The Heart And Circulatory System Flashcards
Why do large organisms need a transport system ?
Small surface area to volume ratio.
Long diffusion pathway therefore requires specialised systems for efficient gas exchange. High metabolic rate requires a lot of oxygen for gas exchange.
What are the benefits traveling from the intestine and stomach to the liver via the hepatic portal vein before rejoining the circulatory system.
Liver processes toxins in ingested food.
What is pulmonary definition ?
Between heart and gas exchange surface
Systemic definition
Between heart and body tissues
All gerund Carey deoxygenated blood apart from …..
The pulmonary vein
Why is the hepatic Portal vein not a true vein ?
Doesn’t take blood back to the heart
Which blood vessel has the thickest walls and why ?
Arteries. To withstand the high blood pressure in the ventricles.
In which blood vessels may backflow be an issue
Veins because there is less blood pressure to transport the blood forwards and the the blood may also have to travel against gravity.
Which blood vessels join the right ventricle to the lung capillaries
Pulmonary artery
Which blood vessel allows oxygenated blood to move away from the heart ?
Aorta
Which blood vsessel allows deoxygenated blood to move away from the liver
Hepatic vein
Which is the first blood vessel which O2 molecules meet after absorption in the alveoli.
Pulmonary vein
Give 2 factors that make it more likely for an organism to have a circulatory system ?
High metabolic rate
Small surface area to volume ratio
What is the advantage of a double circulatory system in mammals.
Increases blood pressure so increased blood flow to tissue.
Why are fish able to have a single circulatory system ?
Fish are cold blooded so don’t require heat from respiration to heat their body. Therefore the energy demand per cell is lower than in mammals so a single circulatory system provides sufficient energy.
Give the main features of transport mediums
Medium to carry materials such as blood plasma.
Closed system of tubular vessels.
Way of moving transport system with vessels.
Way to maintain blood flow in one direction.
Way of controlling flow rate of the transport medium.
What are the main features of arteries ?
Arteries are organs.
They have elastic collagen fibres and smooth muscles to allow recoil during changes in blood pressure.
Smooth endothelium allows high pressure as there is no energy used to overcome friction. No valves
What are the main features of arterioles ?
Smooth muscle cell rings
Smooth endothelium reduces friction.
Elastic layer enable vasodilation and vasoconstriction to regulate blood flow.
No valves
Thick muscle layer to withstand pressure.
Give the main features of veins.
Wide lumen - low pressure
Thin walls - les elastic as pressure is low
Valves- prevent backflow of low pressure in blood
Smooth endothelium - reduces pressure
No pulsating- smooth blood flow
What are the main features of capillaries.
Thin layer of endothelium cells - 1 cell thick for a short diffusion pathway.
Numerous and highly branches capillaries give a high surface area for diffusion.
Narrow linen ensure red blood cells are close to the tissue and give a short diffusion pathway.
Spaces between cells allow white blood cells to espace.
What is the main function of the left side of the heart ?
Pumps oxygenated blood to body tissue
What is the main purpose of the right side of the heart ?
Deoxygenated blood pumped to lungs for gas exchange.
Which side of the heart pumps deoxygenated blood to the lungs for gas exchange ?
Right
Why does the left side of the heart , especially the left ventricle, have more cardiac muscle than the right ?
Allow an increased pressure for blood going to the whole body.
Why are the atria walls elastic
To allow collection of blood from the whole body
Give an adaptation if the atria to collect blood from the whole body.
Elastic walls
Why do the ventricles have thick muscular walls ?
To contract and pump blood to the heart.
What type of muscle is the heart made out of.
Cardiac muscle
What are the purpose of heart valves ?
Prevent backflow.
How are valves controlled.
By pressure changes in the heart.
What is the main purpose of the coronary arteries and cardiac veins ?
Supply the heart muscle with oxygen so that myscles can respite and remove carbon dioxide.
What is the medical term for a heart attack ?
Myocardial infarction
What happens if the coronary arteries or cardiac veins are blocked ?
Muscle is deprived of oxygen and therefore dries.
What causes myocardial infarction ?
Blocked coronary arteries and cardiac veins.
Compare the right and left sides of the heart
Right is less muscular while the left side has more muscle to allow high blood pressure transporting blood to whole body.
Right side carries deoxygenated bloody from body. Let side carries oxygenated blood from lungs.
Right side has the tricuspid valve. Left side has bicuspid valve.
Right side pumps blood to lungs. Left side pumps blood to whole body b
