Nervous System Divisions and Cell Types

Connective tissue layers surrounding the brain and spinal cord.

Outermost meningeal layer, fused to skull, forms sinuses.

Space between dura mater and arachnoid mater.

Middle meningeal layer; contains arachnoid villi for CSF absorption.

Space beneath the arachnoid mater, filled with CSF.

Innermost, delicate meningeal layer, adheres to brain.

Fluid-filled chambers within the brain, produce CSF.

Fluid that cushions and protects brain and spinal cord.

Produced by choroid plexuses in the brain ventricles.

Flows through ventricles to subarachnoid space, absorbed into blood.

Shock absorption, chemical protection, nutrient exchange.

Partitions within the cranial cavity.

Separates the left and right cerebral hemispheres.

A buildup of cerebrospinal fluid (CSF) in the brain's ventricles, causing increased pressure and potentially brain damage.

A protective mechanism that regulates the passage of substances between the bloodstream and the brain.

Neuroglia that help form and maintain the blood-brain barrier (BBB) by creating tight junctions between blood vessel cells.

Allows small molecules (O2, CO2, lipid soluble) to pass while restricting others.

Astrocytes' foot processes contact the capillaries; endothelial cells form tight junctions.

The nervous system's role in receiving and processing information from the external environment.

The nervous system's role in processing and interpreting sensory information.

The nervous system's role in responding to stimuli via muscles and glands.

The diencephalon is a central part of the forebrain, connecting the cerebrum to the brainstem. It includes the thalamus, hypothalamus, and epithalamus.

The thalamus acts as a relay station for sensory information (touch, temp, pain, pressure), relaying it to the cerebral cortex.

The hypothalamus regulates homeostasis (internal balance), autonomic functions, and the endocrine system.

The epithalamus houses the pineal gland, which produces melatonin influencing sleep-wake cycles.

The cerebellum coordinates movement, balance, and posture by receiving input from muscles and the balance system.

The brain stem is the connection between the brain and the spinal cord.

The pons connects the cerebellum to the brainstem and facilitates communication between the cortex and cerebellum, involved in breathing control.

The medulla controls vital life functions like heart rate, blood pressure, and breathing, and handles numerous unconscious reflexes.

The midbrain contains crucial nuclei and tracts controlling visual and auditory reflexes, and muscle movement.

"Fight or flight" response; prepares body for stress. Originates in thoracic and lumbar regions of the spinal cord.

"Rest and digest" response; promotes digestion, & nutrient storage.

Sympathetic preganglionic neurons begin in the thoracic (T1) and lumbar (L2) regions of the spinal cord.

Ganglia are near the spinal cord (sympathetic trunk), or anterior to vertebral bodies (prevertebral).

Modified sympathetic ganglion; releases norepinephrine (NE) and epinephrine (EPI) into bloodstream.

NE (neurotransmitter) or EPI (hormone), released by sympathetic neurons or adrenal gland.

SNS effector tissue that uses ACh, not NE, at postganglionic endings to stimulate sweat.

A rapid, automatic response to a stimulus, helping maintain homeostasis.

The pathway of a reflex, including sensory receptors, sensory neurons, integrating center, motor neurons, and effectors.

A structure that detects a stimulus and initiates a signal.

Carries the signal from the receptor to the integrating center.

Part of the central nervous system (CNS) that processes incoming information and sends signals to motor neurons.

Carries the signal from the integrating center to the effector.

A muscle or gland that responds to the signal from a motor neuron.

Reflex in which the stimulus and response are on the same side of the body.

Reflex where stimulus and response are on opposite sides of the body.

Reflex involving skeletal muscles (voluntary movements).

Reflex involving involuntary actions like heart rate or digestion.

Reflex with one synapse between sensory and motor neurons (e.g., stretch reflex).

Reflex with several synapses involving interneurons (e.g., tendon reflex).

A reflex that prevents overstretching of muscles and maintaing muscle tone.

A reflex that prevents excessive muscle contraction by inhibiting the contracting muscle.

Sensory receptor sensitive to changes in muscle length.

Sensory receptor sensitive to changes in muscle tension.

A functional system in the brain involved in emotion, motivation, and memory.

Part of the limbic system, involved in processing emotions.

Part of the limbic system crucial for learning and memory.

Limbic system structure involved in processing emotions like fear and aggression.

Widening of the spinal cord in the neck region, containing nerves supplying upper limbs and shoulder girdle.

Widening of the spinal cord in the lower back, containing nerves supplying pelvis and lower limbs.

Extension of spinal nerves at the end of the spinal cord.

Central region of the spinal cord containing cell bodies of neurons.

Small opening in the center of the spinal cord, filled with cerebrospinal fluid (CSF).

Part of the gray matter, containing sensory neuron cell bodies.

Connects posterior horns of gray matter.

Part of the gray matter, containing motor neuron cell bodies.

Part of the gray matter containing visceral motor neurons.

Part of white matter carrying sensory information (ascending).

Part of white matter carrying motor and sensory information.

Part of white matter carrying motor information (descending).

Connects white matter on both sides of the spinal cord.

Part of a spinal nerve carrying sensory information into the spinal cord.

Cluster of sensory neuron cell bodies outside the spinal cord.

Part of a spinal nerve carrying motor information away from the spinal cord.

Nerve that connects to the spinal cord and contains both sensory and motor fibers (mixed).

Protective membranes surrounding the spinal cord.

Outermost layer of the spinal meninges.

Space between the dura mater and the bony vertebral column.

Fluid that circulates in and around the brain and spinal cord.

Space between arachnoid mater and pia mater filled with CSF.

Procedure to collect cerebrospinal fluid for diagnostic purposes.