Excretion, Secretion and Homeostasis Flashcards
What is Excretion?
Excretion is the removal of waste products that are formed by metabolic activity.
What products are excreted from the body?
These products include water, carbon dioxide,
oxygen and nitrogenous compounds (ammonia and urea) and bile pigments.
What does Cell Metabolism do?
Cell metabolism breaks down compounds and makes new compounds these waste products could become harmful to the body if allowed to build up in the body, so they need to be removed by the process of excretion.
What are the 4 excretory organs?
The Lungs, The Skin, The Liver, and The Kidneys
How does the skin help in the process of excretion?
It helps the body get rid of excess water, salts, and waste such as urea.
What does sweat contain?
sweat contains metabolic waste such as water, salt, and traces of urea,
a toxic substance formed in the body’s production of energy.
How does sweat come out from the skin?
Waste travels through the sweat gland and out of the body through sweat pores, which are located in the epidermis.
What do the kidneys do?
The kidneys excrete urea and excess water and salts
The kidneys filter the blood, removing urea and excess water and salt,
which forms urine.
What are the 3 parts of the kidney?
Cortex, Medulla, Ureter
What is the cortex?
the outer region of the
kidney
What is the medulla?
the inner region of
the kidney.
What is the ureter?
tubes that transport
urine from the kidneys to the
bladder, where it is stored
before being excreted from the
body
Where does blood enter the kidney?
Blood enters the kidney through the renal artery and exits through the renal vein.
What are the parts of the nephron?
Glomerulus
Bowman’s capsule
proximal tubule
loop of Henle
Distal tubule
Collecting duct
Where does the nephron start?
as a small a cup-shaped structure called the
bowman’s capsule, which contains a mass of thin-walled capillaries called glomerulus
What is the glomerulus?
The glomerulus is where
the blood is filtered and glucose,
urea, water, and salts are
removed.
What is Homeostasis
The maintenance of constant internal conditions in the body.
What is secretion
The release of substance by cells for a useful purpose
Why is excretion important
It keeps the environment in the body constant, It removes toxic substances from the body
What does Ultrafilitration and Selective reabsorption do?
Ultrafiltration is the filtration of small molecules and salts under pressure Selective Reabsorption reabsorbs useful substances from the glomerulus
What is Negative feedback?
It is any change to the body system causes a response that reverses the change, so that conditions return to normal levels.
Human beings have a body temperature of about?
37ºC.
What is Homeothermy and what is responsible for it?
Homoethermy control is due to the body temperature as it passes over the receptors in the hypothalamus. The skin is responsible for this process
The thermoregulatory center in the brain is called the?
Hypothalamus
How can heat be gained?
movement and exercise
shivering
vasoconstriction
wearing extra clothing.
How can heat be lost?
sweating
vasodilation
removing extra clothing.
What is vasoconstriction?
When core body temperature falls, blood vessels in the skin gets narrower.
What is vasoconstriction caused by?
Contraction of the muscular wall of the blood vessels.
What is Antidiuretic hormone (ADH)
a hormone that is produced in the hypothalamus. It is then stored and released from the pituitary in the brain.
