B12 Flashcards
How does your body detect changes in body temperture (eg decreasing)
Your body has to keep your core temperature constant.
The receptor in the thermoregulator centre of the brain (hypothalamus), detect that the core body temperature is too low through: receptors sesitive to the temperature of blood flowing through the brain and nervous impulses from temperature receptors in the skin giving information about the skin temperature.
Body temperature is monitored and controlled by the thermoregulatory centre in the brain. The thermoregulatory centre contains receptors sensitive to the temperature of the blood. The skin contains temperature receptors and sends nervous impulses to the thermoregulatory centre.
Explain how your body changes the temperature through receptors + effectors
Recpetors (in the thermoregulatory centre of the brain and skin) detect a change in your core body temperature -> the CNS (in this case thermoregulatory centre) recieves the information and automatically triggers the effectors -> effectors produce a response such as sweat
Explain what effectors workong “antagonistically” means:
They work at the same time (eg one heating and one cooling) to achieve a very precise temperture. It allows for a more sensative response
What does your body do when your to cold?
Hairs pulled erect by contracting muscles to trap an insulating layer of air reducing energy loss to the environment
No sweat is produced reducing heat loss as no evaporation off the body occours
Blood vessels suppling skin cappilaries constrict to close off the skins blood supply, this is called vasconstriction. This means less blood transfers energy to the environment and more goes through shunt vessels (not sure it your need to know “shunt vessels”
When your cold you shiver (your muscles contract automaticslly). This needs respiration which transfers some energy to warm the body
What heppens in your body when your too hot?
Swaet is produced by sweat glands and evapourates from the skin. This evouration requires energy from the you skin tranfering energy to the environment
Blood vessels supplying blood to your skin dialate so more blood flows through cappilaries close to the surface of the skin. This helps tranfer energy from the skin to the environment as their is a difference in temp between your skin and the environment and is known as vasdialation
How is urea formed?, why is it a waste product? and how is it removed?
The digestion of proteins from the diet results in excess amino acids (which cannot be stored so must be converted into carbohydrates and fata) which need to be excreted safely. In the liver these amino acids are deaminated to form ammonia. Ammonia is toxic and so it is immediately converted to urea for safe excretion. (It is then filterted out of the blood by the kidneys)
A small unregulated amount of urea is also lost from the skin in sweat
Name ways the body looses the body looses resoucres which it has no control over (unregulated)
There is no control over water, ion or urea loss by the skin. There is not control over water loss by the lungs during exhalation
How are ions intaken? why is it a waste product? and how is excess of it removed?
Ions such as sodium are taken into the body by food and then absorbed into the blood
If the ions (or water content) is wrong this could upset the blance between ions and water meaning to much or to little water is drawn into the cells by osmosis (function ineffciently). Having the wrong amount of water can damage cells or mean they don’t work as normal.
Some ions are lost in sweat, however this amount is not regulated so the right balance between ion in the body must be maintained by the kidneys. The right amount of ions is slectively reabsorbed into the blood after filtration and the rest is from the body in urin. This is known as seletive reabsorbtion
How is water kept blanced in the body?
The body has to constantly blanace the water coming in and out of the body
We loose water unregulated (uncontroled) through our skin in sweat and through our lung during exhalation
We can’t control the water we loose through these ways so it is blanced by the amount we consume and the amount reabsorbed by the kidney in urine
How does the “—x-“ hormone control the concintration of urin? Example if there is a hogh water content. What is it an example of
The brain monitors the water content in the blood and instruct the pituitary glands to release ADH in accordance, if there is a high water content dectected by receptors the Cordination centre recieves the information and cordinates a response:
A smaller amount of the anti-diuretic hormone (ADH) is released into the blood stream by the pituitary glands so less water is reabsorbed from the kidney tubles and the permeablty of kidney tubles is not increased
It is a negative feedback loop.
What happens if the kidneys don’t work properly?
If kidneys don’t work waste substances build up in the bloood and you loose your ablity to control the levels of ions and water in your body reulsting in death
Explain how _____ a type of tratments for kidney faliure works?
- In a dialysis the persons blood flows between partially permeable membranes surroudned by dialysis fluid. (Membrane is only permeable to small molecules (not protiens) like kidney)
- the fluid has the same conc of dissolved substances ion and glucose as healthy blood so useful ions and glucose won’t be lost from the blood
- because the dialysis fluid hasn’t got waste products like urea, excess ions and water. These diffuse across the membrane into the dialysis fluid (to maintain a steep concintration gradients the dialysis fliud is being contunually refreshed to prevent there being no net movement because there is equal watse on each side)
What are the negative and postives of dialysis
Postives + keeps the concintration of dissolved substances in the blood at normal levels and removes waste
+provides time before a donor can be found
Negatives - it is very time consuming (3-4 hours) 3 times a week
- can cause blood clotts or infection
- expensive for NHS
Explain the postives and negtives of kidney transplant
+Kidneys are from someone who have recentely died Or they can be transplanted from someone alive (there is a small risk)
+cures (only cure) for kidney faliure
+cheaper in the long run than dialysis
- donor kidney could rejected (often have drugs taken to prevent this)
- long waiting list
How does geotropism work
