Chapters 10, 11, 12

Term Definition
Neuron most important of transmitting electrical signals, non-mitotic, don't replicate self when injured
3 parts of a Neuron Dendrites, cell body, axon
Dendrites tree like structures that receive signals from other neurons, and transfers them to the cell body.
Cell body Contain Nucleus, Gets signal from dendrites, decides which ones it wants to send to the axon
Axon long extensions that carry signals away from cell body, has branches that form axon terminals; in which chemical transmitters are stored
What are the 3 unique structures of the axon terminal? Myelin sheath, neurilemma, nodes of ranvier
Myelin sheath layer of fatty white tissue, protects and insulates axon
In peripheral nervous system the myelin sheath is created by which type of cell? Schwann Cells
In the central nervous system, myelin sheath is created by which type of cell? Oligodendrocytes (glia cell)
Oligodendrocytes produce myelin sheath for neurons in CNS
Nodes of Ranvier axonal areas not covered by myelin, appear at regular intervals along myelinated axon
Why does the Synaptic cleft exist? space exist because the axon terminal of neuron A does not touch the dendrites of neuron B.
Synaptic Cleft Space between 2 neurons
What happens during a synapse? Information from Neuron A has been transmitted by chemicals Ach to Neuron B
What is the purpose of the Synapse? it helps information move from neuron to the next
Events at the synapse Step #1 Nerve impulse travels along neuron A to its axon terminal.
Events at the synapse Step #2 Nerve impulse causes vesicles (neurotransmitters) to fuse w/ membrane of axon terminal. Vesicles open & release Neurotransmitters into synaptic cleft.
Events at the synapse Step #3 Neurotransmitters diffuse across synaptic cleft to bind w/ receptor site (changing membrane potential of dendrite)-causing a nerve impulse.
Events at the synapse Step #4 Electrical information travels toward the cell body & axon of neuron B.
Four areas of the brain…. cerebrum, diencephalon, brain stem, and cerebellum
Cerebrum largest part of the brain, divided into r/l hemispheres, allows us to perform higher mental tasks such as learning, reasoning, language, memory. Has 4 lobes. made up of convulsions or gyri, Sulci and fissures separate the cerebrum into lobes
What are the four parts of Cerebrum? Frontal, Parietal, Occipital, Temporal
What does the Frontal Lobe control? motor, personality,behavior, emotion, intellect, memory storage, (executive functions)—learning, thinking, planning. & memory storage. Plays key role in motor speech.
Contains primary motor area (cortex)—nerve impulses here control voluntary muscle movement. Frontal Lobe
Patrietal Lobe Somatosensory area (especially from skin and muscles, taste speech, reading), located behind central sulcrus.
primary concern is to receive signals from the body. Allows you to fell temperature, pain, light touch, and proprioception ( Parietal Lobe
Occipital Lobe , vision-related reflexes & functions (reading, judging distances, seeing in 3 dimensions). Located in back of head, contains the visual cortex
Temporal Lobe : Hearing (Auditory area), smell (olfactory area), taste, memory storage, part of speech area.
Wernicke's Area broad region, located in temporal & parietal lobe, concerned w/ translating thoughts into words. Damage to this area comes from alcohol abuse-resulting in severe deficits in language comprehension.
Speech area : located in temporal , occipital, and parietal lobe. Located in left hemisphere, allows you to understand words
When thought are put together, what part of the brain enables you to speak? -brocas area directs muscles of larynx, tongue, cheeks, lips to speak.
Diencephalon located beneath cerebrum and above brain stem
Basil Nuceli help regulate body movement & facial expressions. Dopamine is responsible for the activity of this.
What are the structures of the Diencephalon? Thalmus and Hypothalmus
Thalmus relay station for sensory fibers, center for most sensory info going to the cerebrum, gives hint for sensation
Hypothalmus integrated system for ANS, directly below thalmus, regulate body temp, water balance, and metabolism, thirst, sex, appetite, pleasure/fear, regualte pituitary gland and control endocrine function
Pituitary Gland Directly/Indirectly affects every hormone in the body, located under hyothalmus
Brain Stem connect spinal cord w/ other brain structures, has 3 structures, relay tracts for sense info (white matter), has effect on Bp/respiration (gray matter)
What are the 3 structures of the brain stem? Mid-brain, pons, medulla oblongata
Mid-Brains relay station for sensory/motor info. contain nuclei which serve as a reflex function for vision and hearing
Pons has tracts that tavel to brain structures, play a role in regualtion of breathing rate, and rhythm
Medulla Oblongata contain nuclei that control heart rate, bp, respiration, also called the vital center–coughing, sneezing, vommitting, swallowing
Cerebellum maintain balance and muscle tone, coordinates voluntary muscle activity.
Cerebellum Integrate incomiong info. to produce smooth muscle response, damage causes jerky muscle movements–staggering gait, barely maintain balance, may appear intoxicated, play role in eval. sensory input
How is the Vomit Center, activated directly? fear, distressing sights, bad odor, pain, spinning
How is the Vomit Center Stimulated indirectly? Chemoreceptors trigger zone (CTZ)–stimulated by anti cancer & opioid drugs
How Does the vomit center receive its signals? Gets signals from vagus nerves to CTZ–in turn activates this
Limbic System Part of cerebrum & Diencephalon, wishbone shaped group, aka emotional brain, functions in state of emotion/behavior, stimul. by microelectrodes–cause state of extreme pleasure/rage
Reticular formation What keeps up awake. Special gray matter that is concerned w/ sleep-wake cycle & consciousness. Benzodiazepines and alcohol can damage this
Consciousness state of wakefullness, different levels.
What are the 4 levels of consciousness? Attentiveness, Alertness, Relaxation, Inatentiveness
RAS–reticular activating system continuously sample sensory ifo. from all body parts, sends unusual/threatening info. to higher structures w/ion cerebral cortex
Sleep Occur when RAS is slowed/inhibited, Neurotransmitters are repenished
Coma Hyporesponsive state, stages: light to deep, pt (may) respond to light, sound, pain, touch
Clinical conditions that affect level of consciousness… brain tumors, brain injury, drugs, toxins, hypoxia, hyperglycemia, acid-base imbalance, electrolyte imbalance
Stages of sleep REM and NREM
NREM has 4 stages from light to deep, deep to light
REM Sleep total 90-120 minutes per night, characterized byu bp, respiratory rate & rhythm & pulse rate, most dreaming occur here.
Memory ability to recALL thoughts ad images. frontal, parietal, occipital, temporal lobe, limbic system, and diencephalon are concerned w/ memory
Cerebral spinal fluid (CSF) Formed across walls of choroid plexus3rd layer of protection for CNS. circulate through subarachnoid space- cushioning the brain/spinal cord, delivers nutrients and removes waste
Choroid Plexus grape like collection of blood vessels and ependmyl cells, suspended from roof of ventricle
Arachnoid Villus help w/ CSF drainage
What are the 3 layers of protection for the CNS? Bone, meninges, and CSF
Meninges name of the 3 layers of connective tissue that surround the brain and spinal cord
What are the 3 parts of the meninges? dura mater, arachnoid mater, and pia mater
Dura mater outer most layer, thick and tough, the hard mother, form dural sinuses
Arachnoid mater middle layer (spider like) membrane.
Pia matter inner most layer, soft gentle mother, very thin
The nerves are categorized into which 3 ways? sensory nerves, integrative, and motor nerves
Sensory nerves function gather information from inside the body and from the outside enviornment–the nerves then carry the info to CNS
Integrated Nerve function information receives is processed and interpreted, and a plan is set
Motor nerves function carry out plan made by the CNS, send information to muscles and glands of the body
what 2 types of cells make up the nervous tissue? Neuroglia and Neurons
Neuroglia support, protect, and nourish the neuron. has 2 more common glia cells—>astrocytes and ependymal cells (cover entire brain surface)
Astrocytes Cells star shaped cell present in both brain barrier, act as phagocyte, secrete nerve growth factor, bind blood vessels to nerves for support
Ependyml Cells Involved w/ formation of CSF, lines ventricles of the brain as part of choroid plexus
Microalgia protective role, phagocytosis of pathogens and damaged tissue
Schwann Cells Produce myelin sheath for neurons in PNS, assist in regeneration of damaged fibers
Oligodendrocytes produce myelin sheath for neurons in CNS
Types of Neuroglia astrocytes, ependymal cells, microalgia, schwann cells, oligodendrocytes
Nodes of ranvier axonal area not covered by myelin, appear at regular interval along myelinated axon.
How does the nodes of ranvier help w/ transmission of nerve impulse? The nodes of ranvier help the nerve impulses jump from neuron to neuron
Polarization cell is resting, no nerve impulse transmitted, cell is quiet
Chemical change in polarization inside cell has a (-) charge, k+ ions and anions, k+ is pumped in by ATP, k+ leaks out, taking (+) charge w/ it, making inside of cell (-)
Depolarization neuron stimulated, change occur in cells electrical state.
Chemical change in depolarization Stimulated state,permeability changes-allowing Na+ to come into cell, Na+ carries (+) charge, this is caused by inward diffusion of Na+
Repolarization quickly cell becomes (-) again, back to resting state.
Chemical change in repolarization return to resting, after depolarization permeability changes back to stop Na+ from coming into cell, and allow K+ to move out. This is caused by outward diffusion of K+ removes (+) charge bringing the cell back to resting state
Parkinson's Disease deficiency ion dopamine w/in basil nuclei, movement disorder, characterized by shuffling, rislow speech, drooling, mask like expression, aka shaking palsy
CN I olfactory (smell)
CN II Optic (sight) damage causes diminished vision/blindness
CN III Oculomotor (eyeball, raise eyelids, change pupil size) damage causes ptosis, can't focus on objects
CN IV Trochlear Nerve (help us move eyeball) damage causes double vision/inability to rotate eye right
CN V Trigeminal Nerve (mixed nerve chewing of food, sensation in face, scalp, cornea, and teeth. damage causes loss of sensation
CN VI Abducens Nerve (moves eyeball like trochlear nerve, damage causes the eye at rest to drift toward the nose
CN VII Facial Nerve ( mixed nerve expression,saliva, taste, tears, blinking) damage may cause bells palsy can't close eyelid (blink)
CN VIII Vestibulocochlear (hearing and balance) sends info to brain from inner ear. damage causes loss of hearing, and balance
CN IX Glossopharyngeal Nerve (mixed nerve swallowing, regulate bp, and gag reflex) damage causes loss of gag reflex
CN X Vagus Nerve (visceral muscle movement/sensation, movement of secretions of digestive system sensory for reflex regulation of BP. damage causes horse voice
CN XI Accessory Nerve (swallowing, supply sternocleidomastoid and trapezus muscle to move head and shoulder, speaking) damage causes drooping shoulders. inability/difficulty in rotating head
CN XII Hypoglossal (control movement of tongue, speech and swallowing) damage causes tongue to go to injured side
Reflex arch pathway involved in a reflex
5 basic components of a reflex arch…. receptor, afferent neuron (sensory to spinal cord), intergrating center (gray matter), efferent (motor neuron to muscle), and effector organ (leg moves)
Different types of reflexes…. withdraw, pupillary , bp, babinski, knee jerk reation.
Ex of withdrawal reflex hot iron
Ex of Pupillary reflex light in eye
Ex of Bp reflex changes abruptly, fight ot flight
Ex of Babinski reflex touch bottom of foot
Ex of Knee jerk reation Knee jerk
Sympathetic Nerves increase heart rate and strength of contraction, pupils dilate, vessels constrict, no pee or bm, stimulate epinephrine and norepinephrine, mouth waters alot, closes sphincter. Fight or Flight
Parasympathetic Nerves Decrease heart rate, pupils constrict, have to pee, watery secretions, contracts muscles, opens sphincter. Feed or Breed
Adrenergic Receptors Neurotransmitter norepinephrine (sympathetic)
Cholinergic Receptors Neurotrasmitter Acetlycholine (Ach) (immediate response)
Dual innervations single nerves that receive fibers from both Parasympathetic and sympathetic nerves in ANS
Sensory/afferent Neurons carry information from the periphery toward the CNS. (spinal cord)
Motor/efferent Neurons carry information from the CNS toward the periphery.
Interneurons found only in the CNS. They form connections between sensory and motor neurons.

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