Second Test Flashcards
(44 cards)
what is the CNS?
the brain and spinal cord
cordinating system for the body
protected by the skull and vertebral column
tract=bundle of axons traveling together
nucleus=group of cell bodies
what is the PNS?
nerves extending across the body
branch from 12 cranial nerves, originating in the brain
31 spinal nerves, origninating from the spinal cord
AFFERENT: messages sent to the brain
EFFERENT: messages from brain to body
what is the ANS?
shares some nerve structures with both the CNS and PNS
functions without conscious awareness-control basic functions (body temperature, blood pressure, heart rate)
What is a spinal nerve?
31 pairs
branch out from the spinal cord
carry info from receptors to spinal cord
transmit motor information
What is a cranial nerve?
12 pairs
do not enter the spinal cord
allow sensory info to pass from the organs of the head (eyes…) to the brain and convey motor information from the brain to these organs
Example of how cranial nerves are named after the body part they serve.
optic nerve=eyes
olfactory nerve=smell/nose
What is the circle of Willis?
a ring of communicating arteries encircling the base of the brain
supply routes for glucose and oxygen
Why does the brain have a larger surface area than what may be apparent?
the complex folds in the cerbrum, makes the brain have a much larger surface area
What are some defenses that are available to protect the brain from damage?
bony skull: acts as a box to buffer against blows
meninges: 3 layers of membranes that line the skull; providing extra layers of protection
cerebrospinal fluid: nourishes brain tissue and works as a shock absorber
Why are glucose and oxygen so important? How long can you last without it?
glucose: brain’s fuel; 20% of body’s glucose supply; 4oz of glucose/day
last for only 10 minutes without either
Brain Volume and Lifestyle
alcohol consumption–> brain shrinkage
1.6% bigger brain if you abstain from alcohol
aerobic excersise: increase in brain volume in older adults
What is dura mater?
attached to the inside of the skull
outer meninges
tough, strong
What is pia mater?
innermost meninx
Some names for various slices/sections of the brain.
horizontal
coronal (down the center vertically)
sagittal (off-center
medial (down the middle
What is an EEG?
measures electrical activity directly (by nerve cells firing)
electroencephalography
What is a PET scan?
post emission tomography
measure metabolic side effects, alterating in glucose absorption
include radioactive marker
What is an MRI?
better contrast between tissues
causes hydrogen atoms in the body to realign
In order from top to bottom gross anatomical regions of the brain and brief description.
cortical: cerebral cortex; most involved in conscious sensations, absract thought processes, reasoning, planning, working memory, and higher mental processes
limbic: innermost sides, around the brainstem, deal largely with more emotional and instinctive behaviors and reactions, and long-term memory
midbrain: thalamus; preprocessing and relay center, primarily for sensory information coming from lower in the brainstem
brainstem: ‘vegetative’ centers of the brain, sustain life even if the person has lost consciousness
Difference between glial cells and a neuron
glial cells are brain cells that support neurons by performing a variety of ‘housekeeping’ functions in the brain
Difference between sulci and gyri
gyri: bulges of tissue on the surface of the brain
sulci: a vallye/groove in the brain surface
What is afferent?
traveling toward or entering
What is efferent?
leading away from
in relation to the brain, what do the terms symmetry and asymmetry mean?
brain is not symmetric (left/right), not an exact mirror image
lateral sulcus: longer/less curved on the left than the right
What are the differences between the dorsal and ventral fibers of the spinal cord?
dorsal root: sends sensory information from the skin to the brain
ventral: toward the lower, front surface (ex abs)
