Chapter 3 Flashcards
(208 cards)
horizontal section
parallel to floor
coronal section
anterior/posterior
sagittal section
left/right
two parts of the nervous system
central nervous system
peripheral nervous system

central nervous system
- protected within bony encasements
- self repair more limited
- includes: brain and spinal cord
brain and meninges
- brain - enclosed in skull
- meninges (3 layers)
dura mater
tough double layer of tissue enclosing brain in loose sack
arachnoid membrane
very thin sheet of delicate tissue that follows brain contours
pia mater
moderately tough tissue that clings to brain surface
subarachnoid space
filled with CSF
spinal cord
encased in interlocking bony vertebrae
- spinal nerves do not directly control the target organs
- spinal cord is connected to a chain of autonomic control centers
brain’s blood supply
- two internal carotid arteries
- two vertebral arteries that enter the skull
- branch out into smaller arteries through brain stem and cerebellum
- ex: anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA)



peripheral nervous system
- outside the bony protections
- more vulnerable to injury
- can renew themselves after injury by growing new axons and dendrites

stem cells
- originates in single, undifferentiated, neural stem cell, a germinal cell
- self renewing, multipotential neural stem cells give rise to different types of neurons and glia in nervous system
- in developing embryo, stem cells produce progenitor cells

progenitor cells
- produce two types of blasts:
- neuroblasts
- glioblasts
neuroblasts
differentiate into neurons
glioblasts
differentiate into glial cells
stem cell differentiation process
- stem cell divides into two stem cells
- once mature, one stem cell dies for every division to keep constant number of stem cells in brain
- stem cells produce progenitor cells
- progenitor cells produce blasts
- blasts differentiate to neurons and glial cells

vertebrate embryo
(fish, amphibian, reptile)
- prosencephalon
- mesencephalon
- rhombencephalon



prosencephalon
vertebrate embryo
- forebrain
- responsible for function
- includes: telencephalon, diencephalon
- anterior: develops to form cerebral hemisphere, the cortex, and related structures
- posterior: develops to form diencephalon
telencephalon
(prosencephalon)
endbrain
diencephalon
(prosencephalon)
between brain
develops into thalamus, hypothalamus, pineal body, third ventricle
























































