CH 8 Part 1- Nervous System Physiology and Pathology

Comprehensive vocabulary flashcards covering the anatomy, physiology, and pathology of the nervous system based on lecture notes.

Nervous System

The system responsible for controlling body coordination and activities by detecting stimuli, processing information, and initiating responses through electrical and chemical signaling.

Sensory Input

Signals received by sensory receptors that detect changes (stimuli) inside or outside the body and transmit information via afferent neurons to the CNS.

Integration

The process occurring in the brain and spinal cord where the central nervous system interprets sensory information, involving conscious perception, memory, and decision making.

Motor Output

Commands sent from the CNS through efferent neurons (motor neurons) resulting in muscle contraction or glandular secretion.

Central Nervous System (CNS)

The division of the nervous system consisting of the brain and the spinal cord, serving as the site of information processing.

Peripheral Nervous System (PNS)

The division including cranial nerves, spinal nerves, and ganglia that connects the CNS to the rest of the body.

Somatic Nervous System

A division of the PNS that controls voluntary movement and conscious sensation, primarily targeting skeletal muscles.

Autonomic Nervous System

A division of the PNS that controls involuntary body functions and targets cardiac muscle, smooth muscle, and glands to maintain homeostasis.

Sympathetic Nervous System

The part of the autonomic nervous system responsible for the 'fight or flight' response, preparing the body for stress and activity.

Parasympathetic Nervous System

The part of the autonomic nervous system responsible for 'rest and digestion,' promoting energy conservation.

Neuron

The basic unit of the nervous system, designed for rapid electrical communication via action potentials.

Action Potential

A rapid electrical impulse that travels along a nerve fiber.

Neurotransmitters

Chemical messengers that transmit signals across synapses between neurons or between neurons and other cells.

Dendrites

The parts of a neuron that receive incoming signals.

Axon

The part of a neuron that conducts impulses away from the cell body (soma) rapidly and efficiently.

Myelin Sheath

A fatty insulation covering that surrounds axons, increasing the speed and efficiency of impulse conduction while providing protection.

Cerebrum

The largest part of the brain, divided into right and left hemispheres by the corpus callosum, responsible for conscious activities.

Frontal Lobe

The lobe of the cerebrum involved in voluntary motor control, decision making, personality, and speech production.

Parietal Lobe

The lobe responsible for sensory perception (touch, pain, temperature), spatial awareness, and sensory integration.

Temporal Lobe

The lobe involved with hearing, memory, and language comprehension.

Diencephalon

A centrally located brain region connecting the cerebrum to the brainstem, containing the thalamus, hypothalamus, and epithalamus.

Thalamus

A structure in the diencephalon that directs sensory impulses to the appropriate areas of the cortex and is involved in motor signal integration.

Hypothalamus

A structure that maintains homeostasis, regulates the autonomic nervous system, and controls hormone secretion from the pituitary gland.

Epithalamus

A region including the pineal gland that secretes melatonin and regulates circadian rhythms.

Brainstem

The part of the brain connecting to the spinal cord, consisting of the midbrain, pons, and medulla oblongata to control vital life functions.

Medulla Oblongata

The part of the brainstem that regulates heart rate, blood pressure, breathing, and reflexes like coughing or sneezing.

Cerebellum

Located posteriorly and inferior to the occipital lobes; it coordinates voluntary movements such as balance, posture, and muscle tone.

Pituitary Gland

A 'master gland' located in the sella turcica of the sphenoid bone that regulates growth, metabolism, and other endocrine glands under hypothalamic control.

Meninges

Three connective tissue layers (dura mater, arachnoid mater, and pia mater) that surround and protect the brain and spinal cord.

Cerebrospinal Fluid (CSF)

A fluid produced by the choroid plexus that cushions the CNS, delivers nutrients, and removes waste.

Circle of Willis

A vascular structure at the base of the brain that provides collateral circulation.

Conus Medullaris

The tapered distal end of the spinal cord, ending at approximately $L1$ or $L2$ in adults.

Cauda Equina

A collection of nerve roots extending from the end of the spinal cord that resembles a 'horse's tail.'

Meningitis

Acute inflammation of the meninges, specifically the pia and arachnoid mater, often presenting with a triad of fever, stiff neck, and altered mental status.

Lumbar Puncture

The 'gold standard' procedure for diagnosing meningitis by collecting CSF, typically performed between $L3-L4$ or $L4-L5$.

Encephalitis

Inflammation of the brain parenchyma (tissue), most commonly caused by the herpes simplex virus (HSV-1).

Brain Abscess

A localized collection of pus within the brain, most commonly caused by a contiguous spread of infection from sinusitis or otitis media.

Subdural Empyema

An emergency collection of pus between the dura and arachnoid mater that spreads quickly due to a lack of anatomical barriers.

Osteomyelitis of the Skull

A serious infection of the cranial bones, often appearing as 'moth-eaten' lytic lesions on imaging.

Gliomas

A group of primary CNS tumors arising from glial cells, including astrocytomas, oligodendrogliomas, and ependymomas.

Medulloblastoma

A highly malignant primary brain tumor in children, typically occurring in the posterior fossa and showing a tendency for 'drop metastasis' through the CSF.

Meningioma

A primary, usually benign CNS tumor that arises from the meninges and occurs more commonly in elderly patients.

Acoustic Neuroma

A benign, slow-growing tumor arising from the Schwann cells of the vestibular portion of cranial nerve VIII ($CN VIII$).

Pituitary Adenoma

A common benign tumor of the anterior pituitary gland that can be 'functioning' (secreting hormones) or 'nonfunctioning.'

Prolactinoma

The most common functioning pituitary tumor, which secretes excess prolactin and cause galactorrhea or infertility.

Acromegaly

A condition in adults caused by excess growth hormone, characterized by enlarged hands, feet, and coarse facial features.

Cushing's Disease

A condition caused by an ACTH-secreting pituitary adenoma, presenting with physical features like moon face, buffalo hump, and truncal obesity.

Basilar Skull Fracture

A fracture at the base of the skull characterized by 'Battle sign' (bruising behind the ear) or 'raccoon eyes' (periorbital ecchymosis).

Epidural Hematoma

An arterial bleed (often associated with skull fractures) between the skull and dura mater, appearing as a lens-shaped mass on a CT scan.

Subdural Hematoma

A collection of venous blood between the dura and arachnoid mater, appearing as a crescent-shaped mass on imaging.

Cerebral Contusion

A traumatic brain injury consisting of a 'bruise' of the brain tissue, most commonly occurring in the frontal and temporal lobes.

Subarachnoid Hematoma

A neurological emergency involving bleeding into the subarachnoid space, often caused by a ruptured berry aneurysm and described as the 'worst headache of life.'

Sentinel Headache

A sudden, severe warning headache occurring days to weeks before a major subarachnoid hemorrhage.