Excretion (chpt. 31) Flashcards
Excretion
The removal of metabolic waste from the body
Excretory organ in plants
Leaves - through stomata
Vasoconstriction
When we are COLD, blood vessels contract and reduce blood flow to capillaries near the surface
Vasodilation
When we are WARM, blood vessels dilate and increase blood flow near the surface of the skin to increase heat loss
Role of the skin
- Protection (epidermis, melanin, sebum)
- Vitamin Production (vitamin D)
- Food store (fat)
- Sense organ (touch, pain, temperature)
- Excretion (sweat)
- Temperature regulation
Excretory organs in humans
Skin
Lungs
Kidneys
What is excreted by the lungs
Carbon dioxide
What is excreted by the skin
Sweat (water, salts, urea)
Where are the kidneys located in an adult human
Lower abdomen
Location of filtration in the nephron
Bowman’s capsule
Location of re absorption in the nephron
Proximal convoluted tubule
(Or DCT , loop of Henle)
Name the arteriole that enters bowman’s capsule
Afferent arteriole
Structural differences between Afferent and Efferent arteriole & significance of difference
Efferent has a narrow lumen, increases blood pressure
Why would prolonged strenuous exercise lead to production of ADH
Low water content in blood
What part of the nephron is influenced by ADH
Collecting duct
Explain the importance of blood entering the glomerulus under pressure
Force filtered
Two reasons why capillaries surround PCT, loop of Henle, DCT
Reabsorption & secretion
Is it normal for proteins to be found in urine? Why / why not?
No - protein molecules too big to pass into filtrate
Is it normal for glucose to be found in urine? Why / why not?
No - glucose in filtrate should have been reabsorbed
Function of the sweat gland
Temperature regulation
From which germ layer is skin produced
Ectoderm
Identify the non-living layer present in skin
Epidermis
Name two structures in the skin that play a role in temperature regulation
Sweat gland
Hair
What term is used to describe organisms that can regulate their body temperature
Endotherm
