Safran last exam

ventricles

produce and circulate CSF

lateral ventricles (1 &2)

separated by septum pellucidum

3rd ventricle

in diencephalon; communicates with lateral ventricle via interventricular foramen

4th ventricle

extends into medulla oblongata; joins central canal of spinal cord

physical protection of the brain:

bones, meninges, and cerebrospinal fluid (CSF).

biochemical protection of the brain:

blood brain barrier

dura mater

outermost meninge;

outer later - fused to periosteum to cranial bones

inner layer - dural folds that extend into cranial cavity to stabilize and support the brain

arachnoid mater

middle weblike layer of meninges

pia mater

inner most meningeal layer; attached to surface of brain, anchored by astrocytes

cerbrospinal fluid

surrounds all exposed surfaces of CNS; surrounds brain and spinal cord; transports nutrients, waste, and chemicals

choroid plexus

produce CSF in brain

CVA - cerebrovascular accident (stroke)

stops blood flor to a portion of the brain

what do breaks in the BBB do

produce horomones

what horomone does the posterior pituitary gland produce

ADH and oxytocin

what horomone does the pineal gland produce

melatonin

diencehalon = thalamus, hypothalamus

thalamus - relays and processes sensory information

hypothalamus - emotions, autonomic functions, and horomone production

midbrain

processes visual and auditory data; generates reflexive somatic motor responses, maintains consiousness

pons

relays sensory information to cerebellum and thalamus; subconsious somatic and visceral cetners

medulla oblongata

relays sensory info to thalamus, autonomic centers for regulation of visceral function

brain stem conists of what

medulla oblongata, pons, midbrai

are decending or ascending tracts white or gray matter

white

is respiratory system white or gray matter

gray

superior colliculi (midbrain)

visual

inferior colliculi (midbrain)

auditory

cerebellum

responsible for movement coordination

arbor vitae connect cerebellar cortext and cerebellar peduncles

mamillary bodies

feeding reflexes

infundibulum

narrow stalk connecting hypothalamus to pituitary gland

limbic system

facilitates memory formation, storage, and retrival

fornix

primary output of hippocampus; memory encoding, emotion, behavioral regulation

wernickes area

language comprehension; left cerebral hemisphere

brocas area

speech production (motor speech), left cerebral hemisphere, regulares breathing and vocalization

olefactory nerve (i)

smell; ends in olefactory bulbs

optic nerve (ii)

vision; starts at retina-->optic canal-->diencephalon

optic chiasm

where optic nerves converge

vesibulochochlear nerves (viii)

vestibular - balance and equilibrium

cochlear - hearing

primary motor cortex

voluntary skeletal muscles via somatic motor neurons

primary somatosensory cortex

recieves somatosensory information for touch, pressure, pain, vibration, temperature

visual cortex location

occipital lobe

Auditory cortex location

temporal lobe

olefactory cortex location

temporal lobe

gustatory cortex location

insula

somatosensory association

recognizes what is causing touch - parietal lobe

visual associsaion

interprts visual association like reading - occipital lobe

auditory association

recognizes sounds as words - temporal lobe

premotor cortex

somatic motor association, learned movements, frontal lobe

prefrontal cortext

performs intellectual functions - frontal lobe

afferent

goes up to CNS

both visceral and somatic receptors

efferent

down to muscle

motor commands go down from CNS

nocioceptors

pain

thermoreceptors

temperature

chemoreceptors

chemical

mechanoreceptors

have mechanically gated channels - 3 types

tactile receptors (mechano)

touch, pressure, vibration

baroreceptors (mechano)

pressure changes in blood vessesl

proprioreceptors (mechano)

changes in body position

posterior column pathway

highly localized fine sensations

spinocerebellar pathway

proprioceptive input

spinothalamic pathway

poorly localized crude sensations - pain, temp, touch, pressure

decussation

2nd order neurons crossing over to opposite side of CNS

where does decussation occur in the spinothalamic pathway

spinal cord

anterior tract of spinothalamic pathway

crude touch and pressure

lateral tract of spinothalamic pathway

pain and temperature, phantom limb syndrome

where does decussation occur in the posterior column pathway

medulla oblongata

posterior spinocerebellar tract

axons do not cross to opssite side; no need for third order neuron - proprioreceptive

anterior cebebrallar tract

decussation in spinal cord; no need for third order neuron - proprioceptive

corticospinal pathway (also called pyramidal)

voluntary pathway; descending motor; sends signals to skeletal muscles

lateral corticospinal tract decussation location?

dominant tract; crosses over in medulla oblongata

anterior corticospinal tract decussation location?

spinal cord

upper motor neuron

cell body lies in cns, activity facilitates or inhibits lower motor neurons

lower motor neruon

cell body lies in brain stem or spinal cord, axon extends outside cns, innervates a single motor unit

The ANS is visceral, so it does what

operates without conscious instruction

ANS is split into two divisions, what are they

parasympathetic and sympathetic

both the sympathetic and parasymptathetic divisions are responsible for regulation of what parts of the body

smooth muscle, cardiac muscle, glands, adipose tissue

where are preganglionic neurons located

in brain stem and spinal cord

preganglionic fibers

axons of preganglionic neurons; after leaving the CNS, they synapse on ganglionic neurons (postganglionic)

autonomic ganglia

contain many ganglionic neurons that innervate

visceral effectors

Postganglionic fibers

axons of ganglionic neurons

parasympathetic activity

rest and digest - conserves energy, maintains resting metabolic rate

sympathetic activity

fight or flight - prepares body for emergencies

opposing effects of parasympathetic and sympathetic divisions

sympathetic excites, parasympathetic inhibits

sympathetic responses

1. increased mental alertness

2. increased metabolic rate

3. decreased urinary functions

4. increased energy

5. increased respiratory rate

6. increased heart rate and blood pressure

7. increased sweat

parasympathetic responses

1. decreased metabolic rate

2. decreased heart rate

3. increased salivary and digestive glands

4. increased blood flow in digestive tract

what kind of fibers are in the sympathetic division

short preganglionic fibers in the thoracic and lumbar portions of spinal cord; sends long postganglionic fibers to target organs

sympathetic chain ganglia

each ganglion innervates a particular organ; found on both sides of the vertebrael column

collateral ganglia

innervate abdominopevlic tissues

adrenal medullae

modified sympathetic ganglion at center of each adrenal gland; epinepherine(adrenaline) makes up 70-80% of output, one on each kidney

sympathetic activation

entire division coordinates a response, controlled in hypothalamus

stimulation of preganglionic neurons releases what

ACh

ganglionic neurons release what

adrenergic

parasympathetic fibers located where

brain stem and spinal cord

Vagus (X)

responsible for 75% of parasympathetic outflow

all parasympathetic neruons release what chemical

ACh

rods

sensitive to light, no color

cones

color receiving in fovea centralis

cones and rods are connected to ganglion through waht kind of neurons

bipolar

order of light processing

1. axons from ganglion cells converge on optic disc

2. penetrate wall of eye

3. proceed towards diencephalon as optic nerve ii

4. two nerves reach diencephalon after partial crossover at optic chiasm

5. information travels to visual cortex in occipital lobe

6. visual association areas integrate this information to develop a composite picture of the entire field of vision

middle ear (tympanic cavity)

air filled chamber, cotains auditory ossicles (malleus - hammer, incus - anvil, stapes - stirrup)

when soundwaves vibrate the tynaptic membrane, _____ conduct vibrations to internal ear

auditory ossicles

internal ear

bony labyrinth protects membranous labyrinth

vestibulae

detect gravity and linear acceleration, 3 ducts