coordination and response Flashcards
(33 cards)
What is homeostasis
It is the maintence of a constant internal environment
Why is there a need for homeostasis?(body temperature)
Enzymes require a optimum tempreture and pH properly .Below the optimum temp enzymes are inactive.Above the optimum tempreture enzymes are denature
Why is there a need for homeostasis?(water potential)
The water in the blood has to be maintained to ensure that the water potential of cells are kept constant .The cells may crenate or burst in solutions with different water potential in cytoplasm.
Why is there a need for homeostasis?(blood gluscose concentraion)
Gulcose in the body is important as it is being oxidised to release energy.Glucose levels may increase and drecrease.But when glucose concentration chnages drastically it is very fatal
what happens when the blood water potential increases?
When the water potential increases above norm, the hypothalamus in brain stimulus.The pituitary gland releases less ADH into the bloodstream.The Less ADH will be transported tot he kidney.Cells in the walls of the collecting duct becomes less permeable to water.So less water is reabsorbed into the bloodstream ,so more water is excreted out of the body.The urine would be diluted and more urine is produced
What happens when the blood water potential decreases below norm?
When the blood water potential decreases below norm,the hypotalamus in the brain is stimulated .The pituatary gland releases more ADH.The more ADH is transported to the kidney.The cells in the collecting ducts is more permenable to water.More water is reabsorbed,so less water is excreted.The urine is more concentrated and less urine is produced
what happens when the blood glucose concentration increases above norm?
When the blood glucose concentration in the body increases above norm,the islets of lagerhans in the pancreas is stimulated.The islets of lagerhans secrete more insulin into the bloodstream.The liver cells and
muscle cells become more permeable to the glucose.The excess glucose is then converted to gylcogen and stored in the liver and muscles .The blood glucose concentration returns to norm
what happens when the blood glucose concentration is below norm?
When the blood glucose concentration is below norm,the islets of langerhans in pancreas is stimulate.The islets of langerhans secrete glucagon into the bloodstream.The glycoge in the liver is converted to glucose.The blood glucose concentration is back to norm and glucagon production reduceses
Regulation of body tempreture when the body tempreture increases?
During vigorous exercise the body gain heat or heat gain from the external environement.This increases the skin or blood temperture.The thermoreceptors in the skin detects the increase in temperture and send nerve impulses to hypothalamus in the brsin.Increase in blood tempreture is detected by the thermoreceptors in the hypothalamus.The hypothalamus is activated and it send nerve impluses.To increase heat loss:vasodilation of arterioles in skin and construction of hunt vessels.The sweat glands are activated,more sweat produced.Hair erector muscles in skin relax.To reduce heat loss the metabolic rate of body slows down.The body temperture return to norm!
regulation of body tempreture when the body tempreture decreases?
Heat loss to envirnonment,There will be a decrease skin or blood temperature .The thermoreceptors in skin will detect the chnage and send nerve impluses to hypothalamus in the brain.The decrease in the blood temperature will be detected by the thermoreceptors in the brain.Thebhypothalamus will be activated and sends out nerve impluses.to decrease heat loss there will be vasocontriction of arterioles and shunt vessels would dilate.Less swear is produced and the hair erectors musles in the skin contract and stands.The metabolic rate of the body increases,shivering occurs
what happens to the skin arterioles when the body temperature increase?
The arterioles vasodilate which allows more blood to flow through in the capillaries and shunt vessels contrict.This would cause more heat loss through the skin via conduction,convection and radiation.
what happen to the of sweat when the body temp increases?
The sweat glands are more active so they produce more sweat.More latent heat of vaporisation is removed when the water in sweat evaporates
what happens to the hair erector muscles when temp increase?
hair lie flat,allowiungair to circulate over skin and heat is removed
what happen the skin when the temp decrease?
the artierole vasocontriction so less blood flow throught the blood capillaries in the skin.The shunt vessels dilate.less heat will be lost through the skin via conduction ,convection and radiation
what happens to the sweat production when temp decreases?
sweat glands are less active, less sweat is produced.Less latent heat of vapouriation is removed as the water evaporated from the sweat
what happens to the hair erector muscles when the temp decreases?
the hair erector muscles will contrac and hair ‘stands up’ trapping air ,insulating layer of warm air
how does shivering help in increasing the body tempreature ?
the reflex contraction occurs quickly.So there will be oxdiation of glucose to produce energy.The some of the energy would be heat energy which would help to increase the body temp
what are hormones?
Hormones are chemical substances that are produced by the endocrine glands in very small amounts.They are transported via blood to the target organs.After performing their function they are destroyed in the liver and excreted by the kidneys
what is a endrocine gland?
it is a ductless gland that produces hormones into the bloodstream.For example:islets of lagerhans in pancreas produce insulin and glucagon to maintain blood glucose concentration
what makes up the nervous system
nervous system=cns +pns
describe a voluntary action pathway of a impulse?
the forebrain transmits nerve impulses to the relay neurone in the cns across a synapse and nerve impulses is transmitted to the motor neurone and then to the effector
what is a reflex arc?
The shortest pathway which nerve impulses travelk from the receptor to the effector in a reflec action
what happens when a pin is pricked on you?
The pin pricing action stimulates the pain receptors in the skin.Nerve impulses are produced.Nerve impulses travel along the sensory neuron to the spinal cord.In the spinal cord nerve impluses are transmitted across a synapse to the relay neuron and then across another synapse to the motor neuron .The nerve impulse is them transmitted to teh arms musles wwhich contract and withdraw the hand .Pain is perceived when the brain interprets the nerve impulses from the relayh neuron.
what is accomodoation?
is when images are brought to focus by the contaction and relaxation of the ciliary muscles and the sus pensory liagments.
