Anatomy and Physiology I: Nervous System

Central Nervous System (CNS)

• The CNS is responsible for problem-solving skills.
• It includes the brain and spinal cord.

Peripheral Nervous System (PNS)

• The PNS includes the cranial nerves, spinal nerves, and ganglia.
• It is divided into the somatic nervous system and the autonomic nervous system.
• The somatic nervous system is responsible for transmitting information from sensory receptors to the CNS and from the CNS to skeletal muscles.
• The autonomic nervous system regulates digestion, heart rate, and other involuntary functions.

Cranial Nerves

• There are 12 pairs of cranial nerves.
• They are responsible for transmitting information from the senses to the CNS and from the CNS to muscles and glands.

Spinal Nerves

• There are 31 pairs of spinal nerves.
• They are responsible for transmitting information from the senses to the CNS and from the CNS to muscles and glands in the periphery.

Neuron Structure

• Neurons have three main parts: dendrites, cell body, and axon.
• Dendrites are the input part of the neuron and receive signals from other neurons.
• The cell body contains the nucleus and is responsible for protein synthesis.
• Axons are the output part of the neuron and transmit signals to other neurons or to muscles or glands.
• Nissl bodies are ribosomes associated with rough endoplasmic reticulum in the cell body.
• Myelinated axons contain Schwann cells that produce myelin.

Synaptic Transmission

• Neurotransmitters are released from the presynaptic terminal and bind to receptors on the postsynaptic terminal.
• The release of neurotransmitters is triggered by an action potential in the presynaptic neuron.
• The binding of neurotransmitters to receptors causes a change in the postsynaptic neuron's membrane potential.

Types of Neurons

• Motor neurons transmit signals from the CNS to muscles and glands.
• Sensory neurons transmit signals from sensory receptors to the CNS.
• Interneurons transmit signals between neurons within the CNS.
• Afferent neurons transmit signals from sensory receptors to the CNS.
• Efferent neurons transmit signals from the CNS to muscles and glands.

Neuroglial Cells

• Astrocytes are a major component of the blood-brain barrier.
• Microglial cells are responsible for phagocytosing foreign substances and debris.
• Oligodendrocytes produce myelin in the CNS.
• Ependymal cells produce cerebrospinal fluid.

Meninges

• The meninges are three layers of protective tissue that cover the CNS.
• The dura mater is the thickest and outermost layer.
• The arachnoid mater is the middle layer.
• The pia mater is the innermost layer and is in contact with the CNS.

Spinal Cord

• The spinal cord is divided into cervical, thoracic, lumbar, and sacral regions.
• There are 8 cervical spinal nerves, 12 thoracic spinal nerves, 5 lumbar spinal nerves, and 5 sacral spinal nerves.
• The spinal cord is protected by the meninges and cerebrospinal fluid.

Brain

• The brain is divided into the cerebrum, cerebellum, and brainstem.
• The cerebrum is the largest part of the brain and is responsible for higher-level functions.
• The cerebellum is responsible for coordinating muscle movements.
• The brainstem connects the cerebrum to the spinal cord.
• The central sulcus separates the frontal and parietal lobes.
• The lateral fissure separates the temporal lobe from the rest of the cerebrum.
• The gray matter on the outer surface of the cerebrum is called the cortex.

This quiz tests your knowledge of the nervous system, including the central and peripheral nervous systems, and their functions.