Pharmacology Flashcards
What does the autonomic NS consist of?
Consists of all the motor outputs from CNS to heart, smooth muscles and glands, apart from skeletal. All about homeostasis.
Where are the ganglionic neurones located?
The pre-ganglionic neutron has its cell body in the CNS and synapses in the autonomic ganglion. The post ganglionic neuron has its cell body in the autonomic ganglion and synapses within the effector organ.
What are the sizes of the ganglionic neurons in the sympathetic NS?
Short pre-ganglionic, long post-ganglionic
Where do pre-ganglionic sympathetic neurons leave from?
The thoracic and lumbar regions of spinal cord (thoracolumbar system)
Where does the synapse occur in the sympathetic NS?
At ganglia close to the spinal cord, the sympathetic paravertebral chain.
What does the sympathetic NS innervate?
Adrenal medulla releases adrenaline.
What are the sizes of the ganglionic neurones in the parasympathetic NS?
Long pre-ganglionic and short post-ganglionic
Where do the pre-ganglionic post sympathetic neurons leave from?
The brain stem and the sacral region of the spinal cord (craniosacral system)
Where does the synapse occur in the parasympathetic NS?
Synapse at ganglia close to effector organ.
Give an example for the parasympathetic NS?
Cranial nerve 10= vagus nerve
Give the main four functions of the autonomic NS:
- Control of cardiac function
- Contraction and relaxation of smooth muscle
- Control of exocrine (some endocrine) glands
- Regulation of energy metabolism
What are the two major neurotransmitters in the autonomic NS and where do they act?
Acetylcholine- parasympathetic
Noradrenaline- sympathetic
What are the two acetylcholine receptors and what type are they?
1) Nicotinic- ligand gates ion channels
2) Muscarinic- GPCR
What is the noradrenaline receptor and what type are they?
Adrenoreceptors- GPCRs
Subtypes- alpha- adrenoreceptors
- beta- adrenoreceptors
What neurotransmitters are released from the CNS and what receptors do they act on?
ACh and act on nicotinic receptors
What is the main function of the kidney? Give three examples:
Excrete metabolic products:
1) urea- end of amino acid breakdown
2) uric acid- end of nucleotide breakdown
3) xenobiotics
Give four other functions of the kidney:
Regulate body fluid osmolarity and volumes
Electrolyte balance
Acid-base balance, blood 7.4, urine 6- shows getting rid of H+ ions
Endocrine function
Name the eight segments of the nephron in order:
Proximal convoluted Proximal straight Descending LoH- thin Ascending LoH- thin Ascending LoH- thick Distal convoluted Cortical collecting duct Medullary collecting duct
What is the average amount of glomerular filtrate filtered? How many ml of urine a day?
120ml/min and 1.5L
What are the three fundamental processes that account for renal secretion?
1) Glomerular filtration
2) Tubular secretion
3) Reabsorption from tubule
How do you calculate the urinary excretion rate?
Filtration rate+ secretion rate- reabsorption rate
How much of the glomerular filtrate is filtered?
10-20% the rest is passed into the efferent arteriole
What allows a high pressure for filtration?
Lumen of the efferent arteriole is more narrow than the afferent arteriole
Which three layers is fluid filtered through?
1) The glomerular capillary wall
2) The basement membrane
3) Podocytes in the inner layer of Bowman’s capsule
What type of components can filter through easily?
<2000 Daltons easily eg. glucose and amino acids
>50,000 Daltons can’t eg. proteins
Unbound drugs yes but drugs bound to proteins no
What is the glomerular filtration rate regulated by?
Autonomic NS
How much fluid passes through the peritubular capillary in the proximal tubule?
80-90%
What are the two transporters in the proximal tubule?
Organic Anion Transporters (OAT)
Organic Cation Transporters (OCT)
How much of: Water are absorbed?
Na+ ions
Glucose
Urea
99%
99.5%
100%
44%
Where does water move in the proximal tubular function?
Tight junctions
How is glucose reabsorbed in the blood?
Co- transporters with Na+ then with a carrier protein to the peritubular capillary
Why is the ascending loop impermeable to water?
Its tight junctions are tight
Why is the descending loops permeable to water?
Lots of aquaporins
Is the distal tubule permeable or impermeable to water?
Highly impermeable to water
What happens in the collecting duct?
ADH increases the number of aquaporins so more permeable to water so increases reabsorption.
Aldosterone increases Na+ channels so more reabsorption of Na+ and thus increasing blood volume.
Is the inside or the outside of a cell more negative?
Inside
What secondary structure is a transmembrane domain?
a- helices
What is a voltage sensor on a voltage gated ion channel?
Detects electrical charge and rotation and opens the channel pore.