Lecture31metabolism not required
Download as PPT, PDF0 likes426 views
This lecture discusses metabolism and breathing. It addresses the relationship between oxygen uptake, energy from food, and blood flow. The lecture introduces metabolism and the respiratory, circulatory, nervous systems. It covers factors that affect energy balance and expenditure like rate of work, posture, and method of work. Measurement of oxygen usage, heart rate and applications to work physiology are also summarized.
Lecture31metabolism not required
- 1. 09/10/99 LLeeccttuurreess 3311:: MMeettaabboolliissmm aanndd BBrreeaatthhiinngg Readings: Chapanis (1996, chapter 5) Acknowledgement: In addition to the Chapanis text, portions of this lecture were extracted from Other Ergonomics texts
- 2. QQuueessttiioonnss ttoo bbee aaddddrreesssseedd l What is the relationship between oxygen uptake, burning of energy – (digestion and use of the energy in food), l and blood flow – (heart rate)? l What factors affect the energy balance of the body?
- 3. IInnttrroodduuccttiioonn l Breathing and Metabolism are basic functions that allow us to survive. l We need to design tasks that are not too physically demanding, and that have enough rest breaks built into them. l Biochemistry of metabolism is well understood, but beyond the scope of this course (addressed in third year)
- 4. NNeerrvvoouuss SSyysstteemm l Central Nervous System l Peripheral Nervous System l Autonomic Nervous System
- 5. CCeennttrraall NNeerrvvoouuss SSyysstteemm l includes the brain and spinal cord l receives information from our various senses, l transmits it to the central nervous system for control and decision-making
- 6. PPeerriipphheerraall NNeerrvvoouuss SSyysstteemm l includes the cranial and spinal nerves l regulates involuntary functions of – cardiac muscles, blood vessels, digestion, and glucose release by the liver l is responsible for the "flight, fright, or fight” reactions that we experience in emergency or dangerous situations
- 7. RReessppiirraattoorryy SSyysstteemm l It provides oxygen for energy metabolism l It dissipates the by-products of metabolic action
- 8. CCiirrccuullaattoorryy SSyysstteemmss l The main circulatory system – consists of the blood vessels and capillaries that are richly distributed throughout the human body. – provides the means by which these products are transported between lungs, hearts, muscles, and other body cells.
- 9. EEnneerrggyy BBaallaannccee EEqquuaattiioonn l I = M + W + S l where l l I = energy supplied to the body by food or drink l M = metabolic energy l W = work performance l S = energy store in the body
- 10. SSiiggnniiffiiccaannccee ooff ““wwoorrkk pphhyyssiioollooggyy l Safety & health l Methods evaluation l Job evaluation l Rest scheduling l Job specification l Employee selection
- 11. MMeettaabboolliissmm l Definition – Transformation: chemical energy work l – kilocalorie (kcal) – 1 kcal = 1000 cal = 1 Cal = heat required to raise 1 liter H2O 15 °C 16 °C
- 12. MMeettaabboolliissmm ((1)) carbohydrates fats proteins glucose fatty acids amino acids pyruvic acid acetic acid deaminated AAs glycolysis oxidation deamination digestion
- 13. MMeettaabboolliissmm ((22)) carbohydrates fats proteins glucose fatty acids amino acids pyruvic acid acetic acid deaminated AAs glycolysis oxidation deamination digestion CO2 H2O energy
- 14. MMeettaabboolliissmm ((33)) carbohydrates fats proteins glucose fatty acids amino acids pyruvic acid acetic acid deaminated AAs glycolysis oxidation deamination digestion CO2 H2O energy adenosine triphosphate adenosine diphosphate + PO4 creatine + PO4 creatine phosphate
- 15. MMeettaabboolliissmm -- CCoommppoonneennttss Total Metabolism = Basal Metabolism (life support) + Activity Metabolism (work, leisure)
- 16. BBaassaall MMeettaabboolliissmm l Male ( 70 kg ): 1700 kcal/day @ 1.2 kcal/min l Female ( 60 kg ): 1400 kcal/day @ 1.0 kcal/min l Factors: – Sex – Size – Age
- 17. MMaaxxiimmuumm AAeerroobbiicc PPoowweerr ((MMAAPP)) Factors affecting MAP l Age l Sex l Heredity l Physical conditioning
- 18. FFaaccttoorrss AAffffeeccttiinngg EEnneerrggyy EExxppeennddiittuurree l Rate of work l Posture of body l Method of work
- 19. MMeeaassuurreemmeenntt l O2 uptake l Respiration rate (+ vital capacity) l Heart rate l Activity standards
- 20. OOxxyyggeenn UUssaaggee l People are biologically adapted to breathing air that contain 21% oxygen by volume at sea level. l Too little oxygen (hypoxia) induces sleepiness, headache, inability to perform simple tasks l In the extreme lack of oxygen leads to loss of consciousness and death.
- 21. AApppplliiccaattiioonnss ooff WWoorrkk PPhhyyssiioollooggyy l Calculate rough energy balance l Measure physical workload l Adjust physical demands of work as necessary
- 22. QQuueessttiioonnss aanndd EExxeerrcciisseess l Why does oxygen uptake tend to increase when heart rate increases? l Why does the body need oxygen? l Why does dieting sometimes make it more difficult to lose weight in the future? l What is a comfort zone and why should we be designing for it?