forebrain anatomy Flashcards
(134 cards)
1
Q
parts of the forebrain
A
telencephalon: cerebral hemispheres
Diencephalon: thalamus, hypothalamus, epithalamus, subthalamus
Internal Capsule
Limbic system: hypothalamus, Hippocampus, Amygdala
2
Q
parts of the deincephalon
A
Epithalamus (pineal gland, Habenula)
Thalamus
Hypothalamus
Subthalamus
3
Q
where do most pathways in the brain relay
A
Thalamus
4
Q
what all relays in the thalams
A
All sensory (other than olfactory) pathways
Limbic systems
Basal ganglia projections
Cerebellum projections
5
Q
how to pathways that relay in the thalamus use the thalamus
A
use different parts (with some overlap) giving the thalamus distinct nuclei
6
Q
what nuclei are found in the anterior division of the thalamus
A
anterior nucleus
7
Q
what nuclei are found in the medial division of the thalamus
A
dorsomedial nucleus (medial dorsal)
8
Q
what nuclei are found in the dorsal tier of the lateral division of the thalamus
A
Lateral dorsal, lateral posterior, and pulvinar
9
Q
what nuclei are found in the ventral tier of the lateral division of the thalamas
A
ventral anterior ventral lateral ventral posterior lateral medial medial geniculate lateral geniculate
10
Q
what nuclei are found in the intralaminar area of the thalamus
A
centromedian, parafascicular etc
11
Q
what nuclei are found in their own subdivisions of the thalamus
A
midline nuclei
reticular nucleus
12
Q
what defines the subdivions of the thalamus
A
Internal Medullar Lamina
13
Q
where does the anterior subdivision of the thalamus sit
A
sits in a split in the Internal Medullary Lamina
14
Q
what subdivion of the thalamus is the largest
A
lateral subdivision
15
Q
where is the reticular nucleus located along the thalamus
A
discontinuously along the lateral aspect
16
Q
what are the themes of all thalamic nuclei asside from reticular nuclei
A
consist of projection neurons to provide output from thalamus as excititory and interneurons that are small and inhibitior
(proportions vary from nucleus- to-nucleus
17
Q
specific thalamic inputs come from where and travel to where
A
specific subcortical site to convey info to a thalamic nuclei that in turn passes onto the cortex
18
Q
regulatory inputs to the thalamus come from where
A
areas of the cortex to a thalamic nucleus which also contibutes info before passing it on to the cortex
19
Q
the 3 categories of thalamic nuclei
A
relay nuclei
association nuclei
intralaminar and midline nuclei
20
Q
what do Relay Nuclei receive
A
well defined specific input from a subcortical source
21
Q
what do relay nuclei project to
A
sends information to a well-defined area of the cortex
22
Q
what regulates the action of relay nuclei
A
activity is regulated by regulatory input both direct and indirect
23
Q
input and output to anterior Relay nuclei
A
Mammillothalamic tract, hippocampus
Cingulate Gyrus
24
Q
Input and output to Lateral dorsal Relay nuclei
A
Hippocampus
Cingulate Gyrus
25
input and output to VA/VL Relay Nuclei
```
Basal ganglia (VA), cerebellum (VL)
Motor Areas
```
26
Input and output to VPL relay nuclei
Medial Lemniscus, spinothalamic Tract (ALP
| Somatosensory cortex
27
input and output to VPM relay nuclei
Trigeminal system, central tegmental tract
| Somatosensory cortex, insula
28
input and output to MGN relay nuclei
Brachium of inferior colliculus
| Auditory cortex
29
input and output to LGN relay nuclei
Optic tract
| Visual Cortex
30
Association nuclei receive input from and project out to
specific input from and project out to association cortex( the prefrontal cortex)
31
the 2 huge areas of association fortex
Dorsal Medial Nuclei
| Pulvinar-Lateral Posterior Nuclei
32
location of the Dorsal Medial nuclei
Prefrontal
33
roll of Dorsal Medial nuclei
Foresight, organization
34
location of the Pulvinar-Lateral Posterior Nuclei
Parietal-occipital-temporal
35
function of the Pulvinar- Lateral Posterior Nuclei
unknown: maybe in visual perception or attention
36
Intralaminar and midline nuclei receive inputs from and project where
receive a distinct set of specific inputs (basal ganglia and limbic strcutures)
Project to cortex, basal ganaglia, and limbic structures
37
Roll of Reticular Nucleus
Source of regulatory input to the thalamus
38
what does the Reticular Nucleus look like
sheet of neurons, covering th thalamus
39
travel of axons of the Reticular Nucleus
traverse nucleus to enter/leave thalamus and send collaterals to it
40
what are the inputs and the outputs of the Reticular Nucleus
input from the Cortex and the Thalamus and output are inhibitory axons to the thalamus (no projections to the cortex)
41
how fibers project out to the cortex
internal capsule
42
what passes through the internal capsule
thalamocortical and corticothalamic fibers
| almost all fibers going to and from the cortex
43
the collection of fibers in the internal capsule form what
the cerebral peduncle
44
what does the cerebreal peduncle do
Corticospinal, sorticobulbar, and corticopontine fibers descend down it
45
Internal Capsule Divisions
```
Anterior Limb
Genu (G)
Posterior Limb
Retrolenticular Limb
sublenticular parts
```
46
how is the internal capsule devided
based on relationship to lenticular nuclues (plobus pallidus + putamen)
47
where is the Anterior Limb of the Internal Capsule
between the lenticular nucleus and caudate
48
where is the Genu of the Internal Capsule
Between the anterior and posterior limbs
49
where is the posterior limb of the Internal Capsule
between the lenticular nucleus and the thalamus
50
where is the retrolenticular limb of the Internal Capsule
Behind the lenticular nucleus
51
where is the sublenticular part of the Internal Capsule
beneath the lenticular nucleus
52
what projects through the anterior limb of the internal capsule
the anterior nucleus to the cingular gyrus
| the DM to the prefrontal cortex
53
what projects through the posterior limb of the internal capsule
VA/VL to motor areas
motor areas to the brainstem and spinal cord
VPL/VPM to the seomatosensory cortex
54
what projects through the sublenticular limb of the internal capsul
MGN to the auditory cortex
| LGN to visual cortex, the superior visual field
55
what projects through the retrolenticular limb of the internal capsule
Pulvinar/LP to the parietal-occipital-temporal cortex
| LGN to Visual cortex, the inferior visual field
56
Roll of the Hypothalamus
Autonomic, endocrine, emotional, and somatic function
Maintains homeostasis
control pituitary
also can talk to cortex to aid in fight and flight
57
borders of the Hypothalamus
```
Superior border: hypothalamic sulcus
Anterior border: lamina terminalis
Posterior border: midbrain tegmentum
Medial border: 3rd ventricle
Lateral Border: internal Capsule
Inferior border: optic chiasm, tuber cinereum, median Eminence, Mammillary bodies
```
58
Longitudianl organization of the hypothalamus
Anterior: lamina terminalis to infundibulum
Tuberal: Infundibulum to mammilary bodies
Posterior: mammilary bodies to tegmentum
59
the most anterior portion of the hypothalamus
lamina terminalis(the most rostral extent of the neural tube closure)
60
What is included in the tuberal region of the hypothalamus
Median eminence, Tuber cinereum
61
medial-lateral organization of the hypothalamus
Lateral
medial
Periventricular
62
the rostral continuation of the reticular formation
lateral hypothalamus
63
what is contained in the lateral hypothalamus
variety of nuclei and tracts (medial forebrain bundle)
64
the hypothalamic subnuclei
Medial hyopthalamus
65
the rostral continuation of periaqueductal gray from midbrain
Periventricular hypothalamus
66
what is found in the Periventricular Hypothalamus
Contains nuclei and tracts (dorsal longitudinal fasciculus)
67
the superior hypophyseal artery branches from
internal carotid artery
68
what does the superior hypophyseal artery supply
capillary bed in infundibulum
69
the capillary bed in the infundibulum drains into
portal vessels in adenohypophysis (aka anterior pituitary)
70
portal vessels drain to
second capillary bed around endocrine cells of adenohypophysis (anterior pituitary)
71
where do neurons of the hypothalamus secrete their hormones
into the superior hypophyseal artery
72
what do the endocrine cells of adenohypophysis (anterior pituitary) release thier hormones
in the second cappiliary bed to the cavernous sinus
73
The inferior hypophyseal artery branches from what
internal carotid
74
what does the inferior hypophyseal artery supply
neurohyposphysis (posterior pituitary)
75
where do cappliaries of the hypothalamus drain to delive both anterior and psoterior pituitary hormones to systemic circulation
into cavernous sinus
76
what controls pituitary secretions
neuroendocrine cells
77
where do neuroendocrine cells synapse
on walls of capillaries
78
are neuroendocrine cells true endocrine cells
yes, because they release secretions into capillaries
79
where are the somas of neuroendocrine cells
hypophysiotrophic area in the lower half od preoptic and tuberal regions
80
the types of neuroendocrine cells
parvocellular
| Magnocellular
81
neuroendocrine cells that end in the median eminence
parvocellular
82
neuroendocrine cells that end in the posterior lobe
magnocellular
83
nucleus of the parvocellular neucroendocrine cells
preoptic
ventromedial
arcuate
84
nucleus of the magnocellular neuroendocrine cells
supraoptic
| paraventricular
85
what do parvocellular neurons give rise to as a tract
tuberoinfundibular tract
86
what kind of hormoes are carried by the parvocellular neurons
releasing or inhibiting hormes
| all peptide but prolactin IH
87
ant or post pituiary for parvocellular neurons
anterior
88
the two hormes released by posterior pituitary neurons
```
Antidiuretic horme (Vasopressin)
oxytocin
```
89
roll of antidiuretic hormone
increase water uptake by kidney, decrease urine output
90
loss of Antidiuretic hormone leads to
diabetes insipidis
91
what causes a release of antidiuretic hormone
Hypothalamus senses blood osmotic pressure
| input from subfornical circumventricular organ
92
oxytocin leads to
contraction of uterine and other smooth muscles
93
oxytocin is released when
Breastfeeding
| Infant suckling
94
infant suckling reflex
in mom from nipple and spinoreticular tract and spinohypothalamic tract
95
what does stimulation of the anterior hypothalamus lead to
parasympathetic effect: Slow HR, Constrict Pupil, Peristalsis, Salivation
96
stimulation of the Posterior hypothalamus leads to
sympathetic effects: increase HR, BP, dilate pupils, intestinal stasis
97
axons from hypothalamus project down
brainsteam and spinal cord in dorsal longitudinal fasciculus
98
Eating
baseline calorid/nutrient intake
99
Eating is sesnitive to
blood glucose
100
what is involved in creating appestat(appetite set point)
interplay of lateral and ventromedial nuclei
| also serotonin
101
high levels of serotonin effect on appetite
Anorexia
102
low levels of serotonin effect on appetitte
bulimics
103
Lateral nucleus of hypothalamus effect on eating
stimulates eating
104
Ventromeidal nucleus of hypothalamus effect on eating
refuse food
105
Ventromedial lession leads to
overweight
| anger/agressions
106
release of ACTH in males from the anterior pituitary leads to
fight or flight
| increase in cortisol from adrenal gland
107
activation of the fight or flight response in males shows activation where else
lateral prefrontal cortex
108
what is the female reponse for fight of flight due to hypothalamic function
tend and befriend - protect offspring; affiliate with social groups
109
effect of oxytocin released in capillary bed of neurohypophysis and estrogen
counteract sympathetic over activity due to stress
110
activation of the female tend and befriend response shows activation where in the brain
cingulate gyrus (cortical emotional control center)
111
nucleus that gives hypothalmic control of sleep wake cycle
suprachiasmatic nucleus
112
where does the suprachiasmatic nucleus get input
direct input from retina
113
how does the body set the sleep wake cycle
due to the suprachiasmatic nucleus with the pineal gland
114
lesion of posterior hypothalamus leads to
hypersomnolence (increased sleep) or coma
115
what does the tuberomammillary nucleus contain
histminergic neurons with wide projections
116
roll of histiminergic neurons
arousal function
117
what plays a roll in arousal
```
histiminergic neurons
also orexin (PR hormone)
```
118
where is orexin relased
lateral nucleus
119
what nuerons are in control of sexual arousal
subset of neurons in the medial aspect of the preoptic nucleus (contains androgen receptors)
120
size of sex neurons in males and females
2x as large in males
121
what receptors are found in the ventromedial nuclues for female sexual arousal
estrogen rich receptors
122
where do mammillary bodies send info
send infro to anterior nucleus of thalamus(limbic relay)
123
what is invovled in memory in the hypothalamus
memory
124
mammmillary bodies are invovled in what circuit from the hippocampus
Papez circuit
125
what are the 2 main hypothalamic inputs
Parts of forebrain, especially limbic system
| brainstem and spinal cord
126
what info is conveyed from the forebrain, limbic system to the hypothalmus
infro needed for th hypothalamus to mediate autonomic/somatic aspects of emotional states
127
what info is conveyed from the brainstem and spinal cord to the hypothalamus
convey visceral and sensory info
128
how do septal nuclei reach the hypothalamus
via MFB
129
how do ventral striatum reach the hypothalamus
via MFB
130
how do insula and orbitofrontal cortex reach the hypothalamus
via MFB
131
how does the hippocampus reach the hypothalamus
via fornix
132
how does the amygdala reach the hypothalamus
via stria terminalis, ventral amygdalofugal pathways
133
how does the brainstem and the spinal cord reach the hypothalamus
via DLF and MFB
134
pathways of hypothalmic outputs
mirror the inputs
