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Tissues, Organ Systems and Homeostasis. At Last!! Systems!. To refresh:. Atoms form molecules. Molecules (like proteins, carbohydrates, lipids, and nucleic acids) form cell organelles as well as just float around in cells and between cells. Amino Acid. Cell Organelles.
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Tissues, Organ Systems and Homeostasis At Last!! Systems!
To refresh: Atoms form molecules
Molecules (like proteins, carbohydrates, lipids, and nucleic acids) form cell organelles as well as just float around in cells and between cells.
Cell Organelles • carry out specific jobs in the cells, like making certain molecules or digesting waste materials
Are the basic unit of life that is capable of carrying out all the functions of living things independently Work together to form tissues Metabolism Homeostasis Ability to reproduce/Genetic material Growth and Development Response to stimuli Cells
The body must maintain conditions within certain parameters This means control over things like: temperature pH blood gases (oxygen, carbon dioxide) Homeostasis
a. Sensory receptor cells detect specific changes in the environment. b. Integrators act to direct impulses to the place where a response can be made. c. Effectors perform the appropriate response. 5 senses, temperature sensors, etc Brain and spinal cord Muscles and glands Homeostatic mechanisms operate to maintain the body within tolerable limits by using:
Everything has a role to play in homeostasis • The combined contribution of cells and the tissues they form, and the organs and systems formed from these all work to maintain a stable internal environment for a living being
What do the pieces of the body do to help? • Cells are bathed in fluid: 4 Gallons of extra-cellular fluid (between cells- called interstitial fluid) • Each cell carries out metabolic activities to ensure the survival of the cell • Cells of each tissue act together to perform one or more duties that contribute to the survival of an organism as a whole by forming organs that work together in a system
Positive Causes the situation to intensify Cough up germs, produce more mucus, cough more, irritate throat, cough more, more mucus… Sexual response Oxytocin production in labor causes uterine cramping, which causes production of oxytocin which causes cramping which causes more oxytocin production…. Feedback Mechanisms (2 types)
Negative feedback • Causes the situation to stop/ reverse conditions • Like a thermostat turns off the heat when it gets to a preset temperature • Usually things are just turned on or off; you produce insulin (or other hormone) and when you have enough, production stops; when you need more, you produce more
On to the Integumentary System (the Skin)
0 Skin: Your Birthday Suit (also, a marvel of biology)
Skin description: Use the vocabulary from the image to write a description of skin
0 Skin: The Integumentary Systemfrom the Latin integere- to cover • Demonstrates all of the tissues working together to keep on organism alive • The average person has 9 pounds of skin • The skin is about 15-20 square feet
prevents dehydration Prevents microbial invasion/ infection Prevents abrasion Stores blood Provides cushioning Insulation (temp, physical) Receives stimuli (touch, temp, pressure) Temperature regulation Produces vitamin D Pheromone secretion Excrete salt waste (small counts) 0 Functions of the skin:
3 layers (top) Epidermis Dermis Subcutaneous Layer (AKA the Hypodermis) 0 Skin Structure
0 The Epidermis • Has no nerves • Dead layers of flat epithelial cells; the very top is called the stratum corneum • Contains keratin: a tough protein that waterproofs the skin • Quite a bit gets rubbed off each day (dust) • Skin color is due to • melanocytes (pigmented cells- genetics and sun exposure play roles) • blood flow • carotene
Layers of the Epidermis • Stratum corneum • Stratum lucidum • Stratum granuosum • Stratum spinosum • Stratum basale (basal cell layer)
Made from mostly connective tissue Irregular and dense CTs Role is mainly to protect underlying tissues Contains: Blood vessels Lymph vessels Nerve endings Sweat glands Oil glands Hair Nails 0 The Dermis of the skin
0 More on the dermis and sweat glands… • Sweat (sudoriferous) glands are present to control temperature, but respond to • Stress (frightened, upset, etc) • pain, and • sexual stimuli
Types of Sweat Glands • Two types: • Eccrine glands (mostly temperature regulation sweat) • Foredead, neck, back, • palms and soles from stress • Apocrine glands (“scented” sweat glands; sweat is broken doen by bacteria, producing a scent) • Found in the axillary and inguinal areas
0 More on the dermis and sweat glands… • Sweat is made up of • water, • salts, • ammonia, • vitamin C, • other wastes and • (possibly) pheromones
0 Pheromones • Are chemicals secreted by the body that other animals of the same species respond to (communication molecules) • Usually associated with reproduction, but not always • Are well documented in animals • Syrian golden hampsters (dimethyl disulfide to attract, aphrodisin to copulate) • Cockroaches (periplanone B) • Ethiopian civet cat and Himalayan musk deer (musk) • Pigs (androstenone) • Usually have no smell associated with them • Secreted in very small amounts • Some evidence for pheromone presence in humans • VNO (vomeronasal organ) in people; used to detect pheromones in animals
0 Oil glands…. • Otherwise known as sebacious glands • Lubricate hair and skin by producing sebum (fatty substance that includes lipids and cellular debris made in holocrine glands) • Oil kills microbes (bacteria) • None present on soles of feet or the palms of the hands (but they are present on the fingertips)
0 We leave prints behind… • The oil produced from our fingers seeps into the ridges and is left behind when we touch an object • (Locard’s exchange principle: we leave things behind wherever we go, and pick up things wherever we go • Every contact leaves a trace • Lint, hair, fingerprints, tracks, saliva, etc)
0 A few things about prints… • Ridge patterns and the details in small areas of friction ridges are unique and never repeated. • Friction ridges develop on the fetus in their definitive form before birth. • Ridges are persistent throughout life except for permanent scarring. • They can not be burned or scratched off- they will grow back! • Friction ridge patterns vary within limits which allow for classification.
0 Fingerprints • AKA friction ridge patterns • b/c the ridges help increase the friction when we pick up an object, helping us hold onto it • Fingerprints are “the result of genetic factors and random physical stresses and tensions during development on the stratum basale”, the lowest layer in the epidermis.
0 Print Formation • Formation begins at 10 weeks after conception • Is complete at 24 weeks gestation(6 mo of pregnancy) • (**some sources say complete at 14 wks)
0 Dermal papillae
0 Print patterns • 5% of prints contain arches • 65% of all prints contains loops • 30% of all prints contain whorls
0 Print patterns http://www.fbi.gov/hq/cjisd/takingfps.html
0 How unique are you? • Chances are one in a quintillion (1 in 100,000,000,000,000,000,000) that someone will have the same print (singular, not for all 10 fingers) as you • identical twins have similar patterns, but the prints are not the same • Boimetric identification: using fingerprints, ear prints, iris patterns to ID you, as they are each unique
0 Matching prints
0 Minutia points are the small marks in the loops, arches, or whorls
Biometrics take the print and make a digital map that is unique
0 Skin and Sensation • Pacinian corpuscles • Heavy pressure, pain • Meissner’s corpuscles • light touch • Thermoreceptors • Temperature (warm and cold) • Pain receptors • Acute (quick) • Chronic (slower)
0 The Subcutaneous Layer: The Hypodermis • The hypodermis is made up of • Adipose • To insulate (temperature regulation) • Loose connective tissue • Collagen • Elastin • Both to protect • Fibers run parallel to the skin • Rete cutaneum: network of blood vessels at “border” of dermis
0 Hair… (a slight diversion for a moment or two…)
0 I went looking for a picture of hair… I found a few…
0 There were more than a few I had to share…
0 It was sort of like a train wreck…
0 Bad vacation destinations...