Homeostasis Flashcards
draw a feel back system for high calcium and low calcium
low blood calcium STIMULUS Low Blood Calcium Levels RECEPTOR Chemoreceptors on Parathyroid Gland MODULATOR Parathyroid Gland RELEASES Parathyroid Hormone into bloodstream EFFECTOR Bone Kidneys Intestines RESPONSE Bone- osteoclasts break down bone. Kidneys increase reabsorption of calcium from filtrate. Intestines- increase absorption of calcium from diet. FEEDBACK negative Increased Blood Calcium Levels
high calcium STIMULUS High Blood Calcium Levels RECEPTOR Chemoreceptors on Parathyroid Gland MODULATOR Thyroid Gland RELEASES Calcitonin EFFECTOR Bone Kidneys Intestines RESPONSE Bone- osteoblasts build down bone, storing excess calcium. Kidneys decrease reabsorption of calcium from filtrate, so calcium is removed in urine. Intestines- decrease absorption of calcium from diet, so calcium is removed via defaecation. FEEDBACK negative Decreased Blood Calcium Levels
draw a feed back system for metabolism
low metabolism STIMULUS Low metabolism – Low levels of thyroxine. RECEPTOR Chemoreceptors on Hypothalamus MODULATOR Hypothalamus TSH Releasing Factor Anterior Pituitary Gland Thyroid Stimulating Hormone Released EFFECTOR Thyroid Gland RESPONSE Increased production of thyroxine. FEEDBACK Increased levels of thyroxine – increased metabolism
high metabolism STIMULUS High metabolism – high levels of thyroxine. RECEPTOR Chemoreceptors on Hypothalamus MODULATOR Hypothalamus TSH Inhibiting Factor Anterior Pituitary Gland Thyroid Stimulating Hormone Inhibited EFFECTOR Thyroid Gland RESPONSE Decreased production of thyroxine FEEDBACK Decreased levels of thyroxine – decreased metabolism
outline the diseases causes effects and treatment for hyperthyroidism and hypothyroidism
HYPERTHYROIDISM
(over-production of thyroxine)
disease
Grave’s Disease
causes
Autoimmune condition causing an enlargement of thyroid gland.
effect Rapid heart rate. Weight loss. Increased appetite. Fatigue. Sweating. Anxiety. Protruding eyeballs.
treatment
Drugs- block iodine to reduce thyroxine production.
Surgery- remove thyroid gland.
Radioactive iodine destroys thyroid.
HYPOTHYROIDISM
(under-production of thyroxine)
disease
Hashimoto’s Disease
causes
Issues - hypothalamus/ pituitary gland/ thyroid.
Lack iodine in diet- reduced thyroxine.
Autoimmune response that destroys thyroid.
Surgery that removes thyroid (i.e. cancer).
effects Goitre. Low heart rate. Weight gain. Fatigue. Lethargy. Cold intolerance. Foetus- cretinism.
treatment
Thyroxine tablets.
Iodine supplements in diet.
show the dysfunction loop for hyperthyroidism
STIMULUS
High metabolism – high levels of thyroxine.
RECEPTOR
Chemoreceptors on Hypothalamus
MODULATOR
Hypothalamus TSH Inhibiting Factor Anterior Pituitary Gland Thyroid Stimulating Hormone Inhibited.
EFFECTOR
Thyroid Gland
ISSUE: Autoimmune disease- enlarged thyroid gland
TREATMENT: Drugs, surgery, radioactive iodine.
RESPONSE
Decreased production of thyroxine.
issue: Thyroid CONTINUES to produce thyroxine.
treatment: Reduced thyroxine
FEEDBACK
Decreased levels of thyroxine – decreased metabolism.
issue
Thyroxine levels remain HIGH- metabolism remains high.
treatment:Reduced thyroxine, reduced metabolism
outline what occurs surfing conduction, convection, radiation and evaporation
conduction,
This type of heat transfer involves heat energy moving from a warmer object to a cooler object when they are in direct physical contact.
If you touch a cold object heat passes from your body to the object
The reverse happens when you touch something hotter than your body
convection
An object will heat or cool the air as it passes over the object.
Warm air created by contact with a warm body rises and is replaced by cool air.
The currents of moving air remove heat energy from the object
radiation
Heat energy moves from a warmer object to a cooler object across space.
No contact between bodies is necessary
If your body has a higher temperature than the environment you will radiate heat into the environment, which cools the body and vice versa
evaporation
This occurs when liquid water is converted to water vapour
This process requires energy which is taken from the body in the form of heat, thus cooling the body.
As we sweat the evaporation of sweat from the skin cools the body
out line what occurs when regulating high body Temperature
behaviour response
stimulus: high body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: thermoregulotary center in the hypothalamus ‘heat loss center’
effector: cerebral cortex
response: remove clothing, reduce activity, cool environment, sprawl out
feedback: decreased body temperature
sweating
stimulus: high body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: hypothalamus transmits nerve impulse too the sweat glands
effector: sweat glands
response: release sweat water evaporates as the body heats it up heat energy in the body is removed
feedback: decreased body temperature
vasodilation
stimulus: high body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: hypothalamus transmits nerve impulse to arterioles
effector: smooth muscle in blood vessels (arterioles)
response: increase blood flow to extremities and warm blood looses heat via radiation
feedback: decreased body temperature
decreasing metabolism
stimulus: high body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: hypothalamus releases thyroid stimulating hormone inhibiting factor allowing for thyroid stimulating hormone to be released from the ant pit gland and thryroxine will be released from from the thyroid
effector: somatic body cells
response: reduced cellular respiration and there is a decreased heat produced
feedback: decreased body temperature
outline what occurs when regulating low body temperature
behaviour response
stimulus: low body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: thermoregulotary center in the hypothalamus ‘heat production center
effector: nerve impulse is transmitted to the cerebral cortex frontal lobe
response: delibrate movement, putting clothes on, turn oh a heater, find shelter
feedback: increased body temperature
shivering
stimulus: low body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: hypothalamus sends nerve impulse to skeletal muscle
effector: skeletal muscle
response: mussels repeatedly contract and relax to generate heat via friction and cellular respiration
feedback: increased body temperature
vasoconstriction
stimulus: low body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: hypothalmus transmits nerve impulse to blood vessels
effector: smooth muscle in blood vessels (arterioles)
response: vasoconstriction blood flow released to extemities warm blood circulates the core of the body and heat loss is reduced
feedback: increased body temperature
increasing metabolism
stimulus: low body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: hypothalamus releases thyroid stimulation hormone realeasing factor this stimulates the release of TSH from the posterior lobe of the pituitary gland thyroid will realease thyroxine
effector: somatic body cells
response: increase rate of cellular respiration and heat is produced as a by product
feedback: increased body temperature
release of adrenaline and noradrenaline
stimulus: low body temperature
receptor: thermoreceptors in the skin and hypothalamus
modulator: hypothalamus transmits nerve impulse
effector: adrenal medulla
response: release of adrenaline and Nora adrenaline and increased cell respiration
feedback: increased body temperature
what is the normal reading of glucose levels and why do they need to be regulated
Normal reading 4.0-7.8 mmol/L.
Nervous tissue – sensitive to changes in glucose levels.
Excess or deficiency of blood glucose levels for more than a few hours can result in the loss of consciousness and brain damage
The storage form of glucose (glycogen) does not harm the tissues
what is the function of the pancreas and the islets of langerhans and outline the difference between alpha and beta cells
The pancreas is a large mass of glandular tissue enclosed by the duodenum.
Function:
Exocrine- produces digestive enzymes
Endocrine- ‘Islets of Langerhans’ – produce hormones.
Islets of Langerhans
Special cells in the Islets of Langerhans have chemoreceptors that detect the glucose level of the blood – alpha and beta cells
Alpha cells detect low glucose levels
Beta cells detect high levels of glucose in the blood
what are the function of alpha and beta cells
ALPHA cells – low blood glucose levels
GLUCAGON – increases blood glucose levels.
BETA cells- high blood glucose levels
INSULIN- decreases blood glucose levels
what is the role of the the liver in glucose regulation
Major role in glucose regulation.
Blood supply is from the ‘HEPATIC PORTAL VEIN’ – comes directly from the digestive system
Rich in nutrients
Glucose is
Removed by the liver for energy
Stored as glycogen in the liver and skeletal muscles
Circulated the body to provide cells with energy
Converted to fat for long term storage
define what Glycogenolysis, Lipolysis, Gluconeogenesis Glycogenesis ,Translocation, Lipogenesis do
Glucagon causes the following effects;
Glycogenolysis
Breakdown of glycogen into glucose
Lipolysis
Lipids are broken down
Gluconeogenesis
Fats and amino acids combine to produce glucose
Insulin causes the following;
Glycogenesis
Glucose molecules combine to produce glycogen which is then stored in the liver
Translocation
Glucose moves from the blood into the cells (increase cellular uptake)
Lipogenesis
Glucose is converted into lipids
outline what occurs when Low blood glucose levels eg. during exercise also outline what occurs when High blood glucose levels eg after a meal
draw the feed back loop
low glucose
Stimulus
Low blood glucose levels
Receptors
`Islets of Langerhans
Modulator
Alpha cells produce glucagon
Effectors
Liver and body cell
Response
Glycogenolysis, gluconeogenesis, lipolysis
Feedback
Higher glucose in blood
high glucose
Stimulus
High blood glucose levels
Receptors
Islets of Langerhans
Modulator
Beta cells produce insulin
Effectors
Liver, body cell and muscles cells
Response
Glycogenesis, translocation, lipogenesis
Feedback
Lower glucose in blood
these are both negative feeback
how can adrenaline and cortisol affect glucose production display in feedback loop
Effects of Adrenalin
Stimulus
Stress/Exercise
Reduced glucose.
Receptors
Amygdala interprets stressor
Modulator
Hypothalamus- nerve impulse along sympathetic n.d. to adrenal medulla- releases adrenalin
Effectors
Liver, skeletal muscles cells, adipose tissue
Response Glycogenolysis Lipolysis Gluconeogenesis Increased metabolism Increased HR, BP Reduced inflammatory response
Feedback
All responses aimed to enhance body to over stress.
Increased glucose for energy.
Effects of Cortisol
Stimulus
Stress
Low blood glucose
Receptors
Amygdala interprets stressor.
Modulator
Hypothalamus- ACTH RF- Anterior Pituitary Gland – ACTH – Adrenal Cortex - Cortisol
Effectors
Liver, skeletal muscles cells, adipose tissue
Response Glycogenolysis Lipolysis Gluconeogenesis Increased metabolism Increased HR, BP Reduced inflammatory response
Feedback
All responses aimed to enhance body to over stress.
Increased glucose for energy.
these are both negative feedback
how can the hypothalamus regulate glucose levels
Behaviour can also change in response to blood sugar levels
HIGH blood glucose levels-
Hypothalamus acts through the cerebral cortex to decrease appetite
LOW blood glucose levels-
Hypothalamus acts through the cerebral cortex to increase appetite
