which hormones does the posterior pituitary gland relase?
oxytocin and ADH
which hormones fros the anterior pituitary gland release?
ACTH, LH, FSH, TSH, prolactin,growth hormone,
what does oxytocin cause?
muscle contractions in uterus
what does ADH effect?
permeability of kidney tubules
FSH is the production of?
oestrogen and sperm
LH is used in?
ovulation and testosterone production
what does prolactin cause?
milk production from mammary glands
is adrenaline a hydrophobic or hydrophillic hormone?
Hydrophobic
is oestrogen a hydrophilic or hydrophobic hormone?
Hydrophilic
a seed absorbs water, which causes gibberellin to be produced in the embryo. this synthesises amylase, which breaks down starch (in the endosperm) into maltose. this turns into glucose, which is used in the embryo.
auxins bind to cells and cause ph to decrease. this loosens cell wall, so water enters cell, elongating it.
Pr is converted to Pfr when?
daylight
Pfr is converted to Pr when?
night
in long day plants, does Pfr inhibit or promote flowering?
promote
in short day plants, does Pfr inhibit or promote flowering?
inhibit
hormones are produced in the neurosecreatory cells 2, then transported to the posterior pituitary gland once a stimulus has happened.
releasing factors and release-inhibiting factors are released into the portal vessels/anterior pituitary gland, from neurosecretory glands 1 which will then cause other glands to produce hormones.
stimulus —— receptor —— sensory neurone —— relay neurone and CNS —— motor neurone —— effector
In motor and sensory neurone, impulse moves from dendrites to synapticbulbs.Effector is at the synaptic bulb in motor, receptor is at dendrites in sensory
node of ranvier are the gaps between Schwann cells around the axon
threshold potential is the minimum amount of stimulation needed to trigger an action potential in a neuron (-50mV)
during depolarization, voltagegatedNa+channels open and Na+ moves into the cell
during polarization, the voltage gate K+ channels open and K+ moves out of cell
during the refractory period, the levels of Na+ and K+ need to return to normal, so leak K+ channels and na+/k+ pumps are used to restore the resting potential
Steps of synaptic transmission
depolarization causes voltage gated calcium channel to open
causes vesicles with NT to move to membrane
NT diffuse across synaptic cleft, binds with post-synaptic receptors
Sodium channels open, na enters causing depolarization (action potential)
enzymes break down NT in cleft, active transport back in to pre-synaptic neurone
Where does acetate come from in actylcholine?
AcetylCoA
what is actylcholine?
neurotransmitter
where is noradrenaline found?
sympathetic nervous system
where is actylcholine found?
parasympathetic nervous system
lidocaine blocks voltagegatedsodium channels, prevents depolarization so there is no action potential in sensory neurones.
it can also prevent arrhythmias by reducing action potential in pacemaker reigon
cobravenom binds irreversibly to actylcholine receptors on post-synaptic neurone. prevents transmission of impulse across synapses, muscles can’t contract, causing paralysis. it can then cause death if breathing muscle is paralysed
how many bipolar cells do cone cells synapse with?
1
how many bipolar cells do rod cells synapse with?
Multiple
which cells are mainly in your peripheral vision?
rods
which cells are on your fovea?
cones
rod cells are used in low light intensity and have low resolution - because multiple rods synapse with a biopolar cell, so the brain doesn’t know which rod the action potential is coming from, so blurry.