Description of 3-Dimensional Space• Coronal: – section from ear to ear, like a loaf of bread• Axial: – section that parallels horizon• Sagittal: – section from front to back – mid-sagittal shows brain with left and right cortex separated
Corpus Callosum• Fibers that connect left and right cortex
Amygdala The Amygdala consists oftwo lima bean-sized neural clusters linked to the emotions of fear
Brain Areas Important for Hormone Control Rene Descartes • Pineal Gland – Very small subcortical structure – Releases the hormone melatonin • Hypothalamus – Hypo = “below” therefore located under thalamus – Regulates activity of Pituitary – Pituitary communicates with other endocrine glands (e.g. testes) – 4F!
Brain Imaging• Can provide information about anatomy or physiology• Imaging procedures differ in their: – Spatial resolution: the ability to differentiate nearby brain regions – Temporal resolution: the ability to differentiate brain activity at different times
Electroencephalography (EEG) 1873-1941• Developed by Hans Berger in 1929• Electrodes are placed on the surface of the skull• Electrical activity from the cortex is recorded Time
Computed Tomagraphy (EMI scan, axial) Gr: tomos (slice) & graphein (to write).• Developed in the 1970’s• X-ray beams are passed through the head• A 2 or even 3- dimensional structural map is created
Atypical CT 68 year old man Cerebellar hemorrhage extending into midbrain & ventriclesKlein JP, Ryther RC (2009). Images in clinical medicine. Central nervous system hemorrhage. NewEngland Journal of Medicine, 361(18), 1786.http://www.npr.org/blogs/health/2009/10/ghost_in_the_brain_an_appariti.html?sc=fb&cc=fp
Positron Emission Tomography (PET) • Radioactive material is injected into the blood • Scanner records the radioactivity (positron) in different parts of the brain • Provides information about function • Very useful for researchFor more detailed information about PET, goto:http://en.wikipedia.org/wiki/Positron_emission_tomography
Figure 2. Brain Glucose Metabolic Images Showing Axial Planes at the Level of the Orbitofrontal Cortex Volkow, N. D. et al. JAMA 2011;305:808-813Copyright restrictions may apply.
Functional Magnetic Resonance Imaging (fMRI)• A cylindrical magnet creates a magnetic field• A sensor records blood flow and brain activation• Can also be used for just structure • White matter • Gray matter • Ventricle
Comparison of Imaging Techniques MeasuresProcedure Brain: Advantage Disadvantage Function Excellent temporal Measures only from brainEEG resolution (msec) surfaceCT Structure Found in many Some radiation exposure hospitals Function Wide variety of Poor temporal resolution (min),PET Poor spatial resolution (cm) uses Radiation exposurefMRI Function Good temporal Patient cannot have resolution (sec), metal implants Good spatial resolution (0.5cm)
Cranial Nerves• I. Olfactory: smell (S)• II. Optic: vision (S)• III. Oculomotor: pupil construction (M)• IV. Trochlear: eye movement (M)• V. Trigeminal: face & teeth (S), jaw (M)• X. Vagus: heart (SM), autonomic nervous system