logging in or signing up mammals hiratufail Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 2383 Category: Education License: All Rights Reserved Like it (3) Dislike it (0) Added: May 25, 2008 This Presentation is Public Favorites: 3 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Importance of Homeostasis in Mammals : Importance of Homeostasis in Mammals metabolic reactions are controlled by enzymes enzymes work best in a narrow range of temperature & pH only ∴important to keep internal environment as steady as possible Slide 3: Homeostasis Definition: Keeping the internal environment in a Steady state It is controlled by Negative Feedback Mechanism Slide 4: Rise above normal value Fall below normal value normal value Corrective Mechanism Corrective Mechanism NEGATIVE FEEDBACK MECHANISM normal value negative feedback negative feedback Parts of Body involved : kidneys : regulate water & mineral salts concentration skin : regulate body temperature liver & pancreas : regulate blood glucose level Parts of Body involved kidney liver pancreas + skin Osmoregulation (Water & Mineral salts) : Osmoregulation (Water & Mineral salts) Regulate water potential in Tissue Fluid Organ involved: KIDNEYS Slide 7: After Sweating Concentrated Blood Larger proportion of water is reabsorbed Slide 8: After Drinking Diluted Blood Smaller proportion of water is reabsorbed Osmoregulation (Water & Mineral salts) : Osmoregulation (Water & Mineral salts) After having a very salty meal produce concentrated urine to remove excess salts in solution form extra water is needed to be excreted along with the excess salts sensation of thirst (drink more water to compensate for the water loss) Thermoregulation(Regulation of Body Temperature) : Thermoregulation(Regulation of Body Temperature) poikilotherms (cold-blooded animals) body temperatures vary with that of the environment e.g. reptiles, fish, amphibians Thermoregulation(Regulation of Body Temperature) : Homoiotherms (warm-blooded animals) keep body temperature constant even in winter by increasing metabolic rate e.g. birds, mammals Thermoregulation(Regulation of Body Temperature) Slide 12: Maintenance of Body Temperature SKIN Slide 13: Structure of Mammalian Skin Epidermis : Epidermis dead outer layer relatively impermeable easily peeled off protect the underlying tissues to prevent mechanical injury to prevent bacterial entry to reduce water loss Epidermis : middle layer made up of living cells become dead as they approach the surface black inner layer with pigment (melanin) to absorb ultra-violet ray for sunlight have cell division to repair the lost outer layers Epidermis Dermis : Dermis Blood capillaries to nourish the cells of the skin branch into superficial blood capillaries Sweat gland surrounded by a network of capillaries secrete sweat (consists of water, mineral salts, urea & some waste materials) characteristic of mammals Dermis : Hair follicles & Hairs each hair has a nerve & a capillary attached to it nerve: receives stimuli capillary: supply food & oxygen hairs reduce heat loss & assist in temperature regulation Erector muscle controls the hair movement for temperature regulation Dermis Dermis : Sebaceous gland secretes oily substance to make the skin waterproof to prevent bacterial entry Receptors detect pain, pressure, temperature & touch Dermis Subcutaneous Fat : beneath the Dermis for fat storage acts as insulator of heat Subcutaneous Fat Functions of Our Skin : Functions of Our Skin protect the body (epidermis) to provide mechanical protection to prevent bacterial entry to reduce water loss temperature regulation (hair) Functions of Our Skin : Functions of Our Skin excretion of sweat (sweat gland) store fats (subcutaneous fat) sensation (numerous receptors ) production of vitamin D under ultra-violet light (inner epidermis) Slide 22: Control Body Temperature in Hot Conditions Slide 23: More sweat is produced by sweat glands evaporation of sweat takes away heat which produces a cooling effect Vasodilation of skin arterioles arterioles near the surface of the skin dilates to let more blood flows near the skin surface to have more heat lost by conduction & radiation. Slide 24: Erector muscles relax hairs lie flat on the skin reduce thickness of air trapped among the hairs (not effective in human because human’s hairs are short) Slide 25: Develop thinner subcutaneous fat & shed their fur as long term responses increase heat loss Decrease metabolic rate & muscle contraction gain less heat Slide 26: Control Body Temperature in Cold Conditions Slide 27: Vasoconstriction of skin arterioles arterioles near the surface of the skin constrict to let less blood flows near the skin surface to have less heat lost by conduction & radiation Slide 28: Erector muscles contract pull hairs erect for trapping more air thicker layer of air acts as a good insulator of heat Less sweat is produced by sweat glands reduce heat loss by evaporation Slide 29: Develop thicker subcutaneous fat & thicker fur as long term responses reduce heat loss Increase metabolic rate & muscle contraction gain more heat Regulation of Blood Glucose Level : Regulation of Blood Glucose Level controlled by Negative feedback mechanism controlled by insulin secreted from the islets of Langerhans in pancreas Diabetes - malfunction of pancreas (does not secrete enough insulin) Slide 31: normal blood glucose level Blood glucose level falls Blood glucose level rises normal blood glucose level Too High Too Low You do not have the permission to view this presentation. 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mammals hiratufail Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 2383 Category: Education License: All Rights Reserved Like it (3) Dislike it (0) Added: May 25, 2008 This Presentation is Public Favorites: 3 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Importance of Homeostasis in Mammals : Importance of Homeostasis in Mammals metabolic reactions are controlled by enzymes enzymes work best in a narrow range of temperature & pH only ∴important to keep internal environment as steady as possible Slide 3: Homeostasis Definition: Keeping the internal environment in a Steady state It is controlled by Negative Feedback Mechanism Slide 4: Rise above normal value Fall below normal value normal value Corrective Mechanism Corrective Mechanism NEGATIVE FEEDBACK MECHANISM normal value negative feedback negative feedback Parts of Body involved : kidneys : regulate water & mineral salts concentration skin : regulate body temperature liver & pancreas : regulate blood glucose level Parts of Body involved kidney liver pancreas + skin Osmoregulation (Water & Mineral salts) : Osmoregulation (Water & Mineral salts) Regulate water potential in Tissue Fluid Organ involved: KIDNEYS Slide 7: After Sweating Concentrated Blood Larger proportion of water is reabsorbed Slide 8: After Drinking Diluted Blood Smaller proportion of water is reabsorbed Osmoregulation (Water & Mineral salts) : Osmoregulation (Water & Mineral salts) After having a very salty meal produce concentrated urine to remove excess salts in solution form extra water is needed to be excreted along with the excess salts sensation of thirst (drink more water to compensate for the water loss) Thermoregulation(Regulation of Body Temperature) : Thermoregulation(Regulation of Body Temperature) poikilotherms (cold-blooded animals) body temperatures vary with that of the environment e.g. reptiles, fish, amphibians Thermoregulation(Regulation of Body Temperature) : Homoiotherms (warm-blooded animals) keep body temperature constant even in winter by increasing metabolic rate e.g. birds, mammals Thermoregulation(Regulation of Body Temperature) Slide 12: Maintenance of Body Temperature SKIN Slide 13: Structure of Mammalian Skin Epidermis : Epidermis dead outer layer relatively impermeable easily peeled off protect the underlying tissues to prevent mechanical injury to prevent bacterial entry to reduce water loss Epidermis : middle layer made up of living cells become dead as they approach the surface black inner layer with pigment (melanin) to absorb ultra-violet ray for sunlight have cell division to repair the lost outer layers Epidermis Dermis : Dermis Blood capillaries to nourish the cells of the skin branch into superficial blood capillaries Sweat gland surrounded by a network of capillaries secrete sweat (consists of water, mineral salts, urea & some waste materials) characteristic of mammals Dermis : Hair follicles & Hairs each hair has a nerve & a capillary attached to it nerve: receives stimuli capillary: supply food & oxygen hairs reduce heat loss & assist in temperature regulation Erector muscle controls the hair movement for temperature regulation Dermis Dermis : Sebaceous gland secretes oily substance to make the skin waterproof to prevent bacterial entry Receptors detect pain, pressure, temperature & touch Dermis Subcutaneous Fat : beneath the Dermis for fat storage acts as insulator of heat Subcutaneous Fat Functions of Our Skin : Functions of Our Skin protect the body (epidermis) to provide mechanical protection to prevent bacterial entry to reduce water loss temperature regulation (hair) Functions of Our Skin : Functions of Our Skin excretion of sweat (sweat gland) store fats (subcutaneous fat) sensation (numerous receptors ) production of vitamin D under ultra-violet light (inner epidermis) Slide 22: Control Body Temperature in Hot Conditions Slide 23: More sweat is produced by sweat glands evaporation of sweat takes away heat which produces a cooling effect Vasodilation of skin arterioles arterioles near the surface of the skin dilates to let more blood flows near the skin surface to have more heat lost by conduction & radiation. Slide 24: Erector muscles relax hairs lie flat on the skin reduce thickness of air trapped among the hairs (not effective in human because human’s hairs are short) Slide 25: Develop thinner subcutaneous fat & shed their fur as long term responses increase heat loss Decrease metabolic rate & muscle contraction gain less heat Slide 26: Control Body Temperature in Cold Conditions Slide 27: Vasoconstriction of skin arterioles arterioles near the surface of the skin constrict to let less blood flows near the skin surface to have less heat lost by conduction & radiation Slide 28: Erector muscles contract pull hairs erect for trapping more air thicker layer of air acts as a good insulator of heat Less sweat is produced by sweat glands reduce heat loss by evaporation Slide 29: Develop thicker subcutaneous fat & thicker fur as long term responses reduce heat loss Increase metabolic rate & muscle contraction gain more heat Regulation of Blood Glucose Level : Regulation of Blood Glucose Level controlled by Negative feedback mechanism controlled by insulin secreted from the islets of Langerhans in pancreas Diabetes - malfunction of pancreas (does not secrete enough insulin) Slide 31: normal blood glucose level Blood glucose level falls Blood glucose level rises normal blood glucose level Too High Too Low