Which 2 communication systems are involved in homeostasis?
Nervous and hormonal communication systems
2 of 15
What do automatic control systems throughout the body do and why?
Automatic control systems throughout the body maintain a range of factors at steady levels and that this is required for cells to function properly
3 of 15
What do control systems have?
1. receptors to detect changes in the environment, 2. processing centres to receive information and coordinate responses automatically, 3. effectors to produce the response
4 of 15
What is negative feedback?
Negative feedback reverses any changes to the system’s steady state
5 of 15
Why is a balanced water level important?
For maintaining the concentration of cell contents at the correct level for cell activity
6 of 15
What needs to be balances to control water levels?
Water levels are controlled by balancing gains from drinks, food and respiration and losses through sweating, breathing, faeces and the excretion of urine
7 of 15
What is the role of the kidneys?
The kidneys play a vital role in balancing levels of water, waste and other chemicals in the blood
8 of 15
How do the kidneys balance water levels?
By producing dilute or concentrated urine
9 of 15
What affects the concentration of urine?
External temperature, exercise level and intake of fluids and salt
10 of 15
What is the concentration of urine controlled by and where is it released from?
The concentration of urine is controlled by a hormone called ADH, which is released into the bloodstream by the pituitary gland
11 of 15
Explain what happens when there is too little water in the blood
1. Hypothalamus (brain) detects too little water in blood. 2. Pituitary gland releases more ADH. 3. Kidneys reabsorb more water, so less water is lost in urine (urine is more concentrated). 4. Blood water level returns to normal
12 of 15
Explain what happens when there is too much water in the blood
1. Hypothalamus (brain) detects too much water in blood. 2. Pituitary gland releases less ADH. 3. Kidneys reabsorb less water, so more water is lost in urine (urine is more dilute). 4. Blood water level returns to normal
13 of 15
Explain how alcohol affects the production of urine
Alcohol suppresses the production of ADH, so the kidneys reabsorb less water. A larger volume of more dilute urine is produced. As more water is lost in urine this can to dehydration and be harmful to your health e.g. headaches, dizziness and death
14 of 15
Explain how ecstasy affects the production of urine
Ecstasy increases the production of ADH, so the kidneys reabsorb more water. A smaller volume of less dilute urine is produced.
15 of 15
Other cards in this set
Card 2
Front
Which 2 communication systems are involved in homeostasis?
Back
Nervous and hormonal communication systems
Card 3
Front
What do automatic control systems throughout the body do and why?
Comments
No comments have yet been made