cbns 124

midterm 1

what does the PNS include?

ganglia and nerves that innervate the skin, joints, and muscles
30-31 spinal nerves
cranial nerves except 1 & 2

what are sensory neurons?

afferent
carry info from PNS to CNS

what are motor neurons?

efferent
carry info from CNS to PNS

what are DRGs?

located w/in PNS
contains cell bodies of sensory neurons

what is the somatic nervous system SNS?

- associated w external enviorment
sensory and motor
innervate skin muscles and spinal and cranial nerves
conscious skin sensation and motor activity to respond

what is the ANS?

autonomic
internal enviorment
reg of organs glands and blood vessels

what are the divisions of the ANS?

parasym \= important for control of normal body functions (rest & digest)
sym \= important in responding to stress (fight or flight)

what are the divisions of the human brain?

- telencephalon
- diencephalon
- mesencephalon
- metencephalon
- myelencephalon

What does the telencephalon consist of?

cerebrum
cerebral cortex and deep like basal ganglia

what does the diencephalon consist of?

thalamus and hypothalamus

what does the mesencephalon consist of?

midbrain (tectum and tegmentum)

what does the metencephalon consist of?

pons and cerebellum
cortex and deep nuclei

what does the myelencephalon consist of?

medulla

what 3 divisions are part of the brainstem?

mylen
meta
mese

midbrain
pons
medulla oblongata

what are the divisions of the brain?

cerebrum
thalamus (& hypo)
midbrain
pons
medualla oblongata

what isnt considered part of the brain?

spinal cord

how many layers is the neocortex?

6

what is the allocortex?

part of the cerebral cortex first 3 layers

what is gray matter?

collection of neuronal bodies in CNS

what is the cortex?

any collection of nuerons that form a thin sheet at the brains surface

what is a nucleus?

clearly distinguishable mass of neruons usually deep in the brain

what is substantia?

group of related neurons deep w/in the brain but less distinct borders than nuclei

what is locus/loci?

small well defined group of cells

what is ganglion/ganglia?

collection of neurons in PNS
cell bodies of sensory axons

whats a nerve?

a bundle of axons in PNS

whats white matter?

collection of CNS axons

whats a tract?

collection of CNS axons having common site of origin and common destination

whats a bundle?

collection of axons that run together but don't have same origin or destination

whats a capsule?

collection of axons that connect the cerebrum w brain stem

whats commissure?

any collection of axons that connect one side of the brain to the other

what is a lemniscus?

a tract that goes thru brain like ribbon
ex. brings info from spina cord to brainstem

what are the 5 principle grooves?

longitudinal sagittal fissure
central sulcus
lateral sylvian fissure
parieto-occipital sulcus
calcarine fissure

what are the 4 principal fiber tracts?

corpus callosum
internal capsule extending to corona radiata
optic radiations - geniculo-calcarine tract
anterior commissure

which of the following describe nucleus in the brain?

a mass of neuronal cell bodies deep in the brain

how many layers are found in allocortex?

3

in bipedal animal, the midline structures along the entire length of the spinal length are best seen in a cut taken which plane?

midsagittal

what are the functions of the nervous system?

- to detect sensory stimuli from outside and inside the body (sensory)
- to coordinate most physiological functions of the body and to generate behavior (motor)
- to integrate info including memory and thinking processes
- to generate behavior (motor)

afferent neurons of the nervous system:

originate in the sensory receptors

the forebrain can be divided into which of the following embryological divisons?

telencephalon and diencephalon

what is the corpus callosum?

thick band of nerve fibers that connect from left and right cerebral hemispheres
transfers motor sensory and cognitive info between hemispheres

what is the corona radiata?

the radiating crown of projections thru internal capsule to every part of the cerebral cortex

what do ascending fibers do?

bring sensory info to cortex

what do descending fibers do?

from cortex to inferior structures involved coordinating movement

what is the optic radiations or geniculo calcarine tract?

the massive fanlike fiber system passing from the LGN of thalamus to occipital lobe of cortex

what is the anterior commissure?

contains bundle of nerve fibers connecting both temporal lobes
linking 2 hemispheres of brain
interconnects amygdalas w/in temporal lobes (role in memory emotion speech and hearing
contains decussating fibers from olfactory tracts which is vital for sensor of smell and chemoreception

which commissural fiber system below connects the temporal loves in both cerebral hemispheres?

anterior commissure

which of the following is not 1 of the 5 principle fissures?

horizontal fissure

what are the functions of the cerebrum?

- executive\= memory attention flexible thinking
- sensory \= processing info from internal and external enviorment via sensory organs
- voluntary motor activity/behavior

pre motor and motor cortex in frontal lobe

locomotion, ocular movement, speech (brocas area

prefrontal cortex

-intellectual functions complex reasoning skills problem solving planning
- personality and emotional expression and social behavior

what happens if there is a lesion in the frontal lobe

- loss of motor activity
- speech impairment
- emotional deficits (Phineas Gage)
- loss of short term and working memory

what is paresis

muscle weakness causes my frontal lobe lesion

What is Broca's aphasia?

expressive aphasia causes by frontal love lesion

what is abulia

absence of willpower or the inability to act decisively caused by frontal lobe lesion (Phineas Gage)

what are the parietal lobe functions?

- somatic sensation (pain)
- sensory integration ( environmental awareness)
- learned motor adaptation
- language processing (Wernicke's area)
- mathematical functions
- spatial representation of body

what does lesions to the left parietal lobe cause?

- agnosia
- asterogenesis
- SPD
- apraxia
receptive aphasia
- hemispatial need- grestmann syndrome

define agnosia

general loss of perception

define SPD

- sensory processing disorder
- experiencing muted sights sounds...sensory overload

define apraxia

inability to perform learned motor tasks due to damage to the angular gyrus

define receptive aphasia/ Wernicke's Aphasia

speech is fine but meaningless

hemispatial neglect

a failure to attend to stimuli on the opposite side of space to a brain lesion

Gestmann Syndrome

due to damage to angular gyrus
- dysgraphia \= impaired handwriting
- acalculia \= inability to do math
- finger agnosia \= inability to identify ones fingers
- left-right disorientation

what does lesions in the occipital lobe cause?

- antons syndrome
visual anosognsia
cortical blindness

define anton's syndrome

partial or total loss of vision in spite of normal retinal function
- caused by stroke in striate visual cortex
- sometimes triggered by meningitis
- patients are unaware they cant see

what are other functions of the temporal lobe other than auditory perception?

- memory formation and encoding
- processing emotions - due to amygdala contained w/in temporal lobe

what do lesions in the temporal lobe cause?

- deafness
- dec recognition of tonal seq & musical abilities
- impaired speech recognition
anterograde amnesia
- emotional symptoms

define anterograde amnesia

patient H.M. (had bilateral medial temporal lobotomy including hippo to cure seizures)
- impairment to form new memories

what are the general functions of the insular lobe?

- sensorimotor and special sensory processing
- cognitive functions (speech attention decision making)
- socio-emotional processing (empathy ..mutilated body ex)

what happens when insular lobe is lesioned?

deficits in:
- special senses
- vertigo
- somatosensory
- cognitive functions
- anxiety and apathy
- autonomic control (heart rate & blood pressure)

what did Paul Broca discover?

- that the region of the frontal lobe os the cerebrum is responsible for speech
- patients could still understand language
- the cases of Liborngne (5 words) and Lelong (tan)

what did Brodmann's Cytoarchitectural Map show?

- primary motor cortex (area 4)
- primary somatosensory cortex (Areas 1 2 3)
- primary visual cortex (area 17)
- primary auditory cortex (area 42)
- brocas area (area 44 45)
- wernickes area (area 22 39 40)

lesion to broca's area \=

brocas aphasia (loss of ability to speak or write language)

lesion to wernickes area \=

receptive aphasia (major impairment of lang comprehension)

how does wernickes area connect to brocas area?

via arcuate fasciculus
- also has connections to primary auditory cortex

what is the Darwinian view of the nervous system?

- monkeys have sophisticated occipital lobe due to swinging from branch to branch
- mice have no neocortex but relies heavily on tactile sense

What represents the Darwinian view of the nervous system?

nervousa system of diff species evolved from a common ancestor

which Brodmanns area functions in the comprehension of spoken language?

Area 22 (Wernickes Area)

Which cerebral lobes is involved in the memory formation and consolidation and auditory functions?

- temporal

which of the following matches are correct for the cerebral lobes?

vertigo- loss of balance - insular lobe

which of the following matches isnt correct for clinical symptoms and their associated definitions?

asterogenesis - impaired handwriting

Lesions w the frontal lobe produce which of the following symptoms?

- paresis
- broca's aphasia
- impulsivity, apathy
- loss of working memory

Computerized Axial Tomography

CT
- to study brain in details w moderate solution
- X ray beams are used to generate data that generates a digitally reconstructed image

how does a CT scan show a patient w Alzheimers disease?

showing shrunken brain and enlarged vesicles

MRI

Magnetic Resonance Imaging
- better resolution & non-invasive
- electromagnetic signals emitted by hydrogen atoms in brain - signals mapped by computer

what are the advantages of an MRI over a CT?

- more detail (spatial resolution)
- does not require X-irradiation
- brain slice image in any angle

what special about functional brain imaging?

- detects metabolic changes in active neurons
- invasive - requires injectable

what are the 2 methods of functional brain imaging?

- positron emission tomography PET
- functional MRI fMRI

how does PET scan work?

- active neurons take up more radioactive analogue of glucose (2 DG) and then it gets phosphorylated in active neruons and trapped
- 2 DG emits positrons which interact to produce photons that get detected by PET detector

which radiology technique is completely non-invasive, allows fast image acquisition and has best spatial resolution?

MRI

what are the 3 basal ganglia?

* caudate
* putamen
* globus pallidus

whats the role for basal ganglia?

project to motor areas of cortex

play an important role in motor system

what does damage to the basal ganglia cause?

Parkinson’s disease

Amygdala location

adjacent to hippo

deep w/in temporal lobe

Amygdala functions:

* arousal
* endocrine
* emotional
* autonomic responses related to fear

hippocampus functions:

* memory
* spatial navigation
* limbic

whats the amygdala connected to?

hippo, hypo, cortex & brainstem

what happens when you lesion the amygdala?

deficits in detecting danger

reduce fear and aggression

what are disorders related to the amygdala?

* anxiety
* autism
* OCD
* people who are addicted to social media have large ________