Homeostasis/Homeokinesis Flashcards
Homeostasis and Homeokinesis are ___ feedback systems
Negative feedback
What are the physiological control mechanisms of homeostasis
water balance and ionic balance
Homeostasis is defined as:
the ability of the body to maintain a stable internal environment through regulatory processes
Although arterial pressure oscillates over time, mean pressure:
remains consistent
Control Systems
Stimulus > Sensor > Control Center > Effect > Homeostasis
Failure of a biological control system results in:
disease; or failure of any component of a control system results in a disturbance of homeostasis
Example of failure of a biological control system is type 1 diabetes. There is damage to beta cells in the pancreas, causing insulin to no longer be released in the blood. Based on the control system diagram, which part failed?
Represents a failure of the “effector”
What is the primary feedback system in place to maintain homeostasis in our body?
negative feedback
What are some examples of positive feedback?
child birth, breast feeding, blood clotting
What is positive feedback?
keeps pushing body to the extremes
How common is positive feedback in humans?
very rare
Describe what occurs when there is failure within a component of this system designed to maintain homeostasis.
In failure, response would go right, towards death, instead of left, towards normal
If you are not adequately hydrated, performance will increase/decrease?
decrease
A loss of ____% body water will impair exercise performance:
1-2
Total Body Water = __ + ___
Internal Cellular Fluid + External Cellular Fluid
Internal cellular fluid accounts for __ of total body water
2/3
external cellular fluid accounts for ___ of total body water
1/3
When our blood volume is impaired, what happens?
everything starts to go downhill
Water in sweat is pulled from the:
plasma
While sweating, blood becomes more:
osmotic
When blood becomes more osmotic, that causes fluid from __ to move into the blood
tissue
When osmotic pressure of tissue fluid is increased, fluid osmotically:
moves out of cells into tissue
2 basic types of bonds:
Ionic and Covalent
Functions of ions:
membrane potential, nerve impulse, synaptic transmission, osmotic pressure
What happens during nerve impulse/synaptic transmission?
ions will cross the membrane, causing a change in membrane potential (i.e. carry a signal)
H+ is primarily dependent on 3 things:
exercise intensity, amount of muscle mass involved, duration of exercise
Acidosis (too low pH):
CNS dysfunction, cardiovascular dysfunction
Alkalosis (too high pH):
cardiac dysfunction
Acid Base Balance is based on:
concentration of H+
pH of neutral blood:
7.4
pH of chemical neutrality (water):
7.0
In exercise, pH may drop to 7.2 and negative feedback is essential. if pH is too low, the individual will:
fatigue quickly
What is lactic acid?
H+ and lactate
Why is lactate still thought to cause acidosis?
most texts do not provide and explain the chemically balanced reactions occurring during metabolic acidosis. This incomplete description of acidosis in textbooks has led to the acceptance of the misconceptions of lactate
Lactate production is a ___ of cellular acidosis and ___ the causes of acidosis
consequence, not
lactate is a temporary ____ or ___ to the cells elevated accumulation of protons during high-intensity exercise
neutralizer, buffer
Lactate production is __ for contracting muscle
good
Creatine Phosphate (CP) is associated with which kind of exercise?
Anaerobic
Glycolytic Pathway (Glycolysis) is associated with which kind of exercise?
Anaerobic
Aerobic exercise is associated with what cycle?
citric acid cycle
Glucose + NAD > 2 Pyruvate + 2 ATP + 2NADH, 2H+ > 2 Lactate + 2H+
Anaerobic
Glucose + NAD > 2 Pyruvate + 2 ATP + 2 NADH, 2H+ > Krebs + ETC and No lactate
Aerobic
Buffers:
plasma proteins, hemoglobin, carbonate system in acidosis
Plasma proteins:
the more negative charges caused them to be a proton acceptor
Anaerobic exercise has heavier breathing to release more ___ to buffer
CO2
Bicarbonate buffer:
HCO3
Carbonic Acid:
H2CO3
Removal of Acids/Bases
Respiratory, renal (renal tubes secrete ammonia and H+ into urine; reabsorb alkali, CI, and bicarbonate)
Temperature is regulated by the:
hypothalamus
Two mechanisms for activating temperature regulation
central: blood profusion to skin
peripheral: thermal receptors on the skin
What is very effective in transporting heat because it has a high capacity to store heat?
blood
Many exercise physiologists believe that this is the only serious threat to health that exercise presents to a healthy individual
overheating
Factors of heat loss:
Conduction, Convection, Evaporation, Radiation
Conduction:
direct transfer by contact
Radiation:
emission of electromagnetic radiation
Evaporation
Loss of heat by evaporation of water
Convection
moving air removes radiated heat
At rest in a comfortable environment of 21 degrees C, about __% of body heat loss occurs via radiation
61
Factors to increase heat production
shivering, non-shivering thermogenesis
Shivering > increase/decrease metabolism > increase/decrease heat (x3-5)
increase, increase
Non-shivering thermogenesis
catecholamines (norepinephrine and epinephrine), thyroxine to increase resting metabolism
Catecholamines
increase plasma volume, increase mobilization of fatty acids, increase heat production
Non-Shivering thermogenesis is voluntary/involuntary?
involuntary
Metabolism:
all of the chemical reactions within our body that synthesize or break down molecules for survival and function
What are fuels utilized in metabolism?
carbohydrates (main), Fat (second), Protein (last resort)
blood glucose fuels the brain, if the level of it is low, body will switch to __ for fuel
fat
Carbohydrates ares stored as:
stored as glycogen in muscles and liver, converted to fat if not utilized
fat
triglycerides, fatty acids, used or stored as fat (cannot be changed to muscle)
Protein
amino acids converted to glucose or fat if not utilized as amino acids, used during exercise
What is the term for how molecules are moved around the body?
Translocation
What are some types of translocation
diffusion, osmosis, filtration, active transport, membrane gates/channels/etc.: phagocytosis/pinocytosis/exocytosis
Diffusion
tries to even out the concentration, no energy needed
Facilitated or mediated
free > any lipid soluble substance, carrier in the membrane
Osmosis
movement of fluid, osmotic pressure is based off of number of solutes, not size
Filtration
driving/hydrostatic pressure, blood pressure forces small solutes through clefts in capillary cells
Lymphatics:
return fluid to central circulation
Active transport
creates potential energy to do work, acts against uphill gradient, 50% of all body energy is used in active transport, requires ATP
Movement through a membrane
phagocytosis, pinocytosis, exocytosis
phagocytosis:
large, solid, particle being pulled into the cell
pinocytosis
small particle being pulled into the cell
exocytosis
particles being pushed out of the cell
Exercise disrupts homeostasis by changes in:
pH, O2, CO2, water availability, and temperature
over time, our bodies respond to exercise stressors and:
become more efficient, they adapt
Control systems are capable of maintaining steady state during __ exercise in a cool environment:
submaximal
