• The brain is composed of individual cells
• Information is transmitted from cell to cell across synapses

most abundant cells in the brain

involved in thinking

the stain fills the whole cell but only stain a small proportion of neurons

some cells pick up the chemical (1-2%)

dye fills the whole cell but only stains a small proportion of neurons

glass needle pierces 1 cell and injects dye into it

uses radioactive molecules taken up by the cell and then transported to the axon tips

taken up by dendrites and moves down axon to next neuron

taken up in the axon terminals and transported to the cell bodies, then visualized through chemical reactions

moves from axon terminals up axon to the cell body

• one axon, many dendrites 
• most common type 

one axon, one dendrite

Ex: visual system

a single extension branches in two directions, forming a receptive pole and an output zone

Ex: somatosensory system

stimulate muscles or glands

brain --> body

respond to environmental stimuli, such as light, odor, or touch

body --> brain

receive input from and send input to other neurons

integrate info from sensory neurons to motor neurons

star-shaped glial cells with many processes that receive neuronal input and monitor activity

responsible for blood-brain barrier

gaps between sections of myelin where the axon is exposed

where electrical signals can happen

a demyelinating disease

react slower than normal to stimuli

nerves connected directly to the brain

- 12 pairs

- can have motor and sensory functions, only motor, or only sensory

nerves connected to the spinal cord

- 31 pairs

prepares the body for action, excitatory, fight or flight

- has preganglionic neurons only in the spinal cord

- innervate the sympathetic chain, which runs along each side of the spinal cord

slows body down, relaxatory

- has preganglionic neurons that arise in the cranial nerves and the sacral spinal cord

structure in embryo that develops into the forebrain, the midbrain, and the hindbrain

- forebrain then develops into telencephalon, diencephalon, and mesencephalon

becomes the cerebellum and pons

- developed from the hindbrain

medulla

- developed from the hindbrain

important in motor control

- 4 nuclei

1. caudate nucleus

2. putamen

3. globus pallidus

4. substantia nigra

has structures for learning and memory

1.Amygdala

2. Hippocampus and Fornix

3. Cingulate Gyrus

4. Olfactory Bulb

5. Thalamus

6. Hypothalamus

7. Mamillary Bodies

involved in motor coordination and learning

Three layers:

1. Molecular (top)

2. Purkinje Cell (what gets messed up with alcohol)

3. Granule Cell

1. Dura Mater

2. Arachnoid Membrane (filled with cerebrospinal fluid)

3. Pia Mater

1. acts as a shock absorber

2. provides an exchange medium between blood and brain

keeps blood from mixing with structures in the brain

- results from higher resistance in brain capillaries that restricts passage of large molecules

- glial cells transport materials from blood vessels to neurons

a measure of X-ray absorption at several positions around the head

- maps tissue density

gives higher resolution images

1. strong magnets cause protons in brain tissue to line up in parallel

2. A pluse of radio waves knocks protons over

3. Protons reconfigure themselves, emitting radio waves that differ by tissue density

gives images of brain activity

- uses radioactive chemicals injected into the bloodstream and maps their destination by the radioactive emission

- identifies which brain regions contribute to specific functions