1 Case study nervous system diseases The Nervous and Endocrine System a Dementia the loss of cognitive functioning includes thinking remembering and reasoning among other systems that interfere with a person s life i Number of causes 1 Alzheimers is the number 1 reason 2 Vascular dysfunction 3 Injury ii Not a normal effect of aging because many people get to older ages 90 without contracting it b Extreme shrinkage of the hippocampus severely enlarged ventricles and an extreme shortage of the cerebral cortex 2 Relative differences between neurotransmitters and hormones a Neurotransmitters generally a substance secreted from the distal terminal end of a neuronal axon from nervous tissue that stimulates adjacent cells electrically to perform a function effect i Works rapidly milliseconds to seconds in response to stimulus b Hormone generally a substance secreted into the blood by an endocrine gland or isolated gland functioning cells that triggers a physiological response in distant cells with correct receptors i ii iii Can be slow weeks or months of transmission to dosage dependent response 1 Saturation of receptors that hormones binds to Highly specific physiological effects in different tissues only that have correct receptors Examples to hormones include but are not limited to 1 Cortisol stress hormone testosterone growth hormone estrogen ghrelin 3 Chemical signaling a All organisms respond to their environment b Animals i ii Nervous system Endocrine system 1 Regulates metabolic activity via hormone release 2 Hormones to excite transported around the body in the blood c Endocrine blood d Exocrine outside the body e Neurotransmitters and hormones 4 Endocrine vs exocrine a Endocrine cells Not organized 1 They diffuse and spread out G Cells gastrin D cells somatostatin Endocrine gland 1 An organized group of cells 2 Pineal gland 3 Hypothalamus 4 Pituitary gland 5 Thyroid gland 6 Parathyroid gland 7 Thymus thymosin 8 Adrenal glands 9 Pancreas 10 Gonads i ii iii iv v vi vii viii Neurotransmitters Hormones long distance chemical signals 1 Travel in blood or lymph Autocrines chemicals that exert effects on same cells that secrete them Paracrines locally active chemicals that affect cells other than those that secrete them 1 Autocrines and paracrines are local chemical messengers a The book does not consider them part of the endocrine system 5 Hormone characteristics a Secreted by cells Recall G or D cells in the stomach Or groups of cells b Specific Bind to specific receptors 1 Alter cellular activity of targets Systemic rather than local effects c Long distance d Types of hormones Amino acids i 1 Singular amino acids Peptides proteins 1 Large proteins Steroids i ii i i ii iii i ii 1 Have cholesterol as a base for structure e Water vs lipid soluble Water loving or water fearing determines if a hormone can cross the cell membrane phospholipid bilayer or not Lipid soluble hormones can cross cell membrane 1 Steroids 2 Thyroid hormones iii Can enter cell 1 Usually intracellular receptors 2 Usually regulate gene expression a The steroid hormone diffuses through the plasma membrane and binds an intracellular receptor b The receptor hormone complex enters the nucleus c The receptor hormone complex binds a specific DNA region d Binding initiates transcription of the gene to mRNA e The mRNA directs protein synthesis iv Require transport to target cells 1 Binding proteins f Water soluble hormones cannot cross cell membrane i Amino acid based hormones except thyroid a Longer half life 2 Free vs bond 1 No transport proteins a Half life shorter i Will break down quicker in blood ii Receptors on outside of cell 1 Activate second messengers faster response 2 2 main second messengers cascade pathways that have a number of effects steps a Cyclic AMP b PIP2 calcium 6 The hypothalamus In the diencephalon of the forebrain a b Connected to the pituitary gland i Anterior pituitary gland is considered an endocrine gland 7 Pituitary gland a Secretes at least 8 major hormones b Composed of two lobes Posterior pituitary i 1 Nervous tissue ii Anterior pituitary 1 Gland tissue 8 Hypothalamic releasing and inhibiting hormones a This triggers the release of anterior pituitary hormones i Neurohormones released by posterior pituitary hormones 1 Synthesized and released from neuron into blood a Released into portal system ii Tropic hormones released by anterior pituitary gland 1 Act on other endocrine glands a Promote the release or inhibit the release of hormones from anterior pituitary b Seven types i ii iii iv v vi vii Prolactin Releasing Hormone PRH Prolactin Inhibiting Hormone dopamine PIH Thyrotropin Releasing Hormone TRH Corticotropin Releasing Hormone CRH Growth Hormone Releasing Hormone GHRH Growth Hormone Inhibiting Hormone GHIH Gonadotropin Releasing Hormone GnRH c Anterior pituitary hormones 6 peptides proteins i Prolactin 1 2 Thyroid Stimulating Hormone TSH 3 Adrenocorticotropic Hormone ACTH 4 Growth Hormone GH 5 Luteinizing Hormone LH 6 Follicle Stimulating Hormone FSH d Hypothalamic neurohormones posterior pituitary i Oxytocin Peptide of 9 amino acids 1 2 Stimulates uterine contractions during childbirth a Causes smooth muscle contractions in the uterine walls i Via PIP2 calcium second messenger system 3 Triggers milk ejection letdown a Smooth muscle contraction 4 Also important in a Pair bonding i Cuddle hormone ii Antidiuretic hormone 1 2 Peptide of 9 amino acids Inhibits urine formation a Binds to basolateral membrane of collecting duct cell b Activates cAMP 2nd messenger system i Aquaporins inserted in apical membrane c Water is absorbed Increases blood pressure 3