Chapter 6 Flashcards
1
Q
What is the diencephalon?
A
Paired structure located at the base of the hemispheres
Embryologically separate structure from hemispheres and brainstem
Intermediary processing center b/w cerebral cortex and sensorimotor systems such as basal ganglia and cerebellum - skilled movement
Chief location where autonomic, homeostatic, and endocrine processes are orchestrated within the nervous system
2
Q
What separates one side of diencephalon from other?
A
Third ventricle
3
Q
Components of diencephalon
A
Thalamus
Hypothalamus
Subthalamus (links midbrain to diencephalon, part of basal ganglia)
Epithalamus -part of limbic system helps with circadian rhythm
4
Q
Definition of the thalamus
A
Composite of many different nuclei
Connections to many parts of the nervous system
5
Q
Functions of thalamus
A
GATEKEEPER FOR SENSORY INFORMATION (except Olfactory) - relay station, all sensory passes through except olfactory
Modifies incoming sensory info and influences the attentiveness of the cerebral cortex to incoming info
Because of sensory input plays role in motor functions:
Learning complex actions
Choosing Appropriate responses to meet motor goals
Regulating signals related to emotion, memory, and autonomic control
6
Q
Thalamus has 3 regions, and what is it divided by?
A
Internal Medullary lamina (y-shaped) divides thalamus
1. Anterior nucleus
2. Medial nucleus
3. Lateral nucleus
7
Q
Function of anterior thalamic nucleus
A
Integrates emotions of event with memory of same event
8
Q
Dorsomedial thalamic nucleus function (DM)
A
Influences affect, mood, personality, and judgement
Involved in pain modulation
9
Q
Ventral anterior thalamic nucleus (VA)
A
Selection of movement, initiation, and termination of action
10
Q
Ventral lateral thalamic nucleus (VL)
A
Coordination of movement
11
Q
Ventroposterior lateral (VPL) and medial thalamic nucleus (VPM)
A
Tactile, proprioceptive, noxious, and thermal sensations from body below neck
Medial is same except not below nexk
12
Q
Medial geniculate thalamic nucleus (MGB)
A
Auditory processing
13
Q
Lateral geniculate thalamic nucleus (LGN)
A
Visual processing
14
Q
Pulvinar
A
Consciousness and language
15
Q
Specific vs association functions of thalamic nuclei
A
Specific are ones that obtain focused input from a limited number of sources
Output any processed info to localized regions of the cortex
Association nuclei receive input from a variety of different sources
Send output to higher-order regions of the brain involved in integration of perceptual/motor activity with consist ion
Association distribute in a more widespread, diffuse manner
16
Q
What is the primary role of the hypothalamus?
A
Body’s homeostatic regulatory system
17
Q
Functions of hypothalamus
A
Body temp, circadian rhythm, blood pressure, etc
Integrates automatic processes
18
Q
Neural input to the hypothalamus
A
Limbic system
Hippocampus
Amygdala
Reticular formation
Solitary nucleus
Thalamus
19
Q
Non neural input to the hypothalamus
A
Related to temperature, water in body, blood sugar, pH, hormones
20
Q
What connects the hypothalamus to the pituitary gland and what is its role
A
Infundibulum
Passes secretions between the hypothalamus and pituitary gland
21
Q
What is the relationship between the hypothalamus and pituitary gland?
A
Resembles feedback control loop. Hypothalamus activates pituitary gland by way of inputs from CNS and circulatory system. THEN p.g. Secretes hormones into bloodstream that stimulate glands of the endocrine system throughout body. As hormones release, gland secretions circulate in bloodstream. Concentration levels are dented by hypothalamus and associated chemoreceptor sensors. Hypothalamus adjusts its activity and p.g., allowing the negative feedback loop to begin new cycle.
22
Q
What separates and connects cerebral hemispheres?
A
Separated by cerebral longitudinal fissure
Connected by corpus callosum
23
Q
What is the outer layer of the hemispheres called?
A
Cerebral cortex
Gray matter
24
Q
What is another word for sulcus
A
Fissure
25
What are the two main sulci on lateral surface of cerebrum that helps divide hemispheres into lobes
Central - vertical orientation
Lateral (Sylvia’s fissure - horizontal orientation
26
What are the two general functions of the frontal lobe
Planning and execution
27
What are the 3 human specific functions of the frontal lobe?
Produce speech
Plan for the future
Voluntarily inhibit automatic behaviors
28
Anatomical landmarks of frontal lobe
1. Precentral gyrus (PRIMARY MOTOR CORTEX) - anterior to central sulcus
2. Superior, middle and inferior gyri (extend from precentral gyrus)
-inferior gyri has pars triangularis (looks like triangle), pars opercularis (means lid, which covers the lateral sulcus), pars orbitalis (close to the eye).
-pars triangularis and pars opercularis make up Broca’s area
29
Describe the somatotopic organization of primary motor cortex (Precentral gyrus)
Homonculus - lay out the form of a person from the top of the primary cortex down to the lateral sulcus. Feet at top. Organized in a manner that correlates specifically to the body. Bigger parts are more skilled areas.
30
Upper motor neurons vs lower motor neurons origination
UMN extend from the cortex to the brainstem and spinal cord
LMN extend from the brainstem or spinal cord to the muscles
31
Where does the primary motor cortex receive input?
LOT Of AREAS
Cerebellum - helps with coordination
Basal ganglia - initiation and termination of actions- both are through the thalamus
Premotor area
Thalamus
Primary sensory cortex - so we know we respond to sensations
32
Why is it important for motor areas of frontal lobe to be linked to sensory areas?
So we can respond to information in the environment and act on it. Would not necessarily initiate motor movement without the sensory area.
So we can produce skilled and goal-directed actions that match the environmental conditions in which movements are being produced.
33
Describe UMN syndrome
The corticobulbar and corticospinal tract make up the UMN. These are the tracts that carry motor information to the distal muscles
Damage to UMN means the message isn’t getting to the muscles. Results in paresis or paralysis of muscles, hypertonicity (increased muscle tone), spasticity and Babinski reflex
Results in poor precision and skilled movements of distal muscles (outside of trunk)
34
Premotor cortex location and function (Secondary to primary motor cortex)
Composed of superior, middle and inferior gyri
Premotor and supplementary motor areas -Both areas are involved in planning actions to help project from pre motor area to primary.
Anterior/rostral to primary motor cortex
35
Premotor area of the Premotor cortex
Premotor area
Ventral to lateral sulcus
Limb movement, visual input from occipital lobe (look and move)
36
Supplementary area of the Premotor cortex
Dorsal to primary motor area
Plans complex movement and helps inhibit verbal diarrhea
2 areas: pre supplementary – have abstract thinking/connections with prefrontal area and basal ganglia…complex cognitive thought
Supplementary proper – simple motor movement planning
37
Frontal eye fields (Premotor cortex)
Rostral to precentral gyrus
Superior to brocas
Projection to CN 3, 4,6
Help regulate rapid eye movement. Read finite movements with both eyes tracking, scanning a room…cicade? Change point of fixation of eye.
38
Broca’s area (Premotor cortex)
the seat of speech motor control activity
Pars triangular and opercularis
Left frontal lobe
Planning and organization of speech production
Damage - non fluent aphasia – choppy speech and agrammatic sentences
Right hemisphere – similar area but not considered Broca’s area
39
Describe location of the prefrontal cortex
Rostral to Premotor areas
40
What is executive function (happens in prefrontal cortex)
Skills need to function in daily routine. Know what is upcoming, what experienced, organization of thought, work, making good judgments. Recognizing in what need to function in daily routine. Personal responsibility. Expectations of self. Organize time and making good judgments about what you should be doing.
41
What areas of the nervous system provide input to the PFC (pre frontal cortex)
Connected to motor areas through Premotor cortex, basal ganglia, cerebellum, parietal lobe (sensory input), thalamus, hippocampus, parahippocampal gyrus, limbic system, reticular formation…
All aspects of brain, cerebellum, and brainstem.
Damage - Personality changes, poor decisions, poor awareness.
42
Parietal lobe location
The anterior boundary of the parietal lobe is the central sulcus.
The inferior boundary of the parietal lobe is the Sylvia’s/lateral fissure.
The parietal lobe extends posteriorly to the occipital lobe.
43
Anatomical landmarks of parietal lobe
The gyrus just posterior to the central sulcus is the post central gyrus. The remainder of the lateral parietal lobe is divided into two sections by the post central sulcus. This sulcus divides the parietal lobe into superior and inferior parietal lobules.
44
Portion of parietal lobe found on the medial surface
Precuneus
45
Where is the primary sensory cortex location
Postcentral gyrus
46
Describe the functions and the somatotopic arrangement of the postcentral gyrus.
Similar to primary motor gyrus. Brain is correlated to body. More sensory input larger area on postcentral gyrus.
47
What is meant by multimodal integration
Process where neurons are activated simultaneously by different sensory inputs (somatosensory, visual, auditory) that are generated as part of the same process. Constantly using all systems during daily life.
Parietal lobe found is know as the multimodal sensory center of the cerebrum
48
What is the general function of the superior parietal lobule
Superior: input from visual cortex and helps direction to what we are going to do and then help to decide to act. Goal directed. Deficit: visual spatial orientation
49
General functions of inferior parietal lobule
Has the supramarginal gyrus
supramarginal gyrus: important for speech comprehension, word meaning, phonological and verbal memory. Major in language production. Deficit working on naming, processing and some comprehension of language. Agnosias (absence of knowledge)
50
What are the general functions of the precuneus?
Complex function and gestalt thinking. Memory, mental imagery, consciousness
51
Landmarks of the temporal lobe
Superior, middle, inferior temporal gyri.
Superior – PRIMARY AUDITORY CORTEX
Middle – learning, memory, and object recognition. Deficit – agnosia
Inferior- object recognition and categorization
Medial temporal lobe – deeper, next to midbrain, parahippocampal gyrus, uncus and endorhinal cortex
52
Primary auditory cortex
on the transverse temporal gyri of Heschl (aka: Heschl’s gyri),
which are located along the superior surface of the superior temporal gyrus.
It is tonotopically arranged.
53
Describe the location and function of Wernicke’s area
superior temporal gyrus.
Center of language reception and comprehension
Deficit will have hard time understanding a lot.
Wernicke’s aphasia – fluent aphasia – person talks but doesn’t make sense and may not use real words. Don’t know they are making errors because of comprehension.
Surrounds primary auditory cortex. Taking auditory info from primary auditory cortex and comprehending.
54
What are the other areas and functions of the temporal lobe?
Dorsal - sound processing and language comprehension
Central/ventral-semantic knowledge is represented, categorized and stored
Medial - learning, memory, emotional regulation
55
Occipital lobe location and function
Caudal most lobe. Borders temporal and parietal
Primary visual cortex takes optic radiation from lateral geniculate body from thalamus. Retinotopic arrangement – organization how visual info is interpreted.
Color, visual fields and object orientation
Superior and inferior gyri, calacrine fissure and cuneus
56
Insula
Deep to all structures
Peel back at lateral sulcus that is where insula is
Not much info b/c low incidence of lesion
Processing hub for sensory system for pain, vestibular, empathy, affective processing, higher level cognition, contribute to executive functions skills
1. Determine importance and value of internal and environmental stimuli
2 mark these stimuli for additional processing
57
Describe the cerebral cortex
Outer shell that covers cerebrum
Gray matter
Information processing hub
Helps integrate information
Helps with neuroplasticity – learning from experiences, creating new neurons and networks
58
Which is more important? Inhibitory or excitatory cells? In cerebral cortex
Inhibitory. 25% working to inhibit excitatory cells from overreacting. Result in seizures, or no control what you are doing. Inhibitory taking messages for motor acts and making sure that we will function in a way that is smooth interaction/execution.
59
Anatomical features of cerebral cortex
Has 6 layers
Layer III and V contain pyramidal neurons.
III has small and medium neurons and because superior to V it is called the external pyramidal layer
V is the internal pyramidal layer. It has large cells that give rise to axons of key descending efferent paths to subcortical structures of the CNS
60
Broadmans number for Broca’s area
44 and 45
61
Broadmans number for Wernicke’s area
22
62
Broadmans number for primary motor cortex
4
63
Broadmans number for primary sensory cortex
1,2,3
64
What are the global functions of the cerebral cortex
Motor, sensory, limbic, multi-modal, cognitive processing. Cerebral cortex manages all these functions.
65
What is serial processing?
serial processing is that motor and sensory is following specific pathways
Major part of serial processing is the primary aspects of each lobe.
See handout for more info
66
Primary cortices and location
Auditory: (superior temporal gyrus/transverse temporal gyri, Temporal (A1)
Motor: Precentral gyrus – Frontal (M1)
Somatosensory: Postcentral gyrus – Parietal (S1)
Visual: borders calcine fissure – Occipital (V1)
67
Where are all of the sensory inputs relayed (except olfactory)
through the THALAMIC NUCLEI to the primary cortex.
68
What is the role of secondary cortices
supportive in planning and execution of some acts. Modulating and regulating info back into themselves, called GATING. Governing somatosensory info and suppress excessive responses.
See handout for more ifno
69
What are the areas/functions that are linked through tertiary cortices
link b/w perception of what is coming in to areas that are involved in executing behavior
Involve in memory and emotion. Link perception to areas that will produce target, involve memory and emotion. Higher function.
See handout for more info
70
71
What is parallel processing?
Ability of the nervous system to simultaneously manage different parts of a single complex experience at once.
FROM LECTURE: processing multiple sensory systems simultaneously. Feedback system
**all sensory areas of the cortex posses parallel dorsal and ventral processing pathways. See page 220. All dorsal routes appear to project to the parietal cortex while ventral routes, regardless of sensory form, project to the temporal region. Interconnection of parietal and temporal cortices with the frontal lobe provides unique communication. Temporal and parietal then project to frontal lob which maintains the executive control circuitry of the cerebrum.
72
Where do association areas get input?
Thalamus
73
74
What are association areas?
Large expanses of cortical tissue outside of primary cortices area
75
What are the functions of the parietal association area?
participate in the development of spatial awareness and the sensory guidance of action. Helps with attention to environment.
3 key functions: visual guidance of action, spatial perception, and spatial attention.
Damage causes contralateral neglect syndrome, ideomotor apraxia, acalculia, agraphia, alexia.
MOTOR APRAXIA – execution of movement. Comprehend what to do but can’t execute.
76
What is the function of the temporal association area?
active during the production of language, the linking of lexical and semantic information, object recognition, and associative learning. Critical for the ability to recognize, identify, name, or even understand the significance of attended to complex stimuli.
Damage causes agnosia or prosopagnosia. INTEGRATING VISUAL AND AUDITORY TO RECOGNIZE OBJECTS.
77
What are the functions of the frontal association areas?
mediate executive function behaviors and working memory
Damage is noticed as a change in one’s personal character. Through executive processes we use our perceptions, stored knowledge, and intent to help us choose the right action or thought from a range of possibilities that best fit a given situation.
78
What are the functions of the limbic association areas?
serve behaviors spanning from memory to emotional regulation
79
What are the two functional categories of the limbic system?
Emotions and memory
See diagram on pg 229
80
4 structures of the limbic system
1. Hippocampal formation
2. Amygdala
3. Cingulate gyrus
4. Septal area
81
What are the functions of the hippocampal formation?
Spatial learning
Long-term memory
82
What are the functions of the amygdala
It is the threat indicator
Mediates fear, anxiety, and aggression
83
Purpose of cingulate gyrus
Supports functions including attention, cognition, affect, vocalization, motor control, and response selection
84
The septal area forms a key component of what?
Reward system
85
Basic functions of the basal ganglia
Start, stop or modulate movement
Primary sensory talks to basil ganglia, basal ganglia talks to primary motor
86
List each of the basal ganglia and describe their location
1. Caudate NUCLEUS – C shaped mass of cells in the core region of the cerebrum. Head lies anteriorly (rostrum) to the thalamus, develops posteriorly and loops and arcs around the thalamus to terminate in the temporal lobe
2. Putamen – attached to the head of the caudate, WITH CAUDATE MAKE UP STRIATUM
3. Globus Pallidus – medial to the putanem (triangular shape)
4. Subthalamic nucleus – directly beneath the thalamus – ventral to globus pallidus
5. Substantia Nigra-dorsal to the crus cerebri
See diagram in handout
87
What are the basic functions of the cerebellum and identify on a diagram
VERY TIGHTLY COMPACT GYRI. HAS LOBES MORE COMPACT HAS 80% OF NERUONS. MODULATE BALANCE, COORDINATION AND MOTOR LEARNING
Motor coordination and motor learning
88
What separates the cerebellar hemispheres from the cerebral hemispheres?
TENTORIUM cerebeli
89
What is the midline structure that connects the two lateral hemispheres of the cerebellum
Vermis
90
List the 3 principal lobes of the cerebellum
Anterior
Posterior
Flocculonodular
91
How does information get from the brainstem/cerebrum to the cerebellum (and vice versa)?
THROUGH CEREBELAR PEDUNCLES.
SUPERIOR-OUTPUT FROM BRAIN TO MIDBRAIN TO CEREBELLUM.
MIDDLE IS LARGEST – CONNECTS VIA PONS.
INFERIOR CONNECTING TO SPINAL CORD AND MEDULLA.
92
What is the major set of commissural fibers that connects the right and left hemispheres
Corpus callosum
93
Explain cerebral dominance
One side of the brain usually plays a more dominant role in each function compared to the other side.
ONE HEMISPHERE IS MORE DOMINANT. USUALLY LEFT. LEFT HEMI HAS LANGUAGE, ORDER MEMORY, ETC. LEFT CONTROLS RIGHT SIDE OF BODY
DAMAGE TO HEMISPHERE WILL HAVE DIFFERENT RESULTS
94
Study diagrams
See book and slides
