Brain and Behavior exam 3

Ectoderm

external layer, forms the nervous system, skin

mesoderm

middle layer

endoderm

internal layer

neural plate

thickening of cells in ectoderm, uneven rates of cell divison form neural grove

neural tube

gives rise to the central neurvous system

neural crest

forms the peripheral nervous sytems

What if the neural tube doesnt close?

1. Anecephaly: open brain and lack of skull vault

2. Open Spina Bifida: spinal cord is exposed

Neurogenesis

along the lining of the ventricles, central canal, and aquedecits of the ventricles is where neurgenis occurs

When does neurogenis occur?

almost all neurons are bron within first few days of rat, humans first trimester

Differentiation

1. mitotic lineage: uneven distribution of gene expression patterns

2. Cell-cell interactions: one gcell directs gene expression of another due to exposure of intracellular signals

Growth cones

growth a tip of axon and dendrites: Chemo attracts and chemoreppellants

What determines which cells/synases stay/go?

1. different neurotropic factors are produced by different target cell groups

2. innervating neurons take up particular nerotrphic factors and transport them to their sonata

3. when at cell body, nerotrophic factoors regulate the expression of various genes, affecting the developement of the neurons

4. early in developement neurons mangae to gather insffcient trophid factor undergo aptosis

teratogen

extern agel such as various chemicals, hyperthermia, radiation, or viruses that cause abornormalities

Harry Haslow Nature vs Nurture

the monkeys liked cloth over wire with food

Visual Sesnory (seeing)

visible radiant energy

Mechanical (Hearing)

sound vibration in air or water

Mechanical (touch)

contact or deformation of body surface

Mechanical (Proprioception)

Bosdy postiion and movement

Mechanical (Vestibular)

head and movement orientation

Chemical (taste)

substances contact with tongue

Chemical (Smell)

odorous in air or water

Electroprecption

sensing electric fields

Magnetoreception

sensing earth’s magnetic field

sensroy transduction

receptor cells transduce energy in stimulus into change in electrical potential across membrane

Acessory structures

reduce level of input

top down processing

upper brain regions modulate activity of lower centers

Touch Brain Pathway

1. receptors

2. axon enters dorsal horn and goes to brain

3. axon synapses in medula

4. thalamus will send to sensory cortex

Rods

Night vistion

Key players of motor system

1. skeleton and muscles

2. spinal cord

3. motor cortex

4. basal ganglia

5. cerebellum

6. brainstem

Skeletal Muscles

muscle connected to bones by tendon

Myosin

binds to actin, then bend to slide filaments towards one another, causing shortening of musce=le

Motor neurons

located in ventral of spinal cords, recieves input from spinal cord, brain, and dorsal root ganglia

Infradian

more than a day

ultradian

less than a day

Actogram

graphical representations of rhtyms

Reintohypothalamic tract

projection from retinal ganglion cells to SCN