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Word Roots. ecto - = outside; - therm = heat ( ectothermic : organisms that do not produce enough metabolic heat to have much effect on body temperature)
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Word Roots • ecto- = outside; -therm = heat (ectothermic: organisms that do not produce enough metabolic heat to have much effect on body temperature) • endo- = inside (endothermic: organisms with bodies that are warmed by heat generated by metabolism; this heat is usually used to maintain a relatively stable body temperature higher than that of external environment) • fibro- = a fiber (fibrous connective tissue: a dense tissue with large numbers of collagenous fibers organized into parallel bundles) • homeo- = same; -stasis = standing, posture (homeostasis: the steady-state physiological condition of the body) • inter- = between (interstitial fluid: internal environment of vertebrates, consisting of fluid filling space between cells)
Unifying concepts of animal structure and function Each animal species is an accumulation of different structural and functional adaptations to life in its particular environment Go on to the Campbell Biology site, Chapter 20 activities, do them as we learn the work, and then take the activity quiz and submit it to me when we are done with the chapter.
20.1 Structure fits function in the animal body20.2 Animal structure has a hierarchy20.3 Tissues are groups of cells with a common structure and function Read pp. 412-415 Activities 20A (1st of 8), 20B, and 20C
Structure and Function • Anatomy (structure) • Where part is • How it’s structured • How it’s situated in relation to other organs/tissues • Physiology (function) • Mechanisms of structure’s functioning Form fits function
Animal structure has hierarchy • Connection between structure and function • How structural adaptation used by organism Organ system Atom Molecule Macromolecule Organ Organelle Organism Cell Tissue
20.4 Epithelial tissue covers and lines the body and its parts Read pg. 416 Activity 20D
Epithelial tissue • Sheets of closely packed cells • One free surface forms barriers or exchange surfaces (exposed to air or fluid) • Other surface attached to underlying tissues by basement membrane (anchoring junction) • Structure fits functions • Covers outside of body (protection) • Lines organs and body cavities (secretion) -
Categorized by # layers and shape of free surface cells • Cell shapes are cuboidal(dice), columnar(bricks on end) and squamous(flat floor tiles) • Cells can be in single layer, stratified (multilayered) or pseudostratified (single layer of cells giving impression of being layered)
20.5 Connective tissue binds and supports other tissues Read pg. 417 Activity 20E
20.6 Muscle tissue functions in movement20.7 Nervous tissue forms a communication network Read pp. 418-419 Activities 20F and 20G
Slow, strong, involuntary movements (autonomic NS) • In walls of digestive tract, urinary bladder, arteries/ veins, uterus, pupils • Nonstriated, spindle-shaped cells, one centrally located nucleus • Voluntary movement • Attached to bones by tendons • Striated , unbranched cells, multinucleated • Involuntary contractions of heart • Striated, branched cells, single nucleus.
Nervous tissue • Nervous (rapid, not long-lasting)/endocrine (slower/longer lasting) system control and communicate • Consists of interconnected neurons and other supporting cells • Function in transmitting sensory signals and in coordinating internal events
20.8 Several tissues are organized to form an organ20.9 The body is a cooperative of organ systems20.10 New imaging technology reveals the inner body Read pp. 419-423
All animals except sponges/cnidarians have some organs • Organs-several tissues that perform specific functions
Organ system-group of several organs that work together to perform vital body function • Digestive system • Respiratory system • Circulatory system • Lymphatic system • Immune system • Excretory system • Endocrine system • Reproductive system • Nervous system • Muscular system • Skeletal system • Integumentary system
20.11 Structural adaptations enhance exchange between animals and their environments20.12 Animals regulate their internal environment20.13 Homeostasis depends on negative feedback Read pp. 424-426 Activity 20H (last one)
Animals obtain materials from/excrete metabolic wastes into environment • In simple animals w/gastrovascular cavities • Cnidarians/flatworms • Every cell exposed directly to aqueous environment • Most animals have relatively smaller outer surfaces compared to their volumes • Specialized, inner surfaces increase surface area for exchange of materials
Surface areas of lungs, intestines, and kidneys provide exchange of materials between outer environment and blood • Greater #s cells = larger total surfaces of exchange • Interstitial fluid mediates exchange of materials between blood and body’s inner cells
In response to changes in external conditions, animals regulate their internal environment • Achieve homeostasis, internal steady state
Negative feedback mechanisms keep fluctuations in internal conditions within narrow range compatible with life
Integumentary System(integument-Latin for “to cover”) includes skin and accessory organs (hair, nails, glands)
Functions Acid inhibits bacterial growth of body temperature/evaporative cooling Vitamin D synthesis (liver/kidney turns it into calcitriol which regulates Ca/P production) from bumps, chemicals, bacteria, UV radiation, dessication of water, ions, urea, uric acid Nerve endings detect touch/pressure/pain/temperature
7 1 touch/pressure pain 4 2 deep pressure 3 5 (c) 2007 brainybetty.com ALL RIGHTS RESERVED.
Epidermis • Outermost layer • No blood vessels • Flattened, tightly joined, dead epithelial cells on surface filled with large amounts of keratin • Base layer replaces worn away cells • Keratin • Water-resistant tough, fibrous protein • Forms hair, nails, cow horns, calluses, bird feathers, reptile/fish scales, porcupine quills • Thickness varies • 0.07-0.12mm-most body • 0.8mm-palms • 1.4mm-soles
Melanocytescells that produce melanin • Dark brown pigment • Light/dark skinned people have roughly same # • Difference caused by amount of melanin produced/distributed (heredity) • Length of time exposed to UV radiation • Protects skin cells from DNA damage/cancer
Dermis • Has accessory structures derived from epidermis • Epidermis projects down into dermis to form sweat glands, sebaceous glands, hair follicles • Binds epidermis to underlying tissues • Supplies epidermis w/capillaries and nerve endings • Contains fingerlike projections (dermal papillae) that dimple epidermis on palms and soles • Definite patterns of looped and whorled ridges • Increase friction-enhance gripping ability • Ridges of fingertips have sweat pores-leave fingerprints
Deeper dermal layer: thickest layer (4/5) Collagen fibers: strength and ability to stretch Elastin fibers: elasticity (ability to return to original shape after stretching) Many blood vessels, nerves, sensory endings for sensing pressure, pain, heat, cold Thickness-~1-2 mm, 0.6 mm-eyelids, 3 or more-soles/palms
Subcutaneous layer(hypodermis) Functions • Mostly adipose tissue that stores fat • Shock absorber/insulation/protection • Supplies skin with blood vessels • Anchors skin to underlying structures (skin slides almost freely over it) • "Beer belly"/thick thighs/buttocks-too much fat stored • in hypodermis
Accessory Organs of the Skin • Nail/toothenamel derived from epidermis
Sebaceous (oil) glands • Secretesebum (waxy, oily secretion) into follicle or directly onto skin • Functions • Lubricates hair-keeps from becoming brittle • Prevents excessive evaporation of water • Keeps skin soft • Inhibits growth of certain bacteria (toxic to some) • All over except palms/soles and side of feet • Become very active when male hormones produced, so increased oily skin common in adolescence of both sexes
Sweat (sudoriferous) glandssimple coiled tubular glands over most of body Aprocrinearmpits/nipples/groin/scalp) Involved in stress response Merocrine (forehead, palms, soles, neck, back) Primarily thermoregulatory • Modified apocrine sweat glands • Mammary (produce milk) • Ceruminousglands (produce cerumen-earwax)
Regulation of Body Temperature (arrector pili - goose pimples)
Primary function-protection • Everywhere but palms/soles/nipples/lips Color determined by genetics-varying amts. of different types of melanin in follicle- yellow, rust, brown, and black -responsible for most hair colors, but redhair also contains pigment trichosiderin
Burns • First-degree-red skin, mild swelling, some pain • Second-degree-red skin with blisters that may open and ooze clear fluid, very painful • Third-degree-both layers skin destroyed, skin brown or charred • Either extremely painful or painless • Infections/dehydration • Immune system becomes depressed within 1-2 days after severe burns
ABCDE rule for recognizing melanoma are blurred, ragged, or irregular (black, brown, tan, red blue & white) (>6 mm) Elevation if portion is raised from skin Enlarged if portion is growing