Ch 20 Study Guide Version

What is the primary function of the Motor Area (Primary Motor Cortex)?

Generates voluntary somatic movements by sending descending signals through corticospinal, corticobulbar tracts.

What clinical sign is associated with an Upper Motor Neuron (UMN) lesion in the motor area?

Hyperreflexia, test with Babinski sign.

What type of information does the Primary Somatosensory Cortex receive?

Proprioception, touch, pain, temperature from the contralateral body via thalamic relay.

What is stereognosis, a function involving the Sensory Area and association cortex?

Object recognition by touch.

What is the primary role of the Association Areas of the brain?

Integrate incoming data with memory, emotion, reasoning to produce context, comprehension, and planning.

What function is primarily associated with the left cerebral hemisphere?

Language and analytic functions.

What is the main function of the Cerebellum?

Coordinates timing, force, and precision of skeletal muscle contraction; adjusts postural tone.

What symptoms typically result from a Cerebellar injury?

Ataxia (wide-based gait), intention tremor, dysmetria, and nystagmus.

What is the Thalamus often referred to as, regarding its role for the cerebral cortex?

"Gateway to cortex," as it filters, sorts, and amplifies sensory (except olfaction) and motor signals.

What are two key homeostatic functions regulated by the Hypothalamus?

Temperature set-point, hunger, thirst, circadian rhythm, and autonomic/endocrine output (e.g., via pituitary).

Which vital autonomic centers are housed in the Medulla Oblongata?

Cardiovascular (BP regulation), respiratory rhythm, emesis, coughing, and swallowing.

What is the decussation of pyramids?

Approximately 90% of corticospinal fibers cross to the contralateral side in the Medulla Oblongata, leading to contralateral control.

What is the primary function of the Limbic System?

Governs emotion, motivation, and memory consolidation.

What structure is the largest commissural fiber bundle linking the left and right cerebral hemispheres?

Corpus Callosum.

Where is Cerebrospinal Fluid (CSF) primarily produced?

By the choroid plexus (ependymal cells + fenestrated capillaries) mainly in the lateral ventricles.

What type of nerve fibers are carried by the Dorsal (Posterior) Root of a spinal nerve?

Somatic and visceral sensory (afferent) fibers from the periphery to the spinal cord.

Which type of neurons are preferentially destroyed by Poliomyelitis?

Anterior horn Lower Motor Neurons (LMNs).

What is the primary pathological cause of Parkinson Disease?

Degeneration of dopaminergic neurons in the substantia nigra pars compacta.

What are the two main pathological hallmarks of Alzheimer Disease?

β-amyloid plaques and neurofibrillary tangles (hyper-phosphorylated τ).

What does the F.A.S.T. mnemonic stand for in assessing a Cerebrovascular Accident (Stroke)?

Face droop, Arm weakness, Speech difficulty, Time to call 911.