2.77 - Thermoregulation

Part A:

-Homeo means the same
-statis means the fixed point/ conditions
= This means that the condition is kept the same or constant.

Homeothermic= maintaining the same temperature
- some organism like mammals when the environmental temperature increases or decreases, their body temperature remain constant these are homeothermic organism and carry out the process call thermoregulation
- Other organism body temperature varies depending on the environmental temperature.

Part B:

-negative feedback loop: method of control and maintaining constant conditions
> in humans, our fixed point is 37-38 degrees
> We have receptors of body temperature (internal condition)- hypothalamus (region of the brain) this respond to the stimulus which is the temperature of blood in our body.
> body temperature feed into the brain
> if body temperature need to change (increase or decrease) the effector will make a change such as places like the skin

2.76 Sensitivity

MRS GREN
S- SENSITIVITY = characteristic in which organism respond to changed in the environment
type of changes:

• light level
• temperature
• pressure
• chemical

- in order to detect these changes organism requires receptors

- in order to respond to the changes organism have the effectors (muscles and glands)

- the responds ensure that the organism is able to survive the changes in the environment

2.75 Urine

-urine contains water, urea and salt

- the brain influences the functioning of the 2 kidneys

- and how the 2 kidneys are filtering our blood

- the molecules which are removed which come down the ureter collect in the bladder and together this form urine

-the salt and water effects the composition of tissue fluid [ osmoregulation]

- the removal of urea is part of the process of the excretion of metabollic waste

-composition of urine: salt, water and urea

--> varies and depends on the condition which a person is operating

2.74 Anti-diuretic hormone.

-ADH- anti diuretic hormone

- ADH is produce in a region of the brain known as  the hypothalamus, flows through the bloodstream and its target is the kidney (flow through like all hormones)

- the effect of ADH is to control and alter the composition or the quantity of water in the blood

-ADH has the ability to make the blood more or less concentrated- the tissue fluid is isotonic to the cytoplasm of the cell [role of ADH]

-ADH targets the collecting duct

- the effect of ADH is that it allows more water to come out of the collecting duct

- the collecting duct is responsible for the water to be selectively reabsorbed into the blood

-possible to increase the amount of water going into the blood by applying the ADH in 

- ADH makes the collecting duct wall more pores

--> more water can escape from the collecting duct and the water can go back into the blood

- the consequence of ADH secretion is that the urine coming from the nephron would be more concentrated and would have a lower volume, the urine becomes more concentrated

2.73 Glucose Reabsorption

-selective: the molecules is selected (glucose)

-reabsorption: go from the glomerula filtrate and it will go back into the blood, removing the molecule to the blood but put it back

-filtration occurs in the bowmans capsule- containing glucose, water salt and urea

-water is removed back into the bloof in the collecting duct

- at the end of the nephron the urine is coming out,

urine does not contain glucose, 

- if test urine for glucose and receive a positive test it means that have a condition called diabetes

-[normally no glucose in urine]

-However in the start there is glucose in the fluid, this is because in the proximal convoluted tubule (first section) glucose is removed and is taken back into blood, glucose is selectively reabsorbed into the blood in the proximal convoluted tubule.

-proximal= first, convoluted= twisted, tubule=tube

2.72 Water Re-absorption.

- the bowmans capsule (BC) - location of ultralfiltration

- the blood coming into the kidney (under high pressure) the dissolve content of the blood are forced into the bowmans capsule tube, (glumerula filtrate- containing glucose, water, salts and urea)

- when the filtration occurs it will filter out too much water and as the filtrate passes along the tubal and when it reaches the collecting duct, water is removed from the filtrate and the water is return back to the blood vessel/stream

- water has been selected and has been reabsorbed into the blood

-selected reabsorption of water occurring into the collecting duct

2.71 Ultrafiltration

nephron of the kidney- structure which carries out the filtration of our blood

resulting in two things:

- filtered blood (clean blood) with waste product

-urine (largely composed of water, salt ,NACL, MGCL), urea (nitrogen waste of the body very toxic)

bowmans capsule- filtration process begin (ultrafiltration), filtration of molecules

-the filtration of blood begins with bloof arriving in the kidney, in the nephron entering the afferent arteriole (blood enter), high pressure

- the blood vessel coming out has a smaller and narrower bloog vessel

- the blood vessels pressure increases in the glomerulus

- the high pressure forces the liquid within the blood (plasma- containing water, salts, amino acids, glucose, urea) forcing it outside the bowmans capsule

- when the plasma is forced in to the bowmans capsule, its called filtrate, and since its in the glomerulus its called the glomerulus filtrate

- the blood has been filtered by pressure due to the smaller restricted diameter of the blood vessel [efferent arteriole] generating a the pressure to be high