Lecture 1 Chapter 40 Sections 40 1 40 1 and Chapter 41 Sections 41 1 41 2 Pre read Ch 41 Sections 41 3 41 4 and Ch 48 June 27 2013 1 Course introduction 2 Explain and diagram the concepts of homeostasis feedback positive and negative and countercurrent flow 3 Differentiate tissue types by function and cell types 4 Describe the mechanisms used to regulate heat in organisms 5 Explain why cell signaling is important in regulating and controlling cellular responses Ch 7 6 Define and explain the properties of hormones and the significance of receptors 7 Explain the relationship between the brain and endocrine system and the hormones involved Physiology examines the organs tissues and cells of living organisms What do cells need Energy Oxygen Glucose External environment Single celled organism is in direct contact with their environment Multi celled organisms don t have any direct exchange Multi cellularity Multi celled organisms rely on internal environment Multi cellular animals require a stable internal environment Fig 40 1 Intracellular fluid cytoplasm Extracellular fluid plasma interstitial fluid Plasma is inside cells Interstitial fluid is outside cells Internal environment Water protects from harsh conditions Specialization Specialized cells help maintain internal environment Cells can only do a particular function Many cells can act together to do one function Multicellular Cells that evolve new functions Separate systems for waste removal oxygen intake etc Homeostasis is the maintenance of a stable internal environment Fig 40 2 External side Food and water Temperature Behavioral Metabolic processes Carbon dioxide Metabolic wastes Hormonal Regulation Set point Sensors What is maintained Feedback Negative Effector systems Epithelial Tightly packed Create boundaries Move things in and out of areas Filtration Transport Selective transport Absorption Secretion Smell taste Recognizes how far away you are from set point Detects the differences using feedback Majority of feedback Opposite direction of what you currently have Positive Cycle which continually increases the process that is occurring Child birth There are four types of tissue Epithelial Muscle Connective Nervous Fig 40 3 Proteins aquaporins cotransporters antiporters epithelial proteins Tight junctions desmosomes Line gut blood vessels ducts tubules lungs Always create some sort of boundary Squamous Columnar Cuboidal Muscle Elongated Generate force and movement Voluntary involuntary Skeletal Attached to bone used for breathing Voluntary In heart maintain heartbeat moves blood Involuntary Cardiac Smooth Muscles Involuntary Desmosomes gap junctions Connective Cells in extracellular matrix Can be composed of many things Collagen elastin Adipose blood cartilage bone Responsible for electrical signal Nervous Neurons Glial cells Support for neurons Feed Take away wastes Communication signal Electrochemical signals Neurotransmitters Organs consist of multiple tissue types Organ systems Group of organs working together Most organs have all four tissue types Environmental temperature affects living systems Fig 40 8 Heat Start message with electrical signal and then put out a neurotransmitter Message to another cell For every 10 degree increase in temperature you increase the metabolism rate of reaction Various responses to heat or cold Can alter phosphor membrane Some animals can add antifreeze to blood to prevent freezing Cell survival 0 degrees C 40 degrees C Heat denatures protein Breaks down secondary tertiary hydrogen bonds Some organisms live in extreme heat Algae archaeans Hot springs Temperature sensitivity Q10 1 not temperature sensitive Q10 2 reaction rate doubles Q10 3 reaction rate triples Acclimatization Become used to the temperature you are around Animals manage heat exchange differently 40 9 Homeotherm Poikilotherm Endotherm Animals with a constant body temperature Animals with a varying body temperature Animals where the heat is internal Rely on internal mechanisms Metabolic heat Ectotherm Animals where the heat is external Rely on environment Metabolic heat Heterotherm An animal that is both or can be either an endotherm and an ectotherm Ectotherms and endotherms respond differently to environmental changes Metabolic regulation Endotherm Adjust body using metabolic heat Gain heat from pumping sodium and potassium ions across gradient Cells have to work harder because membranes are leaky inefficient Behavioral regulation Ectotherm Thermoneutral zone The area where the body temperature should be Going too far one way or another leads to death Animals exchange heat with the environment Transfer of heat from warmer to cooler objects Radiation Convection Conduction Evaporation Heat transferred to a medium as that medium flows over you air wind Heat transferring directly to an object actually touching Loss of heat by water evaporation Blood flow near skin is adjusted to manage heat exchange Insulation Mammals and birds Keeps heat inside body Can direct blood flow to prevent heat loss Countercurrent exchange Capillary bed are muscles that generate heat Heat exchange occurs Opposite blood flow in artery and vein Vein loops back underneath Causes countercurrent exchange of heat Mammals regulate their body temperature with their metabolic rate Basal metabolic rate BMR Recorded when the organisms is at rest Depends upon size Animal size Larger animals have a higher BMR Not a linear relationship Environmental temperature Thermo neutral zone Area that is close to body temperature Independent of the temperature outside Brown fat evaporation and shivering adjust heat in mammals Adipose tissue Holds lipids Brown fat Smaller animals do more to maintain their BMR than larger animals do Small lots of mitochondria to generate lots of ATP Not found in human adults found in human babies Non shivering heat production Use fat supply White fat Big droplets of fat ATP vs non ATP production The hypothalamus acts as a thermostat and uses feedback information Fever pyrogens Fevers controlled by the hypothalamus Hot enough to kill whats infecting you but not too hot the proteins denature Pyrogens can be bacteria or virus Hypothermia hibernation Hypothermia lowering of body temperature Not regulated Hibernation slowing down of metabolic processes Chapter 41 Genome Control and regulation rely on the cell to cell communication Codes for all genes that are necessary for that organism to function Signaler cell s gland signal chemical hormone