Pharm and Nervous system Flashcards
________ innervates internal organs, blood vessels, glands - essentially all organs that contain at least some smooth muscle; purpose is to maintain homeostasis and respond to stress; referred to as the involuntary nervous system because it is beyond conscious control
Autonomic nervous system -
___________ innervates skeletal muscle; under the conscious control of higher centers in the brain; referred to as the voluntary nervous system
Somatic motor nervous system –
Autonomic nerve has intermediate synpase at:
autonomic ganglion
What is nerve fnx of autonomic nerve
can be excitatory or inhibitor
What are the target organ for somatic nerve
skeletal muscles
intermediate synapse for somatic nerve
none
Nerve myelination is _______ on somatic nerves
present
Nerve myelination is ________ on post gangs of ANS
absent
Consequences of Nerve Sectioning in somatic nerve:
Paralysis and atrophy of muscle
Consequences of Nerve Sectioning in Autonomic nerve
Retain some level of spontaneous activity (Release from central control)
Ratio of Segment Lengths
Short Pre-ganglionic, Long Post-ganglionic is:
Long Pre-ganglionic, Short Post-ganglionic:
SNS
PNS
Degree of divergence in PNS
low, 1:3 for a pre;post ratio
Degree of divergence in SNS
HIGH for Pre:post, very divergent effects
Nerve fnx for SNS
excitatory or inhibitor
nerve funx for PNS
excitatory or inhibitory
What regulates activity of structures not under voluntary control that function below the level of consciousness (respiration, circulation, digestion, temperature, metabolism, sweating, endocrine gland secretion)
Autonomic nerves
Sympathetic
a. normally_________ active
b. the degree of activity varies from moment to moment and from organ to organ thus allowing :
continuously
adjustment to a changing environment
- ___________ heart rate and blood pressure
- shift in blood flow from skin & splanchnic regions to skeletal muscles
- ________ blood glucose and free fatty acids
increased
increase
What happens to bronchioles and pupils during SNS stimulation
dilate
Actions of SNS reinforced by_________ released from the adrenal medulla
epinephrine
concerned with conservation and maintenance of organ function during periods of minimal activity
PNS
PNS causes pupillary______
constriction
emptying of bladder and rectum during PNS or SNS
PNS
How do nerve impulses elicit responses of tissues
through liberation of specific chemical neurotransmitters
Vagusstöff discovered:
Acetylcholine
Acceleranstöff discovered:
Epinephrine
frogs, norepinephrine in mammals
Steps involved in neurotransmission
- Axonal conduction
2. Junctional transmission