Topography of the brain Flashcards
Central nervous system (CNS)
Composed of the brain and spinal cord, which are surrounded by the meninges, and enclosed within the cranial cavity and vertebral column. Responsible for coordination and control.
Peripheral nervous system (PNS)
The rest of the nervous tissues not enclosed by the meninges, responsible for carrying information to and from the CNS. Composed of sensory afferent neurones, which carry signals to the CNS, and motor efferent neurones, which carry signals away from the CNS.
Somatic nervous system (SNS)
Responsible for voluntary movement via the contraction of skeletal muscles.
Autonomic nervous system (ANS)
Responsible for involuntary responses via the contraction of smooth/cardiac muscle and secretion from glands. Can be sub-divided into sympathetic, parasympathetic and enteric divisions.
3 primary vesicles of the brain
- forebrain (prosencephalon)
- midbrain (mesencephalon)
- hindbrain (rhombencephalon)
5 secondary vesicles of the brain
- cerebrum (telencephalon)
- thalamic brain masses (diencephalon)
- midbrain (mesencephalon)
- pons and cerebellum (melencephalon)
- medulla oblongata (myelencephalon)
Regions of the adult neural canal
- two lateral ventricles; houses telencephalon
- interventricular foramina; connect lateral ventricles to 3rd ventricle
- third ventricle; houses diencephalon
- cerebral aqueduct; links 3rd and 4th ventricles
- fourth ventricle; houses hindbrain
- central canal; houses spinal cord
Cerebrum (telencephalon)
The largest part of the brain, divided into two bilaterally symmetrical hemispheres along the longitudinal fissure. Composed of the cerebral cortex and white matter. Responsible for higher neurological functions eg. memory, emotion and conciousness. Sensory and motor functions also occur in the cerebrum.
Lobes of the cerebrum
4 superficial lobes:
- frontal lobe; motor function
- parietal lobe; somesthetic sensation
- temporal lobes; auditory sensation
- occipital lobe; visual sensation
2 deeper lobes:
- cingulate gyrus
- insular
Cerebral cortex
A continuous, highly folded layer of grey matter, located superficially within the cerebrum.
Gyri and sulci
Gyrus= a ridge in the cerebral cortex Sulcus= a groove in the cerebral cortex
Fissures and sulci
- longitudinal fissure; separates cerebral hemispheres
- lateral fissure; separates temporal lobe from frontal and parietal lobes
- central sulcus; separates frontal lobe from parietal lobe
- parieto-occipital sulcus; separates parietal lobe from occipital lobe
Thalamic masses (diencephalon)
Composed of two major regions; the thalamus and hypothalamus, located deep to the cerebrum. Also includes the epithalamus, which contains the pineal gland. Acts as the connection between the cerebrum and the rest of the nervous system.
Thalamus
A bilaterally-symmetrical, egg-shaped structure sitting in the third ventricle. The thalamic nuclei are responsible for relaying sensory and motor information.
Hypothalamus
Located below the thalamus. Responsible for the control of homeostasis and the regulation of secretion by the pituitary gland. Extends inferiorly to form the posterior part of the pituitary gland, connected by the infundibulum.
Epithalamus
Located above the thalamus. Contains the pineal gland, which secretes melatonin to regulate circadian rhythms.