Test Bank - Human Physiology: An Integrated Approach 8th Edition by Dee Unglaub Silverthorn - Complete, Elaborated and Latest Test Bank
Test Bank for Human Physiology: An Integrated Approach 8th Edition by Dee Silverthorn, Chapter 1-26 | All Chapters
2024/25 Test Bank for Human Physiology: An Integrated Approach 8th Ed by Dee Silverthorn. All Chapters Covered| Fully Verified Answers with Rationales| 978-0134605197| A+
All for this textbook (69)
Written for
University of Pretoria (UP)
Applied and Pathophysiology (FLG332)
All documents for this subject (4)
Seller
Follow
micaeladj10
Content preview
FLG 332 Copyright Micaela de Jager
Unit 1 – Body Temperature
LECTURE 1 – THERMOREGULATION
BODY TEMP
Significance of thermoregulation
Why do we need to regulate internal body temperature?
− Homeostatic mechanisms that keep body temperature within acceptable limits
o Regardless of environmental conditions
− NB = enzymes operate over a relatively narrow temperature range
Factors influencing the body temp:
1. Age
• infants vary according to environment
• In children ↑(0.5°C) than adult
• Old age ↓the body temperature
2. Sex/Gender
• Females ↓than males
3. Diurnal variation
• min values in am
• max values pm
4. Meals
• ↑after meals
5. Exercise
• heat production from skeletal muscles can ↑
6. Menstrual cycle
• ↑during ovulation
7. Sleep
• ↓by 0.5°C
8. Emotions
• body temp↑
MICAELA DE JAGER 1
,FLG 332 Copyright Micaela de Jager
Body temperature range is narrow, within 1 degree
36.°C –37.5 °C
Temp influences metabolic processes:
↑temp : destroys protein Corrected by homeostasis
↓temp : inhibits enzymatic reactions = prevent biochemical process
Body is divided into a warm internal core and a cooler outer shell:
Core T Shell T
temp of deeper tissues temp of skin
o relatively constant o fluctuates substantially
- 36.5 °C–37.5 °C - 20 °C–40 °C
o metabolism works optimum o depends on surroundings
o shell insulates heat within the core
• Various parts of the body are at different T
• The extremities are generally cooler than the rest of the body
• T of scrotum is carefully regulated at 32°C
• Rectal T is representative of temp at core of the body and varies least with changes in environmental T
• Oral T < rectal T (normally 0.5°C ↓)
Affected by: ingestion of hot/cold fluids
gum chewing
smoking
mouth breathing
THERMOREGULATION
Skin plays major role
Maintenance of a constant body T
Balance between heat gain and heat loss in body:
More heat gain than loss = T↑
Less heat gain than loss = T↓
MICAELA DE JAGER 2
,FLG 332 Copyright Micaela de Jager
Temp regulation
Heat gain Heat loss
Gained by: Lost by:
- Radiation and conduction - Radiation, conduction and convection
- Muscular exercise - Vaporization of water in the respiratory
- Assimilation of food passages and on the skin (sweat)
- Thermogenic effect of hormone - Evaporative cooling
- All vital processes that contribute to BMR - Small # are removed in urine and faeces
HEAT GAIN MECHANISMS
Biochemical reactions contribute to body heat production
Ingestion of food ↑heat production – sympathetic discharge ↓during fasting and is ↑by feeding
Skeletal muscle contraction e.g. during exercise
Heat production can be varied by endocrine mechanisms in the absence of food intake or muscular exertion:
a) Epinephrine and NE - produce rapid but short-lived ↑in heat production
b) Thyroid hormones - produce slowly developing but prolonged ↑
Brown fat (infants) – highly metabolic and has a thermogenic function
Metabolism: Major source of internal heat generation
7% increase in metabolic rate ⇒ 0.55°C ↑in body temp
metabolic heat production by muscle contractions
↓body temp ⇒ somatic motor neurons
skeletal muscle contractions (agonist and antagonist muscles)
metabolism in muscles
heat production (↑body T )
degree of stimulation varies with demand
if heat-gain center is extremely active, you begin to shiver
shivering ↑rate of heat generation up to 400%
2. Non-shivering thermogenesis
metabolic heat production by fat
↓body temp ⇒ sympathetic neurons & hormones
metabolism in brown fat
heat production (↑body T )
MICAELA DE JAGER 4
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller micaeladj10. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.97. You're not tied to anything after your purchase.