Biology 30S Unit Test Review

Nervous System and Excretion Unit Review

Short Answer

1. What is trepanation? Precisely cut holes in the parietal, occipital, or frontal regions, spanning a few centimeters to approximately 10 centimeters long. Trepanation was used to cure headaches or head injuries, used for religious reasons that involved tribal rituals and superstitions, including the release of evil spirits.

2. What is phrenology? The pseudoscience that suggested that bumps and depressions of the skull corresponded to personality traits.

3. What is an everyday example of pseudoscience? People only use 10% of their brains.

4. How is the nervous system organized? (Draw a concept map). The nervous system is broken up into the central and peripheral nervous system. The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up fo the somatic and autonomic nervous system. The somatic nervous system has motor and sensory branches. The autonomic nervous system has the parasympathetic and sympathetic divisions.

5. What are the three structures that comprise the limbic system? Hippocampus, hypothalamus, and amygdala.

6. What are the three structures that comprise the brainstem? Medulla oblongata, pons, and midbrain.

7. What is the difference between a glial cell and a neuron? Glial cells provide nourishment, maintain homeostasis, and form myelin. Neurons are specialized cells that help you gather information about your environment, interpret the information, and react to it.

8. Draw and label a neuron. (This diagram is missing the Nodes of Ranvier).

Biology 30S Unit Test Review

9. A afferent (sensory) neuron carries signals to the central nervous system, whereas an

efferent (motor) neuron carries information to the body.

10. True or false: interneurons are only found in the central nervous system.

11. Describe a neuron at rest. Include sodium ions, potassium ions, and the sodium/potassium pump.A neuron at rest is not conducting a nerve impulse. There are more sodium ions outside the cell than inside the cell. There are more potassium ions inside the cell than outside the cell. There are many negatively charged proteins inside the cell. The sodium/potassium pump actively transports three sodium outside of the cell for every two potassium it pumps into the cell. This maintains an unequal distribution.

12. Draw a graph showing an action potential and explain all the events that occur.

Depolarization: sodium channels open and sodium ions move inside of the cell, making the cell more positive. Repolarization: sodium channels close, potassium channels open. Potassium ions move outside of the cell, making the neuron more negative.

Biology 30S Unit Test Review

Hyperpolarization: potassium channels take a long time to close, and more potassium ions leave, overshooting resting membrane potential. Resting potential: sodium/potassium pumps pump 3 sodium ions out of the cell and two potassium ions into the cell, bringing back resting membrane potential.

13. Can an action potential increase or decrease in strength? No. It is all-or-nothing.

14. What is the function of myelin? To increase the speed of nerve impulse transmission down the axon of a neuron.

15. After an action potential has propagated down the full length of an axon, it reaches the axon terminal. Describe the events that occur at the synapse that allow two neurons to communicate with one another (synaptic transmission).

16. Describe three differences between the nervous system and the endocrine system. Nervous system: fast, localized communication, and uses neurotransmitters. Endocrine system: slow, bloodstream, uses hormones.

17. What is the difference between the sympathetic and parasympathetic divisions of the autonomic nervous system?Sympathetic NS: fight-or-flight; uses norepinephrine; when stimulated, heart rate increases, respiration rate increases, pupils dilate, bladder relaxes (releases contents), salivary glands and intestines are inhibited, liver releases glucose

8. Reuptake of neurotransmitter, or it is destroyed in the synapse

Biology 30S Unit Test Review

Parasympathetic NS: rest-and-digest; uses acetylcholine; when stimulated, heart rate decreases, respiration rate decreases, pupils constrict, bladder contracts, salivary glands and intestines stimulated, glucose is stored rather than released

18. What are the four organs responsible for excretion? Lungs, liver, kidneys, and skin

19. Draw the human urinary system. Include: kidneys, ureters, urinary bladder, and urethra.

20. Draw a kidney and label: renal medulla, renal cortex, renal pelvis, renal capsule, and ureter.

Biology 30S Unit Test Review

21. Describe how urine is formed in a nephron. Include: filtration, reabsorption, and secretion. Include definitions of each process, which ions are involved, and where each process occurs.

Filtration: occurs in the glomerulus and Bowman’s capsule. Blood flows through the glomerulus from the afferent arteriole and salt, water, waste, and nutrients filter into Bowman’s capsule.

Reabsorption: salt, water, and nutrients are taken from the proximal convoluted tubule and put back into the blood. Water is also reabsorbed from the descending loop of Henle as well as the collecting duct.

Secretion: hydrogen ions, creatinine, and drugs are put from the blood into the distal convoluted tubule of the nephron.

22. If you are dehydrated, explain how the kidneys work to retain water in your body. A signal is sent to the pituitary gland to secrete anti-diuretic hormone. ADH goes through the blood to the kidneys and increases the permeability of nephrons to water.

Biology 30S Unit Test Review

Water flows out of the nephron into the blood, making the urine more concentrated and retaining water in the body.

23. If your blood pressure is too low, explain how the kidneys work to increase your blood pressure back to its normal level. The kidneys secrete aldosterone. Aldosterone increases sodium reabsorption. Water flows by osmosis into the blood from the nephrons, resulting in higher blood volume. Greater blood volume results in higher blood pressure.

24. Draw and label a nephron. Include: glomerulus, Bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct, renal artery, renal vein, efferent arteriole, afferent arteriole, and peritubular capillaries.

Functions

State a function for each term below

1. Frontal lobes – complex planning2. Parietal lobes – pain and touch sensation3. Temporal lobes - speech4. Occipital lobes - vision5. Cerebellum - balance6. Corpus callosum – connect the right and left cerebral hemispheres7. Thalamus – sensory relay station

Biology 30S Unit Test Review

8. Pituitary gland – secrete and store hormones9. Midbrain – direct attention to visual and auditory stimuli10. Pons – sleep and arousal11. Medulla oblongata – heart rate12. Hippocampus – memory 13. Amygdala - anger14. Hypothalamus - homeostasis15. Somatosensory cortex – pain and touch sensation16. Broca’s area – speech production17. Wernicke’s area – understanding of speech 18. Serotonin – mood, sleep, appetite; too much = anxiety, too little = depression19. Dopamine – movement, attention, learning; too much = schizophrenia, too little = depression, Parkinson’s disease20. Endorphins – pain relief and feelings of pleasure and contentedness; too much = fight or flight response; too little = anxiety, sensitivity to pain