BRAIN ANATOMY NOTES THE BRAIN ANATOMICAL REGIONS o Brain Stem o Cerebellum o Cerebrum BRAIN STEM Inferior, posterior portion of brain Regulates involuntary autonomic functions Continuous with spinal cord conduction of signals to and from body to brain 3 Main Parts: 1. Midbrain (mesencephalon) visual reflexes, eye movements, temperature regulation, hearing, sleep, alertness 2. Pons - relay sensory information, sleep, respiration, bladder control 3. Medulla Oblongata heart rate, respiration, blood pressure Midbrain Medulla Oblongata Pons Diencephalon Corpus Callosum CEREBELLUM Balance and coordination of movements (proprioception) Cerebellum - balance, coordination 24-YEAR-OLD WOMAN BORN WITHOUT CEREBELLUM Physicians in China discovered a 24-year-old woman who is only the ninth known case of a living person with cerebellar agenesis. The womans condition was discovered after she sought medical attention due to nausea and vertigo. CT scans and MRI images revealed the missing cerebellum, which readily explains why those symptoms would be present. It also explains why she wasnt able to speak until she was six and wasnt able to walk until age seven. She had never been able to play and jump like normal kids due to this defect. Unsurprisingly, the woman had been unable to walk steadily without support throughout her life. While testing revealed that she had no trouble understanding vocabulary, the missing cerebellum caused her to have difficulties with pronunciation. Her voice trembles, words are slurred, and the doctors described her voice tone as harsh. In the space where the cerebellum should have been, cerebrospinal fluid has filled the gap. The chemistry of the fluid appeared normal, though the pressure was a bit high. Neurological defects do not appear to run in her family, and she was able to get married and have a neurologically- typical daughter without pregnancy complications. CORPUS CALLOSUM Connects the two brain hemispheres (right & left) to allow information processing from both sides White matter (axons) Nonverbal right hemisphere Verbal left hemisphere ?? What did you see? THE SPLIT BRAIN STUDIES Picture to left brain can name the object left hand cannot identify by touch zPicture to right brain ycant name the object yleft hand can identify by touch Using your left hand, Pick up what you saw. I saw an apple. What did you see? Nonverbal right hemisphere Verbal left hemisphere Used to treat severe epilepsy symptoms in some patients LEFT VS. RIGHT DIENCEPHALON Two main parts: 1.Hypothalamus regulates hormones levels, regulates body temperature, hunger, sleep cycles 2.Thalamus - relay station for sensory and motor signals between different parts of the brain, involved in sleep & alertness HYPOTHALAMUS + STRESS Hypothalamus regulates several stress hormones: ACTH (Adrenocorticotropic Hormone), Cortisol Epinephrine (adrenaline) Released from the pituitary gland + adrenal glands PITUITARY GLAND Master gland" of the endocrine (hormone) system Pea-shaped protrusion from the inferior portion of the hypothalamus RELEASES several different hormones as dictated by the hypothalamus Growth, blood pressure, thyroid regulation, menstrual cycle regulation (LH & FSH) water regulation (ADH), breast milk production (prolactin), uterine contractions (oxytocin) Corpus callosum Thalamus Hypothalamus Pituitary gland HIPPOCAMPUS Plays a major role in memory formation and retention (short long term memory), and spatial navigation Linked to olfactory lobes (smell) Crayola crayons are created today with the same scent because it reminds people of their happy times in childhood. HIPPOCAMPUS + STRESS Stress hormones can disconnect neural networks, particularly in the hippocampus Prolonged exposure to stress hormones can lead to hippocampal cell death difficulties with memory retention, problem solving Prevent production of BDNF (brain-derived neurotrophic factor), a protein that stimulates neurogenesis and neural connections CEREBRUM wrinkly, superficial portion of the brain largest area of human brain divided into two hemispheres (left & right) higher mental functions gray matter mostly neuron cell bodies PREFRONTAL CORTEX + STRESS Stress hormones affect the executive functions of the prefrontal cortex. Exposure to long-term stresses makes it harder to concentrate, sit still, rebound from disappointments, and follow directions. This can lead to anxiety, depression, and difficulty learning and regulating emotions.