Physiology Flashcards
Catecholamines
Stimulation of our organs by the sympathetic nervous system.
Trigger “fight or flight” response.
What are some of the catecholamines?
noradrenaline (norepinephrine) and adrenaline (epinephrine)
Miosis
Narrowing the pupil
Constriction
Parasympathetic activation
Contraction of the sphincter muscle
Mydriasis
Dilation
Sympathetic activation
Dilator pupillae muscle contraction
Atropine blocks muscarinic receptors
Hypothalamus
a region of the forebrain below the thalamus which coordinates both the autonomic nervous system and the activity of the pituitary, controlling body temperature, thirst, hunger, and other homeostatic systems, and involved in sleep and emotional activity.
What does NO (nitric oxide) do to vascular smooth muscles?
Muscle relaxation and vasodilation
Parathyroid hormone and calcium
Classic negative feedback system.
The parathyroid hormone helps maintain an appropriate balance of calcium in the bloodstream and in tissues that depend on calcium for proper functioning.
Conservation of calcium by the kidneys.
In the bones, the hormone triggers the release of calcium stores from the bones to the blood leading to bone destruction.
In the intestines, the parathyroid hormone helps with vitamin D metabolism.
Forced Expiratory Volume 1
How much air is exhaled in one second (forced breath).
In healthy individuals, 80% of air is exhaled in the first second.
Good for diagnosing patients with obstructive lung disease
Where is calcitriol vitamin D made?
Kidney
Kep in mind
Steroid hormones vitamin D, thyroid hormone acting through nuclear DNA binding receptors.
or
Vitamin D had nuclear DNA binding transcription regulatory receptors.
Vitamin D receptor in the nucleus…
Binds VDREs
T4
major form of thyroid hormone made in the thyroid gland. It can be activated to T3.
Medulla
Most neurons responsible for respiratory regulation are in the medulla.
Some are in the pons (pneumotaxic control center).
What is the importance of the pneumotaxic
Control of respiratory rate and depth of breathing.
Curare
Competes with ACh for receptors.
It acts postsynaptically.
BoTox
Blocks release of ACh from presynaptic terminals
the neuron botulinum toxin interferes with SNARE proteins responsible for vesicular ACh release and results in flaccid paralysis of muscle exposed to the toxin, including the diaphragm.
What are the slowest fibers?
Unmyelinated C fibers.
Function - postganglionic autonomic fibers; pain and temperature.
Slow, chronic, aching pain.
Remember
The larger the diameter of an axon, the faster it will be.
Rod sodium channels are regulated by binding which of the following
cGMP
Growth hormone
Secreted by the anterior pituitary
Secretion stimulated by GHRH
Secretion inhibited by somatostatin.
Most effects of GH are mediated by IGF-1.
GH stimulates the release of IGF-1 from hepatocytes.
IGF-1 activated tyrosine kinase receptors on cells and stimulates cell division
Alpha motor neurons
they are the motor neurons that innervate the long muscle fibers that go full length
Gamma motor neurons
They innervate short muscle fibers
They innervate muscle spindle cells
Which neurotransmitter is used by alpha motor neurons?
Acetylcholine
What part of the brain controls the body temperature setpoint?
Hypothalamus
What is the hippocampus known for?
Memory storage
Why is GABA so popular as an inhibitory neurotransmitter?
type A GABARs
They are ligand-gated channels.
Which neuron is most likely to be an inhibitory neuron
Interneuron
Which of the following is most likely to cause an inhibitory post-synaptic potential?
GABA
Which ion channel is most commonly associated with hyperpolarization?
Chloride channel
Adrenergic receptors
G Protein-coupled
Troponin
key calcium-binding protein for regulating striated muscle contraction in smooth muscle.
What is the major excitatory transmitter?
Glutamate
involved in memory formation
Cell death if overstimulated
The nicotinic acetylcholine receptor is what type of protein?
Ligand-gated ion channel
Remember
Chronic hypertension is a leading cause of kidney failure.
Short-term: an increase in BP leads to an initial increase in GFR causing pressure diuresis (increased urine).
Long-term: damages the glomeruli eventually destroying it (reduced GFR).
Baroreceptos reflexes - sit to stand
Reduced activity of baroreceptors - reduced parasympathetic stimulation - increased sympathetic stimulation - increased cardiac output and vascular resistance and increased blood pressure.