The Brain Flashcards
Where does the nervous system develop from?
The nervous system develops from a hollow neural tube, which central cavity is modified in embryo
Name the Ventricles of the Brain
The first 2 ventricles are paired and known as the Cerebrum. The 3rd ventricle is the Diancephalon, the fourth is the Brainstem
How many planes can the brain be viewed in and what are their names?
The brain can be viewed in 3 planes: Coronal, Saggital, and Horizontal/Transversal
Name some ways in which the brain is protected
The brain is protected in a number of ways: Skin and hair on head, Cranium, 3 Meningeal sheaths, Cerebrospinal Fluid, and a highly selective blood barrier
Name some facts about the Cerebrum
The cerebrum is the largest portion of the brain, made up of two hemispheres (R&L), connected by a corpus callosum. It is the central processing centre of the brain and its main structures are the cerebral cortex and basal nuclei.
What are the 3 main regions of the brain
The 3 main regions of the brain are: The brain stem, Cerebellum, and Forebrain
What structures are included under the brain stem?
The structures included under the brain stem are: the midbrain, the pons, and medulla
What structures are included under the forebrain?
The structures that are included under the forebrain are: the diencephalon (hypothalamus, and thalamus), the basal nuclei, and the cerebral cortex
What are gyri?
Gyri are the bumps in the brain. They’re also each peak of lumps and bumps
What are sulci?
Sulci are the indentations of the brain. Each lower parts of lumps and bumps.
What is the structure of the cerebrum?
The cerebrum is made up of 2 hemispheres (R&L), it is connected by the corpus callosum. It has a thin outer shell made up of grey matter and a thick central core made up of white matter.
What is grey matter?
Grey matter: consists primarily of neuron cell bodies, but also contains dendrites. It is responsible for information processing, thinking, learning, and decision-making.
What is white matter?
White matter: Composed of long, myelinated axons that transmit signals between different parts of the brain. This facilitates communication between different brain regions. It appears white due to the presence of myelin
Describe the structure of the Cerebral Cortex
The cerebral cortex has a thin outer grey matter layer and a white matter core. In each hemisphere, deep folds divide the cortex into 4 lobes: Frontal. Parietal, Occipital, and Temporal
What are the higher functions of the cerebral cortex?
The higher functions of the cerebral cortex are: Broca’s area, Wernicke’s area, Association cortices, Primary auditory cortex, and Primary Visual cortex.
What is Broca’s area responsible for?
Broca’s area is responsible for speech
What is Wernicke’s area responsible for?
Wernicke’s area is responsible for speech understanding
What is the somatosensory cortex?
The Somatosensory cortex is the site of initial processing and perceptions of body sensations. As well as proprioception, it has information that is received from the CNS.
What is the Primary motor cortex?
The primary motor cortex allows voluntary control over skeletal muscle movement. Stimulation of the primary motor cortex produces movement in parts of the opposite side of the body
What does Homonculi mean?
Homonculi is essentially a distorted map of the body in the brain
What are the three areas of the higher motor cortex?
The 3 higher motor cortex areas are supplementary, Posterior Parietal, and Premotor Cortex.
How does the Cerebellum work with the higher motor cortex areas?
The cerebellum sends input into these regions, and therefore plays a role in initiating, planning, and timing some movements.
What is the limbic system comprised of?
The limbic system is comprised of a ring of interconnected forebrein structures: Thalmus, Hypothalmus, Hippocampus, and Amygdala
What does the limbic system play a key role in?
The Limbic system plays a key role in: Survival behaviour, Subjective emotional feelings, Emotional expression, and memory and learning
What is the role of the basal nuclei?
The role of the basal nuclei is to work with the motor cortex to suppress unwanted or unnecessary movement. It monitors and coordinates slow, sustained movements, and helps maintain posture
What makes up the Basal Nuclei
The basa nuclei is made up of: Caudate nucleus, Putamen, Globus Pallidus, and Nucleus accumbens
What is the role of the Diencephalon?
The Diencephalon is the principle communicator of the brain, it allows sensory information to be enacted on. It is a relay centre for motor responses from cerebrum, and has an integration of conscious & unconscious sensory info & motor commands.
What is the role of the Thalmus?
The thalmus relays all sensory inputs (excl smell) to the cortex, it allows certain sensations to be recognised. It translates information so it is readable by the cortex.
Where does the Thalmus project to for vision?
It projects to the Lateral geniculate nucleus for vision, in the cerebral cortex
What does the hypothalamus have regulatory role in?
It has roles in the regulation of:
Blood pressure, digestive system, bladder, heart rate, and body temp. Thirst and urine output. Food intake. Sleep-wake cycle. Emotions and behaviours, and endocrine control
What is the structure of the hypothalamus?
The hypothalamus is comprised of group nuclei.
What is the structure of the cerebellum?
The cerebellum is highly folded and attached to the back of the upper brain stem. It contains the largest number of neurons in the brain and has 3 functional regions
What are the 3 functional regions of the cerebellum?
The 3 functional regions are: Vestibulo, Spino, and Cerebro
What are the functions of the cerebellum?
The functions of the cerebellum are the maintenance of muscle tone, posture and balance. Fine-tuning conscious and unconscious movements. Proprioception, and also a vital role in subconscious control of motor activity
What are the functions of the Brain Stem?
The functions of the brain stem are the regulation of vital functions, regulation of muscle reflexes, and connecting the cerebrum and SC, and having attachment points for 10 cranial nerves
How many cranial nerves are there?
There are 12 pairs of cranial nerves
What is the name of the holes that the cranial nerves pass through?
The cranial nerves pass through the foramina
What are the 12 pairs of cranial nerves?
The 12 pairs of cranial nerves are: I - Olfctory, II - Optic, III - Oculomotor, IV - Trochlear, V - Trigeminal, VI - Abducens, VII - Facial, VIII - Vestibulocochlear, IX - Glossopharyngeal, X - Vagus, XI - Accessory, XII - Hypoglossal
What is the structure of the RAS?
The RAS is made up of interconnected neurons throughout the brain stem and into the thalamus. It has ascending fibres to the cortex, as well as descending fibres
What does RAS stand for?
RAS stands for Reticular activating system
What is the role of the RAS?
The role of the RAF is to recieve and integrate all sensory synaptic input. It has roles in sleep alertness, emotions and arousal
What is the role of the Pons?
The role of the pons is focused on respiration. It has respiratory (apneustic and pneumotaxic) reflexes.
What does the apneustic centre trigger?
The apneustic centre triggers breathing (inspiration)
What does the pneumotaxic centre trigger and what does it mean?
The pneumotaxic centre triggers exhalation to prevent lung overinflation
How does the pons transfer info?
The pons transfers info via tracts: To the brain, from the brain to the SC, and the pons to cerebellum
