Human Anatomy Essay

2. Discuss the two divisions of the ANS.

1. Sympathetic Division – concerned with increasing alertness, metabolic rate, & muscular abilities A. prepares the body for heightened levels of somatic activity B. when fully activated, produces what is known as the “fight or flight” response C. readies the body for a crisis that may require sudden, intense physical activity D. elevates muscle tone, blood pressure, heart rate, breathing rate, and depth of respiration E. mobilizes energy reserves F. produces a feeling of energy and euphoria, often associated with a disregard for danger and a temporary insensitivity to painful stimuli

2. Parasympathetic Division – concerned with reducing metabolic rate & promoting visceral activities such as digestion A. promotes decreased metabolic rate B. decreases heart rate and blood pressure C. increases secretion by salivary and digestive glands D. increases motility and blood flow in the digestive tract E. stimulates urination and defecation F. sexual arousal and the stimulation of sexual glands in both sexes

Characteristic Sympathetic Parasympathetic

When functioning emergencies normal/everyday

Digestive system inhibits/slows down promotes

Pupil dilates constricts

Heartbeat accelerates retards

Breathing rate increases retards

Neurotransmitter norepinephrine acetylcholine

3. What are “higher-order functions?” Higher-order functions share three characteristics:

1. Cerebral cortex is required for their performance, and they involve complex interactions among areas of the cortex and between the cerebral cortex and other areas of the brain.
2. Involve both conscious and unconscious information processing.
3. Not part of the programmed “wiring” of the brain subject to modification and adjustment over time.

Memory and learning are two examples of higher-order functions.

4. Distinguish between two levels of sleep.

1. Deep sleep A. also called slow wave or non-REM sleep B. entire body relaxes C. cerebral cortex activity is at a minimum D. heart rate, blood pressure, respiratory rate, & energy utilization decline by up to 30% 2. Rapid eye movement (REM) sleep A. active dreaming occurs B. although EEG resembles that of the awake state, you become even less receptive to outside stimuli than in deep sleepmuscle tone decreases markedly C. intense inhibition of somatic motor neurons prevents you from physically producing the responses you envision while dreaming D. neurons controlling eye muscles escape this inhibitory influence, and eyes move rapidly (hence the name, REM) as dream events unfold

Periods of REM and deep sleep alternate throughout the night, beginning with a period of deep sleep that lasts about 1.5 hours. REM periods initially average about 5 minutes in length, but gradually increase to about 20 minutes over an 8-hour night. Each night we probably spend less than 2 hours dreaming, but variation among individuals is significant. Children devote more time to REM than do adults, and extremely tired individuals have very short and infrequent REMs.

The four electrical patterns revealed by EEGsBRAIN WAVES

5. How does brain chemistry affect behavior?

Changes in the normal balance between two or more neurotransmitters can profoundly affect brain function. Examples:

1. Interplay between populations of

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