nervous system Flashcards
what is a hormone?
chemical/molecule that is released into the blood and affects another organ
what is the thalamus and the function?
two oval masses of gray matter covered in white matter
function: relay point and processing center for all sensory impulses except for olfaction
what is the hypothalamus and its function?
autonomic nervous system control center, endocrine system control center, body temperature regulation, water and electrolyte balance, regulation of sleep wake cycles, regulation of hunger/food intake, control of emotional behavior
what is the endocrine system control center function and its structures?
endocrine system which secretes hormones into the bloodstream
hypothalamus which produces two hormones that are secreted by the posterior pituitary, and it produces hormones that regulate hormonal secretion of anterior pituitary
what is the satiety center?
examines glucose levels
what are electrolytes?
ions and molecules that carry an electric current
what are the two hormones produced by the hypothalamus?
oxytocin for reproductive system and antidiuretic for telling kidneys to concentrate urine
what is the thirst center?
examines blood in blood vessels for water/electrolyte balance
how does the hypothalamus show signs of control of emotional behavior?
may express emotional feelings as physical changes
how does hypothalamus regulate circadian cycles?
regulates pineal gland secretion of melatonin and the hypothalamus raises body temp in response to light
what is white matter?
axons
what is the longitudinal fissure?
separates cerebral hemispheres
what is the corpus callosum?
axons that connect the left and right cerebral hemispheres
what is the gyrus?
part of the cerebral cortex that elevates the cortex
what is the sulcus?
part of the cerebral cortex that depresses the cortex
what is the lateral sulcus?
groove that separates frontal and parietal lobes from the temporal lobe
what is the motor speech area?
on the left frontal lobe that controls muscular movements needed for speech
what is the primary motor cortex?
located in precentral gyrus, controls voluntary skeletal muscle movement
what is the primary somatosensory cortex?
located in postcentral gyrus of parietal lobe, receives sensory input from skin, muscles, joints
what is the Wernicke area?
overlaps areas in both parietal and temporal lobes, helps with speech comprehension
what is the primary auditory cortex?
receives and processes incoming sounds
what is the primary olfactory cortex?
processes smell information and provides conscious awareness of smells
what is the primary visual cortex?
receives and processes incoming visual information
what is the insula and its structure?
involved with memory and primary gustatory cortex
what is the primary gustatory cortex?
involved in processing taste information
what is a receptor?
a structure that converts sensory stimulus to a nerve impulse that goes to CNS
what is an exteroceptor?
stimuli from outside environment, near the surface of body, some are cutaneous receptors, and they involve special senses
what are interoceptors?
primary stretch receptors in smooth muscle of viscera
what structure serves as a center for controlling autonomic activity and endocrine activity?
hypothalamus
the primary motor cortex which controls voluntary skeletal muscle movement is located where?
Precentral gyrus
what does the insula interpret?
taste
What is the equilibrium?
Balance, detecting position of head and coordinating movement
what is the denticulate ligament?
in pia mater, extends laterally and attaches to dura and is medially between posterior and anterior roots of spinal cord
what is the filum terminale?
thin strand of pia mater that anchors the conus medullaris to the coccyx
what is the conus medullaris?
pointed tapered end of spinal cord
what is the cauda equina?
collection of nerve roots coming off of the conus medullaris, horse tail
how many cervical nerves and bones are there?
8 nerves and 7 vertebra
how many thoracic nerves and bones are there?
12 nerves and 12 bones
how many sacral nerves are there?
5
how many coccygeal nerves are there?
usually 1
how many pairs of spinal nerves?
31
How many lumbar nerves and bones are there?
5 and 5
what is the cervical enlargement?
between cervical nerve 4 and thoracic nerve 1, contains neurons that innervate the upper limb and form brachial plexus
what is the lumbar enlargement?
between lumber nerve 2 and sacral nerve 3, contains neurons that innervate lower limb and forms lumbosacral plexus
where does the spinal cord end?
mid back at lumbar nerve 1
what is the lumbar cistern?
a space full of CSF and the cauda equina
what is the central canal?
space within gray matter in spinal cord, lined with ependymal cells, contains CSF
what is the spinal cord divided into?
inner gray matter and an outer white matter
what is grey matter?
contains nerve cell bodies, unmyelinated axons, glial cells, and interneurons
what are anterior ventral horns?
cell bodies of somatic motor neurons that innervates skeletal muscle
what are lateral horns?
Cell bodies of autonomic motor neurons, prominent only in thoracic nerve 1 through lumbar nerve 2, that innervates cardiac and smooth muscle and glands
what are posterior horns?
interneurons and axons of sensory neurons
what is a gray commissure?
unmyelinated axons crossing from one side to another, contains central canal
what is white matter?
bundles of myelinated axons, divided into anterior funiculi, lateral funiculi, and posterior funiculi, both ascending and descending spinal cord tracts present
what is the spinal cord tracts?
tracts are bundles of axons that run in the white matter of the spinal cord
what are ascending tracts?
sensory axons that travel from body to brain
what are descending tracts?
motor axons that travel from brain to body
what do spinal nerves exit through?
exit the vertebral canal through an Intervertebral foramen
what is a nerve?
structure that you can see with the naked eye formed from many axons bundled together in connective tissue wrappings
what is an anterior root?
axons of motor neurons
what is a posterior root?
axons of sensory neurons
what is a posterior root ganglion?
contains cell bodies of sensory neurons
what is a posterior ramus?
innervates deep back muscles and skin of back, provides segmental innervation, smaller
what is the anterior ramus?
innervates everything else from the neck inferiorly, larger, and it forms nerve plexuses
what is a plexus?
a network of converging and diverging axons, usually anterior rami
difference between roots and rami?
roots organize by function, rami organize by location
what are a dermatomes?
segments of skin innervated by a single spinal nerve creates a sensory map of the body
