Final Exam Study Guide (4) PDF

Lecture 9: Endocrine System Comparison of Control by the Nervous System and Endocrine System Nervous and endocrine system work together to coordinate all systems of the body Charateristic Nervous System Endocrine System Molecules Neu...

Lecture 9: Endocrine System Comparison of Control by the Nervous System and Endocrine System Nervous and endocrine system work together to coordinate all systems of the body Charateristic Nervous System Endocrine System Molecules Neurotransmitter released Hormone delivered to tissues locally in response to nerve throughout body to blood impulses SIte of action Close to site of release; bind Far to site of release; bind to to receptors in postsynaptic receptors on or in target cells membrane Type of target cells Muscle cells, gland cells, and Any cells throughout the body other neurons Time to onset of action Within milliseconds Seconds → Hours → Days Duration of action Briefly Longer Glandular Epithelium: single cell or mass epithelial cells Endocrine Glands: enter interstitial fluid, the diffuse into bloodstream Include pituitary, thyroid, parathyroid, adrenal, and pineal glands Secrete hormones Unicellular Exocrine Glands: enter ducts that empty onto surface area Include sudoriferous (sweat), sebaceous (oil), digestive and mucous glands Don’t secrete hormone Multicellular Mechanism of lipid-soluble hormone (HYDROPHOBIC) 1. They are hydrophobic, so they need transport proteins to travel around the bloodstream 2. These hormone diffuse into cell and then bind to nuclear receptors, altering gene expression 3. This causes transcription (DNA → mRNA), then mRNA exists from nucleus and finds ribosome, then translation occurs (mRNA → protein) 4. These new protein perform cellular work Ex. Steroid hormone, thyroid hormones, nitric oxide Mechanism of water-soluble solution (HYDROPHILIC) 1. Hormones freely travel through the bloodstream due to their hydrophilic nature 2. Diffuse out of the capillaries into interstitial fluid and bind to G-protein-coupled receptors on target cells 3. Binding of hormone to GPCR causes the activation of enzyme adenylyl cyclase, which converts ATP to cAMP 4. cAMP activates protein kinases that phosphorylate existing proteins 5. Phosphorylation causes them to perform cellular work 6. Phosphodiestease gets rid of cAMP Ex. amine hormone, peptide/protein hormones and eicosanoid hormones Fuction of all Glands Hypothalamus and pituitary gland: work together to control other endocrine glands’ connected by fundibulum Anterior lobe make 75% of weight and secrete 7 hormones Posterior lobe made of neural tissue and releases 2 hormones Thyroid gland: butterfly-shaped located in the neck; releases T3, thyroxine (T4), and calcitonin 2 types of cells: ○ Follicular cells: stimulated by TSH to produce thyroxine- thyroid hormone ○ Parafollicular cells: produce calcitonin to regulate calcium homeostasis It hormones: Help maintain normal body temperature Stimulate protein synthesis ↑ the use of glucose and fatty acids for ATP production Work with nGH and insulin to accelerate body growth Parathyroid gland: has 4 small glands, located in the back of thyroid gland and releases PTH 2 types of cells: ○ Chief cells: produce PTH- release when calcium level are low ○ Oxyphil cells: secrete excess PTH in case of parathyroid cancer Adrenal gland: secretes cortisol (stress hormones) and aldosterone from the outer cortex Cortisol: ↑ blood glucose, ↓ immune system and stimulates “fight or flight” response Aldosterone: ↑ reabsorption of salts and water Pineal gland: attached to roof of third ventricles of brain and secretes melatonin (regulates sleep-wake cycle); regulates circadian rhythms Thymus: produces thymosin, thymic humoral factor (THF), thymic factor (TF), and thymipoientin, pronote maturation of immune system T cells Principle actions of hormones of the anterior pituitary Hormones Principle actions Growth Hormone (GH) Stimulates tissue growth by ↑ the release of insulin; acts on target cells, boosts lipolysis; ↓ glucose uptake Thyroid-stimulating hormone (TSH) Stimulates synthesis and secretion of TH by thyroid gland Follicle-stimulating hormone (FSH) Promotes follicle maturation → estrogen secretion (female); stimulates testes to produce sperm (male) Luteinizing hormone (LH) Promotes ovulation → progesterone secretion, corpus luteum development (female); boosts testosterone leading to sperm production (male) Prolactin Stimulate mammary gland milk production Adrenocorticotropic hormone (ACTH) Stimulate secretion of glucocorticoids by adrenal cortex Melanocyte-stimulating hormone (MSH) Cause skin pigmentation by UV radiation; suppress hunger; enhance sexual excitement Posterior pituitary hormones Hormones Principle actions Oxytocin “Love hormone” Uterine contraction (childbirth) and promote ejection of milk (breast feeding) T3, Thyroxine (T4) Thyroid Hormones ↑ basal metabolic rate, ATP production, body (follicular cells) growth, stimulates synthesis protein, development of N.S. Calcitonin (parafollicular cells) ↓ blood level calcium and hydrogen phosphate by inhibiting bone resorption; ↑ uptake of calcium and phosphate Parathyroid hormones (PTH) ↑ blood calcium level; release of calcium from bone into bloodstream; ↓ calcium loss in urine; and ↑ calcium absorption from food Adrenal Gland Hormones Principal Actions Mineralocorticoids (zona glomerulosa) ↑ blood levels of sodium and water; ↓ blood Secrete Aldosterone level of potassium Glucocorticoids (zona fasciculata) ↑ anti-inflammatory protein expression; Secrete cortisol control blood glucose level through gluconeogenesis and lipolysis Androgens (zona reticularis) Promote early axillary and pubic hair in both sexes; ↑ female libido, provide estrogen post-menopause Epinephrine & Norepinephrine (adrenalle ↑ heart rate and blood flow to muscle, medulla) breathing rate Pancreatic Islet Hormones Principle Actions Glucagon (alpha cells) ↑ blood glucose level (glycogenolysis, glucogeneogenesis) Insulin (beta cells) ↓ blood glucose level (glycogenesis); ↑ lipogenesis, stimulating protein synthesis Somatostatin (delta cells) Inhibits secretion of insulin and glucagon; ↓ absorption of nutrient from GI tract Pancreatic Polypeptide (F cells) Inhibit secretion of somatostatin, pancreatic digestive enzyme, gallbladder contraction The impact of glucagon and insulin on blood glucose level 1. Low blood glucose (hypoglycemia) stimulates alpha cells to secrete 2. Glucagon acts on liver cells to: a. Convert glucogen → glucose; form glucose from lactic acid and amino acid 3. Glucose released by liver cells ↑ blood glucose level 4. High blood glucose (hyperglycemia) stimulates beta cells to secrete 5. Insulin acts on various body cells to: a. ↑ facilitated diffusion of glucose into cells b. ↑ uptake of amino acids and protein synthesis c. Speed up the conversion of glucose to glycogen d. Speed up synthesis of fatty acid Growth Factor Growth factor Principal Actions Epidermal growth factor (EGF) Produce in salivary gland; stimulates proliferation of epithelial cells, neurons, and neuroglia Platelet-derived growth factor (PDGF) Produce in blood platelets; stimulates proliferation of neuroglia, S.M. fibers, and fibroblasts Fibroblast growth factor (FGF) Produce in salivary gland and hippocampus of brain; stimulates growth of ganglia in embryo, hypertrophy, differentiation of neuron; maintain SN Nerve growth factor (NGF) Found in pituitary gland and brain; stimulates proliferation of chondrocytes, S.M. fibers, endothelial cells, and the formation of new blood vessels Tumor angiogenesis factor (TAFs) Produced by tumor cells; stimulates growth of new capillaries, organ regeneration, wound healing Endocrine Disorders Gigantism is caused by excess secretion of growth hormone (overgrowth of hands, feet, and face) Gioter caused by reduction and overproduction of TH (dificulty breathing and swallowing) Hypothyroidism caused by insufficient of TH ( depression, weight gain, and cold intolerance) Graves disease caused by excess TH (irritability, muscle weakness, heat intolerance) Crushing’s disease is caused by excess secretion of glucocorticoids (abdominal obseity, weak muscles and bones, fragile skin). Lecture 10: Reproductive System & Development Male reproductive structures Scrotum: sac of loose skin that contains testes Testes: paired, oral gland in the scrotum Seminiferous tubules: carry sperm produced within them Epididymis: stores, matures, and transports sperms Sperm: designed to penetrate the oocytes for fertilization and zygote formation Semen: a mixture of sperm and seminal fluids Penis: passage for semen and urine; contain urethra Acessory glands: ○ Seminal vesicles: secrete alkaline and viscous fluid containing ○ Prostate: releases milky, slightly acidic fluid with citric acid  ○ Bulbourethral glands: secrete alkaline fluid and neutralize The effect of hormones on male reproductive system Gonadotropin-releasing hormone (GnRH): released by hypothalamus, signals pituitary gland to produce and release FSH and LH Luteinizing hormone (LH): stimulates testes to produce testosterone Follicle-stimulating hormone (FSH): work with testosterone to support sperm production Testosterone: produced by testes, important for muscle growth, sperm production and male features Inhibin: produced by testes, regulates sperm production to reduce FSH release when enough sperm are being made Female reproductive structures Ovaries: paired, produced oocytes and hormones (estrogen, progesterone, relaxin, inhibin) ○ Germinal epithelium: covers the surface of ovary ○ Tunica albuginea: capsule of the germinal epithelium ○ Ovarian cortex: below the tunica albuginea and have ovarian follicles and stromal cells ○ Ovarian medulla: have connective tissue, blood vessels, lymphatic vessels and nerves ○ Ovarian follicles: have oocytes, follicular cells, and granulosa cells ○ Corpus luteum: develops after ovulation when the empty follicle produces progesterone, estrogen, and relaxin Uterine tube: pathway for sperm to reach the ovum; extend from uterus to ovary Uterus: pathway for sperm deposited in the vagina to reach the uterine tube ○ 3 layers of the uterus: perimetrium (outter), myometrium, and endometrium (inner) Cervix: a barrier to infections and dilates during labor ○ External: openning of cervix to vagina ○ Internal: upper opening linking the cervix to uterus Vagina: fibromuscular canal lined with mucus extends from the body exterior to cervix Hyme: thin fold of vascularized mucous membrane Vulva: external genitalia of the female 2 glands: ○ Paraurethral glands: secrete mucus Homologus to prostaste ○ Greater vestibular glands: produce mucus during sexual arousal Homologus to bulbourethral gland Ovarian cycle  has a series of events that occur during and after the maturation of the oocyte. This cycle involves 3 distinct phases. 1. Folicular phase: FSH → follicles (contain eggs) develop and release estrogen 2. Ovulation: Rising estrogen levels triggers LH surges; LH increase triggers ovulation 3. Luteal phase: Follicles become corpus luteum and release progesterone No embryo = no corpus luteum = ↓ progesterone Uterine cycle the change in the endometrium that prepares it for implantation of the developing embryo. It also involved 3 different phases. 1. Menstrual phase: shedding of the stratum functionalis of the endometrium due to the decreased level of progesterone from dying corpus luteum 2. Proliferative phase: regrow stratum functionalis due to the increase in estrogen from follicular phase 3. Secretory phase: Stratum functionalis secretes nutrient broth (to support growing embryo) due to increase in progesterone from luteal phase Hormones involved in the cycles Estrogen: Decrease blood pressure Increase protein anabolism Promote development and maintenance of female reproductive system Stimulate proliferation of the endometrium after menstruation Inhibin: inhibits release of LH and FSH Relaxin: inhibits urine contraction and increases flexibility of pubic symphysis Progesterone: Work with estrogens to prepare endometrium for implantation High levels inhibit release of GnRH, FSH, and LH Birth Control Methods 1. Vasectomy (male); removing portion of vas deferens 2. Tubal ligation (female): tie closed and cut the uterine tubes 3. Non-meisional sterilization: insertion of coil made of plastic and metal into uterine tube 4. Hormonal method (birthcontrol): prevent pregnancy 5. Intrauterine devices (IUDS): can contain hormones or copper toxic to sperm Fertilization: merging of genetic info. from haploid sperm and oocyte 1. Sperm swim from vagina to the cervix and uterine tube 2. Sperm penetrates the oocyte, then the acrosomal enzymes digest through these layers and the head bind to 2P3 receptor in the zona pellcuid and then fertilization starts 3. The male and female haploid merge= diploid nucleus= zygote Cleavage: zygote begins mitotic division Blastmeres: each division result in smaller and smaller blastomeres= a cluster of cells Morula: cluster of cells in early stage of cleavage Blastocyst: structure formed in early stages of embryonic development Embryoblast: inner cell mass Trophoblast: outer cell mass Chorion: outer membrane that develops during early embryonic Lecture 11: Sensory Anatomy and Physiology Sensory Pathway Stimulation: any event that triggers a specific physiological reaction in an organ or tissue Transduction: converting sensory signals into an electrical nerve signal processed by CNS Sensation: conscious or subconscious awareness of changes in the external or internal environment Perception: conscious interpretation of sensations performed mainly by the cerebral cortex Microscopic Structure Basics of classification Description Free nerve ending Bare dendrites associated with pain, thermal, tickle, itch and some touch sensation Encapsulated nerve endings Dendrites enclosed in connective tissue that enhance sensitivity to touch and pressure Seperate cells Receptor cells synapse with first-order sensory neurons Receptor location and activating stimuli Basics of classification Description Exteroceptors Located at or near body surface Provide info. about external environment Interceptors In blood vessels, visceral organs, and NS Provide info. about internal environment Proprioceptors In muscles, tendons, joints, and inner ear Provide info. about body position, muscle length and tension, equilibrium etc. Type of stimulus detected Basics of classification Description Mechanoreceptors Detect mechanic stimuli Thermoreceptors Detect changes in temp. Nociceptors Respond to painful stimuli from physical or chemical Photoreceptors Detect light that strikes the retina Chemoreceptors & Osmoreceptors Detect chemical in mouth, nose, and body fluid Tactile receptors Receptor Type Sensations Messiner corpuscle Onset of touch and low-frequency vibration  Hair root corpuscle Movement on skin surface that disturbs hairs Tactile discs Continuos touch and pressure Ruffini corpuscles Skin stretching and pressure Pacinian corpuscle High-frequency vibrations Itch & tickle receptors Itching and tickling Somatic Sensations Muscles Spindles: type of proprioreceptor, found in skeletal muscles Tendon Organs: type of proprioreceptor, found in junction of tendon and muscle Joint Kinesthetic Receptors: around synovial joints detect pressure, acceleration, and deceleration Somatic sensory pathways 1st order: impulses from somatic receptors to the brain stem or spinal cord 2nd order: impulses from brain stem and spinal cord to the thalamus 3rd order: impulses from thalamus to the primary somatosensory area of the cortex on the same side 5 somatic sensory pathways 1. Doreal column-medial lemniscus (DCML) pathway: help perceive sensations: touch, vibration, proprioreception, pressure from the limb, trunk, neck and posterior head 2. Spinothalamic pathway = Pain & temperature → thalamus a. uses 3 neurons to convey sensory information: impulses for pain, temp., itch and tickle 3. Spinoreticular pathway = Deep, dull pain → reticular formation → thalamus a. uses 4 levels of neurons to convey sensory information; impulses for pain and causes alertness and arousal to painful stimuli 4. Spinotectal pathway = Reflexive response to stimuli → midbrain a. uses 3 levels of neurons to convey sensory information; responsible for visual reflexes 5. Trigeminothalmic pathway: impulses for most somatic sensation from face, nasal cavity, oral cavity and teeth Olfaction: sense of smell Supporting cells: located in mucous membranes lining the nose Brain stem cells: undergo mitosis to replace olfactory receptor cells Olfactory glands: produce mucus that used to dissolve odor molecules Olfactory transduction: the process by which the nose detects and interprets smells 4 types of papillae Vallate papillae: have about 12 that contain 100-300 taste buds Fungiform papillae: scattered over the tongue with about 5 taste buds each Foliate papillae: in lateral trenches of tongue Filiform papillae: cover the entire surface of the tongue 3 cranial nerves Facial nerve (VIII); carries taste info. from the anterior ⅔ of the tongue Glossopharryngeal nerve (IX): carries taste info. from the posterior ⅓ of the tongue Vagus nerver (X): carries taste info. from taste buds on the epiglottis to throat Structure of the eyes Outside orbit Palpebral muscles: contro-eyelid movement Tarsal plate: a fold of CT that gives form to the eyelids Tarsal glands: contain sebacous glands (oil) In order of outer to inner Cornea: transparent anterior of the eye ↓ Anterior chamber ↓ Iris: the color of your eye; control the size and opening of the eye (pupil) ↓ Posterior chamber ↓ Lens: behind iris and focuses light ↓ Cilary body: thickened tissue that encircles the lens ↓ Fovea centralis: the center of retina ↓ Optic disc: the point at which the optic nerve exists (blind spot) ↓ Choriod: prevents scattering of light rays and is highly vascular to deliver nutrients Outer part Sclera: white portion of the eye Conjunctiva: thin and cover the sclera Rod: see dim light Cone: see bright light and produce color vision Anterior chamber vs. Posterior chamber Anterior chamber (between iris and cornea): filled with aqueous humor Posterior chamber (between iris and front lens): filled with transparent gelatinous substance: vitreous humor—everything behind the iris Operation of rod in light and dark In darkness, rod photoreceptors increase release of inhibitory neurotransmitter glutamate (black In light, rod photoreceptors decrease release of inhibitory neurotransmitter glutamate Strutcure of ear External ear Auricle: captures sound External auditory canal: transmit sound to eardrum Tympanic membrane: vibrates according to sound Ceruminous glands: secrete cerumen to protect canal and eardrum Middle ear Auditory ossicles: malleus, incus, and stapes Auditory tube: from the midear into the nasopharynx-regulate air pressure Inner ear Cochlea: translates vibrations into neural impulses so brain interprets sound Semicircular canals: work with cerebellum to sense acceleration for balance Saccule: sense vertical acceleration Utricle: sense horizontal acceleration