Excretion Flashcards
What is metabolism?
This is the name given to the chemical reactions that goes on in the cells that changes food into energy
Differentiate between catabolism and anabolism
Catabolism describes breaking down processes whereas anabolism describes building up processes
Define excretion
This si the removal of waste products made in chemical reactions in the cells, which may be harmful to the body
Differentiate between egestion and secretion
Egestion is the removal of waste products of digestion from the body through the anus
whereas
Secretion is the production and release of useful chemical substances
How do unicellular organisms excrete?
They excrete by simple diffusion through the cell membrane
What are the four main excretory organs found in mammals?
Lungs
Liver
Skin
Kidney
What are the functions of the main excretory organs?
Lungs- removes CO2 and water vapour
Liver - removes bile pigments from the breakdown of haemoglobin in worn out red blood cells which are lost in faeces
Skin - removes salts, water and traces of urea via the sweat glands
Kidneys - removes water and large quantities of urea
What is meant by deamination?
This is the process whereby excess amino acids are removed from the body via urination
Define the skin
This is a tough and flexible covering of the body acting as a mechanical protective external layer
How are the kidneys connected to the urinary bladder?
By two ureters
What is the erector muscle of the skin?
It controls whether hair stands up or lies down
What is the sebaceous gland of the skin
It produces an oil called sebum which lubricates the skin and hair
What is the function of the blood capillaries in the skin?
It controls the amount of blood brought close to the skin(and the amount of heat lost)
What is the function of the hair in the skin?
It regulates temperature
What are the various sensory cells and their functions?
Pain receptor - detects pain
Temperature receptor - detects temperature changes in the environment
Pacinian corpuscles - pressure receptor
Meissner’s corpuscles - touch receptor
Fat cells…
Insulates
Mention 3 functions of the skin
Prevents excessive loss of water from the body
Thermoregulation
A sensory receptor organ which receives the stimuli of touch, pain, heat and cold protecting the body from harm
Protects the body from bacterial and fungal invasion and UV light or radiation
Excretory organ..excreting urea, lactic acid and water
What is the name of the tube which leads from the bladder to outside?
Urethra
What are kidney tubules?
Aka nephrons..the basic units of the kidney
What are the two main regions of the vertical cross section of a kidney?
Medulla - lighter,inner region
Cortex - outer, darker region
How many nephrons are in a kidney?
One million per kidney
The network of capillaries found in the bowman’s capsule is called..
Glomerulus
The capillaries of the glomerulus and bowman’s capsule have special structures to allow small molecules to pass through them. What is the name of this filtration under pressure?
Ultrafiltration
What is the name given to the filtrate that filtrates under pressure in the kidneys?
Glomerular filtrate
What two parts is the skin divided into?
Epidermis - the outer part of the skin which is several layers thick
Dermis - a layer of connective tissues containing relatively few cells and many fibres
The innermost layer of the epidermis is the…
Malpighian layer
Mammals are homoiotherms
True or false
True
What does it mean to be homoiothermic?
The ability to maintain a constant temperature despite changes in the environment
What are the two stages of urine formation?
Ultrafiltration
Selective reabsorption
Define selective reabsorption?
The reabsorption into the blood useful metabolites like glucose and amino acids from the glomerular filtrate into the proximal tubule
Define homeostasis
The process of maintaining a constant internal body environment within a living system
What are the three regions that make up the epidermis?
Cornified or horny layer - the upper, thin region which consists of flats, dead cells which flake off
Granular layer. - below 👆… consists of living cells produced recently by the Malpighian layer
Malpighian layer - below 👆.. continuous layer where cells are actively dividing, continually producing new epidermis
It contains the pigment melanin
