Chapter 11: Control: The Nervous and Endocrine Systems

Question 1

nervous system

Answer 1

-detects and interprets info from the surrounding environment

Question 2

endocrine system

Answer 2

-controls body functions through the use of chemical messengers called hormones

Question 3

nerve cells

Answer 3

• AKA neurons
• highly specialized cells that carry impulses between body parts
• consists of cell body, dendrites, axon terminal, nucleus, myelin sheath

Question 4

resting state of neuron

Answer 4

-polarized (inside of neuron is negatively charged)

Question 5

resting membrane potential

Answer 5

• around -70 mV

- RMP is set up and maintained by 2 membrane proteins (Na+/K+ ATPase and the K+ leak channel)

Question 6

sodium-potassium pump (Na+/K+ ATPase)

Answer 6

-protein channel that uses one molecule of ATP to pump 3 Na+ out of the cell and 2 K+ into the cell

Question 7

leak channels

Answer 7

-potassium channels that are always open and will always allow K+ to leak out of the cell according to its gradient, allowing for a negative charge in the membrane

Question 8

action potential

Answer 8

• once the threshold (-50mV) is reached with a small influx of sodium, voltage-gated sodium and potassium channels open
• sodium enters the cell with concentration gradient, depolarizing the cell further (until 35 mV) before the sodium channels shut
• voltage-gated potassium channels open, allowing potassium to exit with the concentration gradient, repolarizing the cell and reaching -90mV before closing
• membrane proteins return to the RMP

Question 9

Schwann cells

Answer 9

-make up the myelin sheath (speeds rate at which action potential can travel down the axon)

Question 10

nodes of Ranvier

Answer 10

-spaces between the Schwann cells that can fire an action potential

Question 11

saltatory conduction

Answer 11

-the jumping of the axon potential from node to node that increases the traveling of the signal

Question 12

refractory period

Answer 12

• membrane is unable to fire a second action potential until resting potential is set
• ensures that signal travels down one direction

Question 13

synapse

Answer 13

-neuron-to-neuron or neuron-to-organ junction that releases neutrosmitter (chemical such as Acetylcholine that can lead to alzheimers disease) to pass the impulse

Question 14

synaptic cleft

Answer 14

• small gap between neurons
• neurotransmitters are released into synapse by exocytosis where they diffuse across the synaptic cleft and bind to the receptors on the dendrites
• then usually causes the opening of sodium ion channels so sodium flows into the cells, allowing for the threshold to be reached

Question 15

effects of neurotransmitters

Answer 15

-some cause the cell to be stimulated (reach threshold), inhibited (away from threshold)

Question 16

summation

Answer 16

-sum of stimulatory and inhibitory input

Question 17

CNS

Answer 17

-brain and spinal cord that process and integrate info, and then sends decisions to body through PNS

Question 18

interneurons

Answer 18

-part of the CNS that connect sensory and motor neurons

Question 19

sensory neurons

Answer 19

-sends info to the CNS from sensory organs

Question 20

motor neurons

Answer 20

-neurons involved in sending info from the CNS to the organs of the body

Question 21

frequency of action potential

Answer 21

-determines how often the threshold is reached, and therefore how strong the stimulus is

Question 22

spinal cord

Answer 22

-primitive, reflex actions

Question 23

cerebrum

Answer 23

-conscious mind (movement, speech, problem solving, senses)

Question 24

cerebellum

Answer 24

-coordinates movement and balance

Question 25

medulla

Answer 25

-involuntary actions (breathing, blood pressure regulation)

Question 26

hypothalamus

Answer 26

- maintains homeostasis - monitors hormone levels, temperature, etc. - controls pituitary gland

Question 27

somatic

Answer 27

- voluntary movement of skeletal muscles | - when acetylcholine binds to receptors on the muscle, this causes the muscle to depolarize and contract

Question 28

autonomic

Answer 28

- involuntary system - sympathetic: fight-or-flight (increases blood pressure, heartrate, breath rate, blood flows toward skeletal muscles)--> involed with noepinephrine - parasympathetic: rest-and-digest (mostly uses acetylcholine)

Question 29

ganglia

Answer 29

- clusters of nerve cell bodies along the nerve cord - neurons branch from - present in arthropods (insects) and annelids (worms)

Question 30

endocrine glands

Answer 30

-secrete hormones that can only affect organs with a receptor for that hormone

Question 31

peptide hormones

Answer 31

- amino acid-based - bind to receptors outside the cell, quickly turning existing enzymes in the cell on or off - insulin, prolactin, glucagon

Question 32

steroid hormones

Answer 32

- cholesterol-based - bind to receptors inside the cell (intracellular) - bind to DNA and change which genes get transcribed - estrogen, testosterone

Question 33

pituitary gland

Answer 33

- master regulatory gland because its hormones control other endocrine glands - controlled by the hypothalamus - has 2 lobes

Question 34

anterior pituitary gland

Answer 34

- growth hormone (GH) - thyroid stimulating hormone (TSH) - adrenocorticotropic hormone (ACTH) - follicile stimulating hormone (FSH) - luteinizing hormone (LH) - prolactin - for every hormone released by APG, there is a corresponding releasing hormone from the hypothalamus

Question 35

growth hormone (GH)

Answer 35

- target: all tissues and organs - important in children - in adults, stimulates the cell-turnover rate

Question 36

thyroid stimulating hormone (TSH)

Answer 36

-stimulates the thyroid gland to secrete thyroid hormones

Question 37

adrenocorticotropic hormone (ACTH)

Answer 37

-stimulates adrenal cortex (outer layer of the adrenal gland) to secrete its hormones

Question 38

follicile stimulating hormone (FSH)

Answer 38

- target: gonads - causes ova to mature and release estrogen - cases sperm to be produced

Question 39

luteinizing hormone (LH)

Answer 39

- target: gonad - stimulates ovaries, causes development of a corpus luteum - stimulates testes to produce testoterone

Question 40

prolactin

Answer 40

- released after childbirth | - stimulates mammary glands to produce breast milk

Question 41

posterior pituitary gland

Answer 41

- oxytocin: causes uterus to contract during childbirth, causes the mammary glands to release breast milk during feeding - antidiuretic hormone (ADH): causes kidneys to retain water (AKA vasopressin) - oxytocin and ADH are made in hypothalamus and released by an action potential

Question 42

thyroid gland

Answer 42

- secretes 2 hormones - thyroxine (thyroid hormone): affects most of the body's cells by increasing the rate of metabolism - calcitonin: activates special cells in bone that remove calcium from the blood and use it to build new bone (reduce blood calcium levels)

Question 43

hypothyroidism

Answer 43

- lower than normal levels of thryroxine - don't have enough iodine, then not enough thyroxine bc thyroxine contains iron - causes low metabolic rate

Question 44

hyperthyroidism

Answer 44

- overproduction of thyroxine | - produces higher than normal metabolic rate accompanied with weight loss and fast heart rate

Question 45

parathyroid glands

Answer 45

- 4 glands that are found on the back of the thyroid gland - secretes parathyroid hormone/parathormone (activates special cells inthe bone that dissolve the bone to release calcium into the blood)

Question 46

calcium

Answer 46

-functions in nerve impulse conduction, heart contraction, and blood clotting

Question 47

adrenal glands

Answer 47

- located on kidneys | - adrenal medulla and adrenal cortex

Question 48

adrenal medulla

Answer 48

- secretes epinephrine (adreneline) and norepinephrine (noradrenaline) - both hormones can bind to the same receptors and have the same effects on organs - epinephrine and norepinephrine from the adrenal medulla increase and prolong the effects of the Sympathetic NS

Question 49

adrenal cortex

Answer 49

-secretes 3 types of steroids: glucocorticoids, mineralocorticoids, and sex steroids

Question 50

glucocorticoids

Answer 50

- target: liver - cause production of glucose from fats and proteins to release new glucose into the blood (known as gluconeogenesis) - target: body cells - cause use of fats for fuel instead of glucose, causing an increase in blood glucose levels and increased body metabolism - strong anti-inflammatory agents - primary ex: cortisol

Question 51

mineralocortocoids

Answer 51

- target: kidney - primary ex: aldosterone (causes the retention of sodium in the kidneys) - the removal of sodium from the urine causes the removal of H2O, and therefore increases blood volume and pressure

Question 52

sex steroids

Answer 52

-produced by adrenal cortex, but mainly from the gonads

Question 53

pancreas

Answer 53

- secretes hormones and digestive enzymes | - secretes insulin and glucagon

Question 54

Islets of Langerhans

Answer 54

- cells in pancreas that produce insulin and glucagon | - AKA islet cells

Question 55

insulin

Answer 55

- secreted when glucose levels are high - affects all cells in the body, allowing for cells to take in glucose so they can use it in cellular repsiration - stimulates the liver to store glucose as glycogen - blood glucose levels decrease

Question 56

glucagon

Answer 56

- released when blood glucose levels are low - targets liver - causes liver to break down glycogen (stored glucose) and release free glucose into the blood (called glycogenolysis) - blood glucose levels increase

Question 57

gonads

Answer 57

- produce gametes and secrete hormones (sex steroids) - testes and ovaries - male sex steroid: androgen (primary type is testosterone) - female sex steroid: estrogens (most common is estradiol) and progesterone - estrogen: stimulates growth of uterin lining in menstrual cycle, progesterone maintains the lining in the second half