BIOL 204 Lecture 32-Animal Form & Function PDF

Learning Objectives Distinguish between anatomy and physiology Discuss adaptations for increasing surface area What are the relationships among tissues, organs, and organ systems? Identify the four types of tissue Distinguish between different connective tissue fibers, types of muscle...

Learning Objectives Distinguish between anatomy and physiology Discuss adaptations for increasing surface area What are the relationships among tissues, organs, and organ systems? Identify the four types of tissue Distinguish between different connective tissue fibers, types of muscle tissue, and components of nervous tissue What is homeostasis and how is it maintained? Discuss the five adaptations for temperature regulation  Form & Function All animals must obtain nutrients and oxygen, fight off infection, and survive to produce offspring. Why does it vary so widely? Many different body plans have arisen during the course of evolution, but these variations fall within certain bounds. Physical laws that govern strength, diffusion, movement, and heat exchange limit the range of animal forms.  Form & Function Form = Anatomy – biological form of an organism Function = Physiology – biological functions an organism performs Influences ability and survival Anatomy Physiology -Efficient respiratory and circulatory systems provide oxygen to muscles -Signal transmission to/from muscles and eyes to the brain from signal processing  Form & Function Physical laws govern the shape and size of animal anatomy – convergent evolution results among animals facing similar stresses  Exchange with Environment Nutrients, gasses, and wastes must pass through cell membranes Rate of exchange is proportional to a cell’s surface area while amount of exchange material is proportional to a cell’s volume Exchange (surface area: volume) Unicellular organisms living in water have sufficient surface area for exchange 0.1 mm Figure 40.3  Exchange with Environment Nutrients, gasses, and wastes must pass through cell membranes Rate of exchange is proportional to a cell’s surface area while amount of exchange material is proportional to a cell’s volume Multicellular organisms with Exchange a saclike body plan have body walls that are only two Exchange cells thick, facilitating diffusion of materials 0.1 mm Figure 40.3  Exchange with Environment In flat animals, all cells in contact w/ environment  Exchange with Environment In flat animals, all cells in contact w/ environment More complex organisms External Mouth Food have adaptations for CO2 O2 environment Animal body increasing surface area Respiratory system Interstitial Heart fluid Nutrients Cells Circulatory system 100 µm Digestive Excretory system system Anus Lining of small Unabsorbed Metabolic waste matter (feces) products (nitrogenous waste) intestine (SEM) Figure 40.4  Exchange with Environment In flat animals, all cells in contact w/ environment More complex organisms External Mouth Food have adaptations for CO2 O2 environment Animal body increasing surface area Respiratory system Interstitial Heart fluid Nutrients Cells Circulatory system 250 µm Digestive Excretory system system Lung tissue (SEM) Anus Unabsorbed Metabolic waste matter (feces) products (nitrogenous waste) Figure 40.4  Exchange with Environment More complex organisms have adaptations for increasing surface area In vertebrates, space between cells is filled with interstitial fluid for exchange of material Complex body plans also include a circulatory fluid, such as blood  Organization of Animal Bodies Animal bodies consist of cells  tissues  organs  organ systems  Organization of Animal Bodies Animal bodies consist of cells  tissues  organs  organ systems Different tissues have different structures based on function Four categories: – Epithelial – Connective – Muscle – Nervous  Organization of Animal Bodies Epithelial tissue lines the surface of the body, organs, and body cavities – cells are closely joined Epithelial Tissue Stratified squamous Categorized based epithelium on shape and Apical surface arrangement Basal surface Cuboidal Simple Pseudostratified epithelium columnar Simple columnar epithelium epithelium 10 µm squamous epithelium Figure 40.5a  Organization of Animal Bodies Connective tissue binds and supports other tissue Contains cells scattered in extracellular matrix (fibers in liquid, jelly, or solid) Three types of proteinaceous fibers in matrix: – Collagen – provides strength and flexibility – Reticular fibers – connects connective tissue to other tissues Collagenous fiber – Elastic fibers – stretch and snap back to original length 120 µm Elastic fiber  Organization of Animal Bodies Connective tissue binds and supports other tissue Contains cells scattered in extracellular matrix (fibers in liquid, jelly, or solid) Three types of proteinaceous fibers in matrix: – Collagen – provides strength and flexibility – Reticular fibers – connects connective tissue to other tissues Collagenous fiber – Elastic fibers – stretch and snap back to original length 120 µm Elastic fiber  Connective Tissue Loose connective tissue Blood Collagenous fiber Plasma White blood 55 µm cells 120 µm Red blood cells Cartilage Elastic fiber Fibrous connective tissue Chondrocytes 100 µm 30 µm Chondroitin sulfate Nuclei Bone Adipose tissue Central canal Fat droplets 700 µm 150 µm Osteon Figure 40.5b  Organization of Animal Bodies Muscle tissue is responsible for body movement Consists of fibers of actin and myosin (protein) Three types: – Skeletal – voluntary motion Attached to bone by tendons – Smooth – involuntary motion – Cardiac – contraction of heart. Has branched fibers with intercalated disks to relay signals between cells and help synchronize heart contractions Figure 40.5c  Organization of Animal Bodies Nervous tissue receives, transmits, and processes information – Neurons – nerve cells that transmit nerve impulses – Glial cells (glia) – support neurons Nervous Tissue Neurons Glia 15 µm Glia Neuron: Dendrites Cell body Axons of Axon neurons 40 µm Blood (Fluorescent LM) vessel Figure 40.5d (Confocal LM)  Animal Physiology Control and coordination within a body depend on the endocrine and nervous systems Endocrine system – transmits Signaling by hormones STIMULUS chemical signals called hormones Endocrine cell Hormone throughout entire body through blood Signal travels everywhere. - Slow acting, but long lasting Blood vessel Response  Animal Physiology Control and coordination within a body depend on the endocrine and nervous systems Endocrine system – transmits Signaling by neurons STIMULUS chemical signals called hormones Cell body of neuron Nerve impulse throughout entire body through Axon blood Signal travels to a specific location. Nervous system – transmits Nerve impulse information between specific Axons locations - Typically very fast acting Response  Animal Physiology Homeostasis – maintenance of internal environment regardless of external environment Fluctuations above or below a set point detected by a sensor serve as a stimulus, which triggers a response to return body to set point  Thermostat turns heater off. Room temperature Room temperature increases. decreases. ROOM TEMPERATURE AT 20C (set point) Room temperature Room temperature increases. decreases. Thermostat turns heater on. Figure 40.8  Thermostat in Response: Blood hypothalamus vessels in skin dilate. activates cooling mechanisms. Response: Sweat Body temperature Body temperature increases. decreases. NORMAL BODY TEMPERATURE (approximately 36–38C) Body temperature Body temperature increases. decreases. Response: Shivering Response: Blood Thermostat in vessels in skin hypothalamus constrict. activates warming Figure 40.17 mechanisms.  Animal Physiology Homeostasis is maintained by regulating or conforming – e.g., temperature regulation Regulator – internal mechanisms control body (e.g., metabolism); endothermy Conformer – external factors control body (e.g., ambient temperature); ectothermy Figure 40.7  Animal Physiology Homeostasis is maintained by regulating or conforming – e.g., temperature regulation Animal may be a Conformer of some internal conditions, and a Regulator of others E.g., Marine fish conform to the waters temperature, but regulate solute concentration in its blood and interstitial fluid (osmoregulator)  Animal Physiology Body temperature is not always constant, – Homeothermy – body temperature is relatively constant – Poikilothermy – body temperature fluctuates (a) A walrus, a homeotherm (b) A lizard, a poikilotherm  Animal Physiology Temperature regulation is facilitated by radiation, evaporation, convection and conduction Radiation: emission of Evaporation: Colling from electromagnetic waves by all the process of liquid objects warmer than absolute zero converting to gas Convection: transfer of heat through the movement of Conduction: Transfer of liquids and gases heat through direct contact  Animal Physiology Five adaptations for temperature regulation – Insulation – integumentary system (hair, feathers, skin) helps to trap warm air close to the body  Animal Physiology Five adaptations for temperature regulation – Insulation – integumentary system (hair, feathers, skin) helps to trap warm air close to the body and fat/blubber layers (from adipose tissues)  Animal Physiology Five adaptations for temperature regulation – Insulation – integumentary system (hair, feathers, skin) helps to trap warm air close to the body and fat/blubber layers (from adipose tissues)  Animal Physiology Five adaptations for temperature regulation – Insulation – Circulatory adaptations – regulation of blood flow near the surface controls heat loss/ gain (through vasodilation and vasoconstriction)  Animal Physiology Five adaptations for temperature regulation – Insulation – Circulatory adaptations – countercurrent exchange transfers heat from fluids travelling in opposite directions  Animal Physiology Five adaptations for temperature regulation – Insulation – Circulatory adaptations – countercurrent exchange transfers heat from fluids travelling in opposite directions Gray whale tongue (Ekdale & Kienle, 2015)  Animal Physiology Thermoregulating fishes (0.1% of all fishes, e.g. tuna) – High metabolic rate = produces heat – Counter current exchange – Can swim 1.6 times faster than ectothermic fishes biology-forums.com  Animal Physiology E.g., Opah (moonfish) – Can generate heat with its swim muscles and use this heat to warm both its heart and brain – Uses counter-current heat exchange and fatty insulation protects against the cold during deep dives  Animal Physiology Five adaptations for temperature regulation – Insulation – Circulatory adaptations – Evaporative heat loss – lose heat through evaporation of water through skin (e.g., sweating, panting)  Animal Physiology Five adaptations for temperature regulation – Insulation – Circulatory adaptations – Evaporative heat loss – Behavioral – animals will position themselves relative to sun; others huddle together  Animal Physiology Five adaptations for temperature regulation – Insulation – Circulatory adaptations – Evaporative heat loss – Behavioral – Adjusting metabolic heat production – (thermogenesis) increased muscle activity and hormones stimulating mitochondria produces heat (e.g., shivering and non-shivering thermogenesis brown fat cells in mammals)  PREFLIGHT PREFLIGHT FLIGHT WARM-UP 40 Thorax Thorax Temperature (C) 35 Abdomen 30 Abdomen 25 0 2 4 Time from onset of warm-up (min) Figure 40.15  Animal Physiology Unique strategy! E.g., Icefish – Regulate temperature above the frigid Antarctic waters – Have antifreeze proteins that circulate through their bodies to keep them from freezing – Icefishes don't have hemoglobin = they have nearly transparent blood (live in oxygen-rich waters)  Animal Physiology The set points for homeostasis can change under various circumstances – Regulated (e.g., puberty, pregnancy) – Cyclic (e.g., circadian rhythm – physiological changes that occur roughly every 24 hours) Body Melatonin Core body temperature (C) temperature concentration Melatonin concentration 37.1 60 Start of Midnight in blood (pg/mL) Lowest melatonin secretion heart rate Greatest 36.9 40 muscle Lowest body strength temperature 36.7 20 6 PM 6 AM Most rapid rise in blood 36.5 0 pressure 2 6 10 2 6 10 Fastest PM PM PM AM AM AM reaction time Highest risk Time of day Noon of cardiac arrest (a) Variation in core body temperature and melatonin (b) The human circadian clock concentration in blood  Summary – Four tissue types: Epithelial tissue forms active interfaces on external and internal surfaces; connective tissue binds and supports other tissues; muscle tissue contracts, moving body parts; nervous tissue transmits nerve impulses throughout the body. – The endocrine & nervous systems are the two means of communication between different locations in the body. – In thermoregulation, physiological and behavioral adjustments balance heat gain and loss, which occur through radiation, evaporation, convection, and conduction.