Finding Tangent Lines Consider the circle x2 y2 6x 8y 0,as shown in the figure. (a) Find the center and radius of the circle. (b) Find an equation of the tangent line to the circle at the point (c) Find an equation of the tangent line to the circle at the point (d) Where do the two tangent lines intersect?
Chapter 40 – Animal Form and Function I. Overview A. Animals of the world have diverse forms that live in diver environments B. Form relates to Function a. FormAnatomy (study of structure) b. Function physiology (study of function) c. Look at both in regards to: i. Organization ii. Regulation iii. Interaction with environment II. How does environment affect animal form A. Physical Laws a. That governs strength, diffusion, movement and heat exchange B. Animals must adapt to physical laws a. Exchange of energy and materials to environment i. large scale – eating food, getting rid of waste ii. Small scale – exchange across cell membrane b. Animal form is specialized to maximize this function i. Highly folded/branched internal surfaces ii. Gives large surface area for exchange crammed in small space. III. How do form and function relate at different levels of organization Cells Tissues Organs Organ Systems 1. Four Types of Tissues a. 1 – Epithelial Ch 40 1 i. Covers outise of body and internal surfaces ii. Tightly packed cells – barrier against injury, infection, fluid loss iii. Types: 1. Cubodial a. Specialized for secretion b. Find this in our Kidney and many glands 2. Simple Columnar a. Secretion and active absorption b. Find it in our intestines 3. Simple Squamous a. Functions in exchange in materials by diffusion b. Lines blood vessels and air sacs of lungs 4. Pseudostratified Columnar a. Many form mucus membrane lining of respiratory tract 5. Stratified Squamous a. Multilayered and tissues that can regenerate b. Found on surgace common to abrasion, i. E. outer skin and lining of the mouth – when burn it, but it will eventually regernates b. 2 – Connective i. Binds and supports other tissues ii. Cells scattered in extracellular matrix Ch 40 2 iii. Types 1. Cartilage a. Collagenous fibers embedded un chondroitin b. Disks found between vertebrae 2. Bone a. Mineralized connective tissue b. Skeleton 3. Blood a. Liquid extracellular matrix b. Plasma, blood cells and platelets 4. Adipose a. Specialized loose connective tissue b. It is going to pads and insulates the bode c. Which it can stores fuel as fat molecules 5. Collagenous a. Loose connective tissue b. Binds epithelial to tissues c. Hold organs in place 6. Fibrous a. Dense collagenous fibers b. Tendons – attach muscle to bone c. Ligaments – connect bone at joints c. 3 – Muscle i. Long cells ii. Contracts tail tells iii. Types 1. Skeletal (striated) a. Attached to bones by tendons b. Bundles of long cells 2. Cardiac (striated) a. Forms contractile wall of heart 3. Smooth a. Found in walls of digestive tract urinary bladder, arteries, etc. Ch 40 3 b. Cells are spindle shaped c. Responsible for involuntary activities d. 4 – Nervous i. Cells sense stimuli and send signals through body ii. Types 1. Neurons a. Basic unit of nervous system b. Receives nerve impulses and transmit impulses 2. Glia a. Support cells b. Help nourish, insulate and replenish neurons Ch 40 4 2. Moving up: a. Organs i. Layered of different tissues ii. Example: stomach has epithelial, connective and muscle b. Organ Systems i. Responsible for bodily functions ii. Must be coordinated and maintain homeostasis IV. How do we regulate metabolism A. Homeostasis a. “steady state” b. Maintenance of the internal environment c. Keeping the internal environment constant despite changes in external environment. d. Two Aspects of Homeostasis i. Two aspects of homeostasis 1. Regulation a. Internal mechanisms are used to control internal change due to external fluctuations 2. Conformation a. Internal condition changes due to external changes 3. Ex. Fish changes their temp. it might be the same as the water or there might be a combination 2. Non-Living Example (Fig. 40-8) - furnace Ch 40 5 B. Homeostatic Control System (thermostat) a. Receptor (sensor) i. Detects change in environment that varies from set point b. Control Center i. Receives signal from receptor, which generates an output c. Effector (Response) i. Carries out response ii. It is a physiological activity that returns the variable to the set point A living example. Ch 40 6 C. Thermoregulation a. Process by which animal maintain an internal temperature within a tolerable range b. Sources of heat for thermoregulation i. Metabolism ii. External environment c. Ectothermic i. Body heated by external source and can tolerate much larger temperature range and use less food d. Endothermic ( humans) i. Body heat generated by metabolism ii. Can do high level of activity for longer amounts of time e. Poikilotherm Ch 40 7 i. An animal whose body temperature varies with its environment ii. Amphibeiams and lizard f. Homeotherm i. An animal who body temperature is relatively constant 1. Mammals and birds 2. River otter g. No Fixed Relationship i. Ectotherm =/ Poikilotherm =/ does not equal ii. Endotherm =/ Homeotherm iii. Ectotherm and endotherm deal with sources of heat iv. Poikilotherm and hemeothem deal with stability of body temperature D. Four Physical Methods to Exchange Heat with Surroundings a. Conduction i. Direct transfer of heat between object in contact with each other b. Convection i. Transfer of heat by movement of air or liquid past a surface c. Radiation i. Emission of electromagnetic waves by all objects warmer than absolute zero d. Evaporation i. Removal of heat from the surface of a liquid that is losing some of it molecules as a gas e. Thermoregulation – is maintaining rates of heat gain that equals rate of heat loss f. Animals have mechanism to: i. Reduce heat exchange OR ii. Favor heat exchange in a certain direction iii. Usually involves the integumentary system – hair, skin, etc. E. Five Adaptations to Balance Heat Loss/Gain a. 1 - Insulation i. Reduced heat flow between animal and environment ii. Such as skin, fur, fat, blubber iii. Raising feather traps air b. 2 - Circulatory Adaptation i. Change amount of blood flow between body core and skin Ch 40 8 ii. Vasodilation 1. Widening of superficial blood vessels 2. Causes increase of blood flow to skin therefore heat loss iii. Vasoconstriction 1. Decreases diameter of superficial blood vessels 2. Causes decrease in blood flow to skin therefore conserve heat iv. Counter-current exchange 1. Blood vessels in extremities arranges in U- shape a. Artery – carries blood away from the heart b. Vein carries blood to the heard c. 3 - Cooling by evaporative heat loss i. Animals sweat, pant, bathe to cool off d. 4 -Behavioral Responses i. Ectotherms seek out warm places when cold and seek out shade when hot ii. Hibernation iii. Migration e. 5 - Adjusting metabolic heat production i. Thermogenesis – to vary heat production 1. Increase metabolic rate by increasing activity F. Acclimatization – long term a. Insulation i. Adjust amount of insulation ( i.e shedding furs) b. Cellular Adjustments i. More unsaturated fatty acids in cell membrane at lower temperatures 1. Keeps membrane fluid to prevent freezing 2. Needs to do diffusion and osmosis V. What are we going to eat (How are we going to get the energy we need) Growth, Repair, Reproduction, To make ATP Ch 40 9 c. Bioenergetics i. Study of how energy flows through animals ii. Overall flow and transformation of energy in an animal determines nutritional needs and is related to the animal size, activity and environment d. Metabolic Rate i. The amount of energy used by an animal in a specific amount of time ii. Factors that Affect Metabolic Rate: 1. Ectotherm vs. Endotherm 2. Size – smaller animal has higher metabolic rate 3. Activity – high activity yield higher metabolic rate 4. Endotherms rate at rest a. Basic metabolic rate (BMR) 5. Ectoderms rate at rest a. Standard metabolic rates (SMR) e. Energy Budget i. Main things that energy is spent on ii. For a human adult female: 1. Basal(basic) Metabolism 2. Activity 3. Homeostasis of body temperature 4. Reproduction 5. Growth f. Adaptations i. Torpor – a physiological state of decrease activity and metabolism 1. Hibernation a. During cold temperature when food is scarce b. Some cool as low as 1-2 degree Celsius Ch 40 10 c. Arousal unusually about every 2 weeks to raise body temperature slightly 2. Estivation – Torpor during high temperature and low water supply 3. daily torpor a. Adapted to feeding patterns b. Usually small mammals and birds (ex. Bats) Ch 40 11