BIO 123 Study Guide - Midterm Guide: Nervous Tissue, Negative Feedback, Fibroblast
Document Summary
Structures and functions are closely linked at every level of organization. Relatively few cells separated by intercellular substance. Nervous tissue neurons : elongated cells specialized for transmitting impulses. Balanced internal environment, homeostatic mechanisms, control processes that maintain conditions. Deviation from steady state causes changes that intensify the changes. Example: loss of blood -- blood pressure begins to decrease, less blood circulates to his heart, heart function declines, cardiac output decreases. Process of maintaining body temperature within certain limits -- despite surrounding changes. Body temperature depends on temperature of environment. Use behavioral strategies to adjust body temperature. Very little energy used to maintain metabolic rate. High metabolic rate, constant body temperature, active. Nervous and hormone system regulate temperature in humans -- homeostasis on both ends. Feathers and hair help to maintain constant body temperature. Skin and structures that develop from it. Mammalian skin includes: hair, skin, claws, nails, sweat glands. Stratum corneum: most superficial layer, dead cells filled with keratin.
