BIOL 118 1st Edition Lecture 23Outline of Last Lecture I. IntroductionII. Life Cycle of a Flowering PlantIII. EmbryogenesisIV. What Genes & Proteins Set Up Body AxesV. Growth & DevelopmentVI. What Genes & Proteins Determine Leaf Shape?VII. Reproductive DevelopmentVIII. ABC ModelOutline of Current Lecture I. IntroductionII. Form, Function & AdaptationIII. TissueIV. Organ & Organ SystemsV. Surface Area/Volume RelationshipsVI. Homeostasis VII. Heat ExchangeCurrent LectureIntroduction- Anatomy: study of an organism’s physical structureThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Physiology: study of how the physical structuresForm, Function & Adaptation- Biologists who study animal anatomy & physiology are studying adaptationso Heritable traits: allow individuals to survive and reproduce in a certain environment better than individuals that lack those traitso Result from evolution by natural selection- Acclimation: phenotypic change that occurs in an individualo In response to a short-term change in environmental conditionso Often applied to changes that take place in lab setting- Structures that are adaptive will correlate with its functiono If a mutant allele alters the size & shape of a structure to make function more efficient Individuals with allele will produce more offspring Allele will increase in frequency over timeTissue- Tissue: group of similar cells that function as a unito Connective Cells loosely arranged in a liquid, jellylike or solid matric Comprises extracellular fibers Secreted by connective tissue cells themselves Nature of matric determines nature of the connective tissue Loose connective tissue: contains an array of fibrous proteins in a soft matrix (adipose & fat tissue) Dense connective tissue: found in the tendons & ligaments (connects muscles, bones & organs) Supporting connective tissue: firm extracellular matrix (bone & cartilage) Fluid connective tissue: cells surrounded by liquid extracellular matrix (blood) o Nervous Consists of nerve cells (neurons) Neurons have two distinct types of projections from cell body- Dendrites: short & branched; transmit electrical signals from other cells to the cell body - Axons: carry electrical signals from the cell body to other cellso Muscle Functions in movement Skeletal muscle- Long cells- Voluntary movement Cardiac muscle- Branched cells - Involuntary movement Smooth muscle- Tapered cells- Involuntary movemento Epithelial Cover the outside of the body, line the surfaces of organs, & form glands Organ: structure that serves a specialized function & consists of several tissues Gland: group of cells that secrete specific molecules or solutions Carry out protection & transport of water & nutrients Have polarity- Apical: faces away from other tissueso Lines organs & secretes mucus- Basolateral: faces animal’s interioro Basal lamina: connects the epithelial to the connective tissueo Cements apical to basal laminaOrgan & Organ Systems- Tissues are organized into specialized structures called organs- Organs are part of larger units called organ systemso Consist of groups of tissues and organs that work together to perform one or more functionsSurface Area/Volume Relationships- Cell surface area: determines the rate at which gases & nutrients diffuse across membrane- Cell volume: determines rate of diffusiono As cell gets larger its volume increase much faster than its surface area does - Metabolic Rate: overall rate of energy consumptiono Basal metabolic rate (BMR): consumption of energy measurement Rate at which an animal consumes oxygen while at rest with an empty stomach, under normal temperature & moisture conditions Measured in mL of O2 consumed per gram of body mass per hour Small animals have higher BMRs than large animalso As an organism’s size increases, its mass specific metabolic rate must decrease Or surface area available would fail to keep up with metabolic demands- Increases in surface area:o Flatteningo Folding o BranchingHomeostasis- Homeostasis: maintenance of relatively constant internal environment- Constancy of physiological state is achieved byo Conformationo Regulation- Conformational homeostasis: homeostasis that occurs by conformation to the external environmento Body temperature of Antarctic rock cod closely matches that of the surrounding seawater- Regulatory homeostasis: requires physiologicalmechanism that adjusts the internal state to keep it within limits that can be tolerated, regardless of the external conditionso Dog maintains constant body temperature regardless of outside environment- Epithelium plays vital role in maintaining physical & chemical conditions inside an animalthat are relatively constanto Controls the exchange of materials across its surfaces in a way that is consistent with homeostasis- Homeostasis in most animals is achieved by regulatory systems that constantly monitor internal conditions such as temperature, blood pressure, blood pH & blood sugaro Each variable has a set point- normal or target valueo Homeostatic system is based on 3 general components: Sensor: structure that sense some aspect of the external or internal environment Integrator: component of the nervous system that evaluates the incomingsensory information & decides if a response is necessary to achieve homeostasis Effector: any structure that helps restore the desired internal conditiono Homeostatic systems are based on negative feedback in which effectors reduce or oppose the change in internal conditions Changes in blood pH Blood pressure Body temperatureHeat Exchange- All animals exchange heat with their environment in 4 wayso Conduction Direct transfer of heat between 2 physical bodies that are in contact with each othero Convection Special case of conduction in which heat is exchanged between a solid & a liquid or gas rather than between 2 solidso Radiation Transfer of heat between 2 bodies that are not in direct physical contacto Evaporation Phase exchange that occurs when liquid water becomes a gas- There is a continuum regarding whether animals hold their body temperature constanto Homeotherms: keep their body temperatures constanto Heterotherms: can tolerate changes in body temperature- Many animals control their body temperature through
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