BIO202 - Introductory Animal Physiology

Physiology A study of how structures and functions of the body work together to allow for behavioural responses to the environment. Physiology in biological studies: Environment Genotype Evolution Natural selection (Random processes) Development => Molecules, Cells, Tissues, Organs, Organ System => Physiology Anatomy Behaviour => Reproduction Challenges living in Aquatic Environments Wet all the time Less light More dense, more viscous (but body is supported by buoyancy) Oxygen hard to extract

Physiology in Biological Sciences “The study of how animals work” Study of how structures and functions of the body work together to slow got behavioural responses to the environment Linking different scales within organisms Aspect of animal phenotype RELATIONSHIP BETWEEN STRUCTURE AND FUNCTION Coyote (carnivore) has a relatively smaller intestinal tract Koala (herbivore) have a relatively larger intestinal tract an much larger cecum filled with gut bacteria that can break down cellulose Their

Physiology A study of how animals work Adaptations Anatomical and physiological parts of body to allow for adaptations Fur conserve heat Smaller ears and nose area to reduce heat loss Specialized structures capillary structures in feet help conservation of heat and gas exchange also have Reduce metabolic rate to observe energy haps them not be hungry Animal Phenotypes Plastic to environmental response property of animal that is depends on environment: Developmental properties in fetal and e

Homeostatic Loop Relatively stable equilibrium between independent elements. Questions: how do structures work together? Stimulus - Detected by the body by receptors/ nervous system (environment = oxygen, temperature) Sensor - Body receptor Control - Nervous system Effector - Body muscle, gland *Negative Feedback Loop - Doing the opposite of the stimulus *Positive Feedback Loop - Stimulus that triggers an increase in the same direction to the stimulus Ex. Labour/ Blood clot Head of baby pushes

Homeostasis Homeothermic - an animal that controls its own heat If body temp exceeds 37 (threshold), stimulus is detected by body (are receptors that detect change in body). Send that signal to CNS. That will trigger physiological changes in body, and lower internal temp. Muscle, or vessels, will change. Is a negative homeostatic loop Stimulus that triggers an increase in the same direction Is a positive feedback loop e.g.. blood clotting, labor stimulus-stretching in uterus, triggers responses

SUSTAINING ANIMAL LIFE Energy obtained by oxidation of food Oxygen is abundant in air and dissolved in water Mitochondrial respiration is the combination of sugar and oxygen to create energy and carbon dioxide Sugar + O2 Energy + CO2 How do we get this oxygen into the body and mitochondria? SUSTAINING AQUATIC ANIMAL LIFE O2 in aquatic environment: Lower diffusion rates and solubility Less available O2 in a given volume of fluid What is limiting oxygen in the environment? Diffusion and solubili

Diffusion Rates Thickness - Diffusion Distance The smaller the value, the more efficient gap diffusion is (rate ↑) Respiratory Pigments Transportation through circulatory system via respiratory pigments that bind oxygen Haemoglobin (in erythrocytes or red blood cells of blood) Haemocyanin (in hemolymph) - Animals lacking a central pump for blood (snails, crabs, etc.) 4 heme subunits - each carrying iron, having the ability to carry an oxygen molecule Pigments - carry molecules of gas Animals

LC Question X- the smaller the thickness (x), the more efficient gas diffusion is - or diffusion rate is higher There are other ways respiration happens can also happen in skin efficient in species system there is less selective pressure last lecture review Slide 3 Counter current exchange Water is first reaching blood that is high in oxygen When water is passing through part of gill that is poor oxygen, there is diffusion gradient. Same for other end. Birds ceos-current not as efficient in ter

COMPONENTS OF CIRCULATORY FLUIDS Transport via circulatory system via respiratory pigments that bind oxygen Haemoglobin (in erythrocytes or cell blood cells of blood) Haemocyanin (in hemolymph) What carries oxygen is the respiratory pigment These chemicals usually have properties that allow them to bind oxygen, transport them to parts of the body, and then release them to target cells Different types of red blood cells: Shape is most compact in mammals and doesn’t contain a nucleus Fish and rept

Osmosis Movement of water through membrane Semipermeable membrane , ions, proteins, carbohydrates move across with the help of proteins passively/actively (pumps on energy) Hypotonic - More salt inside the animal/cell than environment (H2O moves inside) Hypertonic - Less salt inside the animal/cell than environment and more water (H2O moves outside) QuestioN What challenges do animals have in fresh water, salt water or terrestrial environments, in terms of water and salt balance, and how can do

Osmosis - Add Ions Can move passively or electrical graduates (+ ions attracted to - ions), or can move actively (using energy, typically pumps that use ATP, i.e. ATPase's) Balance of water and salts (or ions) depends on these ATPase's - if didn’t function properly, can’t establish chemical or electrical gradient Hyper-tonic and hypo-tonic pertain to solutions they are in Hypertonic - Cells themselves have high concentration of water than outside environment. There are more salts in outside env

What challenges do animals have in each of the following environments in terms of water and salt balance and how can/do they cope with these challenges? Provide an example. A - Saltwater Cells potentially contain less solutes than the surrounding environment or their extracellular fluid (ECF) Risk of gaining too many salts through diffusion or losing too much water from osmosis (water tends to move though osmosis from the intracellular space to the extracellular space) b - Freshwater Cells poten

FORMS OF BIOLOGICAL ENERGY Energy - Ability to do work Potential energy - Energy to be used up, trapped in a system Kinetic energy - Energy of movement Feces or Urine - Energy that cannot be processed Radiant energy - Energy received or given off by sunlight Mechanical energy - Energy that can be used to move Electrical energy - Energy from movement of ions down a charge gradient Thermal energy - Energy from movement Chemical energy - Energy held in chemical bonds digestion Bold the incorrect p

Filter feeding to obtain particles Other one to obtain nectar Key to transfer resources into energy Energy flow Energy imp for supporting cellular metabolism and processes - example cellular respiration Once have nutrients in body, they are processed and some energy can be released spontaneously and that release energy used by organism to maintain its life to grow - these cost energy so need these energy from nutrients Energy in chemical bonds Animals and Energy Any ability to do work Transfer

Energy Flow Nutrients Energy Plants use photosynthesis to capture sunlight (radiant energy) Consumers obtain energy differently Herbivores eat plants to obtain energy Carnivores eat herbivores and other animals to obtain energy Cellular Processes Some chemical reactions are spontaneous and release energy (chemical/thermal) but is also used to grow Supporting cellular processes Animals and Energy Energy = ability to do work Biological Processes - Transfer between different energy forms (in anim

Connections to muscles and locomotion - foot propel diving to cause less drag Skeletal muscle - group of muscles that help generate motion and control locomotion. It is a conscious control. Vertebrate Sheet Muscles Are consciously controlled in animals Smooth muscles are in the walls of the visceral organs. make blood vessels wider or narrow. involuntarily controlled. Homeostatic and autonomic systems that control these. Cardiac muscle related to heart. Heart walls build out of this muscle. I

Animals and Energy Energy - Ability to do work Potential Energy - Energy to be used up; trapped in a system Kinetic Energy Biological Processes Vertebrate Skeletal Muscles - Types Skeletal - Control locomotion and any movement that can be consciously controlled (voluntary muscles) Smooth - Control of the walls of hollow organs and passages/vessels (involuntary) - no striations like in skeletal muscle Cardiac - In the heart for pumping blood throughout the body and maintaining blood pressure Vert

DIVERSITY OF LOCOMOTOR STRUCTURES Simple solutions are usually structures organized of muscle fibers (these are longitudinal muscles) On any one side that the muscles shortens (contracts), the other side does the opposite (it relaxes) This creates an undulating motion The combination of contracting and relaxing the same region evolved early on when animals were terrestrial Circular muscles are muscles along the entire rim of the muscle, and when these contract, they can contract and expand, caus

CELLS AS CIRCUITS Cells can be electrically neutral because of membranes that exist in the body Your cells are electrically neutral unless something triggers the ions inside to change their concentrations Ohm’s Law V = IR V - Potential energy generated by separate charges I - Flow (current) of energy from one point to another R - Resistance to flow Electrical potential is determined by the flow of energy from one point to another as well as the resistance of this flow Resistors in a cell could b

Cells as Circuits Ohm’s Law V - Potential energy generated by separate charges (membrane potential) I - Flow (current) of energy from one point to another, depends on... Length constant of the membrane (proportional to membrane resistance) Higher the resistance, higher the current Radius (inversely proportional to membrane resistance) Capacitance (proportional to membrane area and thickness or quantity of charge needed to create a potential difference between 2 surfaces of the capacitor) R -