Excretion Flashcards
Excrétion
Removal of waste products of metabolism from the body
Egestion
Removed of unused, unwanted, unabsorbed food
Homeostasis
Maintenance of a constant internal environment within the body
What part of the brain controls homeostasis
hypothalamus
What goes into the kidneys
Water
Uric acid
Urea
Location of kidneys
Back if abdominal cavity
What do kidneys do
Excretion
Osmoregulation
Osmoregulation
Régulation of water and salt concentration in blood
What do the kidneys produce
Urine
What is the Kinsey composed of
Water salts and urea
Ureters
Connect kidneys to bladder
Bladder
Stores urine
Urethra
Releases urine to outside
What is the structural and functional unit of the kidneys
The nephron
How many nephrons in each kidney
1 million
Stages of blood supply in the nephron
Afférent artériole Glomerulus Efférent arteriole To renal vein To the bladder
Where is the nephron located
Cortex and medulla
Where does blood enter the kidney
Through the renal artery
Where is the glomerulus found
Bowmans capsule
Where does blood leave the glomerulus
Efferent arteriole
Active transport
Energy is used to move molecules, often against a concentration gradient
Adaptations of convoluted tubule
Thin walled - one cell thick
Long - gives time for réabsorption
K
Potassium
Deamination
Excess amino acids are broken down to make urea
What is the concentration of the blood monitored by
Hypothalamus
Is blood is too salty
- ADH is released from pituitary
- Travels in blood stream to distal convoluted tubule and the collecting duct
- Walls become more permeable
- Water is then reabsorbed into the body
What is completely absorbed in reabsorbtion
Glucose
Keratin
Waterproof protein in the epidermis
Melanin
Pigment which gives colour to the skin
Collagen
Strenghtens protein in thé dermis
Sebum
Oil produced in the sebaceous glands that prevents skin from cracking
Where is vitamin d produced
The skin
Food store in skin
Fat
What influences the rate of enzyme controlled reactions
Temperature
Endotherms
Their source of heat is internal
Eg mammals
Ectotherms
Body temp varies with external temp
Eg reptiles
Dilate
Gets wider
What happens if temp rises
Blood vessels dilate
Glands release sweat on skin surface
Narrowing of blood vessels
Vasoconstriction
What happens if temp drops
Hairs stand up
Vessels narrow
Hairs stands up
Piloerection
Unit of filtration
Nephron
Adaptions of glomerulus for filtration
Many capillaries
Thin wall
large surface area
What process absorbs amino acid and glucose back into the blood
Active transport and diffusion
Water is reabsorbed by
Osmosis
Adaptions if convoluted tubule for réabsorption
High concentration of mitochondria to provide energy for active transport
Thin walled
Long
What is ADH produced in response to
High level of salt in blood
Low water levels
What happens to blood plasma when we dont drink enough water
Becomes too concentrated
Structural and functional role of kidneys
Nephron
Location of the nephron
Cortex and medulla
How many nephrons in each kidney
One million
Where does blood enter kidney
Through renal artery
What do the efferent artérioles divide to form
Cluster of capillaries
What is the cluster of capillaires in the bowmans capsule called
Glomérulus
How does blood leave the glomerulus
Efferent artériole
What contrains blood with waste products in the nephron
Afférent arteriole
What does glomerular filtrate contain
Water Amino acids Salit Urea Glucose
What substances are too big to be filtrantes out of the blood and remain
Proteins
White blood cells
Hormones
What are useful products for réabsorption
Water and salts
What are reabsorbed blood and into the nephron
Water and salts
Proximal convoluted tubule contains
Water reabsorbed by osmosis
How do glucose, amino acids and vitamins pass from the filtrate into the capillaries
By active transport and diffusion
What passes from the filtrate into capillaries by active transport and diffusion
Glucose
Amino acids
Vitamins
What happens in the loop and henle and the distal convoluted tubule
More water and salts are reabsorbed
What passes from the collecting duct to the ureter
Urine
Homeostasis
Maintenance of a constant internal environment within the body
Osmoregulation
The regulation of water and salt concentration in the body
Osmosis is
Passive
Osmosis
Movement of WATER from an area of LOW concentration across a semipermeable membrane n
Diffusion
Movement of MOLECULES from an area of high concentration to and area of low con
Active transport
Energy is used to move molecules against a concentration gradient
Adaptions of the proximal convoluted tubule
Thin walled (allows substances to move quicker) High concentration of mitochondria (provides energy for active transport)
What is the role of secretion ions
Moved into the blood to filtrate
K
Potassium
H
Hydrogen
Main substance in urine
Water
Composition of urine
Water
Salts
Urea
Where is urea made
Liver
Deamination
Excess amino acids are broken down to make urea
What is the concentration of blood measured by
Hypothalamus
What happens if blood is too salty
ADH is released from pituitary gland
What does ADH cause the distal c.t and collecting duct to become
Causes the walls to become more permeable
Lots of water in blood
ADH production turned off
Body low in water
Salt concentration in blood increases
Receptors in brain (hypothalamus) triggered
ADH secreted
Keratin
Waterproof protein in the epidermis
What is the name of the pigment that gives color to your skin
Melanin
Melanin protects skin from
UV rays
Collagen
Strengthening protein in the dermis
Sebum
Oil produced in sebaceous glands
Sebum prevents
Skin from cracking
What vitamin is produced by skin
Vitamin Do
Functions of the skin
Excretion
Vitamin D production
Sense organ
Protection
Temperature influences
Rate of enzyme controlled reactions
Dilute
Gets wider
Vasoconstriction
Narrowing of blood vessels due to drop in temp
Vasoconstriction causes
Lack of blood flow to skin
Reduces heat loss
ADH
Anti diuretic hormone
Describe the role of ADH
When plasma is too concentrated, the pituitary gland releases ADH -> travels to kidneys
In the kidneys, it cause the distal convoluted tubule and collecting duct to become more permeable to water (more water is reabsorbed in the nephron)
2 structures in the flowering plant which play a role in excretion
Lenticels
Stomata
Metabolism
All chemical reactions in an organism
What is the elders used to describe animals that can vary their metabolic rate
Endotherms
When is metabolism slowed down
When temperature varies
How does the liver help maintain homeostasis
Regulates glucose storage
Produced bile for small intestine
How does the lungs help maintain homeostasis
Balances gases in our body
How does the nephron in kidneys help maintain homeostasis
By regulating concentration and volume of fluids in our bodies