Download Understanding Human Metabolism and Body Temperature Regulation: Terms and Definitions and more Quizzes Animal Anatomy and Physiology in PDF only on Docsity!
Metabolic Rate
Indicates energy expenditure (how much you are burning) Measured in calories (calorie - heat required to raise 1gm H2O 1 degree centigrade) TERM 2
Calories varies according to level of
activity
DEFINITION 2 Minimum expenditure: 1650 calories/24 hours (average)- varies depending on person Maximum expenditure: 6000 - 7000 calories/24 hours TERM 3
Primary factors that affect metabolic
rate
DEFINITION 3 Activity level: how hard a person is working Hormones: Thyroid hormones - catecholamines (epinephrine, norepinephrine) TERM 4
Lowest essential metabolism: basal metabolic
rate (BMR)
DEFINITION 4 bare minimum - Just lying around (just sitting) Metabolism independent of other factors"Average" BMR 70cal/hr (just to stay alive)BMR can be used to compare metabolism in different people TERM 5
Body Temperature
DEFINITION 5 Tissue metabolism generates heat Body temp usually maintained fairly constant (37 degrees C) Rationale for maintaining (fairly) high temp - allows sudden rapid activity; needs less time to "warm up" before moving (activity not dependent on enviornmental temperature) Basic goal: Balance heat production with heat loss/ gain
Types of heat loss (air temp less than 37
degrees C)
Radiation - directly losing heat from body to air (60%) - electromagnetic energy Conduction - direct contact with other surfaces (18%) Evaporation - heat dispersed when water on skin is converted from liquid to gas (22%) - sweating; evaporation is accelerated by "convection (air moving past your skin) TERM 7
Types of Heat Gain (air temp is greater than
37 degrees C)
DEFINITION 7 Radiation (from enviornment into body) Conduction (contact with air, other surfaces that are warmer than body) Evaporation - only other way to lose heat if air is warmer than the body - harder to evaporate when humid because air is full of moisture TERM 8
Skin Blood Flow
DEFINITION 8 If core temp is to high: decrease sympathies to skin --> vasodilation --> disapates body heat to airIf core temp is to low: increase sympathetics to skin --> vasoconstrict --> conserves internal heat TERM 9
Plexus of blood vessels
DEFINITION 9 Lie beneath skinSkin = pale when cold= red when hot TERM 10
Plexus of blood vessels beneath skin
regulated by sympathetic nervous system
DEFINITION 10 Increases sympathetic activity: vasoconstriction (cold)Decrease sympathetic activity: vasodilation (hot) -no parasympathetic system-
If body temperature increases
Turn-on sympathetics to sweat glands; increase sweating (acetocoline - sweating hormones) Decrease sympathetics to skin blood vessels; allows vasodilation (norepiephrene) Inhibit shivering; decrease hormones that stimulate tissue metabolism TERM 17
If body temperature decreases
DEFINITION 17 Turn-off sympathetics to sweat glands; decrease sweating Increase sympathetics to skin blood vessles; cause vasoconstriction Initiate shivering; increase hormones that stimulate tissue metabolism TERM 18
Ingestion
DEFINITION 18 Mastication; breaks-up food; mixes with saliva (chewing) Deglutiion: half voluntary, half involuntary (swallowing) Movement through GI tract: has to go through at the right speed TERM 19
Movement through the GI tract
DEFINITION 19 Smooth muscle layers - longitudinal (outer) and circular (inner) layers GI motility (2 types): segmentation (mixing)... circular layer (mixing food) - peristalisis (propulsion)... longitudinal layer (moving along GI) Control of motility
- sympatetics.......... turn down motility- parasympathetics...... turn up motility TERM 20
Carbohydrates
(sugar)
DEFINITION 20 Ingested as polysaccarides - this chain has to be broken downDigested into monosaccaridesPrimary enzyme and digestion site AMYLASE - saliva; pancreas into upper small intestine
Proteins
Ingested as plypeptide - chain of amino acidsDigested into Amino AcidsPrimary enzyme and digestion site PROTEASES - stomach (10 - 20%); Pancreas into upper small intestine (80 - 90%) TERM 22
Fats (glycerol)
DEFINITION 22 Ingested as TRIGLYCERIDESDigested into fatty acids and monoglyceridePrimary enzyme and digestion site LIPASE; pancreas into upper small intestine TERM 23
Fat......Role of bile
DEFINITION 23 Bile - synthesized in liver, stored in gall bladderHelps break up (emulisify) fat globules...... allows lipase to digest fats more effectively
