cardiovascular physiology Flashcards
define endothelium
the innermost layer of a vein- smooth surface for easy blood flow
define starlings forces, refer to hydrostatic pressure in blood vessels
solutes are pushed out of blood vessels due to hydrostatic pressure. they are reabsorbed at areas of lower pressure to maintain a constant gradient
apart from the heart, what helps blood return to the heart (why staying still for too long is bad)?
movement of skeletal muscles
define the frank-starling law, refer to stroke volume
the larger the diastolic pressure (volume of blood in ventricles), the larger the stroke volume (power of ventricle contraction) will be
what do baro receptors do?
signal to parasympathetic and sympathetic NS to increase or decrease action potentials in SAN to alter heart rate
what neurotransmitters are used to signal to these systems?
acetylcholine (parasympathetic), noradrenaline (sympathetic)
how are tree snakes adapted to keeping blood flowing to their brains?
hearts close to head
how are giraffes adapted to stop blood pooling in their legs?
tight skin
how are giraffes jugulars adapted to preventing back flow to brain when head is below heart?
they have valves to prevent back flow
define haemocyonin
cephalopod equivalent to Hb
why is cephalopod blood blue?
haemocyonin had a copper group (can hold 1 O2 molecule)
what does a lack of a venous reserve mean for cephalopod muscle response?
it is faster
