Hormones
1191713092 | Hormone | Signal that is secreted into extracellular fluid, carried by circulatory system and communicates regulatory messages | 0 | |
1191713093 | Hormones vs. other chemical regulators | Hormones elicit a slower but longer-acting response | 1 | |
1191713094 | What two systems of internal communication do animals have? | Nervous system and endocrine system | 2 | |
1191713095 | Endocrine system | All of an animal's hormone-secreting cells | 3 | |
1191713096 | Endocrine glands vs. exocrine glands | Endocrine glands are ductless, exocrine glands use ducts, exocrine glands are NOT part of the endocrine system | 4 | |
1191713097 | Neurosecretory cells | Nerve cells that release hormones | 5 | |
1191713098 | Neurohormones | Hormones produced by neurons (serve as both hormones in the endocrine system and neurotransmitters, chemical signals in the nervous system) | 6 | |
1191713099 | Examples of neurohormones | Epinephrine, dopamine, oxytocin | 7 | |
1191713100 | Relationship between nervous and endocrine system | They regulate each other, a nerve impulse can cause the secretion of neurohormones which will eventually alter nervous signals as well. Many endocrine glands are located in the nervous system (but they're not neurosecretory cells) | 8 | |
1191713101 | Basic control pathway | receptor detects stimulus → sent to control center → compares value with a reference value → sends signal that directs effector to respond → efferent signal is a hormone or neurohormone | 9 | |
1191713102 | Control pathways are often regulated by | negative feedback loop, like in controlling blood calcium or glucose levels | 10 | |
1191713103 | Why isn't positive feedback a common part of control pathways | Negative feedback helps maintain homeostasis because the response reduces the initial stimulus. Positive feedback amplifies signals, which isn't good for maintaining homeostasis. There are a lot of positive feedback loops, just not within control pathways. Hence the word "control" | 11 | |
1191713104 | Simple endocrine pathway | Signal → receptor on the endocrine cell → endocrine cell/control center → secretes hormone and goes into blood → targets effectors like organs → elicits response | 12 | |
1191713105 | Endocrine glands can act as both | the receptor and control center | 13 | |
1191713106 | Neuroendocrine glands can only act as | the control center (receptor is a sensory neuron) | 14 | |
1191713107 | Simple neurohormone pathway | Signal → sensory neuron → neuroendocrine cell/control center → secretes neurohormone and goes into blood → targets effectors like organs → elicits response | 15 | |
1191713108 | Simple neuroendocrine pathway | Signal → sensory neuron → neuroendocrine cell/control center → secretes neurohormone and goes into blood → receptor on endocrine cell → endocrine cell/control center → secretes hormone and goes into blood → targets effectors like organs → elicits response | 16 | |
1191713109 | Neuroendocrine pathway vs. neurohormone pathway | In neuroendocrine, the neurosecretory cell secretes a neurohormone that triggers an endocrine gland that in turn secretes another hormone that brings about the desired response. Neurohormone pathways bypass the intermediate endocrine gland | 17 | |
1191713110 | What three types of molecules can function as hormones? | Proteins, amines derived from amino acids and steroids | 18 | |
1191713111 | Which hormones are water soluble? | Proteins and amines | 19 | |
1191713112 | Which hormones are lipid soluble? | Steroids | 20 | |
1191713113 | Receptors for water-soluble hormones are embedded in | plasma membrane | 21 | |
1191713114 | Receptors for lipid-soluble hormones are | inside the cell, usually on the nucleus or cytoplasm (hormone penetrates cell and binds to intracellular receptor) | 22 | |
1191713115 | Binding of hormone to receptor causes | signal transduction pathway (like we learned in cell signaling, the hormone is the signal molecule) | 23 | |
1191713116 | Evidence that hormone interaction with surface receptor is a requirement for signaling | if you inject the hormone directly into the cell, nothing happens because there's no transduction pathway | 24 | |
1191713117 | Unlike extracellular hydrophilic receptors, intracellular receptors | perform the entire act of transduction (directly triggers the response). Extracellular responses have more steps | 25 | |
1191713118 | The activated intracellular receptor is usually a__ | transcription factor which causes change in gene expression | 26 | |
1191713119 | Paracrine signaling | Local signaling, not as specific | 27 | |
1191713120 | Neurotransmitters that are local regulators are | amino acid derivatives | 28 | |
1191713121 | Protein local regulators are | cytokines and growth factors | 29 | |
1191713122 | Growth factors allow | cells to grow, divide and develop normally | 30 | |
1191713123 | Nitric oxide local regulator | relaxes smooth muscle to dilate blood vessels and improve blood flow when oxygen levels decrease | 31 | |
1191713124 | Prostaglandin (PG) local regulators | modified fatty acids, stimulate smooth muscles of uterine wall to contract, induces fever and inflammation | 32 | |
1191713125 | Pituitary gland located | in hypothalamus | 33 | |
1191713126 | Parts of the pituitary gland | posterior pituitary (oxytocin and ADH), and anterior pituitary (growth hormone, FSH, LH, TSH). The pituitary gland as a whole is a FUSED endocrine and neuroendocrine gland | 34 | |
1191713127 | Embryonic origin of pituitary gland | posterior pituitary grows downward toward mouth and anterior pituitary grows upwards toward mouth | 35 | |
1191713128 | Oxytocin | Causes uterine muscles to contract, and causes breast milk production, POSTIVE FEEDBACK | 36 | |
1191713129 | Tropic hormones | hormones that regulate functions of endocrine organs. Many of the hormones secreted by anterior pituitary regulate these endocrine glands | 37 | |
1191713130 | The three tropic hormones produced by anterior pituitary | FSH, LH and TSH | 38 | |
1191713131 | Growth Hormone | Has both tropic and nontropic effects, signals liver to release insulin-like growth factors (IGFs) which stimulate bone growth. Also raises glucose levels | 39 | |
1191713132 | Thyroid gland | two lobes on the trachea, produces T3 and T4-thyroxine (number of iodine atoms) and calcitonin | 40 | |
1191713133 | Which is more common, T3 or T4? | Animals have more T4, but it's converted into T3 because receptors are more sensitive to T3 | 41 | |
1191713134 | Thyroid hormone feedback loop | Hypothalamus makes TSH releasing hormone (TRH) which stimulates anterior pituitary to make TSH which uses cAMP to make T3 and T4. When T3 and T4 are too high, TRH production inhibited and levels decrease (NEGATIVE feedback | 42 | |
1191713135 | Thyroid hormones regulate | growth, blood pressure, digestion, heart rate | 43 | |
1191713136 | Deficiency of iodine causes | goiter (enlarged thyroid gland) | 44 | |
1191713137 | Two hormones that maintain calcium levels | parathyroid hormone and calcitonin | 45 | |
1191713138 | Calcium regulation | low calcium levels trigger release of parathyroid hormone which raises calcium levels. High calcium levels trigger release of calcitonin which lowers calcium levels (PTH and calcitonin are antagonistic) | 46 | |
1191713139 | How parathyroid hormone (PTH) raises calcium levels | induces bones to release calcium, or kidneys to reabsorb calcium. Liver and kidney can activate vitamin D, which stimulates intestines to intake calcium | 47 | |
1191713140 | Endocrine cells in pancreas | Islets of Langerhans | 48 | |
1191713141 | Two types of cells in the islets | alpha cells produce glucagon, beta cells produce insulin | 49 | |
1191713142 | Insulin and glucagon are | antagonistic | 50 | |
1191713143 | Glucose regulation pathway | Rising glucose level stimulates beta cells to release insulin which causes liver to take up glucose and store it as glycogen. Insulin also slows glycogen breakdown in liver and conversion of amino acids/lipids to glucose. Glucose levels start to decline and insulin decreases while glucagon is released. Glucagon causes liver to break down glycogen and release glucose. This up and down motion continues until homeostasis (that's why you can't eat too much sugar) | 51 | |
1191713144 | The brain can take up glucose without insulin | has access to energy all the time | 52 | |
1191713145 | What cells store sugar as glycogen? | Liver and muscles | 53 | |
1191713146 | What cells store sugar as fat? | adipose tissue | 54 | |
1191713147 | Diabetes mellitus | Caused by deficiency of insulin or decreased sensitivity. Body can't absorb all the glucose that's taken in, so it's excreted (sweet urine). This causes more water to be excreted also, so causes thirst. Fat is used for respiration since there's not enough glucose | 55 | |
1191713148 | Type I diabetes | immune system destroys beta cells, so no insulin is produced. Usually genetic | 56 | |
1191713149 | Type II diabetes | Reduced sensitivity to insulin (it's still produced), usually not genetic | 57 | |
1191713150 | Adrenal glands | next to the kidneys | 58 | |
1191713151 | Adrenal glands made of | adrenal cortex (outer layer) and adrenal medulla (inner layer). The adrenal gland as a whole is a FUSED endocrine and neuroendocrine gland, like the pituitary gland | 59 | |
1191713152 | Which part of the adrenal gland is endocrine? | Adrenal cortex | 60 | |
1191713153 | Which part of the adrenal gland is neuroendocrine? | Adrenal medulla | 61 | |
1191713154 | Catecholamines | Hormones synthesized from tyrosine amino acid, e.g epinephrine and norepinephrine | 62 | |
1191713155 | Epinephrine and norepinephrine are secreted by the | adrenal medulla (it's not neuroendocrine, but it can still function as a neurotransmitter) | 63 | |
1191713156 | How epinephrine and norepinephrine work | increase glycogen breakdown in liver and muscles, liver releases glucose, glucose used to provide energy. Blood pressure, breathing and metabolic rate increase | 64 | |
1191713157 | Epinephrine vs. norepinephrine | Norepinephrine keeps blood pressure up while epinephrine increases other rates too | 65 | |
1191713158 | Adrenal medulla stimulated by | Sympathetic division of CNS | 66 | |
1191713159 | Adrenal cortex stimulated by | Endocrine signals, unlike the adrenal medulla | 67 | |
1191713160 | What hormone causes adrenal cortex to secrete corticosteroids? | Anterior pituitary secretes ACTH (tropic hormone) which stimulates adrenal cortex to secrete corticosteroids | 68 | |
1191713161 | Two main types of corticosteroids | glucocorticoids (cortisol) and mineralocorticoids | 69 | |
1191713162 | Short term vs. long term stress response | Short term is epinephrine and norepinephrine, long term is glucocorticoids and mineralocorticoids | 70 | |
1191713163 | Primary source of sex hormones | gonads (testes in males, and ovaries in females) | 71 | |
1191713164 | Three major categories of steroids | androgens, estrogens and progestins | 72 | |
1191713165 | Are all sex hormones found within each gender? | Yes! But in different proportions | 73 | |
1191713166 | Testes make | androgens like testosterone. Androgens regulate reproductive system development | 74 | |
1191713167 | Estrogens | Most important is estradiol, maintains female reproductive system | 75 | |
1191713168 | Progestins | Protect uterus | 76 | |
1191713169 | Pineal gland | Near center of brain, secretes melatonin | 77 | |
1191713170 | What controls amount of melatonin secreted? | Length of night, that's why you get jet lag | 78 | |
1191713171 | Suprachiasmatic nuclei (SCN) | Body's biological clock, target of melatonin | 79 |