PHYSIOL2130 - Human Physiology

Physiology Module 1 --> study of function in living organisms --> mechanisms which they control internal environment --> explains physical & chemical factors of function and disease Homeostasis <-- maintenance of internal environment Internal environment <-- interstitial fluid & blood plasma External environment <-- outside body, contents digestive, respiratory & urogenital tracts --> maintains homeostasis via (+) & (-) feedback Negative Feedback Control Systems --> all of them contain same c

Physiology Module 1 --> study of function in living organisms --> mechanisms which they control internal environment --> explains physical & chemical factors of function and disease Homeostasis <-- maintenance of internal environment Internal environment <-- interstitial fluid & blood plasma External environment <-- outside body, contents digestive, respiratory & urogenital tracts --> maintains homeostasis via (+) & (-) feedback Negative Feedback Control Systems --> all of them contain same c

Physiology Module 1 --> study of function in living organisms --> mechanisms which they control internal environment --> explains physical & chemical factors of function and disease Homeostasis <-- maintenance of internal environment Internal environment <-- interstitial fluid & blood plasma External environment <-- outside body, contents digestive, respiratory & urogenital tracts --> maintains homeostasis via (+) & (-) feedback Negative Feedback Control Systems --> all of them contain same

Fluids Module 2 -> Internal environment bathed in fluids Body Fluids Compartments Intracellular (ICF) Inside cells Extracellular (ECF) Interstitial fluid Plasma Plasma - Pale yellow fluid, 92% H2O, 8% (proteins, ions, gas, nutrients & waste) -> colloidal solution (suspended subs that doesn't settle) Chemical Composition of Bodily Fluids -> huge difference in ion concentrations between plasma & interstitial fluid vs intracellular fluid -> small difference between plasma & interstitial

Cells Module 3 Cell membrane selectively permeable -> Carbohydrates for cell recognition -> Cholesterol for stability & immune response -> Associated enzyme act as catalysts for reactions Carriers - Transport molecules across membrane Identity Markers - Distinguish between self & foreign cells Pores - Allows water soluble subs in cell Enzyme - Chemical reactions, breakdown of molecules Receptor - Attach hormones & neurotransmitters Diffusion - Electrically charged molecu

Nerves Module 4 Excitable Cells - Can use resting potential to generate electrochemical impulse (action potential) --> Ex. nerve & muscle cells Action Potential--> rapid reversal of resting membrane Strong depolarization at axon hillock triggers of Na+ Na+ rushes in Membrane depolarizes to +35mV Na+ channels inactivate, K+ open K+ rushes out Membrane re-polarizes +35mV --> 7-0mV K+ rushes out hyper polar -90mV K+ closes channel, slowly back to 7-0mV Voltage Gated Na+ Channel V--> depolariza

Muscles Module 5 Biological machines that utilize chemical energy from breakdown and metabolism of food to perform useful work 600+ muscles Perform 3 main functions Movement Heat production Body support, posture Skeletal Muscle Whole muscles made up of bundles of fasciculi Each fascicle made up of groups cells or fibres Each muscle cell --> bundles myofibrils Each myofibril contains thick and thin myofilaments Thin <-- protein actin with troponin and tropomyosin Thick <-- myosin protein -->

Nervous system Module 6 Central Nervous (CNS) -> brain & spinal cord Peripheral Nervous (PNS) -> nerves that goes to muscles & organs Basic Structure of the Brain Left Hemisphere - Send signals to activate muscles on the right side of body Right Hemisphere - Sensory information from right side goes to left hemisphere (vice versa) Cerebellum - Responsible coordinated movement (above brain stem) Brain Stem -> controls basic functions like heart rate and respiration -> made up of mi

Sensory System Module 7 Transduction Environment --> how external stimuli detected by sensory receptors Environmental Stimuli Stimulus must be detected by sensory receptor Different environmental stimuli, therefore different receptors needed Mechanical Stimuli --> Touch, pressure, vibration, sound, proprioception (muscle sense) Chemical Stimuli --> Taste, pain, odours Electromagnetic Stimuli --> Light Other Stimuli --> Gravity, motion, acceleration, heal Adequate Stimulus Some receptors detec