Nervous System Exam Flashcards
injury to T:1 - L1 causes?
Paraplegic paralysis
Graded potential
a change in the membrane potential that is localized to one area of the plasma membrane; can result from 1) chemical signals binding to their receptors, 2) changes in the voltage across the plasma membrane 3) mechanical stimulation 4) temperature changes 5) spontaneous changes in membrane permeability
Refractory period
once an action potential is produced at a given point on the plasma membrane, the sensitivity of that area to further stimulation decreases for a time
Absolute refractory period
the first part of the refractory period during which complete insensitivity exists to another stimulus
Action potential
electrical impulses carried along the length of the axons; always the same regardless of stimulus; the underlying functional feature of the nervous system
Astrocytes
astrocytes first of the supporting cells;branched glial cells;
they cling to neurons and their synaptic endings, and cover capillaries; anchor neurons to their nutrient supplies, guide migration of young neurons, control the chemical environment, looks like a spider web
CNS
brain and spinal cord
integration and command center
Diencephalon
central core of the forebrain; deepest part of the brain; consists of three paired structures - thalamus,; hypothalamus, and epithalamus; encloses the third ventricle
Gyri
Ridges of cerebral hemispheres
Nodes of Ranvier
gaps in the myelin sheath between adjacent schwann cells; they are the sites where axon collaterals can emerge
Pons
conducting bridge between the midbrain and the medulla oblongata; helps out with regulation of respirations, touch, pain, and temperature
SNS
conscious control of skeletal muscles
Nerve
bundle of axons and their sheaths; connects to the CNS to sensory receptors, muscles, and glands
Synapse
junction that mediates information transfer from one neuron
Somatic vs autonomic
somatic (conscious control of skeletal muscles)
autonomic (regulates smooth muscle, cardiac muscle, and glands)
Blood brain barrier
protective mechanism that allows you to maintain a stable internal environment
selectively lets things in an out of the brain
if it can be diffused through the capillaries, it can be diffused to the brain
Broca’s area
a motor speech area that directs muscles of the tongue
Mature neurons are:
Amniotic
Where are sensory receptors
Peripheral nervous system
CSF
watery solution that contains less protein and different ion concentrations than plasma; forms a liquid cushion that gives buoyancy to the CNS organs
Cerebral white matter
consists of deep myelinated fibers and their tracts
it is responsible for communication between:
the cerebral cortex and lower CNS center, and areas of the cerebrum
Dendrite
conduct the impulses into the soma or cell body
Synaptic cleft
fluid-filled space separating the presynaptic and postsynaptic neurons; prevents nerve impulses from directly passing from one neuron to the next
Axon
Carries information away from soma
Reticular diffusions
diffuse system that involve the “cycles” of activity, such as the sleep-wake cycle
Oligodendrocytes
branches cells that wrap CNS nerve fibers
Schwann cells (neuroelmmocytes)
surround fibers of the PNS
sympathetic division
system that controls the sweat glands
sympathetic and parasympathetic
the divisions of the ANS (autonomic nervous system)
Lumbar plexus branch off
L1-L4
Femoral (anterior thigh)
Obturator (medial thigh)
Brachial plexus branch off
C5-C8 and T1 Ulnar (forearm and hand) Median (forearm and hand) Axillary (shoulder) Musculocutaneous (anterior arm) Radial (posterior arm)
cervical plexus branch off
ventral rami of C1 - C4
Phrenic (diaphragm)
Ansa cervicalis
Function of hypothalamus
regulates blood pressure, rate and force of heartbeat, digestive tract motility, rate and depth of breathing and many other visceral activities
perception of pleasure, fear, and rage
maintains normal body temperature
regulates feelings of hunger and satiety
regulates sleep and the sleep cycle
Various neural circuits
Divergent - spread
Convergent - 1 starts and more come off
Reverberating - keeps repeating
Transmitted nerve impulse
Movement of action potential along a nerve fiber in response to stimuli
Ganglia
Collection of nerve cell bodies found outside CNS
How are basic reflexes learned?
Inate- automatically given at birth
Basic - learned through modifying behavior
How are impulses carried to and from cell?
Axons - carry signals away from
Dendrites - carry signals to
If you injure the hypothalamus?
Hypothalamus controls temperature, endocrine, & thirst
So you would see issues in those areas
Importance of nodes of ranvier
?
Knee jerk reflex
Golgi tendon reflex (releases muscles)
Largest cranial nerve
Trigeminal
What is the resting & digesting division of ANS?
Parasympathetic
Major relay for sensory information
Thalamus
Nickname for sympathetic nervous system
Fight or flight
Number of spinal pairs
31
Association neuron
Interneuron
Any neuron with a specific area it is confined to (like olfactory)
Sheath of schwann cell
?
Voltage is measured how around the membrane potential
?
What are afferent nerves
Neuron that conducts impulses toward CNS from peripheral body
Direct acting neurotransmitters
Opens gates to respond quickly
So— ACH is a quick responding one
Nonspecific ascending pathways
Are involved in emotional aspects of perception
Consist of polymodal neurons
Alertness and arousal
Effector organs of ANS
Cardiac muscle
Smooth muscle
Glands
Water balance regulation
Temperature
Metabolism
Hypothalamus
ANS function
Homeostasis
Regulates cardiac muscle, smooth muscle, and gland activity
What are olfactory receptors
Specialized cell in mucous membrane of nose
Receptor for smell
Structures of a neuron
Cell body (soma)
Dendrite
Axon
Exterorceptors sense
Pain and temperature
Nociceptors sense
Pain and deep touch
Central sulcus separate?
Sulci are shallow grooves in hemispheres
So… Separates frontal and occipital lobes
Ependymal cells?
Lining of ventricular cavities (brain ) and line central canal of spinal cord
Phrenic nerve
Stimulates diaphragm – comes off cervical plexus
Temporal lobe
Auditory
Occipital lobe
Visual
Three major plexuses
Cervical, brachial, lumbar
Thoracic has none
Action potential
Generates electrical current that starts impulse
Medulla oblongata controls
Breathing, digestion, blood flow, temperature, vomiting, swallowing
Medulla controls
Respirations
