Please enable JavaScript.
Coggle requires JavaScript to display documents.
Nervous System Angelynn Torres Period 4 (Drugs that affect the brain…
Nervous System
Angelynn Torres
Period 4
Name of all the lobes and their functions
Occipital Lobe: located at the rear portion of the skull, behind the parietal and temporal lobes
visual processing area of the brain
Parietal Lobe: Sensory, the parietal lobe is at the back of the brain and is divided into two hemispheres.
functions in processing sensory information regarding the location of parts of the body
interpreting visual information and processing language
Temporal Lobe:mainly in the middle cranial space,close to the skull base
involved in vision, memory, sensory input, language, emotion, and comprehension
Frontal Lobe: located near the forehead
cognitive skills, emotional expression, problem solving, memory, language, judgment
Drugs that affect the brain
MDMA: Ecstasy
Taken by swallowing or snorting
Psychoactive Drug, causes euphoria
Stimulants & hallucinogens
Increase in energy & distortion of perception
Felling of euphoria/ emotional connection
Muscle cramping, chills, panic attacks, overheating
Methamphetamine: Meth
Taken by smoking, injecting, or snorting
speeds brain activity & nerve activity
Increased alertness & energy
Decreased appetite
high doses: Seizures, overheating & heart damage
toxic to the brain
Marijuana: Cannabis plant extract, synthetic, edibles, CBD or THC
Taken by smoking, vaping, or swallowing
Stimulant and Depressant
Impairs thinking, memory, and attention,coordination, slow reaction time.
Nicotine: Cigarettes, chewing tobacco, nicotine gum or patches, vapes
Taken by smoking, inhaling, vaping, chewing
Increase nerve activity and heart rate
Can have a calming effect, Health problems include, cancer, heart disease, stroke and lung disease
Inhalents: solvents, aerosol sprays, gases
Taken by inhaling
chemicals/ substances
Hallucinogens
Impair coordination, speech, judgement
Cause hallucinations, confusion, seizures, and brain damage
Psychedelics: Mushrooms, LSD, peyote cactus
Taken by swallowing, snorting, injecting, or smoking
Altered perception, Intensifies sensations and emotions
Hallucinogens
Causes users to see or feel things that are not there
Rapid change of emotions, increased heart rate, panic
Opioids: Heroine
Taken by pills, patch, injecting, snorting, or smoking
Opiates, pain relievers
pinpoint pupils, rush of warmth & pleasure, when injected followed by drowsiness
Itching, nausea, vomiting, lose consciousness
GHB & Rohypnol: GHB & Funitrazepam
Taken by swallowing
Relaxing effect, colorless, tasteless, odorless
Depressant
Can cause Hallucination, nausea, slowed breathing
can be used a s a date rape drug
Cocaine:
Taken by snorting, injecting/ crack taken by smoking
Speeds nerve activity, a numbing effect
Stimulant
Causes increased energy, alertness, confidence, and decreased appetite
large amounts of irritability, irregular heartbeat , stroke, seizure
Dissociative Drug: Ketamine, PCP, Dextromethorphan
Taken by swallowing, snorting, injecting, or smoking
Can Cause people to lose tough with reality
Hallucinogens
People Behave unpredictably, or violently
Can cause fevers, seizures or coma, Terrifying feeling
Alcohol:
taken by drinking
A drug that slows brain & nerve function
Depressant
Impairs coordination, balance, speech, reaction time, and judgement
Tissues
Epineurium: tough fibrous sheath around all fasicles to form the nerve
Pernieurium: coarse connective tissue that bundles fibers into fasicles
Endoneurium: loose connective tissue that encloses axons & their myelin sheaths
Coverings: Layers of the meninges
Arachnoid Mater: Forms a loose brain covering, never dipping into the sulci at the cerebral surface
separated from the dura mater by a narrow serous cavity, the subdural space, which contains a film of fluid
Pia Mater: Composed of delicate connective tissue & contains tiny blood vessels
clings tightly to the brain
Dura Mater: the strongest meninx
surrounds the brain, it is a two- layered sheet of fibrous connective tissue
Major Functions of the Nervous System
Integration: Nervous system processes & interprets sensory input & decides what should be done at each moment.
Motor Input: Nervous System activates effector organ muscles & glands to cause a response.
Sensory Input: Nervous system uses millions of sensory receptors to monitor changes both inside & outside the body.
It gathers information.
Action potential
Action Potential: Brief reversal of membrane potential with total change in voltage of about 100mV
In a Neuron, an Ap is called a nerve impulse, generated only in axons
Depolarization: Voltage gated Na+ channels open
Depolarization reaches a critical level called a Threshold
Depolarization becomes self-generating, urged on by positive feedback
Membrane potential becomes less negative and depolarization is about +30 mV
Repolarization: Na+ channels are inactivating, and voltage gated K+ channels open
Rising phase of action potential
Repolarization occurs
Resting State: All voltage gated Na+ and K+ channels are closed
Only leakage channels are open, maintaining resting membrane potential
Activation gated & inactivation gates - Depolarization opens and inactivates sodium channels
Hyperpolarization: Some K+ channels remain & Na+ channels reset
Caused by the K+ efflux
Spaces and Ventricles
Ventricles
Fourth Ventricle: cavity of hindbrain, located between the brain stem & the cerebellum & connects with the central canal of the spinal cord
cerebrospinal fluid: clear watery fluid which fills the space between the arachnoid membrane and the pia mater.
Third Ventricle: fluid-filled cavities, located in the diencephalon
Subarachnoid space: interval between the arachnoid membrane and the pia mater
Lateral Ventricles: Large C Shaped chambers that reflect the pattern of cerebral growth
Major Part of the brain and their functions
Epithalamus: Dorsal proportion of the dienchephalon
forms the root of the ventricle
includes the pineal gland
Pons: bulging brain stem region wedged between the midbrain & medulla oblongata
Hypothalamus: cups the brain stem & forms the infrolateral walls of the third ventricle
Thalamus: the relay station for information coming into the cerebral cortex
afferent impulses from all senses & all parts of the body coverage on the thalamus & synapse with at least one of its nuclei
Medulla Oblongata: the most inferior part of the brain stem
crucial role as an autonomic reflex center involved in maintaining homeostasis
Diencephalon: forms the central core of the fore brain & surrounded by the cerebral hemisphere
consists of 3 paired structures: thalamus, hypothalamus, and epithalamus
Cerebellum: Located under cerebrum. Provides precise timing & appropriate patterns of skeletal muscle contraction for smooth coordinated movements & agility.
Cerebrum: large part of the brain containing the cerebral cortex
performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement.
Brain Stem: Consists of the midbrain, pons, and medulla oblongata.
The brain stem controls the flow of messages between the brain and the rest of the body
controls basic body functions such as breathing, swallowing, heart rate, blood pressure
Divisions and subdivisions of the Nervous System
Central Nervous System
Brain and spinal cord, dorsal body cavity
CNS, integrating & control center
Interprets sensory input & dictates motor output based on reflexes, current conditions, & past experience
Somatic Nervous System
Composed of somatic motor nerve fibers, conduct impulses from CNS to skeletal Muscles
Voluntary nervous system
Peripheral Nervous System
System outside the CNS
Consists of nerves (bundles of axons) that extend from brain & spinal cord, & ganglia (collections of neuron cell bodies)
Spinal nerves carry impulses to & from spinal cord & cranial nerves carry impulses to & from the brain
PNS has 2 functional subdivisions:
Somatic Sensory Fibers: Convey impulses from the skin, skeletal muscles & joints.
Visceral Sensory Fibers: transmit impulses from the visceral organs
Automatic Nervous System: Visceral motor nerve fibers that regulate the activity of smooth muscles, cardiac muscles and glands
Involuntary
Diseases associated with the brain
Parkinson's Disease: Degeneration of the dopamine- releasing neurons of the substantia nigra
Afflicted individuals have a persistent tremor at rest
A forward bent walking posture & shuffling gait & a stiff facial expression
Huntington's Disease: A fatal hereditary disorder, strikes during middle age
Mutant Huntington protein accumulates in Brain Cells & the tissue dies, leading to massive degeneration of the basal nuclei & later of the cerebral cortex
Alzheimer's Disease: Progressive degenerative disease of the brain results in dementia
patients exhibit memory loss, shortened attention, disorientation, and eventually language loss
Major Nerves of the body
Sensory (afferent) nerves: impulses only toward the CNS
motor (efferent) nerves: impulses only away from CNS
Mixed Nerves: Both contain sensory & motor fibers
Classification of Neurons
Neurons: Conduct messages in the form of nerve impulses from one part of the body to another
Structural
Bipolar Neurons: Have 2 processes, an axon, & a dendrite
rare neuons, found in special sense organs
Unipolar Nuerons: Have short processes that emerge from the cell body & divides T-like into proximal & distal branches
Multipolar Neurons: Have 3 or more processes, one axon & rest dendrites - most common neuron type
Functional
Sensory/ Afferent Neurons: Transmit impulses from sensory receptors in the skin or internal organs toward or into the central nervous system
Motor/Efferent Neurons: carry impulses away from the CNS to the effecter organs of the body
Multipolar
Interneurons: Lie between motor & sensory neurons in neural pathways and shuttle signals through CNS pathways where integration occurs
Spinal Nerves
Thoracic: Control motor and sensory signals mostly for the upper back, chest, and abdomen
12 nerve roots
Lumbar:The lumbar spine is located in the lower back below the cervical and thoracic sections of the spine
control communication between the brain and the legs.
5 Lumbar
Cervical: Distributed over neck, Shoulders, and portions of the upper limb
help control the head and neck, including movements forward, backward, and to the sides
8 cervical
Sacral: the spinal nerves split and form sensory and motor nerves that go to parts of your pelvis, legs, feet, and genitals
5 sacral
Neurotransmitters
The means by which neurons communicate, integrate & send messages
Peptides: Neuropeptides have diverse effects
Purines: one of the classes of nitrogen-containing bases that make up DNA & RNA
Amino acids: amino acids occur in all cells of the body & important in biochemical reactions
Gases & Lipids: short lived - toxic gas molecules messengers
Biogenic amines: include the catecholamines , such as dopamie, norepinephrine & epinephrine & the idolamines which include seratonin & histamine
distributed in the brain, play a key role in emotional behavior & help regulate biological clock
Gasotransmitters: are synthesized on demand & diffuse out of the cells that make them. Zoom through plasma membrane of nearby cells to bind with intracellular receptors.
Acetycholine: released at neuromuscular junctions
Ach is released by all neurons that stimulate skeletal muscles & neurons of he autonomic nervous system
Function: Classified as inhibitory or excitatory & direct or indirect action
Indirect: Acting neurotransmitters act through second messengers
Neuromodulators: act indirectly presynaptically or postsnyaptically to change synaptic strength
Direct: acting neurotransmitters bind to and open ion channels
Neurotransmitter receptors: are either channel linked receptors or G protein coupled receptors
Cranial Nerves
12 pairs of cranial nerves are associated with the brain
Oculomotor Nerves: fibers extend from ventral midbrain through superior orbital fissures to four or six extrinsic eye muscles
Trochlear Nerves: Fibers from dorsal midbrain enters orbits via superior orbital fissures to innervate superior oblique muscle
Optic Nerves: Arise from retina, really a brain tract
Trigeminal Nerves: largest cranial nerves, fibers extend from pons to face
Olfactory Nerves: sensory nerves of smell
Abducens nerves: Fibers from inferior pons enter orbits via superior orbital fissures
Facial Nerves: fibers from pons travel through internal acoustic meatuses & emerge through stylomastoid foramina
Vestibulocochlear nerves: Afferent receptors from hearing
Glossopharyngeal nerves: Fibers from medulla leave skull & run to throat
Vagus Nerves: Only cranial nerves that extend beyond head & neck region
Accessory Nerves: Formed from ventral rootlets region of spinal cord
Hypoglossal nerves: Fibers from medulla exit skull
Anatomy of the Spinal Cord
Lumbar Puncture: Removing cerebrospinal fluid for testing
Conus Medullaris: The spinal cord ends in this cone shaped structure
Epidural Space: Filled with soft padding of fat & a network of veins
Filum Terminate: A fibrous extension of the conus covered by piameter
Spinal Dura Mater: Single-layered, not attached to the bony walls of the vertebral column
Denticulate Ligaments: Secure the spinal cord to the tough dura mater meninx throughout its length
Thirty one pairs of spinal nerves issue from the cord
The cord is enlarged in the cervical & lumbar regions, where spinal nerves serving the limbs arise
Spinal Cord: Provides a two way conduction pathway to & from the brain
Cauda Equina: Collection of nerve roots at the inferior of the vertebral canal
autonomic nervous system
Preganglionic Neuron: Cell body in the CNS with thin, lightly myelinated preglanlionic axon extending to ganglion
Postganglionic Neuron: Cell body synapses with preglanglionic axon in autonomic ganglion with nonmyelinated posganglionic axon that extends to effector organ
Effectors, Efferent Pathways & Ganglia
target organ responses to neurotransmitters
Parasympathetic Division: promotes maintenance functions, conserves energy
Autonomic Nervous System: Consists of motor neurons that
innervate smooth muscle, cardiac muscle & glands
Make adjustments to ensure optimal support for body activities
Shunts blood to areas that need it & adjusts heart rate, blood pressure, digestion
Operates via subconscious control
Involuntary Nervous System
Sympathetic Division: Mobilizes body during activity
Divisions of the PNS of the body
Autonomic Nervous System: divided into three parts
the sympathetic nervous system, the parasympathetic nervous system and the enteric nervous system
The autonomic nervous system controls smooth muscle of the viscera & glands.
Somatic Nervous System:consists of peripheral nerve fibers that send sensory information to the central nervous system
& motor nerve fibers that project to skeletal muscle.
The cell body is located in either the brain or spinal cord and projects directly to a skeletal muscle.
Parts of the reflex arc
Integration Center: Either monosynaptic or polysynaptic region within CNS
Motor Neuron: Conducts efferent impulses from integration center to effector organ
Sensory Neuron: transmits afferent impulses to CNS
Effector: Muscle fiber or gland cell that responds to efferent impulses by contracting or secreting
Receptors: Site of stimulus action