A&P Ch.17 Flashcards
vasoconstriction
decreases blood flow through the dermis and therefor decreases heat loss.
vasodilation
in the dermis increase blood flow to the body surface and loss of heat to the environment.
eccrine sweat glands
secrete sweat (water) onto skin’s surface, and excess body heat evaporates the sweat (ex. hot frying pan is cooled as its heat vaporizes water)
heat is lost by which 3 tracts?
Respiratory tract the warmth of respiratory mucosa evaporates some water from the epithelial surface.
Urinary and digestive- When excreted, urine and feces are at body temperature and their elimination results in a small amount of heat loss.
small amounts of heat are lost in what is called
sensible water loss, however, insensible water loss is a minor source of heat loss.
Heat exhaustion
Is caused by excessive sweating with loss of water and salts, especially NaCI (sodium chloride)
Symptoms of heat exhaustion
Normal body temperature, rapid and weak pulse, low BP due to fluid loss, dizziness, vomiting, and muscle cramps. Treatment is rest, consumption of salty fluids or fruit juices in small amounts and inrervals.
Heat stroke
Life-threatening and may affect elderly or chronically I’ll people on hot, humid days, or other people who experience too strenuously in such weather.
As fluid loss increases, sweating stops to preserve body fluid and the body temp rises rapidly. T or F
T
Symptoms of heat stroke
Dry skin…loses consciousness due to high temp on the brain.
Treatment IV fluids, cool water
metabolism
All of the physical changes and chemical reactions that take place within the body; include anabolism and catabolism.
Total of all reactions in the body.
energy-releasing action
cell respiration
energy-releasing reactions
protein synthesis or dna synthesis for mitosis
The process that releases energy from food to produce ATP & produces heat as one of its energy products
cell respiration
Although cell respiration takes place constantly, many factors influence the rate of this process. T or F
T
Which hormone produced by the thyroid gland increases the cell respiration rate and heat production
thyroxine (and t3), which is the
The secretion of thyroxine is regulated by
the body’s rate of energy production, the metabolic rate itself
What happens when the metabolic rate decreases?
the thyroid gland is stimulated to secrete more thyroxin
what happens when thyroxine increases the rate of cell respiration and raises the metabolic rate
neg feedback mechanism inhibits further secretion until metabolic rate decreases again
________is secreted whenever there is a need for increased cell respiration and is probably the most important regulator of day-to-day energy production. pg 396
thyroxine
Plays a role in body temp
thyroxine, epinephrine ( heart, skeletal, liver- sympathetic stimulation also increases the activity of these organs), stress, intake of food, organs that are normally active (producing ATP) are significant sources of heat when the body is at rest, liver continuously produces ATP & 20% of body heat, peristalsis, digestive organs, increased metabolic energy of digestive tract during food intake,
higher temperatures increase the
metabolic rate, which increases heat production and elevates body temp further
normal muscle tone requires atp, the heat produced is about 25 percent of total body heat at rest
skeletal muscles
always metabolically active, produces as much as 20% of total body heat at rest
liver
Increases activity of GI tract, increases atp and heat production
food intake
blood flow through the skin influences the amount of heat lost by the process of
radiation, conduction and convection
How does sweating decrease temperature?
by evaporation, but it requires a loss of water, which may lead to dehydration.
The amount of heat that is lost is determined by
blood flow through skin and sweat glands
heat is transformed to cooler objects NOT touching the skin
conduction
is the loss of heat to cooler air or objects, such as clothing, that touches the skin.
Convection
means air currents move the warmer air away from skin’s surface and facilitate the loss of heat; this is why the fan feels cooler or wind chill factor
hypothalamus
responsible for the regulation of the body temperature
Cellular respiration involves 3 major stages
krebs cycle, and cytochrome transport system
metabolism
encompasses all of the reactions that take place in the body, which is divided into two parts. (anabolism and catabolism)
Anabolism
Synthesis or “formation” reactions. The bonding of small molecules to form larger ones. Requires energy (atp) and are catalyzed by enzymes
Catabolism
Release energy ro sythesis atp (the heat energy released discussed in previous chapters) and decomposition. The breaking of the bonds of larger molecules to form smaller ones.
The apt formed is used for energy requiring anabolic reactions such as DNA replication that processes mitosis.
Glyolysis
Anaerobic process
Krebs
Cytochome
Glucose
Carbs
amino acids
proteins are made of smaller molecules called amino acids
metabolism
total of all actions that take place in the body.
What does metabolism reactions include?
the energy releasing ones of cell respiration and energy requiring ones such as proteins synthesis or DNA synthesis for mitosis.
normal range of temperature
96.5 to 99.5, with average oral temp of 98.6
In 24 hour period temp fluctuates how many degrees
1 to 2 degrees with lowest temp occurring during sleep
Infants
have more surface area (skin) relative to volume and lose heat more rapidly
cell respiration
the process that releases energy from food to produce ATP, also produces heat as one of its energy products.
epinephrine
increases rate of cell respirations esp. in heart, liver, and skeletal muscle.
The _______in the dermis may constrict or dilate
arterioles
conduction
is the loss of heat to cooler objects, such as clothing, that touches the skin
convection
means that air currents move the warmer air away from the skin surface and facilitate the loss of heat (fan feels good on hot days)
Responsible of body temperature
Hypothalamus. Neurons detect changes in temp of blood that flows to brain and temp receceptoes in skin provide info about the external temps
pyrogens
substance that may cause a fever. Also includens bateria, foreign proteins, and chemical released during inflammation.
What are inflammatory chemicals called
endogenous (“generated within) pyrogens. Raises the setting of hypothamic thermostat. The hypothalamus stimulates responses by the body to raise body temp to his higher setting. Pg 399
Antipyretic
Lowers fevers
During frostbite fingers, nose, and ears are most effected by prolonged exposure to the cold. If body fluid freezes, ice crystals may destroy capillaries and tissues because water expands when it freezes), blisters form, gangrene, tissues dies
T
Low body temp below 95
Hypothermia
Hypothermia symptoms
Confused, slow speech, drowsiness, lack of coordination, decreased or slow heart rate as well as breathing, coma, death
Elderly and quadriplegic who have no sensation are at a high risk
Ketosis
Fats and proteins become energy sources and ketone accumulate blood faster than cells can utilize. Lower physical due to ketone that are organized acids. As kidney excrete keyones buy they must also excrete more water as a solvent, which leads to dehydration.
Ketoacidosis
Diabetics may get this leads to confusion, coma, death. Reversal requires a carbohydrate energy source and insuline.
Glucose is the raw materials for synthesis of another important monoosaccharideis called
Penrose sugars that are part nucleic acids
Any glucose in excess of immediate energy needs or need for penthouse sugars is covered to what?
Glycogen in liver and skeletal system.
Left over glucose is converted to
Fat
GLYCOGEN
A polysaccharide tjst is storage form for excess glucose in liver and muscles
Thiamin function
Conversion of privacy acid to acetyl coa
Vitamin a function
Sythesis of RHODOPSIN
CALCIification FOR BONE
MAINTENANCE OF EPITHELIAL
Vit d
Absorption of calcium and phosphorus in small intestine
Contributed to immune responses, action of insuline preservation of muscle mass and strength
Vit E
Antioxidant- prevente destruction of cell membranes
Helps WOUND healing and detoxifying ability of the liver
Vit k
Sythesis of prothrombin and other clotting factors
Formation if bones and teeth
Neuron and muscle function
Blood clotting
Calcium
Contributed to osmotic pressure of body fluids
Nerve impulse transmission and muscle contraction
Part of BICARBONATE BUFFER
Sodium
