Homeostasis Flashcards
There are two theories for outlining the survival needs of the body describe the Mrs gren theory 
Movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition
Describe the three pillars of survival theory
Communication (transport systems, internal communication, and external communication)
Intake of raw materials and elimination of waste (intake of oxygen ingestion of nutrients, an elimination of waste)
Protection and survival (protection against the external environment and defence against microbial infection and survival of the species)
What is homeostasis?
Maintaining a constant internal environment
What series of steps homeostasis control mechanisms follow
- Set point
- Stimuli.
- Receptor.
- First signal.
- Control centre.
- Second signal.
- Effectors.
- Response.
- Negative or positive feedback.
What is morbidity and mortality?
Mobility is impaired quality of life, leading states and disease. Mortality is loss of life and death.
Describe the healthy and altered state of temperature
The healthy value is 37. 5°.
Altered state and disease caused is hypo/hyperthermia
What is the healthy value and altered state of blood glucose?
Healthy value is 3.5-5DM/cm3 and 90 g/100cm3
Disease caused is diabetes 
What is the healthy value and disease caused by blood pH
The healthy value is 7.4 in blood and 7.1 in cells.
The disease caused is acidosis or alkalosis
What is the healthy value and disease caused by blood pressure?
The healthy value is 120/80 MMHG
The disease caused is hypertension or hypotension 
What is the healthy value and disease caused by tissue maintenance and blood supply
70 BPM heart rate and 70 mL stroke volume which equals 4.9 L per minute cardiac input.
The disease cause is necrosis
What is the healthy value and disease caused by oxygen levels?
Value is 12 KPA/98 MMHG
The disease causes hypoxia
What is the disease caused by nutrients levels?
Scurvy, Ricketts, osteoporosis and anaemia 
What is negative feedback
Negative feedback is a mechanism that reverses a change to restore a level back to normal? 
Describe the steps of negative feedback
- Normal level (optimum)
- Change.
- Altered level.
- Normal level restored.
What happens if blood glucose concentration becomes higher than normal 
The pancreas detects a change and secretes insulin
This hormone travels in the blood and binds to receptors on liver and muscle cells
These respond by bringing about changes which increase glucose uptake by the cells. So Blood glucose concentration falls back to normal. 
Multiple negative feedback mechanisms involve two more homeostasis systems to give what
More control over changes in the internal environment and more rapid response to the changes
Your body reduces blood glucose by secreting insulin, and by 
Secreting less glucagon
What is positive feedback?
A Mechanism that amplifies are change away from the normal level
What is positive feedback used for?
Rapid activation of a process and when homeostasis systems breakdown 
If core body temperature falls below 35°. The brain doesn’t work properly and what happens
And rate of metabolism is slowdowns less heat is produced, and code temp falls more and more
Enzymes have an optimum temperature at which the rate of activity is the fastest as temperature increases. What happens.
Kinetic energy of substrate. An enzyme molecules increases, leading to more successful collisions between them and increased rate of metabolism.
What happens when the temperature is too high? 
Temperature increases the hydrogen bonds which hold the enzymes 3-D shape in place, vibrate so violently. They begin to break disorders, the tertiary structure so that the substrate molecules no longer fit into the enzymes active site very well which leads to decreased rate of metabolism. Enzymes denature at high temperatures. This is when enzymes active site to change shape so much. The enzymes can no longer function as a catalyst.
What disease is suffered when the temperature is too high?
Hyperthermia. Brain affected at 40°, which causes confusion, hallucinations and above 41° proteins denature, organ failure, coma, and death.
What damage is suffered when temperature is too high ?
Heatstroke, dehydration and low blood pressure.
Could be in response to infection or fever, or an inflammatory response, which affect enzyme function and kills microorganisms
What disease is suffered by temperature is too low
Hypothermia. Brain is affected at 34° and there is loss of coordination, confusion, bradycardia and below 32°. This leads to organ Phalia and brain damage.
What damage is suffered from to low of a temperature? 
Frost bite, necrotic cell death from ischemic injury
Why is body temperature controlled?
It shows that the bodies proteins enzymes and functioning properly, and at the optimum rate as proteins denature at too high temperatures, which is hyperthermia and rate of reactions of lower temperatures which is hypothermia
How is body temperature controlled?
- Receptors like skin and the hypothalamus.
- Control centre which is the hypothalamus.
- Effectors which are skin hair cells, thyroid gland, adrenal gland, fat tissue, muscle tissue and blood vessels.
4.response
What are the responses to body temperature?
. Goosebumps(contraction, or relaxation of arrector, pili muscles which trap layer of warm air close to the skin)
. Thyroid hormone(TSH pituitary leading to T3/T4 thyroxine from thyroid)
. fat metabolism
.shivering muscles
.sweat glands(perspiration allows heat release by evaporation)
.vasoconstriction and vasodilation (directing blood flow to core of body, or to body surface for radiation]
. Behavioural changes (seeking out, shelter, shade, change clothing, drinking fluids)
How does negative feedback control body temperature?
Body temperature falls
Sensory nerve endings, stimulated
Hypothalamus sends impulses to muscles and skin
Shivering and vasoconstriction initiated
Temperature rises
Sensory nerve endings simulated
Hypothalamus sends impulses to muscle and skin
Sweating in vasodilation initiated 
Why is it bad if blood glucose concentration falls to low
Because the rate of respiration goes to low, and the cells cannot make enough ATP to stay alive 
Why is it bad if blood glucose concentration is too high
Because of the water potential of the blood falls so low the water leaves cells by osmosis down the water potential gradient and they shrivel up and die 
Blood glucose concentration is too high. What does this cause?
Hypoglycaemia, which leads to dehydration and heart attacks
And on the other hand, if blood glucose levels are too low, what does this cause?
Hypoglycaemia, which causes, fainting or loss of consciousness
How does the body react when blood glucose levels are too high?
An increase in blood glucose levels is detected by the b cells in the pancreas cells secrete insulin to decrease the glucose concentration 
How does the body respond when blood glucose levels are too high
Decrease in blood glucose. Concentration is detected by a cells in the pancreas and these a cells secrete glucagon to increase blood glucose concentration. 
What is glycolysis?
It’s a breakdown of glucose into pyruvate
What is glycogenesis?
Synthesis of glycogen from glucose
What is glyconeogenesis?
Synthesis of glucose from pyruvate 
What is glycogenolysis?
Breakdown of glycogen into glucose 
The endocrine pancreas contains a tissue called what that contains alpha cells and beta cells 
Islets of Langerhans
Insulin decreases, blood glucose concentration by doing what
It binds to the specific insulin receptor is on plasma membrane of liver cells and muscle cells
Causes vesicles storing glucose carrier proteins to fuse with the plasma membrane and more Glucose carriers and increased permeability to glucose. So more glucose enters the cell.
It activates enzymes for glycogenesis
Increases the rate of respiration of glucose
What happens when blood glucose concentration is too high
- The increase is detected by beta cells in islets of Langerhans of the pancreas.
- Insulin secreted by beta cells by exocytosis into the bloodstream.
- Insulin binds to receptors on liver muscle fat in brain tissue.
- Tissues remove glucose from blood for glycolysis or glycogenesis.
- Glucose produces ATP and glucose produces glycogen
- Blood glucose concentration falls
What happens when blood glucose is too low
- fallen blood glucose concentration
- Detected by alpha sales in islets of Langerhans of the pancreas.
- Glucagon secreted by alpha cells by exocytosis into the bloodstream.
- Glucagon binds to the receptor on liver tissue cells.
- Liver cells add glucose to blood by gluconeogenesis or glycogenolysis.
- Pyruvate turns into glucose and glycogen turns into glucose.
- Blood glucose concentration rises.
In type one or two diabetes, which one is insulin-dependent
Type one
In type one or two diabetes can insulin be made
Type to
In type one or two diabetes, what are the causes?
Type one. Caused by an autoimmune disease. B cells are attacked by bodies own immune system.
Type two. Caused by body being insensitive to insulin or loss of functioning insulin receptors on liver and muscle cells.
Is type one or two diabetes onset
Type one starts a childhood, where is type two starts in the Middle Ages onward
What are the risk factors for having a type one and type two diabetes?
Type one is from family history or genetics
Age, obesity, diet high in refined sugars, family history, or ethnicity
What are the treatments for type one and type two diabetes?
Type one can be treated with daily insulin injections
Type two can be treated with dietary control and drugs to slow down glucose absorption from gut
What happens as a result of having any type of diabetes?
Increased heart rate, angiopathy, neuropathy, retinopathy, and cell atrophy
Why does body water need to be maintained?
So that there is enough blood volume and blood pressure
What does having sufficient blood volume and blood pressure enable?
Correct functioning of the circulatory system meaning the blood is able to be transported around the body with enough force to ensure that every tissue in the body is perfused
What does having sufficient blood volume and pressure mean?
The all cells in the body have a supply of oxygen and glucose for respiration therefore, preventing ischemic injuries

What happens if blood volume is too high
Blood pressure is too high, which causes hypertension which is bad for blood vessels and body organs
What are the two functions of kidneys?
- Excretion of diarrhoea from the body and some other metabolic waste.
- Osmo regulation which has control of water and salt levels in the body, which also impacts blood volume and blood pressure. 
What happens in steps in the kidney?
- Ultrafiltration. (Glomerulus)
- Filtrate collect (bowman’s castle)
- Water and glucose removed. (Proximal CT)
- More water removed. (Descending limb of loop of henle)
- Salt removed. (Ascending limb of loop of henle)
- More water removed. (Distal convoluted tubule)
- More water removed. (Collecting duct)
What does the Bowmans capsule filter?
Glucose, ions (which are NA+, Cl-, H+and K+), urea, water and amino acids
What doesn’t it filter?
Blood cells, platelets and large plasma membranes 
What is the role of the hypothalamus?
It contains an osmoreceptor, which detects when water potential falls and water moves out of these cells by osmosis. When this is detected Osmo receptors shrink, and then ADH secretion is stimulated.
What is the role of the posterior pituitary gland?
If the Osmo receptors detect a decrease in the water potential of the blood nerve impulses sent along the sensory neurons to the posterior pituitary gland, these nerve impulses stimulate the gland to release ADH. The ADH molecule enters the blood and travels throughout the body, which causes the kidneys reabsorb more water, which then reduces the loss of water in the urine.
