BIOL1008 Study Guide - Final Guide: Axon Terminal, Sprain, Joint Dislocation
Temperature
Nervous systems
Central nervous system
oBrain
oSpinal cord
Peripheral nervous system
oPeripheral nerves
oSensory system
Autonomic nervous system (ANS)
oSympathetic
oParasympathetic
Enteric nervous system
Skin structure
Outside layer- thin and mostly squamous cells
(epidermis)
Inner layer- thick and contains most living skin
components (endoderm)
Metabolism and body temperature
Body temperature is highly regulated over a
wide range of external temperatures by the ANS
Between the lower critical (LCT) and upper
critical (UCT) external temperatures, the
regulation is passive
Above UCT
oSweating or other processes are initiated
to lose heat
oMore blood goes to the skin surface which radiates heat away
Below LCT
oMetabolic rate increases to generate more heat
oLess blood goes to the skin surface to prevent
heat loss and more blood to internal areas
Heart supplies oxygen and blood to muscles and organs
Red blood cells carry oxygen, so must be moved around
body and to lungs
Heart increases beat and amount of blood per beat
(stroke volume) to ensure enough oxygen is reaching
target organs
When you exercise, heart rate goes up as the muscles
require more oxygen
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Change in blood flow to various organs with exercise
Greater
demand of
blood from
muscles
Often about the
proportion
rather than the
amount of
oxygen to each
organ
You increase
the intake of
oxygen so other
organs also get
more oxygen
Less blood to
skin
Same to brain
Summary of heat regulation and body temperature in endotherms
Core body temperature (brain and thorax) regulated within narrow range (37 1C)
Metabolic rate varies below or above critical range to vary heat production
Within critical range, circulation or insulation changes to control Tbody by changing
heat movement to skin surface
Insulation against heat loss
External
oClothes
oHair
Internal
oLipid and its distribution
oCirculation
Circulatory changes
Vasodilation (Parasympathetic stimulation) in skin occurs to remove heat (increase
convection)
Vasoconstriction (sympathetic stimulation) in skin occurs to conserve heat (decrease
convection) by closing off blood vessels to skin
Piloerection (increased insulation) caused by sympathetic action (“goose bumbs”)
Change in blood flow causes change in skin temperature
Hypothermia
Reduction of body temperature below set point
Exposure to cold environments (air or water)
Unable to produce enough energy to maintain body temperature
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Body temperature begins decreasing, but not necessarily terminal
Controlled hypothermia used in surgery
Humans have a capacity to survive lower temperatures- down to around 17C
Hyperthermia
Uncontrolled hyperthermal conditions
oExercise- metabolic heat production and dehydration
oExposure- external environment heat gain and dehydration
Fever- regulated variation in body temperature set point, body resets thermostat to
be higher to fight disease by killing some bacteria and increasing chemical reactions
associated with the immune system
Can only go up by 5C before dying
Temperature set point
Control in hypothalamus, although peripheral sensors
have some role- hypothalamus manages input from
the peripheral skin sensors and central environment
Controller senses difference between Tset and Tbody
Results in various processes that either heat or cool
body, most processes regulated through the
autonomic nervous system
Set point is different for individuals
Response of temperature-sensitive hypothalamic neurons
Determine the difference between the set point and
the information coming in from all the peripheral
senses
More neurons if goes above set temperature as it is more crucial to maintain
Energy sources (ATP) for muscular contraction
Anaerobic
oProducing lactate, creatine
oOn high exercise diet program
oOnly for very short sprints (lactate lasts longer but creates lactate acid)
Aerobic
oUses mitochondria
oTakes oxygen and converts it to ATP and CO2
Experimental methods
Frequency histogram is used to determine mode
Need to sort data (high to low) to obtain midpoint for
median value
Mean is sum of all values divided by number of observations
Testing for differences between populations/ individuals
Need to ask whether means or variation are different between populations
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Document Summary
Peripheral nervous system: peripheral nerves, sensory system. Autonomic nervous system (ans: sympathetic, parasympathetic. Outside layer- thin and mostly squamous cells (epidermis) Inner layer- thick and contains most living skin components (endoderm) Body temperature is highly regulated over a wide range of external temperatures by the ans. Between the lower critical (lct) and upper critical (uct) external temperatures, the regulation is passive. Above uct: sweating or other processes are initiated to lose heat, more blood goes to the skin surface which radiates heat away. Below lct: metabolic rate increases to generate more heat, less blood goes to the skin surface to prevent heat loss and more blood to internal areas. Heart supplies oxygen and blood to muscles and organs. Red blood cells carry oxygen, so must be moved around body and to lungs. Heart increases beat and amount of blood per beat (stroke volume) to ensure enough oxygen is reaching target organs.
