Transport in animals Flashcards
AVN (3)
Atrio ventricular node
Causes a slight delay to wait for atria to contract
Sends impulse down bundle of His connecting to purkyne fibres
P wave in ECG
Atrial systole
Contraction of atria
Atrial systole (3)
Pressure in ventricle is lower than atria
Blood build up in Atria causes contraction that increases pressure
Forces blood down atrioventricular valves
QRS wave in ECG
Ventricular systole
Ventricular systole (4)
Depolarisation of the parkyne fibres caused ventricular contraction
Pressure in ventricle higher that aorta and pulmonary artery
Atrioventricular valves shut
Forces blood up semi lunar valves
Diastole
Relaxation of ventricle and atria
Ventricles and atria fill with blood
T wave ECG
Diastole
Repolarisation of ventricles and atria
Myogenic contraction.
Heart beating without input from nervous system
Heart beats throughly electrical impulses from myocytes’ membrane
Bundle of His
Cardiac muscle cells that transmits electrical impulses from AV node to apex and
Purkyne fibres
Purkyne fibres (2)
Receive impulse from bundle of His
Cause cardiac cells to contract at apex and cause ventricular systole
SAN (3)
Sino-atrial node
Located at the right atrial wall
Causes depolarisation via impulse which causes atria to contract
Brief description of oxygenated blood pathway in heart (6)
- Comes through Pulmonary vein
- Left atrium
- Atrioventricular/ bicuspid valve
- Left ventricle
- Semilunar/ aortic valve
- Aorta/ Carotid arteries
Deoxygenated blood pathway in the heart (5)
- Superior/ Inferior vena cava
- Right Atrium
- Atrioventricular/ tricuspid valve
- Right ventricle
- Semilunar valve
Brief description of oxygenated blood pathway in heart (6)
- Comes through Pulmonary vein
- Left atrium
- Atrioventricular/ bicuspid valve
- Left ventricle
- Semilunar/ aortic valve
- Aorta/ Carotid arteries
Deoxygenated blood pathway in the heart (5)
- Superior/ Inferior vena cava
- Right Atrium
- Atrioventricular/ tricuspid valve
- Right ventricle
- Semilunar valve
Describe arteries (7)
- Carry blood at high pressure away from the heart
- Folded endothelium to ran able expansion under high pressure
- thickest layer of elastic fibre
- thickest layer of smooth muscle
- thickest layer of collagen to maintain strength under high pressure
- narrow lumen to maintain high pressure
- no valves
Describe veins (7)
- carries blood to heart under low pressure
- thinner smooth muscle later as exertion force is not high
- thinner elastic fibres as low pressure causes less recoil
- contains valves to prevent back flow
- Thin endothelium
- Thin layer of collagen as high pressure is not present
- Wide lumen: allows blood to flow easily.
Describe capillaries (5)
Allows exchange of materials within cells.
One cell thick endothelium which allows short distance for quick diffusion.
Small Lumen (10 micrometers) increase resistance which allows increases time for exchange of material.
Gaps in the walls allow many substances to pass through when materials are exchanges.
Very abundant: provides large surface area for diffusion.
Describe how tissue fluid is created at arterial end (3)
High hydrostatic pressure at arteriole end inside capillary
- outweighs the osmotic pressure forcing fluid inside capillary
- causes net flow of fluid out of capillary
Describe tissue fluid movement at venous end (4)
- osmotic pressure is still constant
- hydrostatic pressure decreased as fluid left at arterial end
- osmotic pressure into capillary outweighs hydrostatic pressure out of capillary
- causes net movement of fluid into capillaries
Describe pathway of electrical impulses in the heart (4)
- SAN depolarises to release impulse that spreads across both atria
- band of tissue prevents conduction into ventricle
- AVN waits for atria to contract before sending impulse down bundle of His
- impulse travels to Purkyne fibres which cause ventricular contraction upwards from the apex
Tachycardia (3)
- rapid heart beat over 100bpm
- occurs during exercise
- has evenly spaced QRS complex
Bradycardia (2)
- very low heart rather; below 60 Bpm
- common amongst for athletes
Ectopic heartbeat (3)
- heart beat out of rhythm
- irregular QRS complex
- long intervals before P wave