Brain Introduction Flashcards
Grey matter
Tissue containing cell bodies of neurons.
Cortex
Outer, or most superficial, layer of an organ.
White matter
Tissue containing axons of neurons.
Primary brain vesicles
Prosencephalon
Mesencephalon
Rhombencephalon
Secondary brain vesicles
Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon
Telencephalon
Cerebral cortex, white matter and basal ganglia
Diencephalon
Pineal gland, dorsal thalamus, subthalamus, hypothalamus
Mesencephalon
Brainstem
Superficial brain features
Gyri = elevated ridges
Sulci = shallow grooves
Fissures = deep grooves
Covered by meninges
Major sulci & gyri
Precentral gyrus Postcentral gyrus Precentral sulcus Central sulcus Lateral sulcus
Lobes of the brain
Frontal Parietal Temporal Occipital Limbic Insular (buried in lateral sulcus)
Corpus Callosum
Major commissure, connection between cortical areas of similar function in both hemispheres
Function of frontal cortex
Supplementary motor area
Function of pre-central gyrus
Primary motor area control voluntary movements on contralateral side of body
Post-central gyrus
Primary somatosensory cortex & gustatory cortex
Parietal lobe
Somatosensory association areas
Temporal lobe
Auditory and auditory association area
Occipital lobe
Visual cortex and visual association area
Motor system: Overview
Produces muscle contraction on contralateral side of body
Controlling movement of feet in the upper part and those controlling movements of face and hands in the lower part
Somatosensory cortex overview
Primary somatosensory cortex.
Nerve cells in this area receive and interpret sensations of pain, temperature, touch and pressure from contralateral side of body
Mostly face, hands and feet and also arms, legs and genitals
Brain structures involved in movement production
• Cerebral cortex • Thalamus • Basal ganglia • Brainstem • Cerebellum Motor pathways transfer information between these structures
Thalamus
Largest division of diencephalon - composed of many nuclei.
Receives and processes precortical input from all sensory systems except olfactory system.
Then conveys information (projects) to the cerebral cortex
Basal ganglia
Sub-cortical grey matter nuclei. Essential component of extra-pyramidal motor system-> role in initiation & execution of motor activity. • Caudate nucleus • Putamen • Globus pallidus
Total cerebral blood flow
~ 750mL/min
250mL/min from 2x carotid, 1x basilar arteries
Arterial blood supply of brain
Internal carotid (anterior circulation) Vertebral arteries (posterior circulation)
Arteries of cerebrum
Anterior cerebral artery (branch of internal carotid artery)
Middle cerebral artery (branch of internal carotid artery)
Posterior cerebral artery (terminal branch of basilar artery)
Distribution of Anterior Cerebral Artery ACA
Occlusion of Anterior Cerebral Artery will lead to sensorimotor function loss in lower limb & bladder weakness
Distribution of Middle Cerebral Artery MCA
Occlusion of Middle Cerebral Artery will lead to sensorimotor function loss primarily in face and hands
Distribution of Posterior cerebral artery PCA
Posterior cerebral artery supplies occipital lobe and branches to the thalamus. Occlusion will lead to visual disturbances.
Possibly cause sensory losses on one side of body if thalamus deprived of blood.
Pineal gland
Seep-wake cycle
