General Terminology

regional neurobiology

study of the structure and function of anatomical parts of the nervous system (e.g. study of the brainstem)

systems neurobiology

study of the functional systems that involve the interaction of multiple regions of the nervous system (e.g. study of the motor system)

terms of relationship and comparison: rostral

head of the organism; towards the face/nose (exclusing brainstem)

terms of relationship and comparison: caudal

tail of the organism; towards the buttocks/tail (exclusing brainstem)

terms of relationship and comparison: ventral/anterior

front of the organism; towards the front or “belly”

terms of relationship and comparison: dorsal/posterior

back of an organism; towards the back

terms of relationship and comparison: superior

toward the top; with reference to the cortex of the brain, dorsal is frequently used

terms of relationship and comparison: inferior

toward the bottom; with reference to the cortex of the brain, ventral is frequently used

planes of the brain sections/brain slices: horizontal slice

cut made in the horizontal plane: mid-horizontal section divides the brain into superior and inferior halves

planes of the brain sections/brain slices: coronal slice

cut made in the coronal plane: mid-coronal section divides the brain into anterior and posterior halves

planes of the brain sections/brain slices: sagittal slice

cut made in the sagittal place: mid-sagittal section divides the brain into right and left halves

structural divisions of the nervous system: central nervous system

consists of the brain and spinal cord

structural divisions of the nervous system: peripheral nervous system

consists of the spinal nerves, the cranial nerves, and the ganglia (collection of cell bodies located outside the CNS) associated with them

functional divisions of the nervous system: somatic nervous system

parts of the CNS and PNS that regulate skeletal muscle and that convey somatic sensory information coming from the periphery

functional divisions of the nervous system: autonomic nervous system

parts of the CNS and PNS that regulate smooth muscle, cardiac muscle, glandular secretion, and that convey sensory information coming from the viscera

• parasympathetic division: rest/digest

• sympathetic division: fight/flight

neuron

(aka nerve cell)- basic structural and functional unit of the nervous system; responsible for receiving, integrating, and transmitting electrical impulses that impact other neurons or target tissue (e.g. skeletal muscle)

neuron: dendrite

branching processes that conduct impulses toward the body of a neuron (receiving end of the neuron)

neuron: soma

cell body- contains all of the organelles that are required to keep the cell functioning

neuron: axon

branching processes that conduct impulses away from the body of the neuron (sending end of the neuron)

neuron: myelin

insulating lipoprotein that surround some axons

neuron: afferent

conduction toward a structure or incoming information (posterior or dorsal root of a spinal nerve)

neuron: efferent

conduction away from a structure of outgoing information (e.g. anterior or ventral root of a spinal nerve)

neuron: synapse

location where information from 1 neuron is transmitted to another neuron or to an effector target (e.g. muscle or gland)

neuron: neurotransmitter

chemical messenger

glia

“glue” supporting cells in the CNS

• astrocytes

• oligodendrocytes

• microglial cells

gray matter

collection of neural cell bodies

gray matter: cortex

(pl. cortices) outer layer of gray matter that covers the surfaces of the cerebral hemispheres and cerebellum

gray matter: nucleus

(pl. nuclei) a distinguishable mass of neuronal cell bodies in the CNS

gray matter: lamina

(pl. laminae) a distinguishable layer of neuronal cell bodies in the CNS

gray matter: posterior or dorsal horn

gray matter in the spinal cord that contains second order sensory neurons

gray matter: anterior or ventral horn

gray matter in the spinal cord that contains somatic motor neurons

gray matter: lateral horn

gray matter in the spinal cord that contains visceromotor neurons

gray matter: ganglion

(pl. ganglia) a distinguishable mass of neuronal cell bodies in the PNS

white matter

collection of axons in the CNS

white matter: nerve

bundle of axons in the PNS

white matter: tract

collection of axons in the CNS that originate from a similar location and go to a similar destination

white matter: commissure

collection of axons that connect both hemispheres or both sides of the spinal cord

white matter: column

axonal tracts that carry information to and from the spinal cord

white matter: lemniscus

(pl. lemnisci) tract that travels through the brain resembling a ribbon

white matter: fasciculus

(pl. fasciculi) bundle or packet of nerve fibers traveling in the CNS (e.g. cuneate fasciculus)

white matter: funiculus

(pl. funiculi) cord- area of white matter that may consist of several functionally different fasciculi (e.g. lateral funiculus of the spinal cord) or tracts

white matter: decussation

point of crossing of paired tracts (e.g. left tract crosses to the right side and vis versa; decussations of the pyramids, the medial lemnisci, and superior cerebellar peduncles are examples)

regions of the brain: telencephalon

consists of the cerebral hemispheres and related deep structures (e.g. insula, limbic structures (e.g. hippocampus and amygdala) and basal nuclei)

• cerebral structures:

  • cerebrum: is divided by a fissure (deep groove) called the median longitudinal fissure into right and left hemispheres, and it has a folded appearance:

    • the ridge or elevated area of the fold is called a gyrus (pl. gyri) and the groove or crease between folds is known as a sulcus (pl. sulci)

      • Gyri and sulci have specific names and are associated with specific functions (e.g. the precentral gyrus is considered the primary motor cortex (M1) and it contributes to the control of voluntary movements

regions of the brain: cerebrum- frontal lobes

mediates motor planning and execution, expressive language, and mental functions (e.g. executive functions, social cognition, and emotional regulation)

regions of the brain: cerebrum- parietal lobes

detection of somatosensory information, and the integration, perception, and interpretation of sensory information (e.g. visuospatial processing, language comprehension, and self-processing operations)

regions of the brain: cerebrum- temporal lobes

detection of auditory information and basic auditory processing, language comprehension, object identification, long-term memory formation, and social cognition

regions of the brain: cerebrum- occipital lobes

detection of visual stimuli and basic visual processing

regions of the brain: cerebrum- insula

considered a 5th lobe in some sources: related to basic survival mechanisms such as taste perception and the processing of visceral sensations; also though to play a role in emotional processing

regions of the brain: cerebrum- deep structures

• basal nuclei: caudate, putamen, and globus pallidus- involved with motor, cognitive, and emotional functions

• limbic structures: hippocampus and amygdala- involved with memory formation and emotional functions

• internal capsule: large fiber bundle that connects the cerebral cortex with the diencephalon

diencephalon

consists of the following structures

• thalamus: contains multiple nuclei and seves as a gateway for information traveling to/from the cortex, as such it is involved with multiple functions

• hypothalamus: contains multiple nuclei and is instrumental in regulating visceromotor, viscerosensory, and endocrine functions

• sub-thalamus: contains the subthalamic nucleus, which plays a role in motor control

• epithalamus: contains the pineal gland which plays a role in regulating circadian rhythms

cerebellum

means “little brain”- plays a prominent role in motor control and motor learning

brainstem

mediates vegetative functions (e.g. control of respiration, blood pressure regulation), auditory and visual reflexes, arousal, sleep/wake patterns, modulation of pain signals, and it plays a role in motor control

• consists of 3 structures from rostral to caudal:

  • midbrain

  • pons

  • medulla

mesencephalon

corresponds to the midbrain during development

metencephalon

corresponds to the pons and cerebellum during development

myelencephalon

corresponds to the medulla during development

prosencephalon

forebrain during development

rhombencephalon

hindbrain during development