Bio 253 Exam 2

What does a central nervous system consists of - Brain and spinal cord What is the function of the CNS - Integrated control center What does a pns consist of - Cranial and spinal nerves What is the function of the pns - Communication lines between CNS and the rest of the body What sends impulses to The pns - Sensory division (afferent) What sends impulses from CNS to effector (muscles or glands) - ...efferent Autonomic nervous system - Involuntary (viseral motor) Conducts impulses from CNS to cardiac muscles smooth muscles and glands Somatic nervous system - Voluntary Conducts impulses from CNS to skeletal muscle Local potential (receptor potential) what does it do - Stimulates gated sodium ion channel What do you need to do for stimulated gates to open - Cell needs to reach threshold Can you simulate neuron during absolute refractory period or hyperpolarization - No Can you simulate neuron during relative refractory time - Yes but you need a powerful stimulus Refractory period - During depolarization sodium ions go inside During repolarization potassium leaves Hyperpolarization needs to be fixed by an exchange and ions so it can rest What is a cell like at rest - Sodium on the outside and potassium inside Layers of the external ear - Auricle or pinna External acoustic meatus Temporal bone Middle ear structure - Tympanic membrane Malleus, incus ,stapes (the 3 ear ossicles) Auditory tube Inner ear structure - Semicircular canals Cochlea Vesible Cranial nerves - What does the cochlea do - Provide hearing What does the vestible do? - Provide equilibrium (balance) Inner eye structure - Retina Middle eye structure - Vascular layer such as the choroid layer Outer eye layer - Fibrous layer such as schlera or the cornea What are cones for and what do they work best in - Konza for color vision and they work best with high light conditions What are rods used for and what do they work best with - Black and white vision and work best with low light Pathway of light into the eye - Enters the eye through the cornea, pupil, and lens, retina What is the pathway for hearing - Pinna, external auditory meatus, tympanic membrane, bone ossicle, oval window, scala vestibuli, helicotrema, scala tympani, spiral organ, hair cells, cochlear nerve, auditory cortex Mechanoreceptors different types and what is it for - Touch and pressure Vicero mechanoreceptors (eating and digestion and kidney filtration) Hair cells in the ear absorb sound waves Chemoreceptors - Taste Viseral chemo receptors - Homeostasis that checks level such as hydrogen oxygen sodium levels Thermoreceptors - respond to changes in temperature adapts Nocireceptors - pain receptors Do not adapt Proprioceptors - monitor the position and movement of skeletal muscles and joints Photoreceptors - respond to light What plexus does the phrenic nerve belong to - Cervical plexus What plexus does the radial and median and ulnar nerves belong to - Brachial plexus What plexus does the sciatic nerve belong to - Lumbosacral plexus What is a plexus - A safeguard or alternate pathway such as if somebody is injured in their sign they may be able to walk again due to a plexus What cranial nerves control eye movement - Trochler Occulomotor Abducens What is the vagus nerve - The longest running cranial nerve What does the facial nerve also involve with - Taste What kind of nerves are spinal nerves - Mixed