Brain and Cranial Nerves

These flashcards cover key terms and definitions related to the brain and cranial nerves, which are crucial for understanding concepts related to the central and peripheral nervous systems.

Cranial Nerves

12 pairs of nerves originating from the brain, part of the peripheral nervous system (PNS).

Central Nervous System (CNS)

Consists of the brain and spinal cord.

Peripheral Nervous System (PNS)

Consists of cranial nerves that leave the brain.

Olfactory Nerve (CN I)

Sensory nerve responsible for the sense of smell.

Optic Nerve (CN II)

Sensory nerve responsible for vision.

Oculomotor Nerve (CN III)

Motor nerve that controls eye movement and pupil size.

Trochlear Nerve (CN IV)

Motor nerve that innervates the superior oblique muscle of the eye.

Trigeminal Nerve (CN V)

Mixed nerve responsible for sensation in the face and control of jaw movement.

Abducens Nerve (CN VI)

Motor nerve that controls lateral eye movement.

Facial Nerve (CN VII)

Mixed nerve that controls facial expressions and taste sensations from the tongue.

Vestibulocochlear Nerve (CN VIII)

Sensory nerve involved in hearing and balance.

Glossopharyngeal Nerve (CN IX)

Mixed nerve that receives taste from the posterior tongue and controls muscles in the pharynx.

Vagus Nerve (CN X)

Mixed nerve that influences involuntary functions like heart rate and digestive tract.

Accessory Nerve (CN XI)

Motor nerve controlling neck and shoulder muscles.

Hypoglossal Nerve (CN XII)

Motor nerve that controls tongue movements.

Brain Development

Begins in the third week of pregnancy with a neural tube that can lead to defects if not closed.

Anencephaly

A neural tube defect resulting in substantial or complete absence of a brain.

Spina Bifida

A defect due to failure to close the caudal portion of the neural tube.

Cerebrum

The largest brain region responsible for complex intellectual functions.

Cerebellum

Coordinates and fine-tunes voluntary movements.

Brainstem

Connects the cerebrum and cerebellum to the spinal cord; includes the midbrain, pons, and medulla oblongata.

Diencephalon

Includes structures like the thalamus and hypothalamus, involved in sensory and autonomic functions.

Lobes of the Brain

Frontal, parietal, temporal, occipital, and insular lobes; each associated with specific functions.

Frontal Lobe

Responsible for motor control, decision making, and personality.

Parietal Lobe

Involved in general sensory functions and processing spatial information.

Temporal Lobe

Responsible for auditory processing and memory.

Occipital Lobe

Processes visual information.

Insula

Involved in taste perception and memory.

Gray Matter

Consists of neuron cell bodies and is found in the cerebral cortex and nuclei.

White Matter

Composed of myelinated axons organized in tracts within the brain.

Cerebral Cortex

The outer layer of the brain made up of gray matter.

Clinical Application: Hydrocephalus

Condition of excessive cerebrospinal fluid causing brain compression, often treated with shunts.

Blood-Brain Barrier (BBB)

Regulates substances entering the brain's interstitial fluid to protect neurons.

Limbic System

Involved in emotion processing and memory formation.

Amygdala

Part of the limbic system, important for emotional memory and fear response.

Hippocampus

Plays a critical role in long-term memory formation.

Cerebrospinal Fluid (CSF)

Clear fluid surrounding the CNS providing protection and stability.

Motor Speech Area (Broca's Area)

Located in the frontal lobe, involved in the production of speech.

Wernicke's Area

Located in the left hemisphere, responsible for language comprehension.

Aphasia

Difficulty in understanding or producing speech, often resulting from brain damage.

Apraxia

Motor disorder affecting the ability to execute learned movements.

Clinical View: Alzheimer's Disease

Leading cause of dementia characterized by progressive memory loss and cognitive decline.

Clinical View: Epilepsy

Neurological disorder involving recurrent seizures due to uncontrolled neuronal firing.

Cerebrovascular Accident (CVA)

Also known as a stroke, a medical condition where blood supply to the brain is interrupted.