TOPIC 7 CNS Flashcards
What are the 3 major functions of the nervous system?
1) sensory input: where information about the body’s tissues and environment are communicated to the CNS via sensory nerve cells of the PNS
2) Integration: where all sensory info is received and perceived by the CNS and appropriate responses are planned and initiated.
3) Motor output: all nervous information leaving the CNS communicating movement info to the muscles (skeletal, smooth and cardiac) and some glands (salivary, sweat glands). This information is communicated from the CNS to the PNS via motor cells of the PNS. They can be under voluntary ( somatic) or involuntary (autonomic).
What is the difference between grey and white matter?
Grey matter is densely packed with nerve cell bodies.
White matter contains very few nerve cell bodies and has many nerve cell fibres (axons). It is white because of the myelin.
What is the location of grey and white matter in the brain and spinal cord.
BRAIN: grey matter is found superficially (in the cerebral cortex) and white matter is found deep.
SPINAL CORD: Opposite to above.
What are the three components that make up the brain?
1) Cerebrum
2) Cerebellum
3) Brainstem
What is the function of the corpus collosum and where is it located?
The corpus collosum is a large mass of white matter -nerve fibres (axons and dendrites) that seperate the L and R hemispheres of the brain and allow these hemispheres to communicate. It is also the site where many nerve fibres cross over (decussate).
What is the function of the basal ganglia and where is it located?
The basal ganglia is a series of grey matter areas deep within the white matter of the cerebral hemispheres. They are very important in activation and co-ordination of voluntary movements and helping to suppress unnecessary movements. Often affected in Parkinsons disease which is often characterised by un-necessary moves. BASAL GANGLIA = COORDINATION
What is the cerebrum?
This is the largest, most easily identified component of the brain. It has a highly folded structure in which the tissue folds are referred to as gyri (singular = gyrus), and the infoldings between them are called sulci (singular = sulcus) or fissures. Think of the gyri as mountains, and the sulci as valleys.
What are the 4 main lobes in the brain and what separates them?
4 lobes -= frontal, parietal, occipital and temporal.
Lobes are divided by major sulci and fissures. They are:
Longitudinal fissure – runs down the mid-sagittal plane and separates the cerebrum into left and right hemispheres;
• Central sulcus – runs perpendicular to the longitudinal fissure, separates the frontal lobes and parietal lobes;
• Lateral sulcus – located on the lateral aspect of the cerebrum, separates the parietal/frontal lobes from the temporal lobes; and
• Parieto-occipital sulcus – found on the posterior aspect of the cerebrum and separates the parietal lobe from the occipital lobe.
What ‘areas’ are found in the frontal lobe and what are their functions?
1) Pre-central gyrus/primary motor cortex: it’s function is to initiate any voluntary motor movements (info to the skeleton). It is located directly anterior to the central sulcus.
2) Premotor sulcus: It is located anterior to the primary motor cortex. It’s job is to plan our motor movements. Communicates directly with primary motor cortex.
3) Broca’s area: Broca’s area is located in the most lateral/inferior gyrus of the frontal lobe. Neurons in this area communicate with the primary motor cortex that control movements of the larynx and some articulators. It is usually only present in the dominant hemisphere.
What ‘areas’ are found in the frontal lobe and what are their functions?
- Primary motor cortex – also known as the pre-central gyrus, this is a gyrus located directly anterior to the central sulcus. It is the area of initiation of all voluntary movement (information sent to skeletal muscles).
- Premotor area – located anterior to the primary motor cortex, this area is where we plan our motor movements. This area communicates directly with the primary motor cortex.
- Broca’s area – the motor planning area specifically for speech. This is located in a lateral and inferior frontal gyrus, usually only in the dominant hemisphere (if you are right-handed, your dominant hemisphere is the left one). Neurons originating in this area communicate with those in the primary motor cortex that control movement of muscles in the larynx and some of the articulators.
What ‘areas’ are found in the parietal lobe and what are their functions?
Primary sensory cortex – also known as the postcentral gyrus, this gyrus is located directly posterior to the central sulcus. It is where all general sensory information (touch, pressure, temperature, pain, prioprioception, etc) is received and perceived. Note that areas for the special senses (hearing, balance, vision, smell and taste) are located elsewhere.
• Angular gyrus – located in the most posterior and lateral part of the parietal lobe, at the junction of the lateral and parieto-occipital sulci. This area is specifically involved in our ability to comprehend written material.
• Supramarginal gyrus – located just superiorly to the angular gyrus and close to Wernicke’s area. This area contributes to speech motor planning (together with Broca’s area).
What ‘areas’ are found in the temporal lobe and what are their functions?
Primary auditory area – located in a deep gyrus in the superior part of the temporal lobe (the lobe must be reflected back from the lateral sulcus to be able to identify it). This is where all primary hearing information is received and processed.
• Wernicke’s area – located in a posterosuperior gyrus. This is the language formulation area, used to put together words into cohesive sentences.
What ‘areas’ are found in the occipital lobe and what are their functions?
The primary visual cortex is located in the occipital lobe. Most posterior part. It is the area that we receive and process visual information.
What is the cerebellum and where is it located? what primary areas does it communicate with?
The cerebellum is a part of the brain. It is the small cauliflower looking structure at the most posterior/inferior part of the cerebrum. It’s function is to aid in the learning of motor skills. Help coordinate voluntary motor movements and to limit the extend of voluntary movements (like not overreaching for a glass for example).
It communicates with the primary motor cortex, the premotor area and the basal ganglia.
What is the diencephalon and where is it located? Describe it’s anatomy and motor functions?
The diencephalon is located deep in the midline of the brain, inferior to the corpus callosum and superior to the brainstem. Two of its major components are the:
• Thalamus – acts as a major relay centre between the brain and spinal cord, and contributes to control of mood and movement
• Hypothalamus – has many roles in controlling normal homeostatic parameters such as body temperature, and it also is an important component of the endocrine system.
