Lecture Exam 2nd Half A&P I Flashcards
Meningeal branch:
reenters the vertebral canal and innervates the meninges, vertebrae, and spinal ligaments w/ sensory and motor fibers.
insula lobe of cerebrum
-small mass of cortex deep to lateral sulcus. taste, pain, visceral sensation, consciousness, emotinoal responses and empathy, and cardiovascular homeostasis
Blood capillaries throughout the brain tissue and Capillaries of the choroid plexus
Blood capillaries throughout the brain tissue- bad stuff doesn’t go through there because of blood brain barrier anything leaving the blood pass through astrocytes contacting the capillaries of both and force endothelial cells to make tight junctions in ependymal cells sealing off gaps. endothelial cells can exclude or not exclude, highly permeable to water, glucose, lipid-soluble substances (o2, CO2, alcohol, caffeeine, nicotine, and anesthetics) slightly permeable to (sodium, potassium, chloride, waste products urea and creatinine) not permeable to (antibiotics, cancer drugs) COV organs barrier absent blood to neurons to monitor blood glucose, pH, osmolarity etc.
Capillaries of the choroid plexus- entrance place for the system. similar system
synapse
contains syanptic vesicles full of neurotransmitter
Ventricles
blood capillary-choroid plexus four internal chamber in brain two lateral (arc in cerebral hemisphere w/ pore connected to third in medial space between corpus collosum from there cerebral aqueduct fourth ventrical triangular chmber inferior end between pons and cerebellum
visceral sensory division
(carry message from viscera of thoracic and abdominal caities, heart, lungs, stomach, and urinary bladder)
Emotion
: emotional feelings and memories are interactions between prefrontal cortex (seat of judgement content and understand of emotions only), (amygdala input from sensory systems mediate emotional responses to hypothalamus and lower brainstem for somatic, feeling themselves and emotional memroy from deeper regions of these two only) hypotahalmus to other motor or prefontal cortex controlling emotions based on behaivor learned associations w/ stimuli and award or punishment
proximal branches
-spinal nerve from two points of attachment to spinal cord. split off first ton of branches that come off. plexi, cervical, thoracic, lumbar bunches of nerves located.
hearing conduction to parts of brain
Sensory fibers sent to pons beginning at hair cells on ear. (vestibula nerve)
–Synapse with second-order neurons that ascend to the nearby superior olivary nucleus
Other cochlear nucleus fibers ascend to the inferior colliculi of the midbrain help w/ locating origina of sound, processing fluctuation and pitch, mediating startle response and head turning
–Third-order neurons begin in the inferior colliculi and lead to the thalamus (functions in conscious perception of sound)
–Fourth-order neurons from the thalamus to primary auditory cortex at superior margin of temporal lobee
what does CNS not have that PNS does
CNS have no neurilemma or endoneurium.
Nervous system
is very complex- provides innervation to muscles, organs, done by three specific steps sense organs receive changes in environment to brain and spinal cord. CNS processes messages sent and relates to past experiences on what needs to happens and response initiating a command gland or muscle cells
is the foundation of our conscious experience, personality, and behavior
Neurobiology combines the behavioral and life sciences
arachnoid mater
arachnoid matter-inner layer five or six layers of squamous to cubdoial cells w/ looser array of cells and collagenous and elastic fibers looks spider webs off nerves sticks to dura mater and seperated from pia mater by fibers w/in space (cerebral spinal fluid).
basic anatomy of a spinal cord
brain from foramen magnum of skull to first lumbar vertebra. long tubes using spinal nerves come out of back 31 pairs of nerves named for level of vertebral column where spinal nerves emerge w/ enlargement of cord for corresponding nerves to limbs and girdles. communicating w/ rest of body. yellow strings spinal cords innervating various parts of body. cord-like organs w/ fibers or axons bound together bound by connective tissue. mixed nerves afferent (sensory) efferent (motor) fibers. carry from sensory to CNS.
pia mater
continuous w/ the spinal cord fuses w/ dura mater down in coccygeal region and helps form ligament. delicate transparent membrane w/ one or two layers of squamous to cuboidal cells and delicate collagenous and elastic fibers. extensions of pia called denticulate ligamens extend through arachnoid to dura, anchoring cord limiting side-to-side
–Antagonistic effect
: oppose each other. parasympathetic heart reate down sympatethic heart rate increase. Affects on same effector cells, or innervates different effector cells that control it
reticular formation functions
Somatic motor control Cardiovascular control Pain modulation Sleep and consciousness Habituation
rhythm of sleep controlled by
complex interaction between cerebral cortex, thalamus, hypothalamus, and reticular formation
postsynaptic potential
-EPSP dont change whether fires just rate of firing by stimulating or inhibiting production of more action potential as it is based on postsynaptic potentials produced by neurotransmitter ex. excitatory or inhibitory. receiving chemical potential. cell have to be excited to threshold, excitatory potential results from sodium flowin into cell. message inhibitory postsynaptic potential becomes more negative than at rest less likely to fire by Cl- enter or K+ leaving. different neurotransmitters cause different things depending on cell bind to depending on type of receptors released or accepting it.
Language centers of left hemisphere-
wernicke area (posterior to lateral sulcus left hemisphere permit recognition of spoken written language) and brocca (left hemisphere inferior to prefrontal cortex larynx, tongue, cheek and mix when one prepares to speak)
brocca apahsia- difficulty in choosing words and using them, slow speech, approximate correct word not actual
wernicke area lesion- speaks normally and excessively uses jargon and invented words making little sense unable to identify written words or pictures
visceral motor divison
(autonomic nervous system, ANS) carries signals to glands, cardiac muscle, and smooth muscle. no voluntary control, visceral reflexes
There are two different classes of receptors for
acetylcholine (secreted by preganglioinc fibers in both dividions and postganlionic fibers of parasympathetic) two classes
muscurinic and nicotinic
touch and sensory
(afferent toward CNS ) neurons- specialized to detect stimuli of light, heat, pressure, and chemicals transmitting info to CNS. begin in body organs end in CNS.
limbic system
important center of emotion and learning. ring of cortex on medial side of hemisphere encircling corpus collosum and thalamus. cingulate gyrus (arches over corpus collosum front and parietal lobes hypocampus in medial and temporal and amygdala rostral to hippocampus. through complex loops of fiber tracts allowing circular patterns of feedback among nuclei and cortical neurons bilaterally paired.
frontal lobe of cerebrum
frontal lighter blue voluntary motor functions, abstract though, foresight, declarative, memory, motivation, planning mood and emotion, social judgement, agression extends to wavy vertical groove central sulcus),
control w/out dual innervation
- in some places only one type of fiber aka sympathetic in blood vessels therefore w/ constant stimulation it dilates w/out it constricts
spatial summation
from several different synapses add up to threshold at axon w/ each possibly weak but together pass axon hillock others allow action potiential post-synaptic neuron to fire. all the little bumps at thresholds line.
muscle spindles
stretch receptors embedded in skeletal muscles body’s proprioceptors sense organs specialized to monitor position and movement of body parts informing brain of muscle length and movement allowing brain to send motor commands back to muscles controling tone, posture, coordinated movement, and corrective reflexes.
autonomic effects on grandular secretion
indirect of action on blood vessels. filtrate of blood then modified by gland cells increasing blood flow through gland increasing secretion and vice versa.
spinal cord function
conduction (info up and down cord connecting diff. levels of trunk w/ eachother and brain), neural integration (spinal neurons receive into from many sources, integrate it, and execute appropritate output ex. peeing), locomotion (repetitive coordinated contractions of several muscle groups central patern generators for alternating movements), reflexes (posture, motor coordination, and protective responses to pain and injury.
excitatory signals for adregernic
adrenergic synapses (norepinpherine-secondary messengery systems cAMP transmembrane protein w/ g protein slower to respond but does amplify w/ enzymes single molecule can produce multiple or vast numbers in cell versus the others.).
reciprocal inhibition
- reflex that prevents muscles from working against eachother by inhibiting antagonist so stimulate interneuons inhibiting antagonist muscle when agonist is excited allowing the movment to occur.
terminal
terminal arborization w/ axon terminal end- extensive complex of fine branches forming synapse. (autonomic neruons varicosisites alone whole length syanptic vesciles and secretes neurotransmitter)
Anterior ramus:
In thoracic region, it gives rise to intercostal nerve, In other regions, anterior rami form plexuses. thoracic forms intercostal nerve along rib in skin and intercostal muscles w/ motor internal and external obliques
stages of sleep
stage 1- drowsy eyes relaxed, drifting, about to fall asleep easily awaken
stage 2- light sleep not as easily awoken
stage 3- moderate to deep sleep 20 minutes after 1 muscles relax vital signs fall.
stage 3- very low muscle very relaxed muscles lowest difficult to awaken
Hypothalamus: function in autonomic control
major visceral motor control center.
what is the node of ranvier
myelin sheath gap, myelin-covered segments from each node to next internodes.
physical memory
Physical basis of memory is a pathway through the brain called a memory trace (engram)
Along this pathway, new synapses were created or existing synapses modified to make transmission easier w/ experience added, taken away, or modified, to make easier or harder
sympathetic lasts longer. why?
parasympathetic secrete ACh quickly broken down, for sympathetic some reabsorbed, some diffuses, and bloodstream exerting for several minutes before broken down. many released as neurotransmitters modulate both of those.
nerves involved in taste
Facial nerve collects sensory information from taste buds over anterior two-thirds of tongue
•Glossopharyngeal nerve from posterior one-third of tongue
•Vagus nerve from taste buds of palate, pharynx, and epiglottis
•All fibers reach solitary nucleus in medulla oblongata
cerebral cortex
neural integration carried out in gray matter of cerebrum in cortex, basal nuclei, and limbic system. stellate cells- spheroidal somas w/ short axons and crazy dendrites sensory input and processing on local level. pyramidal cells (tall and conical- apex toward brain surface thick dendrate many branches small knobby dendritic spines horizontal dendrites into white matter output neruons of cerebrum only part that leaves connecting to rest. 90% is neocortex (six layered vary in thickness, cellular compositon, synaptic connections, size and destination of axon
general fibers-
innervate widespread organs siuch as muscles, skin glands, viscera, and blood vessel.
general senses
distributued over entire body, (touch, pressure, stretch, movment, heat, cold, and pain reach by cranial (trigeminal nerves) or spinothalamic tract from rest of body. head cranial nerves, body diffferent tracks to brain. ascending tracts. thalamus- contralateral side (ooposite) post central gyrus of parietal lobe. somastetic association area caudal to gyrus cognitive sense actual stimuli what sensory input being sent. superior or medial parts of grus face go to lateral parts of gyrus.
motor (efferent) neurons
(efferent away from CNS) neurons- send signals predominantly to muscle and gland cells, effects. lead to muscle cells
senses
Special Senses- draw each pathway to understand
senses important to body w/out hallucination.
blood pressure body temperature sense organs initate homeostatic important to survival
cessation of the nerve signal occurs how?
Synapses must turn off stimulation to keep postsynaptic neuron from firing indefinitely. Presynaptic cell stops releasing neurotransmitter for 1 ms then clear rest diffuses into EC fluid.
monoamide &acetylcholine broken down into fragments by enzymes. transport proteins reuptake breakdown products. astrocytes in CNS absorb stray neurotransmitters and return them to presynaptic neurons, satellite cells in PNS
Neurotransmitter only stays bound to its receptor for about 1 msand then is cleared
Suprachiasmaticnucleus (SCN)
—important hypothalamic area located above optic chasm eyes instead of visual cortex uses to synchronize multipl ebody rhythms w/ day and not body temperature, urine production, hormone secretion
Hypothalamus produces orexins—neuropeptides that stimulate wakefulness
Distal Branches:
Beyond the intervertebral formane, the nerve divides into distal branches:
anterior rams,
posterior ramus
meningeal branch
signal conduction in nerve fibers
speed of nerve signal travels is diameter of fiber and presence or absence of myelin along surface of fiber, w/ large fibers more surface area and conduct more rapidly
occipital lobe of cerebrum
(vision center). caudal to parieto-occiptial culcus (white matter projection (higher and lwoer brain and spinal cord centers aka communication),
Posterior ramus:
innervates the muscles and joints in that region of the spine and the skin of the back
–Cooperative effects
: two divisions act on different effectors to produce a unified overall effect. salivary salus secretion parasympathetic increae salivary mucous cell secretion help eachother out w/ target cells idfferent dont innervate equally or with equal influence
Dual Innervation-
most viscera receive nerve fibers from both parasympathetic and sympathetic divisions: both dont intervate equally ex. in iris sympathetic fibers innervate pupillary dilator cells and parasympathetic innervate constrictor cells
glia
protect neurons help function bind neurons together and provide supportive framework for nervous tissue covering where not in synaptic contact specialized points for signal tranmission. six kinds (oligodendrocytes- myelin sheath in CNS, ependymal-produce cerebrospinal fluid w/ cilia to circulate it, microglia-macrophage, astrocytes-most abundant gray matter, schwann cells-PNS myelin sheath and regeneration, satellite cells-ganglia PNS insulation for chemical environment)
sensory division
(afferent division-toward body)- carries signals from various receptors (sense organs and simple sensory nerve endings to CNS. informs CNS of stimuli w/in and around body.
in the sensory division it is further characterized by the visceral sensory division and somatic sensory division
Two points of entry into brain
Blood capillaries throughout the brain tissue
Capillaries of the choroid plexus-
temporal lobe of cerebrum
hearing, deep lateral sulcus w/ hearing, smell, language, emotion, memory of language, memory consolidation, verbal, visual and auditory memories.
parasympathetic division
: is relatively selective in stimulation of target organ. craniosacral divison calming stuff. arising from brain and sacral region of spinal cord cranial and sacral nerves origin from midbrain pons and medulla. preganlionic to in or near target organs super long preganlionic fiebrs and really short ganglionic fibers super close to organs.
There is only a little neural divergence (less than divergence exhibited by sympathetic division)
ascending tracts-
red0 fibers in a given tract have similar destinations, function and origin. carry sensation information up.
Cauda equina:
formed from roots arising from L2 to Co1
parietal lobe of cerebrum
(start central sulcus parieto-occipital sulcus taste, somatic sensation (touch, heat and pain) visual processing understand world, spatial perception and body orientiation, language processing and numerical awareness
cognition on certain areas of brain
Cognition: range of mental processes by which we acquire and use knowledge. sensory perception, thought, reasonoing, judgement, memory. over cerebral cortex association areas, and 75% of brain tissue parietal (perceive stimuli awareness of objects or themselves), temporal (understand stimuli and recognize identify and name familar objects), frontal (plan and execute behaviors think about world)
Brain barrier system—
regulates what substances can get from bloodstream into tissue fluid of the brain. protection area. antibodies, macrophages, bacterial toxins not allowed in.
Cerebellum-
hindbrain, motor ability, linguistic, emotional. three major parts and stalks ocnnecting brain stem and cerebellum. connected by bridge vermis, w/ slender transverse parallel fold folia by shallow sulci w/ surface cortex of gray matter and deeper white matter.granule cells most abundant neuron w/ purkinje cells dendrites into plane single file parallel deep nuclei on output neurons to brainstem. connected to brainstem by cerebellar penduncles pinacles inferior (medulla oblongata), middle (pons), superior (midbrain) thick bundles of nerve fibers signals to and from. spinal input enter bellum by inferior penduncles, rest of brain via middle, cerebellar output through supeior. functions: touch w/ textures, spatial perception, timekeeper, prediction of movement, and hearing pitches, language difficulty planning and scheduling tasks
neural coding
way in which nervous system converts information to meaninful pattern of action potentials. labeled line code- each nerve fiber to brain leads from receptor specifically recognizes particular stimulus typpe and only that w/ each fiber labeled and recognize by only that simulus.
neuropeptides
Neuropeptides are chains of 2 to 40 amino acids- function as neuro-modulators help something to happen
Beta-endorphin and substance P
Act at lower concentrations than other neurotransmitters
Longer lasting effects
Stored in axon terminal as larger secretory granules (called dense-core vesicles)
Some function as hormones or neuromodulators
Some also released from digestive tract
Gut–brain peptides cause food cravings
What happens when you reach the end of the cell?
When reach end secrete neurotransmitter stimulates new wave of electrical activity in next cell across synapse.
nerve
bundle of nerve fibers wrapped in fibrous connective tissue emerging fro CNS through foramina and carry signal to organs.
excitability- all are excitable and respond to environmental changes, conductive- respond to stimuli by producing electrical signals that are quickly conducted to other cells at distant locations, secretion- signal reaches end of nerve fiber secrete a neurotransmitter crossing gap and stimualting next cell.
afferent
receptor to posterior end of spinal cord to brain.
definition of circuit and the 4 types
neural pool determined by neural circuit. diverging (one nerve fiber/pool branches and synpases w/ post synaptic cells one neuron to 100s of others ex. brain stimulate all muscles), converging (many different nerve fibers coming together to fewer intermediate or output pathways ex. brain taking in SPO2, stretch to adjust respiratory rate), reverberating (neuron stimulate eachother in linear sequences, later cells stimualte first starting all over again like a loop ex. diaphragm and intercostal muscles of breathing), parallel (each chain has different number of synapses reconverging on one or few output neurons. differ in synaptic delay arrive at different times w/ contiued firing. no feedback loops, once all fired output ceases. different loops w/in the loops)
rami of the spinal nerves-
first branches off rootlets posterior and anterior root ganglia becomes spinal nerve have communicating w/ vertical chain and that is sympathetic chain ganglia. splits again posterior and anterior ramus.
Autonomic Nervous System
(ANS)—a motor nervous system that controls glands, cardiac muscle, and smooth muscle. realtes to viscera. viscera thoracic and abdominal categories all of your guts and body walls, cutaneous blood vessels, sweat glands and piloerector muscles.
sleep
temporary state of unconsciousness from which one can awaken when stimulated
Sleep occurs in cycles called circadian rhythms.
action potential
often called a spike,as it happens so fast more dramatic change produced by voltage-gated ion channels in the plasma membrane. w/ high enough density of voltage-gated channels, if excitatory potential spreads to trigger zone is and is strong enough when it arrives, it can open these channels and generate an action potential. rapid up-and-down shift in voltage. Only a thin layer of the cytoplasm next to the cell membrane is affected. In reality, very few ions are involved
all or none law: once threshold is met neuron fires at maximum voltage or doesn’t fire at all.
nondecrimental- action potential at end of nerve fiber is just as strong as first one in trigger zone
irreversible and always goes to depletion w/out losing it cannot be stopped
Drugs and the nervous System
- sympathomimetics (enhance sympathetic activity increaseing norepinepherine release dilating bronchioles constricting nasal vessels) sympatholitics (block norepinephrine release interfere w/ its effects on heart and blood vessels). competes w/ adneosine and gets there first and blocks it. parasympathomimetics (enhances parasympathetic inhibit ACh or blockes recentpors dilating pupils.)
Autonomic Output Pathways-
contrast to somatic motor pathways (motor neuron issues myelinated axon all the way to the skeletal muscle straight thorugh to muscle telling it what to do) signal must travel across two nerve fibershave to have synapse doesnt go straight through target neuron w/ a step in betwen. way for stuff to travel and root.
tongue senses
salty, sweet, glumommy (meaty taste of amino acids), sour, and bitter (affected by aroma, temperature, texture by lingual nerve and something on tongue.
Flexor and extensor reflex arc
flexor ipsilateralreflex arc, (stimulus and response on same side) whereas crossed extension reflex uses a contralateral reflex arc (input and output are on opposite sides)
parasympathetic
parasympathetic division- reduced energy expenditure, bodily maintenance, eating. autonomic tone having both of these active depending on bodies need at the time w/ parasymapthetic tone minatains smooth muscle keeping lowe hear rate
sympathetic chain ganglia-
longitudinal series of ganglia that lie adjacent to both sides of vertebral column from cervical to coccygeal level connected by longitudinal nerve cord. all nerve fibers for sympathtiec division from thoracic and lumbar region. T1-L2.
Sensation:
primary sensory cortex sites of parietal, occipital and temporal lobes, where sensory input is first received and one becomes conscious of stimulus. visual congivnivive sense of visual, motor and integrate into perception of surroundings.
thalamus
(gateway to cerebral cortex taste, smell, hearing, equilbrium, visiona nd general sense. from cerebellum to cerebrum feedback loops between cerebral cortex and basal nuclei (deep motor centers) w/ memory and emotional functions of limbic system w/ ovoid mass superior end of brainstem beneath cerebral hemisphere lateral ventricles and third ventricle),
Anterior (ventral) root
is motor output out of spinal cord
