Physiology is the investigation of the functioning of a living organism and its component parts. It is an integrative science, studying how the different organ, tissue and cellular systems co-ordinate in the intact organism. A changing external environment (aquatic or terrestrial) usually presents the greatest problem for animals and plants and the module will explore physiology in relation to environmental conditions.
This module begins with a discussion of problems faced by animals and plants living in a variety of environments and describes the "solutions" that have evolved to overcome these issues. The lectures expand on other themes that form the basis for investigating animal and plant physiology, such as control, integration of function, metabolism and growth.
The first set of lectures in the control section describes the major features of animal sensory physiology (e.g. function and organisation, neurons, action potentials and synapses of nervous systems and components of a sensation, sensory pathways, receptor classification and neural circuitry). Plant sensory physiology and plant positioning is also discussed (e.g. gravitropism - response to gravity, phototropism - growth response to light, thigmomorphogenesis - growth response to mechanical action). The module then explores chemical communication (types of secretion, generalized animal exocrine and endocrine gland structure). The endocrine system of an animal is closely associated with the nervous system, and neurons and hormones often work together to control a single process. Animal hormones influence behaviour via sensory mechanisms, activity in the central nervous system and effector mechanisms. Plant hormones are involved in the control of growth and development. Therefore, a set of lectures will explore the basis of hormonal activity (structure, mechanisms of action, transport and elimination/degradation) and the structure and function of key animal endocrine glands e.g. pituitary, thyroid and adrenals. The final lecture set in this block describes the motor systems in animals that produce adaptive responses. Animal motor systems consist of motor organ (muscles) and the neural circuits that control them.
The integration section starts with an assessment of the key elements of fluid transport in animals and plant. The animal circulatory system (basic parts and diversity, the concept of open and closed circulation, structure of the heart, arteries, capillaries and veins) and the concept of cardiovascular control is explored. The transport of water and solutes is considered in plants (e.g. xylem and associated cells - tracheids, vessel elements, fibres, parenchyma and phloem). An understanding of transport systems logically allows a consideration of respiration in animals (i.e. the basic components of a gas-transfer system, transport of gases in blood, functional anatomy of gas-exchange and function of haemoglobin). The structure and function of lungs, control of respiration and types of breathing in animals are also examined. Plants do not have a pumping mechanism for moving gasses and rely on diffusion and bulk flow. Transpiration, evapotranspiration, translocation and stomatal regulation of gas exchange are considered in plants.
The module will also review the relationship between ionic and osmotic balance (osmosis/osmotic concentration and water/ion budgets) and mechanisms used by animals and plants to respond to change in their environment. The effect of temperature change on physiological and behavioural processes is also investigated.
The lecture course concludes with a study of heterotrophy (organisms which obtain their nutrients from the environments, e.g. animals) and autotrophy (organisms which can make their own nutrients e.g. plants).
The practical sessions with living animals (behavioural physiology in beetles) and plants (phloem transport and stomatal movements) develop the key issues that are raised in the lectures. There are no dissections.