Final Exam - Anatomy

Nervous System

Nervous System

First system to begin formation during embryonic development (2wk), responsible for coordinating body activities by transmitting signals between different parts.

What tissue is the Nervous System derived from?

Ectoderm.

Gastrulation

Head-head/side-side folding; what the germ layers go though, results in neural fold and neural groove which will fold and create the neural tube and ultimately form the central nervous system.

Neural Tube

Structure that develops from the neural fold and gives rise to the central nervous system, including the brain and spinal cord.

Mesoderm

The middle germ layer that develops into muscles, bones, and the circulatory system in addition to making vertebral column and cranial, protection of nervous system.

Central Nervous System

The part of the nervous system consisting of the brain and spinal cord, responsible for processing and transmitting (creating) information throughout the body.

CNS sends signals back to PNS via…

efferent pathways and nerves.

Peripheral Nervous System

The part of the nervous system that connects the central nervous system to the limbs and organs, comprising all the nerves outside the brain and spinal cord (cranial and spinal nerves). It plays a crucial role in relaying information between the CNS and the rest of the body.

Function of PNS

Monitor external and internal environment (sight, smell, hear, feel, taste).

PNS receives external/internal stimuli and transmits this info to..

Afferent branch

Afferent Branch

The part of the peripheral nervous system that carries sensory information from the body to the central nervous system for processing.

Efferent Branch

The part of the peripheral nervous system that transmits motor commands from the central nervous system to the muscles and glands of the body.

Motor Division

The part of the peripheral nervous system responsible for controlling voluntary and involuntary movements by transmitting signals from the central nervous system to skeletal muscles. (split from efferent branch)

Autonomic Division

The part of the peripheral nervous system that regulates involuntary bodily functions, such as heart rate and digestion, and is divided into sympathetic and parasympathetic systems. (Split from efferent branch)

Parasympathetic System

A division of the autonomic nervous system that conserves energy and promotes rest-and-digest functions, counteracting the effects of the sympathetic system.

Sympathetic Systems

A division of the autonomic nervous system that prepares the body for stressful or emergency situations, often referred to as the "fight or flight" response.

Enteric Nervous System

A complex network of neurons that governs the function of the gastrointestinal(digestive) system, often considered a part of the autonomic nervous system, operating independently but also interacting with the sympathetic and parasympathetic systems.

Nervous system is only composed of…

Nervous tissue

Glial Cells

Supports, mitotically active; goes through cellular division, can grow and replace selves; Does not send signals.

Neuron Cells

Transmits signals allowing communication between body and brain; not mitotically active and cannot regenerate after injury.

Mylonation

The process of forming a myelin sheath around the axons of neurons, which increases the speed of signal transmission.

Oligodendrocytes

A type of glial cell in the central nervous system that produces myelin sheath around neuronal axons, aiding in signal transmission.

Ependymal Cells

Glial cells that line the ventricles of the brain and central canal of the spinal cord, involved in the production and circulation of cerebrospinal fluid.

Astrocytes

Star-shaped glial cells in the central nervous system that support neurons, maintain the blood-brain barrier, and regulate nutrient and ion balance.

Microglial Cells

A type of glial cell in the central nervous system that acts as the primary immune defense, responding to injury and disease by removing debris and pathogens. (modified WBC)

Mylon

A type of glial cell that insulates neuronal axons to enhance signal transmission and speed up electrical impulses.

How much of CNS is mylonated?

Approximately 50%

How much of PNS is mylonated?

About 95%

Satellite Cells

Glial cells in the peripheral nervous system that provide support and nutrients to neurons, and help regulate the environment around them.

Schwann Cells

Glial cells in the peripheral nervous system that produce myelin, insulating axons and aiding in the regeneration of damaged nerves.

Sensory Nurons

Neurons that transmit sensory information from the body's sensory receptors to the central nervous system. (unipolor)

Interneurons

Neurons that connect sensory and motor neurons within the central nervous system, facilitating communication and processing of information. (bipolor)

Motor Neurons

Neurons that transmit signals from the central nervous system to muscles and glands, enabling movement and response. (mulitpolor)

Synapses

Presynatic neuron transmits signals to a postsynaptic neuron through neurotransmitters, allowing communication between neurons.

Dendrites

Branch-like structures of neurons that receive signals from other neurons and transmit them to the cell body.

Soma

The cell body of a neuron that contains the nucleus and organelles, responsible for maintaining the cell's health and function.

Axon Hillock

The region of a neuron where the axon begins, connects cell body to (long) axon.

Axon

A long, slender projection of a neuron that conducts electrical impulses away from the cell body to other neurons or muscles.

Synaptic Knobs

The small swellings at the end of axons that release neurotransmitters into the synapse, facilitating communication between neurons.

Axodendritic Synapse

A type of synapse where an axon terminal connects to the dendrite of another neuron, allowing for communication between the two. (most common type of synapse in the nervous system)

Axosomatic Synapse

A type of synapse where an axon terminal connects directly to the cell body (soma) of another neuron, facilitating communication between the two.

Axoaxonomic Synapse

A type of synapse where an axon terminal connects to another axon, influencing the communication between neurons. (fastest)

Synaptic Cleft

The small gap between the axon terminal of one neuron and the dendrite or cell body of another neuron, where neurotransmitters are released to facilitate communication.

Selective Serotonin Uptake Inhibitors

A class of medications used primarily to treat depression and anxiety by increasing the levels of serotonin in the brain.

Multiple Sclerosis

A chronic autoimmune disease that affects the central nervous system, leading to the degeneration of myelin sheaths and causing various neurological symptoms.

Gray Matter

The darker tissue of the brain and spinal cord, primarily composed of neuronal cell bodies, dendrites, and unmyelinated axons.

White Matter

The lighter tissue of the brain and spinal cord, primarily composed of myelinated axons that facilitate communication between different brain regions.

Cerebrum

The largest part of the brain, responsible for higher brain functions such as thought, action, and sensory processing. It is divided into two hemispheres and further into lobes.

Diencephalon

The part of the brain located between the cerebrum and the brainstem, which includes structures such as the thalamus and hypothalamus, playing key roles in sensory and autonomic functions.

Midbrain

The upper part of the brainstem, involved in vision, hearing, motor control, sleep/wake cycles, and arousal.

Cerebellum

The part of the brain located under the cerebrum, responsible for coordination of voluntary movements, balance, and motor learning.

Brainstem

The posterior part of the brain that connects the cerebrum with the spinal cord, consisting of the midbrain, pons, and medulla oblongata, and responsible for regulating vital functions such as breathing, heart rate, and blood pressure.

Sinus

A cavity within a bone or tissue, often filled with air or fluid, that can also refer to channels for blood or lymph in the body.

Falx Cerebri

A sickle-shaped fold of dura mater that separates the two cerebral hemispheres in the brain.

Tentorium

Cerebellar tentorium that separates the cerebellum from the inferior portion of the occipital lobes.

Cerebral Spinal Fluid

A clear, colorless fluid that surrounds and protects the brain and spinal cord, providing cushioning and nutrient (and oxygen) delivery. Derived from filtered plasma and produced in the ventricles of the brain. Collects waste and takes to another sys. for disposal.

Lateral Ventricle

The largest of the brain's ventricles, located within each hemisphere, responsible for the production and circulation of cerebrospinal fluid.

Choroid Plexus

A network of cells in the ventricles of the brain that produces cerebrospinal fluid.

Third Ventricle

A narrow, fluid-filled cavity located between the two halves of the thalamus, involved in the circulation of cerebrospinal fluid.

Cerebral Aqueduct

A narrow channel connecting the third and fourth ventricles, allowing the flow of cerebrospinal fluid.

Fourth Ventricle

A cavity located between the brainstem and the cerebellum, it is involved in the circulation of cerebrospinal fluid and connects to the central canal of the spinal cord.

Caudate Nuclei

A pair of structures located near the lateral ventricles, part of the basal ganglia, involved in the regulation of movement and various cognitive functions.

Amygdaloid

nuclei, a set of almond-shaped structures located deep within the temporal lobes, involved in emotion regulation and processing of fear.

Association Tracts

bundles of nerve fibers that connect different regions of the brain, facilitating communication between them.

Commissural Tracts

bundles of nerve fibers that connect the two hemispheres of the brain, allowing communication between them.

Projection Tracts

bundles of nerve fibers that connect the cerebral cortex to lower brain regions and the spinal cord, facilitating communication between the brain and the rest of the body.

Insula

a region of the brain located deep within the lateral sulcus, involved in various functions including perception, emotion, and self-awareness.

Primary Motor Cortex

the region of the brain located in the frontal lobe, responsible for the planning and execution of voluntary movements.

Precentral Gyrus

the fold in the frontal lobe that contains the primary motor cortex, playing a crucial role in motor control.

Central Sulcus

the prominent groove that separates the frontal lobe from the parietal lobe, serving as a landmark for the location of the primary motor and somatosensory cortices.

Primary Somatosensory Cortex

the region of the brain located in the parietal lobe, responsible for processing sensory information from the body.

Visual Association Area

a region in the occipital lobe that integrates visual information and contributes to visual perception and recognition.

Visual Cortex

the part of the brain located in the occipital lobe that processes visual stimuli, including patterns, colors, and motion.

Wernickes Area

a region in the temporal lobe involved in the comprehension of language and speech.

Diencephleion

the part of the brain that includes structures such as the thalamus and hypothalamus, playing a crucial role in sensory and autonomic functions.

Thalamus

a structure within the diencephalon that acts as a relay station for sensory information, directing it to the appropriate areas of the cerebral cortex.

Pineal Gland

a small endocrine gland in the brain that produces melatonin, regulating sleep-wake cycles.

Epithalamus

a part of the diencephalon that includes the pineal gland and is involved in the regulation of circadian rhythms and emotional responses.

Hypothalamus

a region of the brain located below the thalamus that plays a crucial role in maintaining homeostasis by regulating body temperature, hunger, thirst, and circadian rhythms. It also controls the pituitary gland, influencing hormonal balance.

Paraventricular Nucleus

a cluster of neurons in the hypothalamus that is involved in the regulation of the autonomic nervous system and the release of hormones such as oxytocin and vasopressin.

Pre Optic Area

a region of the hypothalamus that plays a key role in thermoregulation and reproductive behaviors, influencing body temperature and hormonal responses.

Anterior Nucleus

a part of the hypothalamus involved in thermoregulation and the sleep-wake cycle, playing a role in the body's response to temperature changes.

Posterior Pituitary Gland

the part of the pituitary gland that stores and releases hormones produced by the hypothalamus, including oxytocin and vasopressin.

Anterior Pituitary Gland

the part of the pituitary gland that produces and secretes its own hormones, including growth hormone, prolactin, and adrenocorticotropic hormone.

Limbic System

a complex set of structures in the brain that includes the hippocampus, amygdala, and cingulate gyrus, involved in emotions, memory, and behavior.

Hippocampus

a critical region of the brain involved in the formation of new memories and spatial navigation.

Cerebral Peduncles

bundles of nerve fibers in the brainstem that connect the cerebrum to the brainstem and spinal cord, playing a key role in motor control.

Optic Chiasm

the X-shaped structure formed by the crossing of optic nerves from both eyes, essential for visual processing.

Infundibulum

a funnel-shaped structure that connects the hypothalamus to the pituitary gland, playing a crucial role in hormone regulation.

Pons

a structure in the brainstem that regulates breathing, communication between different parts of the brain, and sensations such as hearing, taste, and balance.

Medulla Oblongata

The lower half of the brainstem that controls vital functions such as heart rate, blood pressure, and breathing.

Olfactory Bulb

The brain structure responsible for processing smell information, located at the base of the frontal lobe; sensory nerve 1

Optic Nerve

The second cranial nerve responsible for transmitting visual information from the retina to the brain; sensory nerve

Oculomotor Nerve

The third cranial nerve that controls most of the eye's movements, as well as the constriction of the pupil and maintaining an open eyelid; motor nerve.

Trochlear Nerve

The fourth cranial nerve that innervates the superior oblique muscle, allowing for downward and lateral eye movement; motor nerve.

Trigeminal Nerve

The fifth cranial nerve responsible for sensation in the face and motor functions such as biting and chewing; mixed nerve.

Abducens Nerve

The sixth cranial nerve that controls the lateral rectus muscle, enabling outward eye movement; motor nerve.

Facial Nerve

The seventh cranial nerve that controls the muscles of facial expression and conveys taste sensations from the anterior two-thirds of the tongue; mixed nerve.

Vestibulocochlear Nerve

The eighth cranial nerve responsible for hearing and balance. It transmits sound information from the inner ear to the brain and helps maintain equilibrium; sensory nerve.

Glossopharyngeal Nerve

The ninth cranial nerve that plays a role in taste sensation from the posterior one-third of the tongue, as well as in swallowing and salivation; mixed nerve.