Exam 3, Ch. VII Flashcards
Parts of the prosencephalon
- 3rd ventricle
- epithalamus
- thalamus
- hypothalamus
- subthalamus
Functions of the prosencephalon
- relay center to the cerebrum
- integrative
- autonomic and endocrine
What does the epithalamus include?
Pineal gland, posterior commissure
What is the other name for the pineal gland?
Hypophysis cerebri
What is the pineal gland filled with?
Epiphysial cells
T/F: the pineal gland is less numerous in capillary beds and glial support cells
False- more numerous
What is brain sand?
Calcifications in the pineal gland
Why are pineal tumors hard to remove?
- located behind major structures
- in geographic center
- posterior side of brain stem
*What does the pineal gland secrete?
Melatonin, serotonin, norepinephrine
Is the pineal gland sensitive to light directly?
No
What is involved with the circadial cycle?
Melatonin
How many people are affected by SAD?
1 in 20
*What is the largest commissure?
Corpus callosum-> 300 million neurons
Is the posterior commissure small or large?
Small, but identifiable
*What is located in the posterior commissure?
Pupillary light reflex fibers and nuclei
Just inferior and anterior to the posterior commissure is the ___, which may produce aldosterone
Subcommissural organ
What is included in the thalamus?
Lateral and medial geniculate bodies
*What joins each half of the thalamus?
Massa intermedia
*The thalamus forms the bulk of the ___ walls of the 3rd ventricle
Lateral
*All sensory input to the cerebral hemispheres, except ___, is relayed in the thalamus
Olfaction
An ___ of myelinated fibers runs through the substance of each thalamic mass and helps divide them into subdivisions
Internal medullary lamina
*What is the largest part of the thalamus only found in high primates?
Pulvinar
What forms the floor of the 3rd ventricle and portions of the 3rd ventricle’s lateral walls?
Hypothalamus
Is the hypothalamus small or large?
Small
*What is included in the hypothalamus?
Infundibular stalk and optic chiasma
Subdivisions of the medial zone of the hypothalamus?
Anterior, intermediate and posterior
T/F: the hypothalamus works unaided or uninfluenced from other centers
False- does not
The hypothalamus has vague control over the basic drives of ___
Hunger, thirst and sex
What controls the physical aspects of emotional expression?
Hypothalamus
The hypothalamus has central control over ___ functions
Fight or flight
Endocrine control of the HT: directly via ___ axon extensions into the ___ pituitary
Neuron, posterior
Endocrine control of the HT: indirectly via ___ to control the release of ___ pituitary hormones
Neurohormones, anterior
*Supraoptic and paraventricular nuclei send axons down through the infundibular stalk via the ___ tract
Hypothalamohypophyseal
*The supraoptic and paraventricular nuclei release ___ and ___
Oxytocin and ADH
What does oxytocin do?
Stimulates uterine contractions and ejection of milk
What does ADH do?
Increases water resorption
What nucleus is responsible for circadial rhythms?
Suprachiasmatic nuclei
The anterior nucleus of the HT is know for ___ functions
Parasympathetic
The ___ is a thermoregulator, especially as the body heats up
Preoptic area
What does the preoptic area stimulate?
Sweating
The dorsomedial nuclei of the intermediate area of the HT has ___ influence
Parasympathetic
The ventromedial nuclei of the intermediate area of the HT is a center for ___
Eating and thirst gratification-> “satiety center”
*Arcuate nuclei release ___ -> hypothalamic hypophysiotropic hormones
Releasing factors
What is the tuber ceinereum?
Bulge between the infundibular stalk and mammillary bodies
*Mammillary bodies deal with ___
Short-term memory
What is Korsakov’s Syndrome?
Lack of vitamin absorption, causes you to invent memories
What is anterograde amnesia?
Where forward memories stop being created for a while
What is retrograde amnesia?
Not remembering things prior to an event
___ is a thermoregulatory, especially as the body cools down
Posterior nuclei
What would fibers from the hypothalamic nuclei be doing if they descend to specific nuclei for CNs III, VII, IX, or X?
Parasympathetic fibers
Which area gives rise to the anterior pituitary and intermediate pituitary?
Rathke’s Pouch
The anterior pituitary must receive its hypothalamic influence via the ___
Bloodstream
Blood supply and portal system pathway
Internal carotid arteries-> fenestrated sinusoids-> pick up releasing factors-> hypophyseal portal veins
Nuclei included in the subthalamus
- parvocellular region of the red nucleus
2. superior portion of the SN
___ sends and receives fibers to and from the globus pallidus
Corpus Luysi
Lesions of the ___ may lead to ballism or hemiballism
Extrapyramidal system-> Corpus Luysi
Are the cerebral hemispheres the same anatomically?
Yes
Are the cerebral hemispheres the same functionally?
No
Functions of the left cerebral hemisphere
- grammar
- vocabulary
- linear reasoning
- speech
- tool use
Functions of the right cerebral hemisphere
- prosotic language
- spatial manipulation
- singing
The outer convoluted gray cerebral cortex is called the ___
Pallium
The underlying mass of white fibers in the cerebral cortex is called ___
Centrum semiovale
The collections of neuron cells bodies deep within the white matter are called ___
Basal ganglia
The ___ and limbic region are sometimes called lobes or pseudolobes
Isle of Reil
Functions of the telencephalon
- thinking
- initiation
- memory
- integration
Abstract thinking serves as a basis for much of our ___ in Brodmann areas 9-12
Emotional response
In most areas, the ___ cortex is thicker than the ___ cortex
Gyrus, sulcus
How many neurons are in the cerebral cortex?
100 billion
Subdivisions of the cortex
- neocortex
2. allocortex
Which occupies the majority of the cerebral cortex: neocortex or allocortex?
Neocortex
6 laminae of the neocortex
- molecular lamina I
- external granular lamina II
- external pyramidal lamina III
- internal granular lamina IV
- internal pyramidal lamina V
- multiform lamina VI
Characteristics on the molecular layer
- outermost-> nearest to pia matter
2. synaptic activity
Characteristics on the external granular layer
- granular neurons
- axons extend to deeper lamina
- intracortical association layer
*Characteristics of the external pyramidal layer
- pyramidal-shaped neurons
* 2. axons extend to white matter and the return to gray - inter cortical association layer
Which lamina are called the associative lamina?
Lamina II and III
Characteristics on the internal granular layer
- small, closely-packed cells
- thalamic inputs
- well-developed in sensory areas
Characteristics on the internal pyramidal layer
- large pyramidal-shaped neurons
- giant pyramidal (Betz) cells
- axons project to other brain and cord centers
Characteristics of the multiform layer
- incoming and outgoing fibers
2. projection neurons
Which lamina are called the projection laminae?
Lamina V and VI
*Brodmann area 4
- pre central gyrus
- most fibers to pyramidal system
- voluntary motor initiation
- distal extremities and facial and oral musculature
- giant pyramidal (Betz) cells
- lamina V and VI
- multiple fibers originate here
*Brodmann areas 1, 2, and 3
- post central gyrus
- body sensing
- VPL, VPM, lamina IV
- voluntary motor initiation pathways
- lamina V and VI
*Brodmann areas 6 and 8
- premotor
2. directly and indirectly to pyramidal system
*Brodmann area 6
Proximal extremities
*Brodmann area 8
- voluntary eye movements
- 6 eye muscles
- CNs III, IV, VI
*Brodmann areas 9, 10, 11, 12
- lamina II and III
- highly developed
- thought, reasoning, imaginative and emotional uniqueness
*Brodmann area 44
- frontal operculum
- Broca’s speech area
- tongue, laryngeal, pharyngeal muscles
- speaking, writing, signing
What is aphasia?
Loss of power to communicate through writing, speaking, or signs
Which artery is involved with strokes?
Middle cerebral
Speech in specific and communicative skills are dominate on the ___ side of the brain
Left
*Brodmann areas 17, 18, 19
- occipital lobes
2. visual cortex
*Brodmann area 17
- calcarine sulcus
- lateral geniculate body
- primary visual cortex
- striate cortex
*Brodmann areas 18 and 19
- integrating
- memory storage for visual sensations
- lesions inhibit correlating present images with past experience
What is prosopagnosia?
- damage to areas 18 and 19
2. being unable to recognize faces
What macula lutea?
- portion f the retina with the clearest vision
2. part that is affected by macular degneration
*Brodmann area 41
- superior temporal gyrus
- Heschl’s gyrus
- fibers come from the medial geniculate body
- hearing-> pitch, tone, loudness
*Brodmann area 22
- Wernicke’s area
- nearly to the parietal lobe
- hearing memory
- formation of written word
- lesion results in dysphasia
*Brodmann area 5, 7, 39, 40
- parietal lobe
- sensation memory
- reading, writing, language
- lesions in 39 result in Alexia and agraphia
*What is the arcuate fasciculus?
- connection between 22 and 44
2. use tools
*What is the gustatory area?
- taste reception
- parietal operculum
- gustatory center
*What are the olfactory areas?
- only sense that skips the thalamus
- stem cells are constantly replaced
* 3. interpretation comes from 34 in the uncus and 28 in the parahyppacampal gyrus
Name of the caudate and putamen nuclei
Neostriatum
Name of the caudate, putamen and globus pallidus
Corpus striatum
Name of the caudate, putamen, globus pallidus, and amygdaloid complex
Basal ganglia
*Name for the putamen and globus pallidus
Lenticular nucleus
Features of stratal lesions
- caudate, putamen, globus pallidus
2. lead to dyskinesia
What are types of dyskinesia (muscle tone disturbances)?
- tremor
- chorea
- ballism or hemiballism
Features of tremors
- shaking of digits and lips at rest
2. action of voluntary muscles-> lesion to the cerebellum
Features of chorea
- involuntary movements
- deficiency of GABA
- corpus striatum begins to deteriorate
Features of ballism or hemiballism
- violent movement
- lesions of the globus pallidus
- Corpus Luysi
Function of the corpus stratum
Regulating movement
*Characteristics of the caudate nucleus
- head is continuous with the putamen nucleus by gray matter bridges
- afferent fibers synapse in the cortex, thalamus, substantial nigra, putamen
- efferent fibers extend to the putamen, globus pallidus, substantial nigra, thalamus
Characteristics of the putamen nucleus
- afferents synapse in the cortex, thalamus, SN, putamen
- efferents extend to the putamen, GP, SN, thalamus
- stored dopamine
Characteristics of the globus pallidus nucleus
- medial and lateral medullary lamina
- afferents: caudate, putamen, sub thalamic nucleus (GP)
- efferents: primary efferent outflow from the corpus striatum-> anterior aspect
*Characteristics of the amygdala
- temporal lobe
- introvert have a higher functioning one
- limbic system
* 4. increased inhibition-> must be intact to sense fear and anger
What is the name of the white matter of the telencephalon?
Centrum semiovale
Where do white matter fibers travel in the telencephalon?
Corona radiate and internal capsule
*How many neurons does the corpus callosum have?
300 million neurons
Parts of the corpus callosum
- splenium
- body
- genu
- rostrum
- forceps anticus
- forceps posticus
- tapetum
Which is the largest of all commissures?
Corpus callosum
Lesions and surgery of the corpus callosum can cause ___
Alien hand syndrome
*What is the most abundant part of the white matter in the telencephalon?
Association axon bundles
Short association axon fibers connect adjacent or ___
Near gyri
Long association axons fibers connect distal parts of the ___
Same hemisphere
Clinical considerations of the telencephalon
- trauma-> mild traumatic brain injury (biomechanical forces)
- concussion
- dementia pugilistica (repeated head trauma)
- plasticity (map, redundancy, rewiring, neglect)