B5 Flashcards
Where is aveoli found?
In the lungs
Summarize the gaseous exchange system
Oxygen is inhaled
Oxygen from the aveoli diffuses into the blood stream
Carbon dioxide from the blood stream diffuses into the aveoli
Carbon dioxide is exhaled
What is the enzyme in saliva that breaks down carbs into sugars called?
Amylase
Where are villi found?
In the small intestine
What is the function of villi?
They absorb nutrients, and then pass them into the bloodstream
What do aveoli do?
They allow oxygen and carbon dioxide to move between the lungs and bloodstream
Summarize the digestive system
Amylase breaks down carbs into sugars
Food is mechanically churned in the stomach, and chemically broken down by gastric acids
Villi pass absorb necessary nutrients and pass them into the bloodstream
Waste is stored in the rectum, and eventually excreted
What are the two main circulatory systems?
Systemic and Pulmonary
What is the role of the systemic circulatory system?
It carries oxygenated blood away from the heart and to other parts of the body
What is the role of the pulmonary circulatory system?
It carries oxygen-depleted blood away from the heart, to the lungs (where it is oxygenated), and then back to the heart, ready for the systemic circulatory system
Summarize the excretory system
The kidneys filter out any waste from the blood
This waste is then stored until excretion
What are the 3 blood vessels?
Veins, arteries and capillaries
What are the properties of veins and why?
They have valves to prevent backflow
They have a large lumen to allow easy flow of blood
What are the properties of arteries and why?
Thick muscular wall to withstand pressure
What are the properties of capillaries and why?
One cell thick wall allows efficient and rapid diffusion in substance exchange
What does the blood contain?
Red blood cells, white blood cells and blood plasma
What is blood plasma and what does it do?
It is the liquid part of the blood, made up mostly of water
It carries blood cells and many substances like CO2, sugars, amino acids and proteins
What are red blood cells and what do they do?
Cells that are packed with a protein call haemoglobin, which binds with oxygen. Oxygen is released from the haemoglobin around the body where neccersary
What can white blood cells do?
They can engulf and destroy pathogens
They can produce antibodies to destroy particular pathogens
They can produce antitoxins that counteract the toxins released by pathogens.
What are platelets and what do they do?
They are fragments of cells
When a blood vessel is damaged, platelets send out substances that trigger a series of reactions, which creates a blood clot at the cut site.
This prevents pathogens from entering, and stops you from losing too much blood
What do the sensory neurons do?
They carry information from receptors to the CNS
What is urea?
A waste product from the breakdown of proteins in the liver
What is diffusion?
The movement of particles from an area of high concentration to an area of low concentration
What is osmosis?
The movement of solvent (e.g. water) molecules across a partially permeable membrane from an area of high concentration to an area of low concentration
What is active transport?
The movement of particles across a permeable membrane from an area of low concentration to an area of high concentration, requiring energy
How are alveoli specialised for maximising the rate of diffusion of O2 and CO2?
- Very large surface area to volume ratio
- Very thin walls
- Good blood supply
Villi has a small surface area to volume ratio (true or false)
False- villi has a very large surface area to volume ratio which allows quick transport of nutrients into the bloodstream
How are villi specialised for maximising the rate of diffusion of O2 and CO2?
- Very large surface area to volume ratio
- Single layer of surface cells
- Good blood supply