Nervous System: Part IV The Central Nervous System The Brain

2 Can you survive when part of your brain is destroyed?

2. Cells communicate with each other through direct contact with other cells or from a distance via chemical signaling. 3 Essential Knowledge 3.D.2

Central nervous system (CNS) Brain Spinal cord Peripheral nervous system (PNS) Cranial nerves Ganglia outside CNS Spinal nerves

Gray matter White matter Ventricles What accounts for the difference between white and gray matter?

The central canal of the spinal cord and the ventricles of the brain are hollow and filled with cerebrospinal fluid The cerebrospinal fluid is filtered from blood and functions to cushion the brain and spinal cord as well as to provide nutrients and remove wastes Cerebrospinal Fluid

Glia Glia have numerous functions including to nourish, support, and regulate neurons – Embryonic radial glia form tracks along which newly formed neurons migrate – Astrocytes induce cells lining capillaries in the CNS to form tight junctions, resulting in a blood-brain barrier and restricting the entry of most substances into the brain

Efferent neurons Afferent neurons Central Nervous System (information processing) Peripheral Nervous System Sensory receptors Internal and external stimuli Autonomic nervous system Motor system Control of skeletal muscle Sympathetic division Parasympathetic division Enteric division Control of smooth muscles, cardiac muscles, glands

Efferent neurons Afferent neurons Central Nervous System (information processing) Peripheral Nervous System Sensory receptors Internal and external stimuli Autonomic nervous system Motor system Control of skeletal muscle Sympathetic division Parasympathetic division Enteric division Control of smooth muscles, cardiac muscles, glands

The Vertebrate Brain Is Regionally Specialized Specific brain structures are particularly specialized for diverse functions These structures arise during embryonic development

Embryonic brain regions Brain structures in child and adult Forebrain Midbrain Hindbrain Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon Cerebrum (includes cerebral cortex, white matter, basal nuclei) Diencephalon (thalamus, hypothalamus, epithalamus) Midbrain (part of brainstem) Pons (part of brainstem), cerebellum Medulla oblongata (part of brainstem) Midbrain Forebrain Hindbrain Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon Spinal cord Cerebrum Diencephalon Midbrain Pons Medulla oblongata Cerebellum Spinal cord Child Embryo at 5 weeks Embryo at 1 month

Brain structures in child and adult Forebrain Midbrain Hindbrain Myelencephalon Cerebrum (includes cerebral cortex, white matter, basal nuclei) Diencephalon (thalamus, hypothalamus, epithalamus) Midbrain (part of brainstem) Pons (part of brainstem), cerebellum Medulla oblongata (part of brainstem) Midbrain Forebrain Hindbrain Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon Spinal cord Cerebrum Diencephalon Midbrain Pons Medulla oblongata Cerebellum Spinal cord Child Embryo at 5 weeks Embryo at 1 month

Cerebrum Diencephalon Midbrain Pons Medulla oblongata Cerebellum Spinal cord Child

Adult brain viewed from the rear Cerebellum Basal nuclei Cerebrum Left cerebral hemisphere Right cerebral hemisphere Cerebral cortex Corpus callosum

Diencephalon Thalamus Pineal gland Hypothalamus Pituitary gland Spinal cord Brainstem Midbrain Pons Medulla oblongata

Motor cortex (control of skeletal muscles) Frontal lobe Prefrontal cortex (decision making, planning) Broca’s area (forming speech) Temporal lobe Auditory cortex (hearing) Wernicke’s area (comprehending language) Somatosensory cortex (sense of touch) Parietal lobe Sensory association cortex (integration of sensory information) Visual association cortex (combining images and object recognition) Occipital lobe Cerebellum Visual cortex (processing visual stimuli and pattern recognition)

Language and Speech Studies of brain activity have mapped areas responsible for language and speech Broca’s area in the frontal lobe is active when speech is generated Wernicke’s area in the temporal lobe is active when speech is heard These areas belong to a larger network of regions involved in language

Information Processing The cerebral cortex receives input from sensory organs and somatosensory receptors Somatosensory receptors provide information about touch, pain, pressure, temperature, and the position of muscles and limbs The thalamus directs different types of input to distinct locations

Frontal lobe Parietal lobe Primary motor cortex Primary somatosensory cortex Genitalia Toes Abdominal organs Tongue Jaw Lips Face Eye Brow Neck Thumb Fingers Hand Wrist Forearm Elbow Shoulder Trunk Hip Knee Tongue Pharynx Jaw Gums Teeth Lips Face Nose Eye Thumb Fingers Hand Forearm Elbow Upper arm Head Neck Trunk Hip Leg

Primary motor cortex Toes Tongue Jaw Lips Face Eye Brow Neck Thumb Fingers Hand Wrist Forearm Elbow Shoulder Trunk Hip Knee

Primary somatosensory cortex Genitalia Abdominal organs Tongue Pharynx Jaw Gums Teeth Lips Face Nose Eye Thumb Fingers Hand Forearm Elbow Upper arm Head Neck Trunk Hip Leg

Frontal Lobe Function Frontal lobe damage may impair decision making and emotional responses but leave intellect and memory intact The frontal lobes have a substantial effect on “executive functions” of thinking making decisions.

Created by: Debra Richards Coordinator of Secondary Science Programs Bryan ISD Bryan, TX