Neuroanatomy: Synopsis and revision Flashcards
What does the Forebrain/Prosencephalon primary vesicles develop into ?
The forebrain (prosencephalon) develops into the Telencephalon and the Diencephalon.
The Telencephalon becomes the cerebral hemispheres in the adult and the cavities of it becomes the lateral ventricles.
The Diencephalon becomes the Thalamus and its cavities become the third ventricle
What does the Midbrain/Mesencephalon primary vesicles develop into ?
The Midbrain (Mesencephalon) stays as the Mesencephalon and becomes the Midbrain in the adult and the cavities of it becomes the cerebral aqueduct
What does the Hindbrain/Rhombencephalon primary vesicles develop into ?
The hindbrain (rhombencephalon) develops into the Metencephalon and the Myelencephalon.
The Metencephalon becomes the pons and cerebellum in the adult and the cavities of it becomes the upper part of the fourth ventricle.
The Myelencephalon becomes the Medulla and its cavities become the lower part of the fourth ventricle
What are the different parts of the CNS?
- CNS; Encephalon + Spinal Cord
- Encephalon (Brain); Cerebrum + Brain stem + Cerebellum
- Cerebrum; Telencephalon (Cortex + white matter + basal nuclei - grey matter) + diencephalon
Brainstem; - Midbrain + Pons + Medulla
Name all of the cerebral lobes
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Insula
Limbic lobe (debate whether this one exists or is a border)
How do we know the functions of each lobe?
By studying the relation between lesions and the change caused in patient
Animal Experiments
Functional imaging techniques (PET, fMRI - looks at brain blood movement) helped us understand the functions of different regions of the nervous system
What is the function of the frontal lobe?
The frontal lobe is responsible for ;
Voluntary muscle movement;
- Primary motor cortex
- Premotor cortex
Language production;
- Front operculum in dominant hemisphere (90% people dominant in left) - Broca’s area
Higher cognitive functions (impulse control, decision-making, problem solving, social interaction, attention)
- prefrontal cortex
What is the function of the parietal lobe?
The parietal lobe is responsible for;
Integration of somatosensory information
- Primary and secondary somatosensory cortices
Movement
- Primary Somatosensory cortex
Language
- Wernickle’s area (partially) in the dominant hemisphere
Reading
What is the function of the temporal lobe?
The temporal lobe is responsible for;
Conscious memory
- Medial temporal lobe esp. Hippocampus and neighbouring cortices
Auditory processing
- Auditory cortices
Comprehension of speech
- Wernicke’s area (primarily)
Olfaction
- Medial temporal lobe, temporal pole
What is the function of the occipital lobe?
The occipital lobe is responsible for;
Visual perception and processing
Memory
What is the function of the insula?
The insula is responsible for;
Olfaction
Taste
Discriminative touch
What is the function of the limbic lobe?
The limbic lobe (means frame) is responsible for;
Behavioural and emotional responses
Learning and memory
What is the uncus and its significance ?
The uncus is the innermost part of the temporal lobe and receives its name from its hook-shaped structure. Anatomically, the anterior segment of the uncus overlies the amygdala and belongs to the parahippocampal gyrus
The uncus can turn into an uncal herniation which can lead to death
What is in the diencephalon?
Made up of the Thalamus and Hypothalamus
What is the function of the Thalamus?
The Thalamus is the major relay station for;
- Sensory impulses ascending to sensory cortex (except smell)
- Inputs from subcortical motor nuclei and cerebellum travelling to the cerebral motor cortex
What is the function of the Hypothalamus?
The Hypothalamus is the major relay station for;
- Autonomic control
- Endocrine control (w/pituitary gland)
- Regulation of thirst -> fluid electrolyte balance
- Eating -> energy balance
- Sexual behaviour, reproduction
- Body temperature
How does the pituitary gland (hypophysis) develop ?
It develops in part from diencephalon called Neurohypophysis and a part from the roof of the mouth (the anterior lobe) called the adenohypophysis
They are attached to hypothalamus so functions are closely related to the hypothalamus
How is the neurohypophysis formed and what does it do?
The Neurohypophysis is formed by the median eminence, pituitary stalk and posterior lobe of the hypophyseal gland
The neurohypophysis secretes 2 hormones that are produced in the hypothalamus (produced in hormone precursors higher up called paraventricular nucleus and the supraoptic nucleus).
How is the adenohypophysis formed and what does it do?
The adenohypophysis produces and secrets hormones of its own into the hypophyseal portal system
What is in the midbrain and their functions?
The midbrain contains superior and inferior colliculi and they are the visual and auditory reflex centres respectively
Red nuclei containing the subcortical motor centre
Substantia nigra is involved in reward-seeking, motor caring and others
The red nucleus and substantial nigra and parts of the basal nuclei (not basal ganglia as that is in PNS! - same structures and function, different location)
What is the basal nuclei + ganglia
Masses of grey matter embedded and surrounded by white matter