Chapter 3 Flashcards
(113 cards)
Central Nervous System
includes the brain and spinal cord
Neuron
a single neural cell
Nerve
a bundle of axons running together
- term only used in the peripheral nervous system
Tract
a bundle of axons running together in the CNS
Nucleus
group of cell bodies in CNS
Ganglion
group of cell bodies in PNS
Forebrain
contains two cerebral hemispheres, the thalamus, and the hypothalamus
Cerebral Hemispheres
large, wrinkled structures dominating brain’s appearance
- the dorsal or superior part of the brain that are covered by the cortex
Longitudinal Fissure
division running length of the brain separating cerebral hemispheres
Gyrus
each ridge in the surface of the brain
Sulcus
groove or space between two gyri
Fissure
large groove or space between two gyri
Cortex
outer surface of brain
- mostly made up of the cell bodies of neurons
The Cortex
- 1.4 to 4.0 mm thick
- convolutions provide 3x more surface area; also allow more access to cell bodies
White Matter
- primarily made up by myelinated axons
- inner cortex
Gray Matter
- made up of neuronal cell bodies
- outer cortex
Cortex; Layer 1
inhibitory
- outer most layer
Cortex; Layer 2 and 3
associational
Cortex; Layer 4
sensory
Cortex; Layers 5 and 6
motor functions
- inner most layer
Brain Size and Intelligence
- brain size does not determine intelligence, brain size is more related to body size
- the complexity of the brain is what determines intellectual power
Dorsal
toward the back
Ventral
toward the stomach
Anterior
toward the front