Central nervous system CNS Brain -divisions –Hypothalamus –Medulla oblongata –Cerebellum Suprachiasmatic nucleus in hypothalamus is major circadian clock of mammals

Figure 10.4 Nervous systems of different phyla (Part 1)

Figure 10.4 Nervous systems of different phyla (Part 2)

Figure 10.6 The organization of a vertebrate central nervous system

The central nervous system Begins as a hollow tuve Embryonic development- 5 regions Telencephalon Diencephalon Mesencephalon Metencephalon myelencephalon

Figure 10.8 A schematic of vertebrate brain structure

Evolution of the vertebrate brain

Figure 10.9 Localization of function in the mammalian brain: old and current views (Part 1)

Cerebrum 2 hemispheres –Outer gray matter –Inner white matter Specialization of functions Left hemisphere –Dominant in language and analytical ability Right hemisphere –Pattern recognition, Communication between hemisphere –Corpus callosum

Figure 10.9 Localization of function in the mammalian brain: old and current views (Part 2)

Cerebral Lateralization Cerebral dominance: –Specialization of one hemisphere. Left hemisphere: –More adept in language and analytical abilities. –Damage: Severe speech problems. Right hemisphere: –Most adept at visuospatial tasks. –Damage: Difficulty finding way around house.

Figure Functional neuroimaging demonstrates localization of function in cerebral cortex

Figure Maps in the human brain (Part 1)

Figure Maps in the human brain (Part 2)

Homeostatic role of hypothalamus Autonomic control center Center for emotional response and behavior Body temperature regulation Regulation of food intake- satiety and hunger center Regulation of water balance and thirst Regulation of sleep-wake cycle Control of endocrine systems

Pituitary Gland Posterior pituitary: –Stores and releases ADH (vasopressin) and oxytocin. Hypothalamus produces releasing and inhibiting hormones that are transported to anterior pituitary. –Regulate secretions of anterior hormones. Anterior pituitary: –Regulates secretion of hormones of other endocrine glands.

Role of medulla oblongata – maintain homeostasis Cardiac and vasomotor center –Adjust force and rate of heart contraction –Regulate blood pressure by acting on smooth muscle of blood vessels Respiratory center –Control rate and depth of breathing Other regulatory activities –Vomiting, hiccupping, swallowing, coughing, sneezing ….. etc

Role of cerebellum Process inputs received from the motor cortex, brain stem nuclei, and sensory receptors Provide precise timing and appropriate patterns of skeletal muscle contraction Needed for smooth coordinated movements Needed for equilibrium

Figure Suprachiasmatic nucleus in hypothalamus is major circadian clock of mammals (Part 1)

Figure Daily rhythm of several physiological functions in a human

Figure Circadian rhythm of metabolic rate and motor activity for a chaffinch (Part 1)

Figure Circadian rhythm of metabolic rate and motor activity for a chaffinch (Part 2)

Figure Activity rhythms of two nocturnal flying squirrels (Glaucomys volans)

Figure Suprachiasmatic nucleus in hypothalamus is major circadian clock of mammals (Part 2)

Figure 10.3 The neural circuit mediating the startle response in the cockroach Periplaneta (Part 1)

Figure 10.5 The organization of an arthropod central nervous system

Figure 10.3 The neural circuit mediating the startle response in the cockroach Periplaneta (Part 2)