THIS OR THAT

Chapter 2: How Does Biology Influence Our Behavior?

Figure 2.9 The Human Hindbrain, Midbrain, and Forebrain The human hindbrain (shown in purple) governs basic and life-sustaining functions. The midbrain (shown in red) connects the lower structures of the hindbrain with the higher structures of the forebrain. The forebrain (shown in tan) governs complex processes such as cognition, sensory processing, and the planning and execution of behaviors.

The Brain and Spine: The Central Nervous System Structures composed mostly of neurons and glia cells Hindbrain Most primitive part of brain; brainstem Forebrain Regulates higher-order processes; largest part of brain Midbrain Regulates functioning between basic and higher level functions « Technology Tip This Brain Explorer site has interactive information on the brain and its function: http://www.brainexplorer.org/index.html This Comparative Mammalian Brain Collections site has pictures of brains from a vast number of mammals: http://brainmuseum.org/ « Discussion Tip Show some of the slides from the Comparative Mammalian Brain Collection (http://brainmuseum.org/) and discuss with students the cognitive abilities of the different species and how these abilities correlate with the development of the species’ cortex. Do more intelligent species have more evolved cortical regions?

Figure 2.10 The Brain and Its Structures This figure shows the cortex and the subcortical structures of the brain.

Figure 2.11 The Cerebral Hemispheres The cerebrum is divided into the right and left hemispheres. The outside covering of the hemispheres, the cortex, is where the higher-order processing in the brain takes place.

Figure 2.13 Cortex of a Human Brain and a Cat Brain Note how much more convoluted or folded the human brain is compared to the cat brain. Many of the higher order processes that humans engage in, such as language and thinking, are processed in the cortex.

Figure 2.14 The Human Brain (a) The lobes of the brain. (b) The language centers of the brain are found in the left hemisphere. Wernicke’s area in the left temporal lobe allows us to comprehend speech. Broca’s area in the left frontal lobe allows us to produce speech. From Gaudin and Jones, Human Anatomy and Physiology, Fig 12.2, p. 294. Reprinted by permission of the author.

The Endocrine System: Hormones and Behavior Nervous system is regulated by electrochemical system; fast communication Endocrine system is regulated by release of hormones; slower communication since sent through blood stream Pituitary gland regulates hormone release in other endocrine glands Heavily influences sexual activity, eating, sleeping, physiological arousal, and growth « Discussion Tip Ask students to share stories of times when they were angry or afraid, and have them describe their physiological sensations during these events. Then explain their experiences in terms of the functioning of the endocrine and sympathetic nervous systems. Ask students to share stories of times when they were nervous or afraid, such as before giving a speech or on a first date. Then have them describe how they felt after these events. Did they experience fatigue or relaxation as their parasympathetic system rebounded?

Figure 2.17 Major Endocrine Glands of the Body The glands of the endocrine system make and release hormones into the bloodstream. From Starr & McMillan, Human Biology, 2/E, p. 271, © 1997 Wadsworth. Art by Kevin Somerville.

Glands of Endocrine System Ovaries and testes – sexuality and reproduction Estrogen (female) and androgens (male) Adrenal – arousal and sexual behavior Adrenal medulla Activates during stress, releases adrenaline Adrenal cortex Produces adrenal androgens, related to sexual characteristics, physiological functioning Interacts with immune system to fight disease