Exam1 Flashcards
CNS
Structures encases by bone (brain enclosed by cranium and spinal cord by vertebral column)
PNS
Ganglia and nerves that innervate skin, joints, and muscles
Parasympathetic nervous system division
Important for control of normal body functions. Rest and digest
Sympathetic nervous system division
Fight or flight. important in coping with stress
Telencephalon
cerebrum (cerebral cortex and deep nuclei like basal ganglia)
Diencephalon
thalamus and hypothalamus
Mesencehalon
midbrain (tectum and tegmentum)
Myelencephalon
medulla
Sensory or afferent fibers
Carry information toward a particular point. Afferent information travels from the PNS to the CNS
Motor or efferent fibers
Carry information away from a point. Efferent information travels from CNS to PNS.
Cuvier’s fraction
E/S where E=brain weight and S=body weight. Not the best way to represent intelligence
Encephalization
Amount of brain mass exceeding that related to an animal’s total body mass
EQ
Encephalization Quotient [cephalization factor]/[average mammalian value]
Cortical folding
In higher mammals, the surface of the cerebral cortex is folded, creating grooves (sulci) and bumps (gyri), increasing surface area of the cortex.
Neocortex in mammals
made up of 6 layers. outermost 2-5 mm contain 20 billion neurons in the human brain.
Gray matter
A generic term for a collection of neuronal cell bodies in teh CNS. When a freshly dissected brain is cut open, neurons appear gray.
Cortex
Any collection of neurons that form a thin sheet, usually at the brain’s surface. Cortex is Latin for “bark.” Example: cerebral cortex, the sheet of neurons found just under the surface of the cerebrum.
Nucleus
A clearly distinguishable mass of neurons, usually deep in teh brain (not to be confused with the nucleus of a cell). Nucleus is from teh Latin word for nut. Example: lateral geniculate nucleus, a cell group in teh brain stem that relays information from teh eye to the cerebral cortex.
Substantia
A group of related neurons deep within the brain, but usually with less distinct borders than those of nuclei. Example: substantia nigra (from the latin for black substance), a brain stem cell group involved in the control of voluntary movement.
Locus (plural: loci)
A small, well-defined group of cells. Example locus coeruleus (latin for blue spot) a brain stem cell group involved in the control of wakefulness and behavioral arousal
Ganglion (plural: ganglia)
A collection of neurons in the PNS. Ganglion is from teh Greek for knot. Example: the dorsal root ganglia, which contain teh cell bodies of sensory axons entering the spinal cord via the dorsal roots. Only one cell group in teh CNS goes by this name: the basal ganglia, which are structures lying deep within the cerebrum that control movement.
Nerve
A bundle of axons in the PNS. Only one collection of CNS axons is called a nerve: the optic nerve.
White matter:
A generic term for a collection of CNS axons. When a freshly dissected brain is cut open, axons appear white.