Nervous system III Flashcards
What is a reflex?
it is a rapid, automatic reponse to stimuli. It always causes the same motor response and is usually protective.
What is the minimum amount of neurons that are involved in a Relfex?
2 or more neurons are involved
What are the effectors in both the somatic and vesceral(autonomic) reflex?
In the somatic reflex, the effector is a skeletal muscle.
In the visceral reflex, the effector is a smooth muscle, a cardiac muscle or glands.
When is a reflex considered an ipsilateral refex?
when the sensory and motor neurons are on the same side.
When is a reflex considered contralateral
when the sensory + motor neuron are on oposite sides
What is a monosynaptic reflex?
when theri is only 1 synapse between one sensory and 1 motor neuron
What is a polysynaptic reflex?
when there is 2 or more synapses between 3 or more neurons.
Give an example of the stretch reflex and explain it. (knee jerk reflex)
The knee jerk relfex: when you tap someones patellar ligament and the extensor muscle contracts. the receptor in this case is the muscle spindle in the quadricept, the effector is the quadricep skeletal muscle. This is considered an Ipsilateral, monosynaptic relfex.
Explain the Flexor (withdrawal) Reflex. (stepping on a nail example).
You step on a nail and a pain receptor fires, causing the effector (hamstring…“flexor”) contract witch pulls the foot in danger away from nail. this is considered a Ipsilateral, polysynaptic reflex.
Explain the cross extensor reflex with the “stepping on a nail” example.
when you step on a nail, the foot that is in danger of the nail is the one that undergoes the withdrawal reflex so the cross extensor relfex is the one that will keep you from falling and use the effector (in this case the quadricep) to extend the leg. this is considered a contralateral polysynaptic relfex.
what is Reciprocal Inhibition?
where the agonist contracts and the antagonist is prevented from contracting.
what is the Micturition Reflex
where the urinary bladder is stretched and causes the detrusor muscle (wall of bladder) to contract and internal urethra is opened and causes you to pee.
What does the Cerebellum do?
interprets general info from general senses and special senses. Initiates and controls skeletal muscles. Involved in memory and relaying info to other areas of the brain.
in short, what does the Brian Stem do?
the part that keeps you alive. Involved in the basic functions of life. Breathing, circulation.
what are the three part of the Brian Stem.
Midbrain, Pons, Medulla oblongata
What is the Midbrain involved in?
Auditory and Visual reflexes
What are the Pons involved in?
Functions with the medulla to regulate breathing.
where does decussation of sensory + motor tracts happen and what does it mean?
Medulla Oblongata, and it means the the right side of the brain controls the right skeleton and vice versa.
what drives Breathing rate in the brain?
the repiratory area in the Medulla Oblongata
What controls blood vessel diameter and modifies heart rate in the brain?
the cardiovascular Center in the Medulla Oblongata.
Other, non-vital areas, in the Medulla Oblongata control what ?
control swallowing, vomitting, coughing, sneezing etc.
What part of the brian regulates ANS (smooth muscle & cardiac muscle, glands)
Hypothalamus.
Which area of the Brain Regulates parts of the endocrine system?
Hypothalamus.
What regulates Temperature in the Body?
the hypothalamus.
