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D3.2 Homeostasis

Homostasis is the maintence of the internal environment — keep it in a very small range of conditions

some examples are glucose concentration, blood water levels, blood ph and body temperature

Regulation of blood glucose as an example of the role of hormones in homeostasis

we need glucose for respiration to make atp but we don’t want to have high levels of glucose because it can damage cells, so it needs to make it regulated and in a stable range. blood glucose will fluctuate during periods of the day

2 hormones that are antogonistic (opposite effects)

insulin and glucogen

both come from the pancreas and they comme from the islets of langerham and they act on the liver. there are 2 types of cells in pancreas; alpha cells and beta cells.

High glucose levels (for example after a meal)

  • insulin from the beta cells from the pancrease by stimulating the liver to produce glycogen which means glucose decreases and increases the rate of gluvose breakdown (by increaseing cell respirtation rates)

  • insulin tells adipose tissue to store glucose in the form glycogen

low glucose levels (for example, excercise)

  • glucogen is released from alpha cells of the pancreas and cause an increase in blood glucose concentration

  • glucogen stimulates glycogen to breakdown to glucose which gets released into the blood stream and increeasing the glucose levels

glucose is usable energy, glcyogen is the stored form of glucose, glucagon is the hormone that increase glucose levels

negative feeback loop - put it into a set level

positive feedback loop (NaK, membrane ) - keeps the change going

physiological changes that form the basis of type 1 and type 2 diabetes

metabolic disorder that results from a high blood glucose concentration over a prolonged period is diabetes

there are 2 types

type 1- body cannot produce insluin

type 2- body fails to respond to insulin production (insulin resistance)— environmental changes, non-communicable disease

it is treated with either insulin injections (type 1 only) or by carefully monitoring and controlling dietary intake (type 2)

Type 1

Type 2

age onset (generally)

usually occurs during childhood early onset

usually when ur older aged 30 ++

cause

abnormality in pancreas and inabillity to produce insulin

caused by the destruction of beta cells (autoimmune)

environmental changes

body does not respond to insulin production

caused by the down regulation of insulin receptors

treatment

insulin injections to regulate blood glucose

monitering and controlling dietary intakes as well as regulating lifestyle choices

thermoregulation as an example of a negative feedback loop

Responses to the cold

Responses to the heat

Vasocontradiction

muscles surrounding arterioles contract and blood flow decreases. less blood flow to the skin and less heat is lost from the body

Vasodilation

muscles surrounding arterioles relax and blood flow is increased. more blood flow to the skin and heat is lost to the external environment

Shivering

muscles contract to cause movement a side effect tof the movement is a heat production

Sweating

wagter evaporates from the surface of ths kin water has a high latenet heat of vaporisation and evaporation of water causes a cooling effect. blood flowing through the skin loses heat and then cooles other part of the body

sweat production is controlled by the hypothalamous

Uncoupled respiration

lots more mitochondria than regular fat so fat tissue has more atp, more heat production

Hair erection (goosebumps)

erector muscles in the skin can make hair on the skin stand up.

SL

D3.2 Homeostasis

Homostasis is the maintence of the internal environment — keep it in a very small range of conditions

some examples are glucose concentration, blood water levels, blood ph and body temperature

Regulation of blood glucose as an example of the role of hormones in homeostasis

we need glucose for respiration to make atp but we don’t want to have high levels of glucose because it can damage cells, so it needs to make it regulated and in a stable range. blood glucose will fluctuate during periods of the day

2 hormones that are antogonistic (opposite effects)

insulin and glucogen

both come from the pancreas and they comme from the islets of langerham and they act on the liver. there are 2 types of cells in pancreas; alpha cells and beta cells.

High glucose levels (for example after a meal)

  • insulin from the beta cells from the pancrease by stimulating the liver to produce glycogen which means glucose decreases and increases the rate of gluvose breakdown (by increaseing cell respirtation rates)

  • insulin tells adipose tissue to store glucose in the form glycogen

low glucose levels (for example, excercise)

  • glucogen is released from alpha cells of the pancreas and cause an increase in blood glucose concentration

  • glucogen stimulates glycogen to breakdown to glucose which gets released into the blood stream and increeasing the glucose levels

glucose is usable energy, glcyogen is the stored form of glucose, glucagon is the hormone that increase glucose levels

negative feeback loop - put it into a set level

positive feedback loop (NaK, membrane ) - keeps the change going

physiological changes that form the basis of type 1 and type 2 diabetes

metabolic disorder that results from a high blood glucose concentration over a prolonged period is diabetes

there are 2 types

type 1- body cannot produce insluin

type 2- body fails to respond to insulin production (insulin resistance)— environmental changes, non-communicable disease

it is treated with either insulin injections (type 1 only) or by carefully monitoring and controlling dietary intake (type 2)

Type 1

Type 2

age onset (generally)

usually occurs during childhood early onset

usually when ur older aged 30 ++

cause

abnormality in pancreas and inabillity to produce insulin

caused by the destruction of beta cells (autoimmune)

environmental changes

body does not respond to insulin production

caused by the down regulation of insulin receptors

treatment

insulin injections to regulate blood glucose

monitering and controlling dietary intakes as well as regulating lifestyle choices

thermoregulation as an example of a negative feedback loop

Responses to the cold

Responses to the heat

Vasocontradiction

muscles surrounding arterioles contract and blood flow decreases. less blood flow to the skin and less heat is lost from the body

Vasodilation

muscles surrounding arterioles relax and blood flow is increased. more blood flow to the skin and heat is lost to the external environment

Shivering

muscles contract to cause movement a side effect tof the movement is a heat production

Sweating

wagter evaporates from the surface of ths kin water has a high latenet heat of vaporisation and evaporation of water causes a cooling effect. blood flowing through the skin loses heat and then cooles other part of the body

sweat production is controlled by the hypothalamous

Uncoupled respiration

lots more mitochondria than regular fat so fat tissue has more atp, more heat production

Hair erection (goosebumps)

erector muscles in the skin can make hair on the skin stand up.

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