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Phys Lect 20
Question | Answer |
---|---|
What are 2 components of BP? | 1.CO (cardiac output: BP/total resistance). 2.Peripheral vascular resistance. |
What ANS system is almost entirely responsible for blood vessel control? | SYMPATHETIC |
Adrenergic receptors found in the smooth muscle of Blood Vessels | 1.Alpha 1: contraction: Vasoconstriction. 2.Beta 2: relaxation: Vasodilation |
What type of adrenergic receptors are crucial for the tissue utilized during exercise? | B2. you want to be able to induce vasodilation in the arterioles of the Heart, Skeletal Muscle, and Liver during exercise to keep nutrients flowing to the appropriate locations. |
What will happen to the Blood vessels if chromaffin cells have been sympathetically stimulated? | The Chromaffin cells will dump large amounts of Epi into the BL. Since B2 receptors have a very high affinity for Epi, they will have increased binding activity over the A1 receptors which will induce vasodilation via smooth muscle relaxation. |
Parasympathetics affect on the Intestine | M Receptors activated by bound ACh will cause: 1.Sphincter relaxation. 2.Smooth muscle contraction (peristalsis) |
Sympathetics affect on the Intestine | 1.Alpha 1 receptors: Smooth muscle contraction: Sphincter closing. 2.A2 and B2 receptors: smooth muscle relaxation: slow down motility. |
Sympathetics affect on Bladder | FILLING, NO PEE PEE (http://www.youtube.com/watch?v=wlli9ci2DqU) 1.A1 receptors: contract trigone and Int sphincter. 2.B2 receptors: smooth muscle relaxation: relax Detrusor muscle and allow filling |
Parasympathetics affect on Bladder | ACh stimulates M receptors causing EMPTYING: 1.Sphincter relaxation: Trigone and Int sphincter relax. 2.Smooth muscle contraction: Detrusor muscle contraction and emptying |
Is Micturation under the brains control? | NO, SPINAL REFLEX. 1.Strech sensors send afferents to spinal cord (Sacral level). 2.Parasymp NS sends efferents to M receptors causing emptying. |
Is Urination under the brains control? | YES. If it is socially unacceptable, the brainstem & cortex send IPSPs inhibiting micturition reflex. **When it is acceptable, brain sends EPSPs to micturition reflex and relaxes the external urethral sphincter. |
How could sacral spinal cord damage affect urination? | 1.loss of micturition reflex. 2.Overflow dribbling (fullness of bladder will overcome sphincter control). 3.Reflex intact but no longer recieves IPSPs from the brainstem & cortex. |
Which ANS system is responsible for controling the skin? | SYMPATHETICS |
What type of adrenergic receptor is targeted by the sympathetic nervous system in the skin? where is it and what does stimulation cause? | Alpha1 receptors: Cause smooth muscle contraction: cause piloerrection of hairs by errector pili muscles. **These A1 receptors also cause increase sweating in the hands. |
What type of sympathetic receptors are responsible to increased sweating in the skin? | M receptors (except in palms) ***EXCEPTION*** this is the only time the sympathetic postsynaptic neurons release ACh to target M receptors. Increases sweating. |
ANS control over renal BL flow regulation? | minimal. |
What type of receptors are targeted on the Juxtaglomerular cells? | Located on the afferent arteriole, the have B1 receptors that respond ot sympathetic NE: Causes secretion of Renin->Angiotensin->AngiotensinII (vasoconstriction). |
Mechanism of Erection | Parasymp (CNS independent). 1.Dilation to both penile arteries (NO released from endothelial cells aids in this). 2.Engorgement of of corpus cav & spong. 3.Compression of venous drainage. |
Mechanism of Emission | Symp (CNS independent). 1.A1 receptors cause smooth muscle contractions (epididymis, vas def, seminal ves, prostate). 2.Propulsion of fluid into posterior urethra. 3.A1 receptors also cause contraction of int urethral sphincter and trigone muscle. |
Mechanism of Ejaculation | Symp (CNS independent). 1.A1 receptors cause contraction (bulbospongiosus, ischiocavernosus). 2.Expulsion of semen |
How can the male erectile, emission, and ejactulatory processes bypass CNS? | Sensory afferents from stimulation come into sacral spinal cord, synapse on interneurons which activate efferent parasympathetic neurons. With enough continued stimulation, the sympathetics will also be stimulated causing emission and ejaculation. |
What causes transudation in the mysterious vaginia? | Continued parasymp AND symp stimulation. Leads to lubrication (so you don't need one little bottle of spermicidal lube). **Bartholin's glands also contribute |
What occurs during the Orgasmic platform? | 1.Contraction of outer vagina. 2.shortening of uterus. 3.dilaiton of cervix. **Higher brain centers are very involved (seafood dinners increase response) |