Anatomy: Deep Brain Structures

1. DEEP BRAIN STRUCTURES
ANATOMY

2. BASAL GANGLIA
ANATOMY

3. 2 MIN NEUROSCIENCE:
BASAL GANGLIA
https://www.youtube.com/watch?v=OD2KPSGZ1No

4. BASAL GANGLIA
OVERVIEW
▸ The basal ganglia consists of a number of subcortical
nuclei
▸ The grouping of these nuclei is related to function rather
than anatomy – its components are not part of a single
anatomical unit, and are spread deep within the brain
▸ It is part of a basic feedback circuit, receiving
information from several sources including the cerebral
cortex

5. BASAL GANGLIA
OVERVIEW
▸ The basal ganglia feeds this information back to the cortex, via the
thalamus
▸ In doing so, it acts to modulate and refine cortical activity – such as
that controlling descending motor pathways
▸ Although widely used, the term basal ganglia is a misnomer, as
ganglia are collection of cell bodies outside of the central nervous
system
▸ Since a collection of subcortical cell bodies inside the nervous
system are known as nuclei, the name basal nuclei is more accurate

6. BASAL GANGLIA
NUCLEI OF THE BASAL GANGLIA
▸ The anatomy of the basal ganglia is complex since it is spread
throughout the forebrain
▸ Its components can be divided into
▸ input nuclei
▸ output nuclei
▸ intrinsic nuclei
▸ Input nuclei receive information, which is then relayed to intrinsic
nuclei for processing, and further passed to output nuclei

7. https://teachmeanatomy.info/neuroanatomy/structures/basal-ganglia/

8. BASAL GANGLIA
NUCLEI OF THE BASAL GANGLIA
▸ In the telencephalon, the caudate nucleus (CN) and the putamen (Pu) are
collectively called neostriatum, and their functions are closely related
▸ The most rostral aspect of the neostriatum, where the caudate nucleus
and the putamen join together, is termed nucleus accumbens (Acb),
which is part of a functionally separate domain named ventral striatum
▸ The globus pallidus is divided in an external (GPe) and an internal (GPi)
domains, which are functionally different
▸ The subthalamic nucleus (StN) lies in the diencephalon
▸ In the mesencephalon, the substantia nigra is divided into two parts; the
pars compacta (SNc) and the pars reticularis (SNr)

9. BASAL GANGLIA
NUCLEI OF THE BASAL GANGLIA - CAUDATE NUCLEUS
▸ The caudate nucleus forms the lateral wall of the lateral ventricle
and follows the telencephalic expansion during development
▸ It has a characteristic ventricular C-shape when fully developed
▸ It can be identified as the collection of gray matter on the wall of
the lateral ventricles
▸ During development, the caudate nucleus is separated from the
putamen by descending white matter fibres, which at this level
are known as internal capsule

10. https://teachmeanatomy.info/neuroanatomy/structures/basal-ganglia/

11. BASAL GANGLIA
NUCLEI OF THE BASAL GANGLIA - LENTIFORM NUCLEUS
▸ Lentiform Nucleus = Globus Pallidus and Putamen
▸ The lentiform nucleus is comprised of globus pallidus and the putamen
▸ Although anatomically related, they share no functional relationship
▸ It can be identified as a collection of gray matter laying deep within the
hemispheres
▸ The putamen forms the lateral aspect of the lentiform nucleus
▸ On its concave inner surface lies the most exterior of the globus
pallidus, the GPe, and the most internal structure is the GPi

12. BASAL GANGLIA
NUCLEI OF THE BASAL GANGLIA - LENTIFORM NUCLEUS
▸ The putamen is separated from the GPe by the lateral medullary
lamina, and the medial medullary lamina separates the GPe from the
GPi
▸ Note that, laterally to the putamen, there is another collection of white
matter fibres known as the external capsule
▸ A thin bundle of grey matter can be seen lateral to the external
capsule: this is the claustrum, once thought to be part of the basal
ganglia
▸ More lateral to the claustrum is the extreme capsule, which are white
matter tracts separating the claustrum from the neocortical insula

13. https://teachmeanatomy.info/neuroanatomy/structures/basal-ganglia/

14. BASAL GANGLIA
NUCLEI OF THE BASAL GANGLIA
Substantia Nigra
▸ The substantia nigra is conspicuous in gross specimens
and can be seen in cuts through the midbrain, having a
dark appearance due to the neuromelanin present in the
cells of the SNc
Subthalamic Nucleus
▸ The subthalamic nucleus, as the name implies, lies inferior
to the thalamus, and right above the substantia nigra

15. BASAL GANGLIA
FUNCTION
▸ In simple terms, the basal ganglia provide a feedback
mechanism to the cerebral cortex, modulating and refining
cortical activation
▸ Its main function is related to motor refinement, acting as a
tonically active break, preventing unwanted movements to start
▸ Much of this involves reducing the excitatory input to the
cerebral cortex
▸ This prevents excessive and exaggerated movements

16. BASAL GANGLIA
FUNCTION
▸ The basal ganglia also plays an important role in modulating
cognitive and emotional responses
▸ The putamen receives almost exclusive inputs from motor and
somatosensory cortices and projects back to motor areas, and is
thus related to the motor loop
▸ The caudate nucleus receives input from cortical association
areas and projects to prefrontal areas
▸ In contrast, the ventral striatum (including the Acb) receives
limbic inputs and is thus related to emotions

17. BASAL GANGLIA
VASCULATURE
▸ The arterial supply to the basal ganglia comes mainly from the middle
cerebral artery, a continuation of the internal carotid artery
▸ The main artery is named lenticulostriate artery and, as the name implies,
provides most of the circulation to the striatum and the lenticular nucleus
▸ There is also a small amount of supply from the anterior cerebral
artery and the anterior choroidal artery, both of which are also branches
of the internal carotid artery, supplying the more anterior aspect of the
ganglia, (i.e. the head of the caudate nucleus and the nucleus accumbens)
▸ This particularly large artery is referred to as medial striate artery (of
Heubner)

18. BASAL GANGLIA
VASCULATURE
▸ The substantia nigra and the subthalamic
nucleus are more posterior and thus receive
its vasculature from branches of the posterior
cerebral and posterior communicating arteries
▸ The venous drainage is via striate branches of
the internal cerebral vein, which drain into the
great cerebral vein

19. https://teachmeanatomy.info/neuroanatomy/structures/basal-ganglia/

20. BASAL GANGLIA
REVIEW QUESTIONS
▸ This is a coronal
section of the
cerebrum
▸ Which of the
following labels
corresponds to an
intrinsic nuclei of the
basal ganglia?

21. BASAL GANGLIA
REVIEW QUESTIONS
▸ 'C' corresponds to the external globus
pallidus, which an intrinsic nuclei of the
basal ganglia

22. BASAL GANGLIA
REVIEW QUESTIONS
▸ In the basal ganglia, which structures collectively
form the neostriatum?
▸ Caudate nucleus and subthalamic nucleus
▸ Substantia nigra and subthalamic nucleus
▸ Putamen and globus pallidus
▸ Putamen and caudate nucleus

23. BASAL GANGLIA
REVIEW QUESTIONS
▸ The caudate nucleus and the putamen
are collectively known as the neostriatum

24. BASAL GANGLIA
REVIEW QUESTIONS
▸ Which structure separates the caudate nucleus
from the putamen?
▸ Lateral ventricle
▸ Internal capsule
▸ Globus pallidus
▸ Claustrum

25. BASAL GANGLIA
REVIEW QUESTIONS
▸ Descending white matter fibres, known
as the internal capsule, separate the
caudate nucleus from the putamen

26. THALAMUS
ANATOMY

27. 2 MIN NEUROSCIENCE:
THALAMUS
https://www.youtube.com/watch?v=IF8_82e9RmQ

28. DEEP BRAIN STRUCTURES
THALAMUS
▸ LOCATION
▸ Surrounding the third ventricle, just above the midbrain
▸ STRUCTURES
▸ Many nuclei
▸ BLOOD SUPPLY
▸ Posterior communicating artery
▸ Anterior choroidal artery (a branch of the internal carotid artery)

29. DEEP BRAIN STRUCTURES
THALAMUS
▸ FUNCTIONS
▸ Sensory relay station:
▸ The thalamus receives sensory input of all sensory modalities
▸ Sensory input is "filtered"
▸ The thalamus sends processed signals to other areas of the cortex
▸ Emotion and memory:
▸ The thalamus is part of the Papez circuit, which is involved in emotion and memory
▸ Motor relay station:
▸ Receives input from the motor cortex and basal ganglia and sends signals to the
descending motor tracts

30. DEEP BRAIN STRUCTURES
THALAMUS
▸ Lesion
▸ associated with motor and sensory deficits
involving multiple areas of the body
▸ thalamic pain syndrome
▸ pain perceived without an appropriate
stimulus

33. HYPOTHALAMUS
ANATOMY

34. 2 MIN NEUROSCIENCE:
HYPOTHALAMUS & PITUITARY
GLAND
https://www.youtube.com/watch?v=TVhm2rBGhB0

35. DEEP BRAIN STRUCTURES
HYPOTHALAMUS
▸ FUNCTIONS
▸ Involved in homeostasis and instinctive actions
▸ Eg. eating, drinking, sleeping, and sex
▸ STRUCTURE
▸ Like the thalamus, it is divided into several
nuclei controlling various functions

38. CNS GLANDS
ANATOMY

39. PITUITARY GLAND

40. CNS GLANDS
PITUITARY GLAND: OVERVIEW
▸ The pituitary gland, also known as the
hypophysis, is a major gland of the
endocrine system
▸ It secretes hormones that control the
actions of other endocrine organs and
various tissues around the body

41. https://teachmeanatomy.info/neuroanatomy/structures/pituitary-gland/

42. CNS GLANDS
PITUITARY GLAND: ANATOMICAL POSITION AND RELATIONS
▸ The pituitary gland is a pea-sized oval structure, suspended from
the underside of the brain by the pituitary stalk (known as the
infundibulum)
▸ It sits within a small depression in the sphenoid bone, known as
the sella turcica (‘’Turkish saddle’’)
▸ The superior surface of the gland is covered by a reflection of
the dura mater – the diaphragma sellae
▸ This membrane has a central opening which allows passage of
the infundibulum

43. CNS GLANDS
PITUITARY GLAND: ANATOMICAL POSITION AND RELATIONS
▸ The gland has several key anatomical relations:
▸ Anteriorly – sphenoid sinus (the pituitary gland is accessed surgically
via the sphenoid sinus, known as a trans-sphenoidal approach)
▸ Posteriorly – posterior intercavernous sinus, dorsum sellae (posterior
wall of the sella turcica), basilar artery and the pons
▸ Superiorly – diaphragma sellae (fold of dura mater that covers the
pituitary gland), optic chiasm
▸ Inferiorly – sphenoid sinus
▸ Laterally – cavernous sinus

44. https://teachmeanatomy.info/neuroanatomy/structures/pituitary-gland/

45. https://teachmeanatomy.info/neuroanatomy/structures/pituitary-gland/

46. CNS GLANDS
PITUITARY GLAND: ANATOMICAL STRUCTURE
▸ Anatomically, the pituitary gland is a ‘’two-in-one’’ structure
consisting of the anterior pituitary and the posterior pituitary
▸ These parts have different embryonic origins and function very
differently
Anterior Lobe
▸ The anterior lobe (adenohypophysis) is derived from an
outpouching of the roof of the pharynx, called Rathke’s pouch
▸ It is composed of glandular epithelium and secretes a number of
hormones

47. CNS GLANDS
PITUITARY GLAND: ANATOMICAL STRUCTURE
▸ The anterior lobe can be further divided into three parts:
▸ Pars anterior – the largest part, responsible for
hormone secretion
▸ Pars intermedia – a thin epithelial layer that separates
the pars anterior from the posterior lobe
▸ Pars tuberalis – an upwards extension of the pars
anterior that surrounds the anterolateral aspect of the
infundibulum

48. CNS GLANDS
PITUITARY GLAND: ANATOMICAL STRUCTURE
▸ The release of hormones is under the control
of the hypothalamus, which communicates
with the gland via neurotransmitters
secreted into the hypophyseal portal vessels
▸ These vessels ensure that the hypothalamic
hormones remain concentrated, rather than
being diluted in the systemic circulation

49. CNS GLANDS
PITUITARY GLAND: ANATOMICAL STRUCTURE
Posterior Lobe
▸ The posterior lobe (neurohypophysis) consists of nervous tissue
▸ It arises from the embryonic forebrain, and is, in essence, an extension of
the hypothalamus
▸ Upon stimulation, the posterior lobe secretes two hormones – ADH
(responsible for control of blood osmolarity), and oxytocin (involved in
parturition and milk secretion)
▸ Both of these substances are produced in the supraoptic and
paraventricular nuclei of the hypothalamus and then subsequently stored
in the posterior pituitary gland, ready for release

50. https://teachmeanatomy.info/neuroanatomy/structures/pituitary-gland/

51. CNS GLANDS
PITUITARY GLAND: VASCULATURE
▸ The vasculature of the pituitary gland is
complex and unique
▸ The anterior lobe and posterior lobe have
the same venous drainage (anterior and
posterior hypophyseal veins)
▸ But they have an individual arterial supply

52. CNS GLANDS
PITUITARY GLAND: VASCULATURE - ANTERIOR PITUITARY
▸ The anterior pituitary gland receives arterial supply from the
superior hypophyseal artery (a branch of the internal carotid artery)
▸ This vessel first forms a capillary network around the hypothalamus
▸ Blood from this network is then transported to a secondary capillary
plexus surrounding the anterior pituitary
▸ Known as the hypothalamo-hypophysial portal system, this
structure allows the hypothalamus to communicate with the
anterior pituitary via the release of neurotransmitters into the
bloodstream

53. CNS GLANDS
PITUITARY GLAND: VASCULATURE - POSTERIOR PITUITARY
▸ The infundibulum and posterior pituitary gland
receive a rich blood supply from many arteries
▸ Of these, the major vessels are
▸ superior hypophyseal artery
▸ infundibular artery
▸ inferior hypophyseal artery

54. https://teachmeanatomy.info/neuroanatomy/structures/pituitary-gland/

55. CNS GLANDS
REVIEW QUESTIONS
▸ Which of the following structures is located
inferiorly to the pituitary gland?
▸ Sphenoid sinus
▸ Cavernous sinus
▸ Optic chiasm
▸ Basilar artery

56. CNS GLANDS
REVIEW QUESTIONS
▸ The sphenoid sinus is located inferiorly
to the pituitary gland

57. CNS GLANDS
REVIEW QUESTIONS
▸ What structure can become compressed in a
pituitary adenoma, leading to problems with vision?
▸ Basilar artery
▸ Cavernous sinus
▸ Optic chiasm
▸ Pons

58. CNS GLANDS
REVIEW QUESTIONS
▸ Optic chiasm - leading to bitemporal
hemianopia

59. CNS GLANDS
REVIEW QUESTIONS
▸ What part of the anterior pituitary gland is
mainly responsible for hormone secretion?
▸ Hypothalamus
▸ Pars tuberalis
▸ Pars intermedia
▸ Pars anterior

60. CNS GLANDS
REVIEW QUESTIONS
▸ Pars anterior – the largest part,
responsible for hormone secretion

61. PINEAL GLAND

62. 2 MIN NEUROSCIENCE:
PINEAL GLAND
https://www.youtube.com/watch?v=R0VPDd0JwCE

63. CNS GLANDS
PINEAL GLAND: OVERVIEW
▸ The pineal gland is a small endocrine gland
located within the brain
▸ Its main secretion is melatonin, which regulates
the circadian rhythm of the body
▸ It is also thought to produce hormones that
inhibit the action of other endocrine glands in
the body

64. CNS GLANDS
PINEAL GLAND: ANATOMICAL STRUCTURE AND POSITION
▸ The pineal gland is small glandular body, approximately 6mm
long
▸ It is shaped like a pine cone, from which its name is derived
▸ There are two types of cells present within the gland:
▸ Pinealocytes – hormone secreting cells
▸ Glial cells – supporting cells
▸ In middle age, the gland commonly becomes calcified, and can be
subsequently identified on radiographs and CT scans of the head

65. CNS GLANDS
PINEAL GLAND: ANATOMICAL STRUCTURE AND POSITION
▸ The pineal gland is a midline structure, located
between the two cerebral hemispheres
▸ It is attached by a stalk to the posterior wall
of third ventricle
▸ In close proximity to the gland are the superior
colliculi of the midbrain – paired structures that
play an important role in vision

66. https://teachmeanatomy.info/neuroanatomy/structures/pineal-gland/

67. CNS GLANDS
PINEAL GLAND: VASCULATURE
▸ The arterial supply to the pineal gland is profuse,
second only to the kidney
▸ The posterior choroidal arteries are the main
supply
▸ They are a set of 10 branches that arise from the
posterior cerebral artery
▸ Venous drainage is via the internal cerebral veins

68. https://teachmeanatomy.info/neuroanatomy/structures/pineal-gland/

69. CNS GLANDS
REVIEW QUESTIONS
▸ Which of these substances is produced by the
pineal gland?
▸ Melatonin
▸ Calcitonin
▸ Serotonin
▸ Thyrotropin-releasing hormone

70. CNS GLANDS
REVIEW QUESTIONS
▸ The pineal gland produces melatonin,
which regulates the circadian rhythm of
the body

71. CNS GLANDS
REVIEW QUESTIONS
▸ The pineal gland is attached by a stalk to the
posterior wall of which ventricle?
▸ First
▸ Second
▸ Third
▸ Fourth

72. CNS GLANDS
REVIEW QUESTIONS
▸ It is attached by a stalk to the posterior
wall of third ventricle

73. CNS GLANDS
REVIEW QUESTIONS
▸ The posterior choroidal arteries originate from
which main artery?
▸ Anterior cerebral artery
▸ Middle cerebral artery
▸ Posterior cerebral artery
▸ Posterior communicating arteries

74. CNS GLANDS
REVIEW QUESTIONS
▸ posterior choroidal arteries (main
supply) are a set of 10 branches that
arise from the posterior cerebral artery

75. LIMBIC SYSTEM
ANATOMY

76. 2 MIN NEUROSCIENCE:
LIMBIC SYSTEM
https://www.youtube.com/watch?v=LNs9ruzoTmI

77. DEEP BRAIN STRUCTURES
LIMBIC SYSTEM
▸ The limbic system is a set of structures in the brain that
deal with emotions and memory
▸ A set of brain structures located on both sides of
the thalamus, immediately beneath the medial temporal
lobe of the cerebrum primarily in the forebrain
▸ It regulates autonomic or endocrine function in
response to emotional stimuli and also is involved in
reinforcing behavior

78. https://integratedlistening.com/meet-the-limbic-system/

79. References
▸ These slide reflect a summary of the contents of TeachMeAnatomy.info
and are to be used for educational purposes only in compliance with
the terms of use policy.
Specific portions referenced in this summary are as follows:
▸ https://teachmeanatomy.info/neuroanatomy/structures/meninges/
▸ https://teachmeanatomy.info/neuroanatomy/vessels/ventricles/
▸ https://teachmeanatomy.info/neuroanatomy/structures/basal-ganglia/
▸ https://teachmeanatomy.info/neuroanatomy/structures/pineal-gland/
▸ https://teachmeanatomy.info/neuroanatomy/structures/pituitary-
gland/
Additional sources are referenced on the slide containing that specific
content.