Human Physiology Derrickson 2026 A GUARANTEED

Derrickson Human Physiology 2026 Study Guide | Expert-Verified Solutions Anatomy - answer - the study of the parts of an organism physiology - answer - the study of how those parts function homeostasis - answer - the relative constancy of the internal environment in the face of a fluctuating external environment Physiology can be defined as the study of? - answer - homeostasis what are the two primary methods of maintainging homeostasis in the human body? - answer - positive and negative feedback Negative feedback - answer - aimed at maintaining both short term and long term homeostasis positive feedback - answer - aimed at maintaining long term homeostasis Negative feedback control examples - answer - -temperature -O2, CO2, glucose, and water concentrations -NA+, K+, Ca++, Cl-, and H+ ion concentrations -levels of hormones, receptors, cholestrol; body weight -levels of transcription factors and gene expression -rates of cell division and cell death -erythrocyte and leukocyte numbers; iron concentration -blood pressure, lymph flow, stomach acidity -muscle lengths; rhodospin Positive Feedback Control Examples - answer - -contractions during labor -immune response -blood clotting -ovulation -action potential in nerve cells how is physiology studied? - answer - with the scientific method and Drug development steps - answer - 1. in vitro (cells cultured outside the body) 2. in vivo (cells cultured in the body) 3. animal testing 4. Phase I clinical trials (tested on healthy humans) 5. Phase II clinical trials (tested on target population) 6. Phase III clinical trials (maximize range of subjects and conditions) 7. Phase IV clinical trials (other potential uses) 4 types of human tissues - answer - -epithelial -connective -muscle -nervous Muscle Tissue - answer - generate mechanical activities that produce force and movement -heart, limb, intestines, uterus Nerve Tissue - answer - Initiate and conduct electrical impulses Epithelial Tissue - answer - Selectively secrete and absorb ions and organic molecules, membranes, & glands -intestines, salivary glands Connective tissue - answer - connect, anchor, and support structures of the body -cartilage, blood, bone, adipose Elements - answer - the basic building blocks of molecules What makes up the central nucleus of the atom? - answer - protons and neutrons Protons - answer - -positively charged -weigh 1 Dalton Neutron - answer - -neutral charge -weigh 1 Dalton Electrons - answer - -negatively charged -weigh ~1/2000th of a Dalton What happens when you change the number of PROTONS in an atom? - answer - it changes the element and its mass What happens when you change the number of NEUTRONS in an atom? - answer - produces an isotope of the same element that has a different mass What happens when you change the number of ELECTRONS in an atom? - answer - creates an ion of the atom without changing its mass What 4 elements make up 99% of the body? - answer - Carbon C Oxygen O Hydrogen H Nitrogen N What are the 3 primary chemical bonds that hold the body together? - answer - -Covalent -Ionic -Hydrogen Covalent bond - answer - when atoms share one or more pairs of electrons. Increasing the number of pairs increases the strength. Single covalent bond - answer - if atoms share one pair of electrons Double covalent bond - answer - if atoms share two pairs of electrons Triple covalent bond - answer - if atoms share three pairs of electrons Ionic bonds - answer - a strongly electronegative atom "steals" an electron from a weakly electronegative atom to create a negative charge on one atom and a positive charge on the other. They then attract each other and form a bond. Hydrogen Bonds - answer - when there's an electrical attraction between the H atom in a polar bond with a strongly electronegative atom (O, N, Cl) in polar bond of another molecule (or the same molecule) What is the most common molecule in the body? - answer - water what makes up 60% of the body? - answe