KIN 292 1st Edition Lecture 4These are the notes from Professor Starnes’ lecture of Clinical Human Physiology. These come from the slideshows provided by the professor and include extra notes and explanations. Highlighted or bolded information are things that I believe to be information that is important to look over multiple times. The notes in red are my personal additions and quotes of Professor Starnes from the class lecture. Outline of Last Lecture I. 5.3 Signaling Transduction MechanismsOutline of Current Lecture I. Introduction. Long-distance communication by nervous and endocrineII. systemsIII. 6.1 Primary Endocrine OrgansIV. 6.2 Secondary Endocrine OrgansV. 6.3 Hormone Actions at the Target CellVI. 6.4 Abnormal Secretion of HormonesVII. 6.5 Hormone InteractionsCurrent LectureThe Nervous and Endocrine Systems provide communication throughout the body•They communicate using different types of secretory cells, messengers, and receptors; however, there is some overlap.•The systems work in a coordinated and integrated manner to attempt to maintain homeostasisthroughout the body. Chap. 5.4 Long-DistanceCommunication for brief intro.•Sometimes called the Neuroendocrine system because they work so closely together.Figure 5.20 Signal transmission in neurons vs endocrine glands- Nerve cells can transmit signals long distances then secrete messengershort distance across synapse to target cell- Receptors are generally ion channels, which communicate very fast andfor a short duration- Endocrine glands secrete messenger long distances via the bloodThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Generally communicate with receptors that alter protein synthesis or activate G proteins, which are relatively slow but longer lasting processes.We’ll start with endocrinesystem- All endocrine glands derived from epithelial tissueHypothalamus and Pituitary Gland•Hypothalamus: Located in the brain•Pituitary gland•Anterior lobe•Posterior lobe•InfundibulumHypothalamus and pituitary gland regulate almost every body system through the secretion of many different hormones. Connected by infundibulum- Pineal gland - Secretes melatonin- May be involved in circadian rhythms – daily day-night cycles. Neural input from hypothalamus inhibits melatonin release in daylight hours.Melatonin release at night may help with sleeping and is usedtherapeutically for sleep disordersFigure 6.3 Connection between the hypothalamus and the posterior pituitary gland.- Oxytocin & ADH are called “neurohormones” because they are secretedinto blood by neurons - not endocrine glands.Hormones of Posterior Pituitary•Antidiuretic hormone (also called ADH or vasopressin)•Target tissue: kidney•Water balance and osmolarity•Oxytocin•Target tissues: uterus in pregnancy; breasts postbirth•Uterine contractions; Milk ejectionFigure 6.4 The hypothalamic-pituitary portal system. Anterior pituitary hormones- Portal systemo Links two capillary beds. Hypothalamic tropic hormones are deliveredo fairly precisely and in high concentration to their target cells in the ant. pit.o tropic hormones –Those that regulate secretion of other hormonesHypothalamic-Pituitary Portal System - Summary•The hypothalamus secretes releasing or inhibiting hormone into theprimary capillary bed•Blood with tropic hormones enters the portal vein•Hypothalamic tropic hormones access the anterior pituitary secretory cells through the secondary capillary bed•Anterior pituitary tropic hormones enter the bloodstream in the same secondary capillary bed•They travel to the distant endocrine gland to trigger release of the hormoneHypothalamic and anterior pituitary tropic hormones – hormones that regulate secretion of other hormones- Axis: The relationship among a hypothalamic tropic hormone, its anteriorpituitary tropichormone, and the target endocrine gland. Note not alltargets are endocrine glands, ex. BreastsThyroid and parathyroid glands- Thyroid hormones: T4: Tetraiodothyronine (thyroxin) and T3:Triiodothyronine - Regulate metabolism; Calcitonin - Regulates calcium levels in the blood- Parathyroid hormone - Regulates calcium levels in the bloodThymus- Thymus – big role in immune system- T cells used in immune system mature here- Secretes thymosino Regulates T-cell functionFigure 6.9a Anatomy of the adrenal gland- Medulla secretes catecholamines.- Stimulates Flight-or-fight- Secretory cells known as chromaffin cells- 80% epinephrine- 20% norepinephrine- <1% dopamine- Under neural controlHormones of the Adrenal Cortex: secretes Adrenocorticoids•Mineralocorticoids (aldosterone)- Regulates sodium and potassium levels•Glucocorticoids (cortisol)- Regulates the body's response to stress- Regulates metabolism•Sex hormones (androgens)- Regulate reproductive functionFigure 6.10 Anatomy of the pancreas.Controls of Hormone Release•Neural input – starts in the brain•Hormonal- Negative feedbackFigure 6.6 Negative feedback loops affecting hypothalamic and anterior pituitary tropic hormones.- Prevents buildup of excess tropic hormone- May also loop to hormone 2 secretion as shown in next slideFigure 6.7 Regulation of cortisol releaseMany hormones are not under control of the brain. Examples of humoral control of hormone release.- Hormone secretion is typically in response to either neural signals orhumoral (bloodborne) signalsHormone Concentration in Blood has a very big impact on the magnitude of the response by its target cell. See ch. 5 for relationship of [M] and receptor binding•Hormone level controlled by:•Rate of hormone secretion•Half-life in plasma- Hydrophobic hormones bound to plasma proteins have longer half-lifethan hydrophilic•Rate of hormone metabolism- Primarily by target cell and liver6.4 Abnormal Regulation of Hormone Secretion or Tissue Response can Cause Disease•Hormone levels must be kept in balance•Pathologies- Hyposecretion: Too littleo Diabetes mellitus type 1- Hypersecretion: Too mucho Acromegaly•Abnormal tissue responsiveness- Normal hormone levels- Tissue responds inappropriatelyPrimary Versus Secondary Secretion Disorders•Primary- Abnormality in the endocrine organ secreting the hormone•Secondary- Abnormality in tropic hormoneo Hypothalamic tropic hormoneo Anterior pituitary tropic hormoneFigure 6.13aAbnormal secretion of cortisolo Abnormality in the