Lecture 18 Flashcards
Forebrain= _____________
Two divisions
1.
2.
prosencephalon
1. Telencephalon
2. Diencephalon
Diencephalon
- located:
- primary subdivisions:
- centrally deep within the forebrain, surrounding the third ventricle, above the brainstem and below the cerebral cortex
- thalamus; epithalamus; hypothalamus; subthalamus
Function of thalamus:
sensory relay station
-each side of the brain has a thalamus (works together as one)
Function of epithalamus:
emotions & circadian rhythms
Functions of hypothalamus:
major control center of endocrine and autonomic nervous systems
Function of subthalamus:
motor functions (forms part of the basal ganglia circuit–> involved in regulating voluntary motor movements)
The thalamus main functions
- it acts as a “_____ _______ or gateway” for information traveling to and from different parts of the brain. Nearly all input to the ________ synapses in the thalamus
- sensory signals that typically pass through it: __________ and ________ info plus _______________ info from the periphery
- __________ (smell) and _________ (taste) sensory signals DO NOT PASS it
-relay station; gateway
- cerebrum
- visual; auditory; somatosensory
- olfactory; gustatory
5 major function groups of nuclei (thalamus):
1.
2.
3.
4.
5.
- Medial group
- Anterior group
- Lateral group
- Posterior group
- Ventral group
Medial group on thalamus function:
emotions
Anterior group on thalamus function:
part of limbic system (memory and emotion)
Lateral group on thalamus function:
somatosensory output to association areas of cortex
Posterior group on thalamus
- composed of two nuclei
1. ___________: relays visual signals to occipital lobe
2. __________: relays auditory signals to temporal lobe
- lateral geniculate nucleus
- Medial geniculate nucleus
Ventral group on the thalamus function:
somatosensory output to primary cortex (postcentral gyrus)
signals from cerebellum & basal nuclei to motor areas of cortex
Epithalamus
- very small mass of tissue composed mainly of:
1.
2.
- habenula
- Pineal body (gland)
Habenula of epithalamus function:
a relay from the limbic system to the midbrain
Pineal gland function:
endocrine gland
produces melatonin
homeostasis=
- the ________ plays a pivotal role in maintaining homeostasis
the body’s ability to maintain a stable internal environment despite external changes and fluctuations
- hypothalamus
The hypothalamus has a collection of around ______ nuclei (____ pairs)
22; 11
Hypothalamic nuclei responsible for hormone secretion:
1.
2.
3.
4.
- Arcuate nucleus
- Medial preoptic nucleus
- Paraventricular (PVN)
- Supraoptic nuclei
Hypothalamic nuclei and their functions
- Suprachiasmatic nucleus:
- Mammillary nucleus:
- Dorsomedial nucleus:
- the master circadian clock
- memory formation
- rage & other emotions
3 Hypothalamic nuclei related to feeding behavior and their functions:
1. _________: receives signals from GI tract and adipose tissue (leptin) & regulates both satiety and feeding centers
2. __________: “Satiety center”= decrease eating; also contains glucose sensing neurons (sense and respond to changes in blood glucose levels)
3. _______________: “feeding center”= hunger; increase eating
- arcuate
- ventromedial nuclei
- lateral hypothalamic area
5 lobes of the cerebrum
1.
2.
3.
4.
5.
- Frontal
- Parietal
- Occipital
4.Temporal - Insula
Functions of the frontal lobe:
- planning and judgement
- speech production (Broca’s area)
- voluntary motor control
- social interaction
Functions of the parietal lobe:
integrates general senses (pain, temp., touch, vibration, and proprioception) and taste info
Functions of occipital lobe:
principal visual center of brain
Functions of temporal lobe:
hearing, smell, verbal/visual/auditory memory, language comprehension (wernicke’s area)
Functions of insula:
- visceral sensation
- empathy
___________= decision-making, impulse control, and reasoning
- ______ lobe is responsible for this
executive functions
- FRONTAL
White matter tracks are classified according to the __________ they run:
Types
1.
2.
3.
direction
1. Association tracts
2. Projection tracts
3. Commissural tracts
Association tracts:
-they ________ different regions within the same cerebral hemisphere= also called ______________ tracts
Types
1. _______: connect lobes
2. _______: connect gyri within a lobe
connect; intrahemisphereic
1. long fibers
2. short fibers (subcortical U-fibers)
Long fiber association tract that is the core part of the limbic system=
Cingulum
Projection tracts
- extend _______ between higher and lower brain and spinal cord centers
- they may be ________ or _________ tracts
examples:
1. _____________
2. _____________
- vertically
- efferent; afferent
1. corna radiata (corticospinal tract)
2. Fornix–> main efferent system of the hippocampus & important part of the limbic system
Commissural tracts
- transmit information from one __________ to the other
Example:
1. ____________: consists of more than ______ million fibers that interconnect the corresponding regions of almost all parts of the two hemispheres
2. __________: plays a role in the inter hemispheric transfer of ___________ information between temporal lobes
- hemisphere
1. Corpus callosum; 200
2. Anterior commissure; olfactory
Basal nuclei=
group of nuclei (clusters of neurons) buried deep in the white matter, lateral to the thalamus
3 components of the basal ganglia (nuclei)
1.
2.
3.
the basal nuclei is involved in _______ control: receive input from the __________ ______ of the midbrain and motor areas of the cortex (and send signals back)
- Putamen
- Globus pallidus
- Caudate
motor; substantia nigra
The putamen and caudate together is referred as=
“corpus striatum or striatum”
There are ______ pairs (____ total) of cranial nerves that are part of the ______
except for CN I & II (_______ and ______) which are part of the CNS
-they arise primarily from the ________ (except for CN XI which arise from _________)
- 12; 24; PNS; olfactory and optic
- brainstem; spinal cord
In cranial nerves:
- most carry fibers between the brainstem and ____________ receptors and effectors: a lesion in ONE side of the brainstem causes a sensory or motor deficit on the same side of the head
-exception: CN ____ and _____
- ipsilateral
- II and IV
Recall the cranial nerves:
OLd
OPpie
OCcasionally
TRes
TRIgonometry
And
Feels
Very
GLOomy
VAgue
And
HYPOactive
I: Olfactory
II: Optic
III: Oculomotor
IV: Trochlear
V: Trigeminal
VI: Abducens
VII: Facial
VIII: Vestibulocochlear
IX: Glossopharyngeal
X: Vagus
XI: Accessory
XII: Hypoglossal
Olfactory Nerve (I)= _______
-sense of ______
-damage= ___________
sensory
- smell
- anosmia (loss of smell)
The Optic Nerve (II)=______
- transmits _______ signals from the ________ of the eye to the brain
- damage=__________
sensory
-visual; retina
-blindess
The Oculomotor Nerve (III)=_______
- it controls most of the ________ ________, allowing for precise eye movements
- innervation of the ______ and ______, and upper eyelid
- damage=
motor
- extraocular muscles
- pupils; lens
- impairment in normal vision
The Trochlear never (IV)= ______
- it control muscles that allow us to look _______ and move our eyes towards or away from our ______
- damage=
motor
- down; nose
- double vision
The Trigeminal Nerve (V): ________
-it divides into 3 branches:
1. ___________= sensory
2. __________= sensory
3. __________= both (mastication–> CHEWING)
- Damage=
both
1. ophthalmic division
2. maxillary division
3. mandibular division
- to one of these divisions results in loss of sensation from the respective region of the face
Abducens Nerve (VI)= _____
- eye movement for ________ vision
motor
- lateral
Facial nerve (VII)=________
-the major motor nerve control ______ _______
- sensory for ______
5 branches:
1.
2.
3.
4.
5.
both
- facial muscles
- taste
1. Temporal
2. Zygomatic
3. Buccal
4. Mandibular
5. Cervical
Vestibulocochlear nerve (VIII)= ______
- ________ and ________
-_________ nerve and ________ nerve combined
- damage=
sensory
-hearing; equilibrium
- vestibular; cochlear
- deafness, nystagmus
Glossopharyngeal Nerve (IX)=________
- innervate ______,______, and ________
- damage=
both
- pharynx, tongue, parotid gland
- difficulty swallowing, loss of bitter and sour taste sensations
Vagus nerve (X)= _______
-it has the most extensive distribution of any CN
- it supplies the ______ of the chest and abdomen
- it is primarily associated with the __________ division of the autonomic NS
- major role in the control of __________, ___________ ,_________, and _________ function
- damage=
both
-organs
- parasympathetic
- cardiac, pulmonary, digestive, urinary
- a variety of clinical conditions, FATAL if both are cut
The (Spinal) Accessory Nerve (XI)= ______
- it arises from the upper ____ ____
- controls ________ and the _______ and _______ muscles
- damage=
motor
- spinal cord
- swallowing; neck; shoulder
- shoulder pain
Hypoglossal Nerve (XII)= ______
- controls ______ movements of speech, food manipulation, and swallowing
- ________ and _______ muscles of the tongue
motor
- tongue
- intrinsic; extrinsic
