Chapter 2 Flashcards
Neurons
“Nerve cell” Brain contains nearly 100 billion. Basic unit of the nervous system composed of dendrites, cell body, conducting and transmitting axon.
Glial Cells-(Oligodendrocytes, Schwann, Astrocytes, Microglial)
“Glia” Nonneuronal brain cells that provide structural, nutritional, and other support for the brain
Oligo and Schwann wrap around segments of axons to insulate them with a myelin sheath. Oligo=brain and spine, Schwann=rest of body.
Astrocytes weave around and between neurons with tentacle-like extensions (star shaped) control blood flow etc.
Microglial-contain and clean up sites of injury
Synapse
Between Neurons where information is transmitted.
Neuron-Input zone
Dendrites of neurons receive information from other neurons.
Neuron-Integration zone
Neuron cell body (soma), integrates information received to determine whether or not to send a signal.
Neuron-Conduction zone
Single axon (nerve fiber) extension to conduct the output information and form electrical impulses.
Neuron-Output zone
Specialized swellings at the ends of the axon called axon terminals that transmit neuron’s signals across synapses to other cells
Motoneurons (Motor neurons)
Large and have long axons reaching out to synapse on muscles causing muscular contractions.
Sensory Neurons
Gather sensory information, very diverse shapes depending on what they detect.
Interneurons
analyze information gathered from one set of neurons and communicate with others.
Multipolar neurons
many dendrites and a single axon (most common)
Bipolar neurons
single dendrite and single axon (most common in sensory systems ex. vision)
Unipolar neurons
(monopolar neurons) single extension from cell body that branches an axon into two directions. One is an input zone with dendrite like branches, and the other axon terminals. Transmit touch information from the body to the spinal chord.
Presynaptic/Postsynaptic
Pre-located on the transmitting side (axon terminal)
Post-Region that receives and responds to neurotransmitter (dendrite or cell body)
Synaptic Cleft
Gap that separates Pre and Post synaptic membranes measuring 20-40 nanometers
Synaptic Vesicles
Microscopic hollow spheres that contains molecules of neurotransmitter.
Neurotransmitter + receptors
(synaptic transmitter, chemical transmitter, transmitter) Chemical released from presynaptic axon terminal that serves as basis of communication between neurons.
Neurotransmitter receptors-protein molecules that stud the postsynaptic membrane, capture briefly and react to neurotrasmitter molecules
Neuroplasticity
ability of nervous system to change in response to experience or the environment
Axon hillock, axon collaterals, axonal transport
1-cone-shaped area on cell body which axon emerges
2-branch of an axon
3-transportation of materials from cell body to terminals and back. (Outside electric signal, inside substance transport)
Myelin sheath
Contain nodes of Ranvier which are bead of uninsulated patches on the axonal membrane. Increases the speed of the electrical signal.
Edema
swelling of tissue in response to injury, damages neurons and is responsible for some brain injuries
Gross Neuroanatomy
Anatomical features of the nervous system that are apparent to the naked eye
Central Nervous System (CNS)
Portion that includes the brain and spinal cord
Peripheral Nervous System
Portion that includes all nervous and neurons outside the brain and spinal cord.
Motor/Sensory Nerves
Motor-transmit information from CNS to muscles and glands
Sensory-convey information from body to CNS
Somatic Nervous System/Autonomic Nervous System
Somatic-part of peripheral nervous system that supplies neural connection mostly to muscles and sensory systems. Consists of cranial nerves and spinal nerves. (connect brain to major muscles and sensory systems)
Autonomic-part of peripheral nervous system that provides the main neural connection to glands and to smooth muscles of internal organs (connect to internal organs or viscera)
Spinal Nerves
Spinal-nerves that emerges from the spinal cord. Cervical (neck), thoracic (trunk), lumbar (lower back), sacral (pelvic), coccygeal (bottom). (31 pairs)
Sympathetic and Parasympathetic Nervous System
Symp-part of the autonomic nervous system, activates the body for action.
Parasymp-part of autonomic nervous system, prepares body to relax and recuperate
Cerebral Hemispheres and Cortex
Hemispheres are the two halves of the brain. Cortex is the outer covering of the cerebral hemispheres, consisting largely of nerve cell bodies and their branches.
Gyrus and Sulcus
Gyrus-ridged or raised portion of the brain surface
Sulcus-crevice or valley of the brain surface
Frontal/Parietal/Occipital/Temporal Lobe/(s)
Frontal-most anterior portion of cortex
Parietal-between frontal and occipital lobes in each hemisphere
Occipital-coves posterior
Temporal-large region of cortex and continuous with parietal but separated from the frontal by Sylvian fissure. Spans “underneath” all the other three
Sylvian Fissure/Central Sulcus
Sylvian-“lateral sulcus” deep fissure that demarcates the temporal lobe
Central-fissure that divides the frontal from parietal lobes
Corpus Callosum
Main band of axons that connects the two cerebral hemispheres
Postcentral and precentral gyrus
Post-strip of parietal cortex just behind central sulcus that receives somatosensory info from the entire body (touch etc.)
Pre-strip of frontal cortex just in front of central sulcus that is crucial for motor control
Gray and White Matter
Gray-cell bodies and devoid of myelin, mostly receives and processes information
White-mostly myelin sheathed axons underneath gray matter, mostly transmits information
Neural Tube
Embryonic structure including formation of forebrain, midbrain and hindbrain (pg 37)
Cranial Nerves
Cranial-Nerves that are connected directly to the brain.
3 sensory- Olfactory I (Smell), Optic II (vision), Vestibulocochlear VIII (hearing /balance
5 motor- Ocolumotor III, Trochlear IV, Abducens VI (eyes), Spinal Accessory XI (neck), Hypoglossal XII (tongue)
4 both- Trigeminal V (facial sensation, chewing muscles), Facial VII (taste sensation, facial muscles), Glossopharyngeal IX (throat sensation, throat muscles), Vagus X (heart, liver, intestines)
Oh, Oh, Oh, to touch and feel very good velvet, such heaven (names in order with number)
Some stars make money but my brother says big brains make more (sensory/motor or both)
Medial/Lateral
Toward midline/closer to outsides
Ipsilateral/Contralateral
related to the same side/opposite of the midline
Proximal/Distal
Close by/far away
Afferent/Efferent
arriving information (to the brain)/sending information out (from the brain)
Planes (Horizontal, Saggital, Coronal)
divides upper lower, divides left and right, divides front and back
Pyramidal Cell
pyramid shaped cell body in layer II or V of the cortex
Cortical columns
extend through the thickness of the cortex
Basal Ganglia
contains caudate nucleus, putamen, and globus pallidus. Plays a critical role in control of movement
Limbic system
overlaps/curls around the basal ganglia, involved with emotion and learning. (includes amygdala, hippocampus/fornix, and cingulate gyrus, and the olfactory bulb
Amygdala
Consists of several subdivisions, with diverse functions including emotional regulation and perception of odor.
Hippocampus/Fornix
Important for learning and memory
Cingulate gyrus
in each hemisphere which is implicated in many cognitive functions including direction of attention
Olfactory bulb
sense of smell
Thalamus/Hypothalamus
toward medial and basal aspects of the forebrain. Thalamus directs incoming sensory information to the appropriate regions of the cortex. Hypothalamus contains vital nuclei for hunger, thirst, temperature, sex etc.
The Midbrain (tectum, superior colliculi, inferior colliculi, tegmentum, substantia nigra, periaqueductal gray, reticular information)
Tectum-top of midbrain, has two bumps, one in each hemisphere, roles in sensory processing
Superior colliculi-visual processing
Inferior Colliculi-process sound
Tegmentum-main body of the midbrain, contains substantia nigra, periaqueductal gray, and is part fo the reticular formation
Substantia nigra-many ways part of the basal ganglia and is a major source of dopaminergic projections
Periaqueductal gray-midbrain structure, perception of brain
Reticular information-loose collection of neurons that are important with sleep and arousal.
Cerebellum
posterior cortex attached to the dorsal brainstem. Made up of a 3 layered tissue. Crucial for motor coordination and control, also aspects of cognition including learning.
Pons
contains many nerve fibers, important motor control and sensory nuclei, point of origin for several cranial nerves. wrapped by cerebellum
Medulla
transition from brain to spinal chord, connected to pons. Conveys all major motor and sensory fibers to and from the body. Also contains nuclei that drive essential process such as respiration and heart rate.
Meninges
Three layers of membranes around the brain. Tough outer sheet called dura mater, then arachnoid a webby substance which suspends the brain in a watery liquid called cerebrospinal fluid (CSF), then pia mater which adheres tightly to the surface of the brain. (Meningitis, meningiomas-tumors)
Ventricular System
series of chambers in the cerebral called cerebral ventricles.
Lateral ventricle
Each hemisphere contains one which extends into all 4 lobes. Lined with Choroid plexus.
Choroid plexus
Produces CSF by filtering blood, membrane of lateral ventricle(s)
Third ventricle/4th Ventricle
CSF flows from lateral into this and to the 4th. Midline ventricle, conducts CSF from lateral to 4th.
Fourth-passageway with the pons which receives CSF and releases it to surround the brain and spinal cord.
Cerebral arteries
Three pairs of large arteries within the skull that supply blood to the cerebral cortex
Blood-brain barrier
Highly resistant capillaries in the brain (to large molecules) in order to protect the brain from infection.
Computerized axial tomography (CAT or CT)
examines brain structure through computer analysis of x-ray absorption at several positions around the head
Magnetic resonance imaging (MRI)
examines brain structure through magnetism and radio-frequency energy to create images of the gross structure of the brain.
Functional MRI (fMRI)
magnetic resonance imaging that detects changes in blood flow/ identifies regions of the brain that are active.
Positron emission tomography (PET)
brain imaging technique that tracks the metabolism of injected radioactive substances in the brain to map brain activity.
Transcranial magnetic stimulation (TMS)
examines brain function by applying a strong magnetic field to stimulate cortical neurons to identify discrete areas of the brain that are active with specific behaviors.
Magnetoencephalography (MEG)
brain-imaging technology that creates maps of brain activity during cognitive tasks by measuring tiny magnetic fields produced by active neurons.
Nissl Stains/Golgi Stains
Nissl Stains outline all the cell bodies
Golgi stains fill the whole sell including dentritic spine details
Immunocytochemistry
Capitalizes on the affinity of antibodies for specific proteins.
Brain slices are exposed to antibodies that are selective for a particular protein of interest.
Immediate early genes (IEG)
Uses ICC to label IEG, researchers can identify brain regions that were active during particular behaviors.
Horseradish Peroxidase
an enzyme found in the roots of horse radish which is taken up into an axon at the terminals and transported back into the cell body,
