Nervous System Anatomy and Function PDF

1.State the overall functions of the Nervous System. Communication: Transmits signals throughout the body. Coordination: Integrates sensory input and motor outputs. Homeostasis: Regulates internal conditions. Response: Facilitates reactions to environmental changes. Cognition: Enables thought proces...

1.State the overall functions of the Nervous System. Communication: Transmits signals throughout the body. Coordination: Integrates sensory input and motor outputs. Homeostasis: Regulates internal conditions. Response: Facilitates reactions to environmental changes. Cognition: Enables thought processes, memory, and learning. 2.Describe the structure and function of nervous tissue. Structure: Composed of neurons and neuroglia (glial cells). Function: Neurons transmit electrical signals; neuroglia support and protect neurons. 3.List the organs of the Nervous System. Brain Spinal cord Nerves Ganglia 4.Identify and describe the divisions of the Nervous System according to: Central Nervous System (CNS) Includes the brain and spinal cord; processes information and coordinates activity. Peripheral Nervous System (PNS)Connects the CNS to limbs and organs; facilitates communication. afferent & efferent fibers- Carry sensory information to the CNS. Somatic Nervous System- Controls voluntary movements via skeletal muscles Autonomic Nervous System (ANS)-Regulates involuntary functions (e.g., heart rate, digestion). Sympathetic Nervous System-Prepares the body for 'fight or flight' responses.  Parasympathetic Nervous System- Promotes 'rest and digest' activities 5.Identify the two types of cells of the nervous system and describe their overall functions. Neurons: Transmit signals. Neuroglia: Support, protect, and nourish neurons. 6.Identify and describe functions of neuroglial cells:supports and protects neurons: astrocytes-Maintain blood-brain barrier, provide nutrients, and repair tissue. microglial- Act as immune defense in the CNS. oligodendrocytes-Form myelin sheath in CNS. ependymal- Line ventricles and produce cerebrospinal fluid (CSF). Schwann cells- Form myelin sheath in PNS 7.Describe neurons according to: cell body-Contains the nucleus and organelles. dendrites-Receive signals from other neurons axons-Transmit impulses away from the cell body to other cells Schwann cells-Wrap around axons in PNS. myelin sheath-Insulates axons to speed up signal transmission. nodes of Ranvier- Nodes of Ranvier are small gaps in the myelin sheath of myelinated axons. They facilitate rapid conduction of nerve impulses via saltatory conduction, allowing the impulse to jump from one node to the next.  neurilemma- Neurilemma is the outermost layer of the myelin sheath surrounding a nerve fiber. It contains Schwann cells and is crucial for the repair and regeneration of damaged nerve fibers. 8.Define a nerve.- A nerve is a bundle of axons (nerve fibers) wrapped in connective tissue, transmitting signals between the central nervous system (CNS) and the peripheral nervous system (PNS), facilitating communication throughout the body. 9. Describe the structural characteristics of a nerve according to: fascicles- Groups of nerve fibers (axons) bundled together, each surrounded by a perineurium. epineurium- : The outermost layer of connective tissue that encloses the entire nerve, providing protection and support. perineurium- A protective sheath surrounding each fascicle; it helps maintain the internal environment of the nerve endoneurium- The delicate connective tissue surrounding each individual nerve fiber, providing nourishment and support. white matter gray matter- White matter consists of myelinated axons, while gray matter contains neuronal cell bodies and unmyelinated fibers. tracts- Bundles of axons in the CNS that carry specific types of information. 10. Briefly describe the structure and functions of a components of a nerve/spinal cord according to: sensory receptors-Structures that detect stimuli and convert them into neural signals.  sensory nuerons- Neurons that carry information from sensory receptors to the CNS. motor neurons-Neurons that transmit signals from the CNS to muscles or glands. dorsal root and ventral root- Dorsal roots carry sensory information to the spinal cord; ventral roots carry motor commands away from the spinal cord. dorsal root ganglion- Cluster of sensory neuron cell bodies located just outside the spinal cord. synapse- the meeting point between 2 neurons via neurotransmitters. interneuron- Neurons that connect sensory and motor neurons within the CNS, allowing for processing and reflex actions motor neuron- A type of neuron that transmits signals from the CNS to effector organs (muscles and glands). Central Nervous System 11. List the two main parts of the central nervous system. Brain Spinal Cord 12.Identify the regions of the brain. Cerebrum Cerebellum Brainstem (midbrain, pons, medulla oblongata) Diencephalon (thalamus, hypothalamus, epithalamus) 13. Describe the structural characteristics of the cerebrum according to:  cerebral hemispheres-Two halves of the cerebrum, each responsible for different functions. corpus callosum- A bundle of nerve fibers connecting the two hemispheres, facilitating communication. lobes-Divided into frontal, parietal, temporal, and occipital lobes, each with specific functions. fissure- Deep grooves in the brain. Longitudinal Fissure: Divides the two hemispheres. Transverse Fissure: Separates the cerebrum from the cerebellum Gyri & Sulci-Gyri are ridges, and sulci are grooves on the brain's surface, increasing surface area. Central Sulcus: Divides the frontal and parietal lobes. Occipito-Parietal Sulcus: Separates the occipital lobe from the parietal lobe. Lateral Sulcus: Separates the temporal lobe from the frontal and parietal lobes. 14. Identify the location and structure of the cerebral cortex. The cerebral cortex is the outer layer of the cerebrum, composed of gray matter, responsible for higher brain functions, including thought, perception, and voluntary movement. 15.Describe the location and function of the basal nuclei within the cerebrum.Location: Deep within the cerebral hemispheres. Function: Involved in the regulation of voluntary motor control, procedural learning, and emotional responses. 16. Describe the location and structure of the diencephalon according to: Thalamus: Relay station for sensory information. Epithalamus: Involved in emotional and visceral responses; contains the pineal gland. Hypothalamus: Regulates homeostasis, including temperature, hunger, and circadian rhythms. Pineal Gland: Produces melatonin, regulating sleep-wake cycles. 17.Describe the location and structure of the brainstem and its parts: Midbrain: Controls reflexes and pathways for visual and auditory information. Pons: Connects different parts of the brain and regulates sleep. Medulla Oblongata: Controls vital autonomic functions like breathing and heart rate. 18. Identify the location and structure of the cerebellum. Located at the back of the brain, the cerebellum coordinates voluntary movements, balance, and posture. 19. Identify the spinal cord according to: Approximate Length: About 42-45 cm in adults. Starts: At the base of the skull (foramen magnum). Ends: Around the L1-L2 vertebrae. Regions: Cervical, thoracic, lumbar, sacral, and coccygeal. Cauda Equina: A bundle of spinal nerves below the end of the spinal cord. 20. Identify the following parts of the spinal cord: Dorsal Horn: Contains sensory neurons. Ventral Horn: Contains motor neurons. Lateral Horn: Found in thoracic and upper lumbar regions, contains autonomic neurons. Central Canal: Contains cerebrospinal fluid (CSF). Anterior Median Fissure: A deep groove along the front of the spinal cord. Posterior Median Sulcus: A shallow groove along the back of the spinal cord. Dorsal Root Ganglion: Contains sensory neuron cell bodies. 21. Differentiate between cranial and spinal nerves. Cranial Nerves: Emerge directly from the brain and brainstem; primarily involved in sensory and motor functions of the head and neck. Spinal Nerves: Emerge from the spinal cord; involved in transmitting signals to and from the rest of the body. 22. Describe the meninges according to:dura, arachnoid, and pia mater subdural and subarachnoid space cerebrospinal fluid Dura Mater: The outermost, tough layer. Arachnoid Mater: The middle, web-like layer. Pia Mater: The innermost layer, adhering to the brain and spinal cord. Subdural Space: The space between the dura mater and arachnoid mater. Subarachnoid Space: Contains CSF, located between the arachnoid and pia mater. Cerebrospinal Fluid: Cushions the brain and spinal cord. Dural Sinuses: Venous channels between the layers of the dura mater, draining blood from the brain. 23. Describe the location and structure of the ventricles of Lateral Ventricles: Two large cavities in each hemisphere. Septum Pellucidum: A thin membrane separating the lateral ventricles. Interventricular Foramen: Connects lateral ventricles to the third ventricle. Third Ventricle: Located in the diencephalon, connects to the fourth ventricle via the cerebral aqueduct. Cerebral Aqueduct: A narrow channel connecting the third and fourth ventricles. Fourth Ventricle: Located between the brainstem and cerebellum. Medial & Lateral Apertures: Openings allowing CSF to flow into the subarachnoid space. 24. Describe cerebrospinal fluid (CSF) according to: Origin: Produced by the choroid plexus in the ventricles. Choroid Plexuses: Networks of blood vessels in the ventricles that produce CSF. Components: Clear fluid containing glucose, electrolytes, and proteins. Flow: Circulates through the ventricles and subarachnoid space. Arachnoid Villi: Projections that allow CSF to be absorbed into the venous system. Dural Sinuses: Drainage points for CSF back into the bloodstream. Functions: Provides cushioning, buoyancy, and nutrient transport for the brain and spinal cord. 25. Briefly describe the function and structural of the blood -brain barrier Function: A selective permeability barrier that protects the brain from harmful substances while allowing essential nutrients to pass. Structure: Composed of tightly packed endothelial cells and astrocytic end-feet that restrict the passage of substances. Satellite cell: Found In the PNS they surround and support neuron cell bodies