Case 19- Brain anatomy Flashcards
Primary development divisions of the brain- based on embryological structures
- Forebrain (Prosencephalon)- forms the Telencephalon and Diencephalon
- Midbrain (Mesencephalon)- forms the Mesencephalon
- Hindbrain (Rhombencephalon)- forms the Metencephalon and Myelencephalon
Secondary developmental divisions of the brain- what do the primary developmental divisions give rise to
- Telencephalon- forms the Cerebral hemispheres, deep structures
- Diencephalon- forms the Diencephalon (Hypothalamus, Thalamus, Subthalamus, Epithalamus)
- Mesencephalon- forms the Midbrain
- Metencephalon- forms the Pons, Cerebellum
- Myelencephalon- forms the Medulla (Oblangata)
Structural development divisions of the brain- what do the secondary developmental divisions develop into:
- Cerebrum- made of Cerebral hemispheres and deep structures
- Diencephalon- made of Hypothalamus, Thalamus, Subthalamus, Epithalamus
- Brainstem- made of Midbrain, Pons and Medulla
- Cerebellum
Corpus callosum
Connects the two cerebral hemispheres. It function is to communicate between the right and left cerebral hemispheres of the brain.
Septum pellucidum
Thin membrane which separates the two lateral ventricles of the brain, extends down from the corpus callosum
Hypothalamus
Its function is homeostasis, regulation of metabolic processes. It links the nervous system and the endocrine system via the pituitary gland.
Thalamus
The inter thalamic adhesion connects the halves of the thalamus. The thalamus functions as a relay system. Site either side of the third ventricle
Subthalamus
Below the thalamis. It contains the subthalmic nucleus which is associated with the basal ganglia and controls motor control and learning, behaviour and emotions.
Epithalamus
Links the limbic system to other parts of the brain. The Limbic system is involved in emotion, behaviour and long term memory.
Midbrain
First part of the brainstem, involved in motor control, alertness, auditory processing and visual processing. The cerebral aqueduct runs through the midbrain.
Superior and inferior Colliculi
In the posterior part of the midbrain, there are two Superior and two Inferior Colliculi, its involved in visual and auditory processing.
Pons
Closely related to the cerebellum and the 4th ventricle, part of the brainstem. Contains Cranial neve nuclei and relays signals to the Cerebellum.
Medulla Oblongata
Final part of the brainstem. It has functions in reflexes, autonomic function, cardiac, respiratory and vasomotor centres.
Infundibulum
The pituitary stalk, connects the hypothalamus to the posterior pituitary
Mammilary bodies
Part of the limbic system
Pineal gland
Produces melatonin, controls the wake/sleep pattern. Has photoperiodic function
Anterior commissure
Connects the right and left temporal lobe. Forms the connection between structures of the limbic system. Allows for the transfer of auditory and olfactory information.
Posterior commisure
Connection between the left and right hemispheres. Allows for the pupillary light reflex.
Fornix
Part of the limbic system
Optic chiasm
Where the optic nerves cross over
Cerebrum
1) Largest part of the brain, it is located in the anterior and middle cranial fossae.
2) It extends from the frontal bone anteriorly and the occipital bone posteriorly.
3) Split into left and right hemispheres
The medial/great longitudinal fissure
The medial/great longitudinal fissure separates the cerebral hemispheres, this is a deep groove. The fissure contains the falx cerebri and the hemispheres are covered by the meningeal layers. The corpus callosum connects the right and lefts cerebral hemispheres.
Internal structures of the Cerebrum
- Grey matter- on the surface of each cerebral hemisphere, this is known as the cerebral cortex. Contains neuronal cell bodies
- White matter- in the deeper parts of the brain, the Myelinated axons
The lobes of the Cerebrum
Each lobe is named after the bone it sits under. The lobes are just structural but contain the cortical areas that perform the function. Includes Frontal, Parietal, Temporal and Occipital. The two additional small lobes are the limbic and insular lobes
Frontal lobe of the Cerebrum
Controls voluntary movement (primary motor cortex), higher intellect, personality, mood, social conduct and language (dominant hemisphere side only). Contains the pre-motor and pre-frontal cortex
Parietal lobe of the Cerebrum
Controls somatosensory information processing (primary somatosensory cortex). Language and calculation on the dominant hemisphere side and visuospatial functions on the non-dominant hemisphere side.