or removed surgically 3. Melanoma: -least common, most dangerous skin cancer -cancer of melanocytes; can begin wherever there is pigment; 1/3 develop from preexisting moles -appears as spreading brown to black patch -highly metastatic and resistant to chemotherapy -treated by wide surgical excision with immunotherapy; key to survival is early detection; poor prognosis if >4mm thick
Explain the steps in tissue repair (Figure 4.12, page 144).
1. Inflammation: -severed blood vessels bleed and inflammatory chemicals are released -local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins and other plasma proteins to seep into the injured area -clotting occurs; surface dries and forms a scam 2. Organization: -the clot is replaced by granulation tissue, which restores the vascular supply -fibroblasts produce collagen fibers that bridge the the gap -surface epithelial cells multiply and migrate over the granulation tissue 3. Regenration: -the fibrosed area matures and contracts; the epithelium thickens -a fully regenerated epithelium with an underlying area of scar tissue results
Describe the main functions and distinguishing characteristics of connective tissue.
1. Main functions of connective tissue: -binding and support: bone and cartilage -protection: bone, cartilage, and fat -insulation: fat -transportation: blood -storage: fat 2. Distinguishing characteristics of connective tissue: -common origin: all connective tissues arise from mesenchyme (a type of embryonic tissue) -varying degrees of vascularity- from avascular (noble vessels) to richly vascular (rich supply of blood vessels) -extracellular matrix: nonliving material that makes up most of connective tissue; allows connective tissue to bear weight, withstand great tension, and endure physical trauma
State Wolff's law. Explain its effects upon different bones and/or bone structures.
Wolff's law- a bone grows or remodels in response to the demands placed on it; a bone's anatomy reflects the common stressors it encounters -long bones- thickest midway along shaft -curved bones- thickest where they are most likely to buckle -trabeculae- forms trusses along compression lines -large projections- form where heavy, active muscles attach -handedness- causes the bones of the most used upper limb to be thicker; tennis players are great examples
Differentiate between cutaneous, mucous, and serous membranes.
a. Cutaneous- skin; unlike other epithelial membranes, it is exposed to the air and dry -layers- 1. epidermis- top layer of keratinized stratified squamous epithelium 2. dermis- deeper layer of connective tissue b. Mucous- moist membranes that line all body cavities that open to the outside of the body; digestive tract, respiratory, and urogenital tracts; often secrete mucus -layers- 1. epithelial sheet- stratified squamous or simple columnar epithelial 2. lamina propria- loose connective tissue 3. smooth muscle- in some mucosae c. serous- moist double-layer membranes found in closed ventral body cavities; serous fluid- lubrication between the membranes -layers- 1. mesothelium- simple squamous epithelium 2. areolar connective tissue -each series is given two names: 1. first name is for site- a. parietal- lines body cavity b. visceral- covers organ 2. second name is for associated organ a. lungs b. heart c. abdominopelvic organs
Recall structural/functional characteristics and products of the following glands: a. Eccrine sweat glands b. Apocrine sweat glands c. Ceruminous glands d. Mammary glands e. Sebaceous (oil) glands
a. Eccrine (merocrine) sweat glands: -structure- simple, coiled tubular gland; duct connects to a pore on skin's surface -functions- produce sweat; hypotonic filtrate of blood; mostly water with some salts, vitamin C, antibodies, a microbe-killing peptide called dermcidin, and traces of metabolic wastes; prevents overheating -locations- found almost everywhere; more abundant on palms, soles of feet, and forehead b. Apocrine sweat glands: -structure- merocrine glands; ducts empty into hair follicles; larger lumens compared to eccrine glands -functions- produce product similar to sweat plus fatty substances and proteins; precise function is unknown; increased activity during pain, stress, sexual arousal, and passes of menstrual cycle; cause of "body odor" -locations- axillary (armpit) and anogenital areas c. Ceruminous glands: -structure- modified apocrine glands -functions- produce a substance that helps form cerumen (earwax); deters insects an blocks entry of foreign material -location- found in linings of external ear canals d. Mammary glands: -structure- specialized sweat glands -function- secretes milk to nourish a newborn baby -location- breasts; present in both sexes but normally function only in females e. Sebaceous (oil) glands: -structure- simple branched alveolar glands that develop mostly from hair follicles; holocrine glands -functions- secrete an oily substance called sebum; sebum softens and lubricates hair and skin- keeps hair from becoming brittle; slows water loss from skin; bactericidal (kills bacteria); production increases at puberty -location- all over body except palms and soles of feet
Give description, function, and location of the following connective tissues: a. Areolar connective tissue b. Adipose connective tissue c. Reticular connective tissue d. Dense regular connective tissue e. Dense irregular connective tissue f. Elastic connective tissue g. Hyaline cartilage h. Elastic cartilage i. Fibrocartilage j. Bone k. Blood
a. areolar connective- gel-like matrix with all 3 fiber types that are loosely arranged; cells include fibroblasts, macrophages, mast cells, white blood cells, and fat cells -functions- supports and binds other tissues- fibers; holds body fluid- ground substance; excess fluid causes edema; defends against infection- white blood cells and macrophages; stores nutrients- fat cells -location- widely distributed under epithelia (this is a pattern); present in muses membranes as lamina propria b. adipose connective- closely packed adipocytes (adipose or fat cells); scanty matrix similar to areolar connective tissue matrix; richly vascularized; also called white fat or white adipose tissue; brown fat occurs mostly in babies and uses lipid fuel to warm the body -adipocytes- large fat droplet (almost pure triglyceride) occupies most of cell volume, pushing nucleus tone side of cell; cells become plumper or more wrinkled as they gain or release fat -functions- energy storage; insulates against heat loss; supports organs; protects organs from shock -locations- found under skin (subcutaneous); serves general nutrient needs of the entire body; around organs with high energy needs like the heart, lymph nodes, some muscles, and bone marrow; surrounds the kidneys; behind the eyeballs; found in genetically determined fat depots such as abdomen and hips; in breasts c. reticular connective- delicate work or reticular fibers in a loose ground substance; reticular cells (fibrocells) are scattered throughout network -function- forms stroma (internal framework) or organs supports many free blood cells -locations- lymphoid organs- lymph nodes, bone marrow, sperm d. dense regular connective- closely packed bundles of collagen fibers running in the same direction, parallel to the direction of pull; wavy arrangement allows tissue to stretch a bit; a few elastic fibers; few cells other than fibroblasts -functions- withstand tensile stress when pulling force is applied in one direction; attaches muscle to bone, muscle to muscle, or bone to bone -locations- tendon- cord attaching muscle to bone; ligament- connects bone to bone; aponeurosis- sheet-like tendon; fascia- fibrous wrapping around muscles, blood vessels, and nerves e. dense irregular connective- thick bundles of collagen fibers that are irregularly arranged; forms tough sheets where tension is exerted in different directions; major cell type is fibroblasts -function- withstands tensile stress when pulling force is applied in may directions -locations- found in skin as the dermis; fibrous joint capsules; fibrous coverings of some organs f. elastic connective- dense regular connective tissue containing a high proportion of elastic fibers -functions- allows recoil of tissue following stretching; maintains pulsatile flow of blood (pulse) through arteries; aids passive recoil of lungs following inspiration -locations- within certain vertebral ligaments; walls of large arteries; within bronchial tube walls g. hyaline cartilage (gristle)- glassy matrix composed of evenly distributed collagen fibers; major cell type is chondrocytes -functions- supports and reinforces; cushions; resists compression -locations- forms most of the embryonic skeleton; covers the ends of long bones; costal cartilage of ribs; tip of nose; trachea and larynx h. elastic cartilage- nearly identical to hyaline cartilage, but has more elastic fibers in matrix -function- maintains shape of a structure while allowing great flexibility -locations- supports external ear (pinna); epiglottis- flap that covers the respiratory tract when we swallow; prevents food and fluid from entering the lungs i. fibrocartilage- rows of chondrocytes (a feature of cartilage) alternate with rows of thick collagen fibers (a feature of dense regular connective tissue) -functions- provides strong support; withstands heavy pressure -locations- intervertebral discs- cushion between bony vertebrae; pubic symphysis; menisci- discs of knee joint j. bone (osseous tissue)- hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae; very well vascularized -functions- supports and protects body structures; provides levers for muscles to act on; stores calcium, minerals, and fat; forms blood (hematopoiesis) in its bone marrow -location- bones k. blood- red and white blood cells surrounded by a fluid matrix called blood plasma; most cells are red blood cells (RBC's, erythrocytes); scattered white blood cells (WBC's, leukocytes); atypical connective tissue develops from mesenchyme -functions- transports respiratory gases, nutrients, wastes, and many other substances -location- contained within blood vessels
5. Describe the structure, function, and location of the following epithelia: a. Simple squamous epithelium b. Simple cuboidal epithelium c. Simple columnar epithelium d. Pseudostratified columnar epithelium e. Stratified squamous epithelium f. Stratified cuboidal epithelium g. Stratified columnar epithelium h. Transitional epithelium
a. simple squamous- single layer of flattened cells with disc-shaped central nuclei; sparse cytoplasm -functions- absorption, secretion, filtration -locations- in kidney glomeruli- urine formation walls of alveoli- air sacs in lungs- gas exchange; endothelium - slick, friction-reducing lining in lymphatic vessels, heart lining, & blood vessels; mesothelium - in serous membranes lining the ventral body cavity & covering its organs b. simple cuboidal- single layer of cube-like cells with large, spherical, central nuclei -functions- secretion and absorption -locations-kidney tubules; ducts and secretory portions of small glands; ovary surface c. simple columnar- single layer of tall cells with round to oval nuclei; some have cilia on apical surface -functions- absorption; secretion of mucus, enzymes, and the substances -locations- nonciliated- line most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; cilitated- line bronchi, uterine tubes, and some regions of the uterus d. pseudostratified columnar- single layer of cells of differing heights with some not reaching free surface; nuclei are seen at different levels; false impression of several layers; may contain mums-secreting cells and bear cilia -fuctions- mucus secretion and propulsion of mucus by cilia -locations- nonciliated- male sperm-carrying ducts and ducts of large glands; ciliated- line trachea and most of the upper respiratory tract e. stratified squamous- several layers of cells; its apical cells are squamous and its basal cells are cuboidal or columnar; contain 2 or more layers; basal cells divide and push apically to replace older cells; more durable than simple epithelia -function- protects underlying areas from abrasion -locations- keratinized type- skin's epidermis; nonkeratinized type- moist linings of esophagus, mouth, and vagina f. stratifitied cuboidal- typically has 2 layers of cuboidal cells; rare in the body -location- ducts of larger glands (sweat and mammary glands) g. stratified columnar- columnar apical layer; limited distribution in the body -location- pharynx, male urethra, and lining some glandular ducts; also seen at transition areas or auction between two other types of epithelia h. transitional- resembles both stratified squamous and stratified cuboidal; cuboidal or columnar basal cells; apical cells vary in appearance depending on degree of urinary organ distension (domelike apical cells flatten and become squamous-like when organ is filled with urine) -functions- cells flatten to permit urinary bladder distension; allows greater volume of urine to flow through tube-like organ; allows more urine to be stored in bladder -location- linings of hollow organs (ureters, bladder, and part of urethra)
Give the description, function, and location of the following types of muscle tissues: a. Skeletal muscle b. Cardiac muscle c. Smooth muscle
a. skeletal- contains long, cylindrical, multinucleate skeletal muscle cells (also called muscle fibers); striated (banded) appearance reflects myofilament arrangement -function- initiates and controls voluntary movement; voluntary muscle (under our conscious control) -location- found in skeletal muscles attached to bones, skin, or other muscles b. cardiac- cells are striated but generally only have one nucleus; cells branch and fit together tightly at junctions called intercalated discs -function- contraction propels blood through blood vessels; involuntary muscle -location- walls of the heart c. smooth- spindle shaped cells with central nuclei; no striations; cells are closely arranged in sheets -function- squeezes substances (food, urine, babies, blood) through hollow organs by alternately contracting and relaxing; involuntary muscle -locations- walls of hollow organs other than the heart
