BIOL 118 1st Edition Lecture 23 Outline of Last Lecture I Introduction II Life Cycle of a Flowering Plant III Embryogenesis IV What Genes Proteins Set Up Body Axes V Growth Development VI What Genes Proteins Determine Leaf Shape VII Reproductive Development VIII ABC Model Outline of Current Lecture I Introduction II Form Function Adaptation III Tissue IV Organ Organ Systems V Surface Area Volume Relationships VI Homeostasis VII Heat Exchange Current Lecture Introduction Anatomy study of an organism s physical structure These 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 structures Form Function Adaptation Biologists who study animal anatomy physiology are studying adaptations o Heritable traits allow individuals to survive and reproduce in a certain environment better than individuals that lack those traits o Result from evolution by natural selection Acclimation phenotypic change that occurs in an individual o In response to a short term change in environmental conditions o Often applied to changes that take place in lab setting Structures that are adaptive will correlate with its function o 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 time Tissue Tissue group of similar cells that function as a unit o 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 cells o Muscle Functions in movement Skeletal muscle Long cells Voluntary movement Cardiac muscle Branched cells Involuntary movement Smooth muscle Tapered cells Involuntary movement o 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 tissues o Lines organs secretes mucus Basolateral faces animal s interior o Basal lamina connects the epithelial to the connective tissue o Cements apical to basal lamina Organ Organ Systems Tissues are organized into specialized structures called organs Organs are part of larger units called organ systems o Consist of groups of tissues and organs that work together to perform one or more functions Surface Area Volume Relationships Cell surface area determines the rate at which gases nutrients diffuse across membrane Cell volume determines rate of diffusion o As cell gets larger its volume increase much faster than its surface area does Metabolic Rate overall rate of energy consumption o 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 animals o 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 Flattening o Folding o Branching Homeostasis Homeostasis maintenance of relatively constant internal environment Constancy of physiological state is achieved by o Conformation o Regulation Conformational homeostasis homeostasis that occurs by conformation to the external environment o 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 conditions o Dog maintains constant body temperature regardless of outside environment Epithelium plays vital role in maintaining physical chemical conditions inside an animal that are relatively constant o 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 sugar o Each variable has a set point normal or target value o 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 incoming sensory information decides if a response is necessary to achieve homeostasis Effector any structure that helps restore the desired internal condition o 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 temperature Heat Exchange All animals exchange heat with their environment in 4 ways o Conduction Direct transfer of heat between 2 physical bodies that are in contact with each other o Convection Special case of conduction in which heat is exchanged between a solid a liquid or gas rather than between 2 solids o Radiation Transfer of heat between 2 bodies that are not in direct physical contact o Evaporation Phase exchange that occurs when liquid water becomes a gas There is a continuum regarding whether animals hold their body temperature constant o Homeotherms keep their body temperatures constant o Heterotherms can tolerate changes in body temperature Many animals control their body temperature through thermoregulation o Endotherm produces adequate heat to warm its own tissue Basal metabolic rates are extremely high Can be much more active Heat is given off to warm the body Mammals birds retain heat b c of elaborate insulating structures feathers
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