The Nervous System

Neurotransmitters

Reflex Arc

Compare and Contrast the Autonomic Nervous System

Major Functions of the Nervous System

Drugs That Affect the Brain

Spaces and Ventricles

Name of All the Lobes and Their Functions

The Layers of the Meninges

Major Divisions and Subdivisions of the Nervous System

Divisions of the PNS of the Body

Major Parts and Functions of the Spinal Cord

Diseases Associated with the Brain

Major Parts of the Brain and Their Functions

Action Potential

Anatomy of the Spinal Cord

Classification of Neurons

Tissues (Structure and Function of a Neuron)

Coverings

Central Nervous System (CNS)

Peripheral Nervous System (PNS)

Integrative Function: analyzes sensory information, stores some aspects, and makes decisions regarding appropriate behaviors

Motor Function: may respond to stimuli by initiating muscular contractions or glandular secretions

Sensory Function: detects changes (stimuli) within body and outside body

Spinal Cord: conducts signals to and from the brain, controls reflex activities

Brain: receives and processes sensory information, initiates responses, stores, memories generates thoughts and emotions

Sensory Neurons: sensory organs to CNS

Motor Neurons: CNS to muscles and glands

Somatic Nervous System: controls voluntary movements

Autonomic Nervous System: controls involuntary responses

Parasympathetic Division: "rest or digest"

Sympathetic Division: "fight or flight"

Fascicle: a group of nerve fibers (group of wrapped axons)

Perineurium: surrounds a group of nerve fibers (surrounds a fascicle)

Endoneurium: surrounds individual fibers within a nerve

Epineurium: surround the entire nerve

  1. Sensory/Afferent Neuron —> sends signal to CNS (reflex center)
  1. Synapse/Interneuron Integration Center —> connection between sensory neuron and motor (efferent) neuron
  1. Sensory Receptor —> afferent nerve ending detects stimulus
  1. Motor/ Efferent Neuron —> delivers response to target organ

Reflex Arc: nerve pathway of a reflex response

  1. Effector —> target organ responds to signal

Neurotransmitters: binds with receptors on the postsynaptic neuron's cell membrane; at least 30-50 different are identified

Synaptic end bulbs may contain 2 or 3 different neurotransmitters

Needs to be removed or will influence nerve indefinitely; some degraded by enzymes; some reuptake into cells

Lumbar Enlargement: rise to those innervating the lower limbs (T9 to T12)

Cervical Enlargement: rise to nerves leading to the upper limbs (C4 to T1)

Spinal Cord: connection between the brain and brainstem to the rest of the body; begins at the base of the brain (medulla oblongata) to the level of the intervertebral disc between the first and second vertebral; 31 pairs of spinal nerves

Major Functions: transmit nerve impulse to and from the brain; house the spinal reflexes

Diencephalon: processes sensory input and controls many homeostatic processes; sits on top of the brain stem;

Brain Stem: coordinates and regulates visceral activites; contains midbrain, pons, medulla oblongata, reticular formation

Cerebrum: largest portion and associated with higher mental functions

Cerebellum: coordinates muscular activity to move smoothly; controls equilibrium and balance

Gyrus (gyri): bump; elevated ridges of tissues

Fissures: deeper grooves; usually separate large parts of the brain

Sulcus (sulci): creases; shallow groove

Temporal Lobe: hearing, speech, memory, sequencing, organization, primary auditory processing and Wernicke's area

Occipital Lobe: sensory area responsible for main processing center of vision (visual cortex)

Parietal Lobe: size, shape, color; associated with touch, pain, temperature, speech; somatic sensory area (interprets sensory information)

Frontal Lobe: personality, emotions, intelligence; attention, concentration; logic, problem solving; motor cortex (control movements of voluntary skeletal muscles); broca's area (ability to vocalize words)

Dura Mater: (tough mother) outer layer; tough, white dense connective tissue, contains many blood vessels

Arachnoid Mater: looks like cob webs, middle layer, very thin, lacks blood vessels

Pia Mater: (gentle mother) inner layer, covers every fold of the brain, attached to the surface of the brain, thin, contains many blood vessels and nerves

  1. if strong, depolarization occurs, threshold potential is reached, impulse is sent down axon
  1. nerve impulse is transmitted; only axons are capable
  1. K+ rush out of neuron after Na+ rush in causing repolarization of the membrane back to resting potential
  1. strong stimulation or nerve impulse causes Na+ gates to open —> Na+ rush into cell (depolarization) membrane potential goes unpolarized and becomes positively charged for a little

Motor (efferent) Neuron: transmits impulses away from CNS to effectors (muscle and glandular epithelial tissue)

Interneurons (central or connecting neurons): transmit impulses from sensory neurons to motor neurons, multipolar neurons in CNS

Sensory (afferent) Neuron: transmit impulses to CNS from all parts of the body; have specialized receptor ends at tips of dendrites etc.

Dendrite: (highly branched) portion of a neuron that receives impulse and sends signal to the cell body

Cell Body: the metabolic center; contains nucleus and other organelles

Axon: portion that conducts signal away from cell body, start as a single fiber, may give off branches (collateral axon),

Synaptic End Bulbs: axon and collaterals end in axon terminals which end in these

Neurotransmitters: chemical messengers, carry out the signals in the synaptic cleft

Myelin: fatty substance that surrounds axon, insulates signal, allows signal to be sent faster

Node(s) of Ranvier: spaces between myelin/ Schwann cell

Synapse: the junction between two communicating neurons

Presynaptic Neuron: the neuron sending the impulse; Postsynaptic Neuron: the neuron receiving the impulse

Synaptic Cleft: space between which the impulse must be conveyed

Synaptic Knobs: contain synaptic vesicles filled with neurotransmitters

Axon Hillock: the junction between the cell body and axon, site of action potential initiation

Marijuana: slows down movement, gives relaxing feeling, cannabinoid receptors turn off inhibitory neurotransmitter release

Opioids: stimulant, lose consciousness, withdraws symptoms, stomach aches

Heroine: feeling of sedation and well being, dopamine is released without inhibition

Cocaine: controls voluntary movement and the reward pathway, dopamine binds continuously and over the receptors over stimulate the cell

Inhalants: considered a depressant, can cause sudden death, brain damage, seizures, and hallucinations

LSD: interacts with particular receptors, sometimes inhibits or excites them

Grey Commissure: where fibers cross from side to side

Central Canal: center of gray commissure; continuous with 4th ventricle, carries CSF

Dorsal Root Ganglion and Dorsal Root of Spinal Cord are included

Grey Matter: butterfly shaped core in the center; containing posterior and ventral horns (located in the back); lateral horns (located on the side; cell bodies of motor neurons to cardiac and smooth muscles and glands; part of ANS)

White Matter: made of myelinated nerve fibers (nerve tracts); contains posterior, lateral, and anterior funiculus that then contains tracts

Anterior Median Fissure and Posterior Median Sulcus: deep longitudinal grooves divide the cord into left and right halves

Sensory (afferent) Nerve: relay information from skin, muscles, and glands to CNS, afferent by the environment or sense the environment; interneuron: nerves that connect sensory nerves to motor nerves

Autonomic Motor Neurons: automatic, involuntary control, unconscious, responds to internal environment, brings info from receptors in internal organs to CNS and motor neurons to smooth muscle, cardiac muscle and glands

Somatic Motor Neurons: conscious voluntary control part of PNS, sense and respond to enteral environment brings information from skin, special senses, body wall and limbs to CNS, and motor neurons to skeletal muscles

Parasympathetic Nervous System: "feed and breed"

Sympathetic Nervous System: "fight or flight"

Motor (efferent) Nerve: carry impulses from CNS to organs and muscles, cause an efferent or response; two types: somatic nervous system and autonomic nervous system

Meningitis: infection in the meninges that can spread to the CNS, dangerous, often fatal

Injuries: concussion, contusion, intracranial hemorrhage

Anencephaly: cranial portion does not close, brain and skull do not develop

Lateral Ventricle: 1st and 2nd, each side of the head, connected to the 3rd ventricle; 3rd ventricle is in the middle; 4th ventricle between the brainstem and the cerebellum

Ventricles: spaces inside the brain that produce CSF