Flashcards
Anatomy Test 3
Cards in this deck (200)
- 1Primary function of the endo system?Produce and release hormones or paracrine
- 2Neuroendocrine system general functionsCommunication, integration and control
- 3Nervous vs Endo systemNervous - fast and can respond to stimuli in seconds
Endocrine - takes longer and effects typically occur beyond tissue of origin. Endo organs secrete hormones into the blood where they travel to the effector tissues. - 4Example of shared chemical messengersEpinephrine - hormone when released into the blood and NT when released across a synapse
- 5Intercellular communicationThrough extracellular fluid - paracrine and autocrine communication
Though gap junctions - direct communication
Through the blood stream - endocrine communication
Across synapses - synaptic communication - 6Paracrine vs autocrine communicationParacrine limited to certain local area
Autocrine limited to the cell that secretes the chemical (self) - 7Direct communicationLimited to adjacent cells of the same type
Signals are usually ions or small solutes that are lipid soluble - 8Endocrine communicationInvolves the secretion of hormones into the blood stream. Target cells can be relatively far away
- 9Synaptic CommunicationNT sent across synapses. Limited to very specific area
- 10Neurosecretory CellsEndocrine tissue that secretes hormones that also act as NT when secreted by nervous tissue
- 11Hormone Classificationaa derivatives
peptide hormones
lipid derivatives - 12aa derivativesbiogenic amines
created from tryptophan or tyrosine - 13Tryptophan vs tyrosine hormonesTryptophan - derived from hormone melatonin (converted from serotonin). Both help regulate appetite, mood and sleep.
Tyrosine - catecholamines (epi, norepi and dopamine) and thyroid hormones (thyroxine [T3] and triiodothyronine [T4]). - 14Are catecholamines hormones or NT?Either depending on where they are produced and where they have there effect
- 15Peptide hormonesProhormone - inactive form
Glycoproteins - more than 200 aa long. Carb side chains
Short polypeptides and small proteins - 16Lipid derivativesEicosanoids - fatty acid side groups, paracrines (coordinate cellular activities and effect enzymatic processes), leukotrienes (involved in immune and inflamm response) and prostaglandins (tissue/local hormones)
Steroid hormones - cholesterol side groups, circulate bound to transport proteins - 17ProstaglandinsSecreted directly into bloodstream, rapidly metabolized, coordinate local cellular activities, typically only travel short distances and only effect area in which they are produced, circulating levels are very low
- 18Example of prostaglandin releaseTissue injury. Some will stimulate nerves and cause the sensation of pain
- 19Transport and inactivation of hormonesTypically released where capillaries are abundant and quickly enter bloodstream for distribution
- 20Hormones can circulate ...Freely - remains functional for less than 1 hour
Bound to special carrier proteins - helps protect - 21Equilibrium between free and boundFree hormones used up, inactivated or degraded and equal amount of bound hormone is released to replace it. Gives us several weeks of stored hormone ready for action.
- 22A hormones is inactivated when it ...Binds to receptors on target cells
Becomes absorbed and broken down by cells of the liver or kidneys
Is broken down by enzymes in the blood or interstitial fluid - 23General principles of hormone actionHormones signal a cell
Bind the target cell’s specific receptors (in cytoplasm, nucleus or on plasma membrane)
Signal transduction - different hormone-receptor interactions produce different regulatory changes within the target cell through chemical reactions - 24Why are hormones able to have varied effects on different and specific tissues?Cells in different tissues have different combinations of receptors.
- 25How can hormones actions be combined?Synergism, permissiveness and antagonism
- 26SynergismWhen two or more hormones acting together have a greater effect than anyone of them acting alone
- 27PermissivenessOne hormone on its own does not cause the desired action but it helps another hormone have its full effect.
- 28AntagonismTwo different hormones have the opposite effect. Ex. One amplifies the effect and one turns it down
- 29First and second messenger systemTwo systems for how hormone can cross target cells plasma membrane and elicit the desired changes
- 30First messenger systemHormone is able to diffuse across the plasma membrane and directly bind intracellular receptors or transported across the membrane by carrier mediated processes (Ex. steroid and thyroid hormones)
- 31Second messenger systemReceptors for the hormone are on the target cells but when bound a direct effect is not produced. Instead this hormone, the first messenger, uses a second messenger to exert the effects. Link between the first and second messenger usually involves a G protein (enz. Complex coupled to a membrane receptor). Second messenger may act as an enz. Activator, inhibitor or co factor. (Ex. catecholamines, peptide hormones and most eicosanoids)
- 32Steroid vs thyroid hormones and the first messenger systemSteroid – hormone-receptor complexes alter the activity of specific genes. Alters the rate of DNA transcription and changing protein synthesis.
Thyroid – in nucleus they act the same as steroid hormones. In mitochondria they increase the rate of ATP synthesis. Amount of hormone present determines the magnitude of target cell response.
Since the main action of this system is to regulate the production of proteins, responses are relatively slow - 33How G-proteins help in the second messenger systemHormones message is passed into the cell and G protein serves as a link between the first and second messenger.
- 34Two most important second messengersCyclic AMP (derivative of ATP) and calcium ions.
- 35Hormone message effect on cAMPIf hormone message is to increase production of cAMP enz are activated or ion channels are open – either way metabolic activity of the cell is accelerated
If hormone message is to increase the breakdown of cAMP, enz activity is decreased, inhibiting metabolic activity in the cell. - 36Hormone message effect on Ca2+Calcium acts with calmodulin to activate enz. Both of these act as cascade type of reactions which can amplify the action – the action is generally much quicker than the first messenger system
- 37Regulation of hormone secretionUsually, part of a negative feedback loop
Called endocrine reflexes - 38Hormone mech of hormone influenceDirect route - the gland that secretes the hormone responding to changes in the target cells or around the target cells (ex. PTH increases calcium in blood)
- 39Tropic hormonesHormones that target other endocrine glands besides the one they are secreted by (ex. Pituitary --> TSH --> thyroid gland --> hormones)
- 40Ex of influenced by nervous system inputPituitary secretion influenced by hypothalamus
- 41Regulation of target cell sensitivityUp-regulation and down-regulation
- 42Up-regulationIncreased number of hormone receptors
Increases sensitivity
May happen in response to low levels of the circulating hormone – making the cells more sensitive so they can bind to any of the hormone that’s available and do so more quickly. - 43Down-regulationDecreased number of hormone receptors
Decreases sensitivity
Less receptors are produced in response to an increased amount of the hormone in circulation. Ensures the hormonal response is not too dramatic. - 44Diseased glands or target cells can lead to ...Target cell insensitivity
Hyposecretion - not enough hormone produced
Hypersecretion -too much hormone produced - 45Mechanisms of hypersecretionTumors (may stimulate hyper proliferation of endocrine cells, or may damage or destroy the endocrine cells leading to hypersecretion)
Autoimmunity (antibodies may be produced that end up stimulating the target receptors or bind to and block receptors)
Failure of feedback mechanisms - 46Mechanisms of hyposecretionTumors
Autoimmunity
Abnormal feedback mechanisms
Insensitivity of target cells - 47Where does the highest level of endocrine control come from?Hypothalamus
- 48The 3 endocrine areas that are controlledPosterior lobe of the pituitary gland
Anterior lobe of the pituitary gland
Adrenal medulla - 49Neurons of the hypothalamusSynthesize and secrete two hormones that are released by the posterior lobe of the pituitary gland
- 50What do autonomic centers of the hypothalamus do?Exert direct neural control over the endocrine cells of the adrenal medulla. Activate adrenal medulla immediately whenever the sympathetic division is activated – secrete epinephrine and nor epinephrine
- 51What advantage does releasing regulatory hormones into the hypophyseal portal system provide?Efficient method of communication ensures that all hormones entering the portal vessels will reach their target cells in the anterior lobe quickly and before being diluted through mixing with the general circulation – one way circulation
- 52Releasing and inhibiting hormonesReleased to instruct the anterior lobe when to synthesize and secret and when to stop or slow down synthesis and secretion
- 53What connects the small pituitary gland to the hypothalamus?Infundibulum
- 54What encircles the base of the infundibulum and what is its purpose?Fold of dura matter and this helps to anchor the pituitary gland into position, and it also isolates it from the cranial cavity.
- 55Name of the 2 fused glands of the pituitaryAdenohypophysis (anterior pituitary gland)
Neurohypophysis (posterior pituitary gland) - 56Roles of the two pituitary lobesThe adenohypophysis is the anterior lobe that produces and releases hormones under the control and direction of the hypothalamus. And the neurohypophysis is a posterior lobe that releases hypothalamic hormones.
- 577 tropic hormones of the anterior pituitaryGrowth hormone (GH)
Adrenocorticotropic hormone (ACTH)
Thyroid stimulating hormone (TSH)
Prolactin (PRL)
Luteinizing hormone (LH)
Follicle stimulating hormone (FSH)
Melanocyte stimulating hormone (MSH) - 58What does the MSH do?Stimulates the melanocytes in the skin to increase production of melanin. But in adults this is thought to be nonfunctional and our circulation does not contain MSH.
- 59What are the 2 hormones that the posterior pituitary stores and secretes and is synthesized by the hypothalamus?Oxytocin (OXT) and antidiuretic hormone (vasopressin - ADH)
- 60Role of oxytocinThe main function of oxytocin is to stimulate uterine contractions during childbirth. It does also play a role in milk production after delivery
- 61Role of antidiuretic hormoneThe main function of ADH is to stimulate the kidneys to retain water and decrease urine output. It also causes vasoconstriction that helps to increase blood pressure. (Alcohol inhibits ADH release).
Responds to - Increased solute concentration in the blood and decrease in blood volume or pressure - 62Release of posterior pituitary hormonesReceives direct hormones from the hypothalamus.
- 63Release of posterior pituitary hormones examplesAntidiuretic hormone - targets the kidneys Oxytocin - targets the smooth muscles in the uterus, stimulating contraction during childbirth.
- 64Release of anterior pituitary hormonesReceives a variety of releasing and inhibiting regulatory hormones from the hypothalamus. This affects release of its various Tropic hormones.
- 65Release of anterior pituitary hormones examplesACTH - targets the adrenal glands, regulating the release of glucocorticoids, or steroid hormones.
TSH - targets the thyroid gland to release its thyroid hormones.
Growth hormone - targets the liver, which then releases somatomedins, also known as insulin like growth factors (IGF). These hormones stimulate tissue growth in many different ways. Growth hormone can also act directly on a variety of tissues, doing things like stimulating cell division, metabolism, etc.
Prolactin - targets the mammary gland and stimulates its development and also stimulates milk production during and shortly after pregnancy.
Follicle stimulating hormone - targets the ovaries to secrete estrogens and also targets the testes promoting the maturation.
Luteinizing hormone - targets the ovaries and testes, promoting the release of reproductive cells and the females and the release of estrogens and progesterone. - 66Thyroid gland secretes hormones that regulate what?Growth, development and metabolism
- 67Cells in the thyroid gland use what element from the blood to synthesize the thyroid hormonesIodine
- 68Structure of the thyroid glandComposed of follicles - cavities surrounded by simple cuboidal epithelium
- 69What is the follicle of the thyroid gland filled with?Colloid – fluid containing many dissolved proteins. Also synthesize a protein called thyroglobulin and secrete this globular protein into the colloid
Thyroglobulin contains the aa tyrosine - 70Where is calcitonin produced?Parafollicular cells (C cells) of the thyroid gland
- 71What is calcitonin role?Helps regulate calcium concentrations. This hormone is an antagonist to the main calcium regulator, parathyroid hormone. Its release causes a decrease in blood calcium levels.
- 72What are the two thyroid hormones?Tetraiodothyronine (T4 - thyroxine) - 4 iodine's
Triiodothyronine (T3) - 3 iodine's - 73What is the principle thyroid hormone?T3 is considered the principle thyroid hormone because its metabolic effects are much stronger - more potent. However, we make much more T4 - approx. 90% of all thyroid secretions
- 74Main function of thyroid hormoneRegulation of metabolic rate, growth and development of all cells
(not essential for life but do affect the quality of life) - 75Effects of decreased amounts of thyroid hormoneWeight gain, feeling extremely fatigued, brain fog, aches and pains, cold intolerance and mood disorders
- 76Thyroid hormone calorigenic effect on target cellsTarget enzymes involved in glycolysis and ATP production
This increases metabolic rate of the cells
Cells consume a lot of energy and produce a lot heat - 77How do children adapt to colder climates?We know that metabolism generates heat, so not as much of this heat is produced if the metabolic rate is not increased. In children, the production of thyroid stimulating hormone increases in cold weather.
- 78HyperthyroidismIncreased levels of thyroid hormone
Changes in metabolism, nervous system and heart
Muscle weakness and weight loss (due to increased protein catabolism)
Irritability, insomnia to psychosis
Graves disease - 79How is the nervous system affected in hyperthyroidism?The nervous system is affected due to hyper excitable reflexes and this can cause a range of symptoms leading all the way up to psychosis.
- 80What is Graves disease?Graves' disease is one specific cause of hyperthyroidism and it often presents with exophthalmos, which is a dramatic protrusion of the eye or eyes due to the soft tissue around the eyes becoming swollen and inflamed.
- 81HypothyroidismSame systems affected but are slowed down instead of more reactive
Metabolic rate slowed
Decreased protein synthesis
Bradycardia
Cretinism - decreased mental capacity - 82What is cretinism?Cretinism is a lack of thyroid hormone from birth or even in utero. This usually causes very severe and irreversible defects because everything is being slowed down right at the point of intense growth. This is often due to a damaged or completely absent thyroid gland in the baby, or lack of iodine in mom.
- 83GoiterAn abnormal and visible enlargement of the thyroid gland, and this can occur with either hypo or hyperthyroidism.
Result of an excessive TSH production from the anterior pituitary. - 84Difference of hyper vs hypothyroidism and a goiterHypothyroidism, the low levels of thyroid hormone, stimulates the pituitary to secrete more TSH to try and correct the lack of thyroid hormone. In hyperthyroidism, we would expect lower levels of TSH because thyroid hormone is high. In graves disease, this auto immune condition produces antibodies that mimic the action of TSH, they will bind with the TSH receptors and enlarge the gland. The body's own negative feedback system can decrease TSH, but not the antibodies.
- 85Treatment of hypothyroidismOral thyroxine (T4) - this form is usually given because our bodies naturally convert it to T3
- 86Treatment of hyperthyroidismRemoval of some or all of the gland
Destruction of cells with radioactive iodine (iodine is absorbed and concentrated by thyroid tissue only, it does not harm other tissue)
Drugs that block either hormone synthesis - 87Which hyperthyroidism treatment is the most reliable?Radioactive iodine treatment (permanent cure)
- 88Primary vs secondary issue with thyroid diseasePrimary issue - issue is with the thyroid gland itself
Secondary issue - may involve the pituitary or the hypothalamus. - 89What levels should be checked when investigating thyroid issues?TSH and T4 levels
- 90TSH and T4 levels expected for hypo and hyperthyroidismHyperthyroidism - no matter what the source, we expect low TSH levels and high T4 levels.
Hypothyroidism - TSH is expected to be elevated if the thyroid is the problem. This is because if the pituitary or the hypothalamus are both working more TSH will be secreted to try and bring those low T4 levels back up again. If the problem lies with the pituitary or the hypothalamus, both the TSH and T4 levels will be decreased. - 91Structure of the parathyroid glandTwo pairs of parathyroid glands, and these are found on the back of the thyroid.
4-5 glands are embedded in the posterior surface of the thyroid’s lateral lobes
Tiny, rounded bodies within thyroid tissue
Formed by compact, irregular rows of cells - 92Parathyroid hormone (PTH) main targetsBone and kidney
- 93Effects of parathyroid hormoneRegulation of plasma calcium levels
Antagonist to calcitonin
Primary hormone for calcium homeostasis - 94Parathyroid hormone effects on calciumWhen blood calcium levels are low, more parathyroid hormone is secreted and this targets the kidneys and the intestines to increase calcium uptake and also the bones where osteoclast activity is increased to release more calcium into the blood. When calcium levels are high, the release of parathyroid hormone is reduced.
- 95Structure of the adrenal glandsLocated on top of the kidneys
Two distinct regions.
The outer adrenal cortex - endocrine tissue and secretes steroid hormones
The inner adrenal medulla - neurosecretory tissue and secretes modified neurotransmitters epinephrine and norepinephrine. - 96What is aldosterone?Important mineralocorticoid
Adrenal cortex
Hormonal effect (increases renal reabsorption of Na+ and water and
accelerates urinary loss of K+)
Primary target are the kidneys - 97Aldosterone secretion is stimulated by ...Drop in blood Na+ level, BP, or blood volume
Rise in blood K+ level
Angiotensin II - renin-angiotensin-aldosterone system (RAAS) - 98What is cortisol?Glucocorticoid
Also produced in the cortex, also known as hydrocortisone.
All cells have receptors for cortisol - 99What the actions of cortisol?Involved in the stress response
Accelerates protein metabolism
Gluconeogenic & Hyperglycemic (glucose metabolism and protecting the body from hypoglycemia)
Shift to lipid catabolism
Maintaining normal BP - aiding norepinephrine and epinephrine in reaching their full effect, causing vasoconstriction
Anti-inflammatory effects - suppresses the immune system
Causes negative calcium balance
Influences brain function - 100Why does cortisol have anti-inflammatory properties?it inhibits the activities of our white blood cells and other immune cells. For example, it slows the migration of phagocytes and decreases their activity and it also inhibits the release of histamine. This anti-inflammatory function makes it an ideal topical medication for skin irritations like Poison Ivy.
- 101Cortisol SecretionIncreases in response to stress
Controlled by ACTH from anterior pituitary - adrenocorticotropic hormone (cortisol levels naturally have diurnal rhythm, peeking in the morning)
Continuous
Strong diurnal rhythm - 102HypercortisolismIncreased levels of cortisol
Cushings syndrome
Excess cortisol redistributes extra fat - fat deposits in trunk area
Moon face with red cheeks
Dark striations in skin - protein breakdown - 103HypocortisolismAddisons disease - usually an autoimmune condition that damages and potentially destroys the adrenal cortex, resulting in low levels of cortisol.
Much less common than Cushings
Usually due to autoimmune destruction of adrenal cortex
May lead to drop in BP and glucose - 104ACTH Stimulation TestCan differentiate if the problem is in the pituitary rather than the adrenal glands.
Serum cortisol levels tested
Patient injected with ACTH
30-60 minutes - retest serum cortisol
Measures how well adrenal glands respond - 105Results of the ACTH stimulation testIf an initially low level of cortisol corrects with the addition of ACTH, the problem must be with the pituitary not secreting enough ACTH. If low levels do not correct, addisons is suspected because the patient is not producing enough cortisol even in the presence of ACTH.
- 106Role of the inner medulla of the adrenal glandsThis neurosecretory tissue plays a vital role in our fight or flight response, secreting epinephrine and norepinephrine under the influence of the sympathetic nervous system.
Release of these hormones prolongs the initial sympathetic response by the nervous system by binding to receptors on sympathetic effectors - 107The metabolic changes that occur due to epinephrine and norepinephrine release as neurotransmitters by the nervous system typically peaks after how long?30 seconds
But with the addition of the adrenal response, it can last for several minutes. - 108Their main hormonal effects of the inner medulla are ...To increase cardiac activity, blood pressure, glycogen breakdown and blood glucose levels.
- 109Pineal gland structureTiny pinecone–shaped structure
Dorsal aspect of the diencephalon - 110What does the pineal gland contain?Neurons, neuroglia, and endocrine cells that synthesize melatonin from the neurotransmitter serotonin.
- 111Pineal gland neurons and melatoninAs the neurons detect more light, less melatonin is secreted and the levels rise at night. We experience even higher levels of this hormone at night during winter months when there is less natural daylight
- 112Pineal gland nervous vs endocrine systemNervous system - receives visual stimuli
Endocrine system - secretes hormones - 113Pancreas structure and locationElongated gland
Head lies in the duodenum - in the first fold of the small intestine
Close to the stomach
Endocrine & exocrine (majority of the pancreas volume is exocrine with small clusters of endocrine tissues). - 114Pancreas endocrine and exocrine tissuesEndocrine tissue - pancreatic islets (islets of Langerhan). Will stain slightly paler with the routine histology stain. 1% of all cells of the pancrease
Exocrine cells - pancreatic acini. Secrete serous fluid containing digestive enzymes into ducts draining into the small intestine (continuous with the main pancreatic duct). - 1155 types of endocrine cells in the pancreatic IsletsJoined by gap junctions
Alpha, beta, delta, epsilon and PP cell - 116Alpha vs beta endocrine cellsAlpha cells - produce glucagon (the main blood glucose increasing hormone)
Beta cells - produce insulin (the main blood glucose lowering hormone). Beta cells make up approximately 75% of the pancreatic islet cells. - 117Glucagon and insulin working together to maintain homeostasisGlucagon rises or raises the blood glucose levels by increasing the rate of glycogen breakdown and glucose release from storage in the liver.
Insulin lowers blood glucose by increasing the uptake of glucose by the liver and most cells of the body and also by increasing the synthesis of glycogen, which is the main storage form of glucose in the skeletal muscles and the liver. - 118Diabetes MellitusHyposecretion of insulin
Abnormal target cell response to insulin
These patients have high blood glucose levels due to lack of insulin production or a functional problem with insulin or a combination of both - 119Diabetes InsipidusHyposecretion of ADH
nothing to do with insulin and patients do not have high blood glucose. In this disease, there is hyposecretion of anti diuretic hormone, so water is not being reabsorbed and this leads to massive loss in the urine - 120Diabetes symptomsPolyurea - increased urination
Polydipsia - increased thirst
Polyphagia - increased hunger (often present with diabetes mellitus) - 121Glucagon vs insulin - just ingested a mealIncreased glucose oxidation (process of breaking down glucose to provide energy for cellular work), glycogen synthesis, fat synthesis, protein synthesis --> building more of these essential biomolecules we remove more glucose from the blood
- 122Glucagon vs insulin - fasting stateIncreased glycogenolysis, gluconeogenesis (building of glucose from non carbohydrate building blocks), ketogenesis (production of ketone bodies - happens during the metabolism of fats)
- 123Upper digestive tract anatomyFacilitates ingestion and initial phases of digestion
Oral cavity, pharynx, esophagus - 124Lower digestive tract anatomyDigestion, absorption and excretion
Stomach, Small intestine, Large intestine, anal canal - 125Accessory organs of the upper digestive tractTeeth, tongue, salivary glands, liver, gallbladder, pancreas
- 1264 tissue layers of of the alimentary canalMucosa - inner layer
Submucosa
Muscularis externa
Serosa or adventitia - outer layer - 1273 layers of the mucosaMucous epithelium - lines the inside of a hollow tube or the lumen. Stratified squamous in the upper tract and simple columnar small intestine, stomach and most most of the large intestine.
Lamina propria - layer of areolar connective tissue under the epithelium. contains blood vessels, sensory nerve endings, lymphatic vessels, smooth muscle cells and lymphoid tissue and mucous glands in some of the regions.
Muscularis mucosae - thin layer of smooth muscle. - 128Purpose of villi on the mucosa layerStick into the lumen of the small intestine and this increases the surface area immensely for efficient absorption of nutrients.
- 129Histology of the submucosaLayer of connective tissue - thicker layer than the mucosa
Contains blood vessels, lymph vessels, glands, nerves
Submucosal neural plexus - network of nerves that contain sensory neurons, parasympathetic and sympathetic components that innervate the mucosa and submucosa. - 130Histology of the muscularis externaThick layer of muscle
Myenteric plexus - found between the circular and the longitudinal layers of muscle and it works with the submucosal plexus to control the enteric nervous system. - 131Myenteric plexus and submucosal neural plexus rolesParasympathetic stimulation increases muscle tone and activity and sympathetic stimulation decreases it. Increasing activity helps digest the food mechanically and move it along the digestive tract.
- 132Histology of the serosa or adventitiaSerosa - in regions that lie within the peritoneal cavity. Loose CT
Adventitia - for the regions outside the peritoneum. Dense CT tissue - sheaths
Thin outer layer of connective tissue - 133MesenteriesFolds of tissue - attach the intestines to the posterior abdominal wall, helping to stabilize. These folds are actually double folds of peritoneum in between the double folds are blood vessels, nerves and lymphatics, providing a route to a from the digestive tract.
- 134Digestion begins in the oral cavityMechanical digestion through accessory organs the teeth and the tongue. They also mix the food with salivary secretions.
No nutrients are absorbed in the oral cavity. - 135Cells of the buccal/oral cavityLined with stratified squamous epithelium that is referred to as the oral mucosa. There are keratinized areas as well, the areas that are exposed to the most severe abrasion, such a superior service of the tongue.
- 136TongueSkeletal muscle - for voluntary control
Tiny raised protrusions on the surface of the tongue that house taste buds.
Covered by a mucous membrane
Extremely maneuverable - 1373 parts of the tongueRoot, tip and body
- 138Lingual frenulumAnchors the tongue to the floor of the mouth to help stabilize it
- 139AnkyloglossiaLingual frenulum that is too short
- 140Floor of the mouth and undersurface of tongueRichly vascularized
Deep lingual vein
Many veins are superficial - great for sublingual meds - 141Histology of the TongueStratified squamous with varying levels of keratinization
Skeletal muscle - interlacing bundles, 3 layers of muscle (circular, longitudinal and oblique) - 142TeethOrgans of mastication
Cut, tear, grind ingested food - smaller the pieces, the more effective digestive enzymes are
Increase surface area for food - 143Outer portion of toothCrown and it's composed of a hard enamel, ideally suited for withstanding abrasion during mastication or chewing
- 144Area where blood vessels or nerves are in the toothPulp cavity. Surrounded by dentin - similar to bone but does not contain cells
- 145What covers dentin at the root and exposed surfaces?Root - cement
Exposed surfaces - enamel - 1463 pairs of major salivary glandsParotid, submandibular, sublingual
- 147Minor salivary glandsBuccal glands
In mucosal lining of cheeks and mouth
Less than 5% of total salivary volume - 148Parotid vs submandibular vs sublingualParotid - Largest, exclusively serous cells (pair normally affected when we get the mumps)
Submandibular - Second largest, mostly serous, some mucous
Sublingual - Smallest, mostly mucous - 149SalivaWatery, viscous (due to mucus content) suspension
~750-1200 mL produced daily
Immunoglobulins
IgA, IgM, IgG
Bacterial lysozyme - helps protect against damage and cavities
Alpha amylase - kicks off the chemical digestion of carbohydrates - 150PharynxTube through which a food bolus passes
Moved from the mouth to the esophagus
Process of deglutition/swallowing
Air passes through all three divisions
Only terminal portion involved in digestive system - 151EsophagusFirst segment of the digestive tube
Each end encircled by muscular sphincters
Gastroesophageal reflux disease (GERD) - failure of the sphincter and the acidic stomach contents corrode the esophagus - 152Esophageal sphinctersUES - pharynx and the esophagus at the border of the helps prevent air flow into esophagus
LES - helps prevent reflux of gastric contents - 153PeristalsisHow the esophagus moves partially digested food along the tube
Bolus of food in the pharynx is pushed into the esophagus by the contraction of the pharyngeal muscles, the rhythmic contractions of peristalsis push it down along the track towards the stomach - 154Histology of the esophagusLined with stratified squamous epithelium
- 1554 layers of the esophagusMucosa
Submucosa
Muscularis externa
Adventitia (most superficial) - 156Modifications in muscularis externa of the esophagusTwo layers of muscle (inner circular and outer longitudinal layer which is thicker)
Upper portion- both layers are skeletal muscle only
Middle portion - smooth muscle (circular) is internal to skeletal muscle (longitudinal)
Lower portion - both layers are smooth muscle only - 157What contributes to the potentially rapid spread of tumor cells outside the oesophageal boundaries?Lack of serosa and the majority of the esophagus - serosa provides more of a barrier with its serous fluid secretions
- 158Esophageal hiatusAn opening in the diaphragm
Permits passage of esophagus into abdomen
May become stretched or enlarged - bulging, hiatal hernia (opening stretches too far) - 159Esophagogastric JunctionJunction between lower esophagus & stomach
Clinically important area - site for many pathological conditions and most common site for esophageal carcinoma
Stratified squamous to simple columnar
Mucosa texture from smooth to plicated/folded - 160Esophageal varicesAbnormally dilated submucosal veins
Lower third of esophagus
Prone to rupture and hemorrhage - can be life-threatening
Leading causes are alcoholic liver disease
and viral hepatitis - 161Barrett EsophagusAbnormal growth occurs above the junction
Metaplasia of esophageal epithelium (caused by damage at or near the junction)
Columnar replaces stratified squamous
Anywhere above the junction
Response to esophagitis or injury
Patients with GERD are predisposed
May lead to more serious adenocarcinoma - 1624 anatomical regions of the stomachCardia - portion that lies next to the junction between the esophagus and stomach. There are abundant mucous glands here that help coat the junction for protection from acids and enzymes
Fundus - superior to the junction
Body - mixing bowl for ingested food and secretions that the stomach produces
Pylorus - forms a sharp curve and connects to the first part of the small intestine, the duodenum - 163Gastric mucosaSimple columnar epithelium
Rugae - temporary folds in epithelial lining that allow the lumen to expand
Gastric pits - depressions in lining that open up into the gastric surface - 164Gastric GlandsFound below the gastric pits
Parietal cells - secrete hydrochloric acid and intrinsic factor (essential for vitamin B12 absorption)
Chief cells - secrete digestive enzymes such as pepsinogen (when activated to pepsin digests proteins)
G cells - endocrine cells that produce a variety of hormones - 165Glands in the fundus vs pyloric regionFundus - secrete gastric juices
Pyloric region - secrete mucus and hormones involved in the coordination and control of digestive activity - 166Muscularis externa of the stomach3 layers of smooth muscle - longitudinal (superficial), circular, oblique (innermost layer)
- 167Main functions of the stomachLimited amount of absorption occurs in the stomach
Act as a temporary storage for the ingested food and the mechanical and chemical digestion or breakdown of food through enzymes and acid. - 168AdenocarcinomaMost stomach cancers
Often metastasized before discovered
Tumor originates from glandular structures in epithelial tissue - 169PeritonitisLocalized or diffuse inflammation of peritoneum
Usually due to bacteria in peritoneal cavity (normal flora basically relocates the normal bacteria that resides in our intestines)
Can be life threatening if not treated - 170Small IntestineMost convoluted part of the digestive tract
Lies in the abdominal cavity
Suspended by mesenteries - 1713 segments of the small intestineDuodenum - uppermost & shortest, horseshoe shaped. Receives chyme from the stomach and also digestive enzymes from the pancreas and liver - more mixing here. Retroperitoneal or behind the peritoneal cavity
Jejunum - where most of the chemical digestion and absorption of nutrients takes place
Ileum - longest portion that delivers undigested food to the next part of the digestive tract, the large intestine - 172Histology of the small intestineInner lining contans series of folds called circular folds (plicae) - these are permanent features that do not disappear when the small intestine it fills.
Muscularis externa - 2 layers of smooth muscle
Simple columnar epithelium - composed of enterocytes and goblet cells - 173Most of the circular folds are in which segment of the small intestine?Jejunum - increase surface area which increases absorption
- 174Intestinal VilliSmall finger-like projections - circular folds facing into the lumen
Vascular network that originates in the sub mucosa - 175MicrovilliSmaller projections on villi epithelium
- 176Intestinal crypts (crypts of Lieberkuhn)At the base of the villi - entrances to the intestinal glands
Between villi
Epithelium dips
Forming simple, tube-like invaginations - 177What do the capillaries in villi do?Carry absorb nutrients to the hepatic portal system, which delivers them to the liver
The liver will modify, detoxify, and make any other necessary changes before the blood heads to general circulation - 178LactealCentral lymphatic - a pillar in each villi
Transport things that are not able to enter capillaries - 179Brush BoarderMicrovilli that carpet the cells project into the lumen and they look like the bristles on a brush
Enterocytes on surface of villi
Absorptive cells - where absorption happens - 180Stem cellsNear the base of each intestinal gland
Divide continually replacing epithelial cells at the surface - 181Paneth cellsFound right at the base of the crypts and they play a role in nonspecific immunity by releasing substances that kill some bacteria and allow others like the normal flora to thrive
- 1823 segments of the large intestineCecum - pouch that receives material from the ileum. Appendix attached here
Colon - subdivided into the ascending, transverse, descending and sigmoid
Rectum - 183What are the main functions of the large intestine?Reabsorb water and compact the intestinal contents into feces for elimination
Some absorption takes place here - particularly some important vitamins that are generated by bacterial action. Temporary storage of fecal matter prior to defecation - 184Histology of the large intestineSimple columnar epithelium
Mucosa is relatively flat
No villi – but cells do have microvilli
Intestinal crypts are longer
Ratio of goblet cells to enterocytes is greater - also increases distally
Paneth cells in cecum and appendix
2 layers of smooth muscle - 185Anorectal junctionSimple columnar to stratified columnar to stratified squamous (at the junction between the rectum and the anal canal) Anus is keratinized
Clinically important area - common site of neoplastic changes - 186Inflammatory Bowel DiseaseDistortion of the mucosa, goblet cell depletion, and Paneth cell metaplasia
Inflamed lining of the digestive tract disrupts the body's ability to digest food, absorb nutrients and eliminate wastes in the normal healthy manner. - 187Difference between ulcerative colitis and Crohn's diseaseUlcerative colitis - limited to the colon
Crohn’s disease - anywhere in the digestive tract - 188Colorectal CancerMalignancy in colon or rectum
Usually adenocarcinoma
Screening with occult blood - fecal occult (hidden) blood test (FOBT) and fecal immunochemical test (FIT) - 189Associated tissues of the digestive tractLiver, gallbladder and the exocrine portion of the pancreas
- 190LiverLargest and heaviest internal organ
Most versatile and vascular organ
Sits just below diaphragm in right upper quadrant of abdominal cavity - 191What separates the lobes of the liver?Falciform ligament - thickens posteriorly and is called the round ligament, which is quite fibrous, and this marks the path of the fetal umbilical vein
- 192Hepatic LobulesAnatomical/functional units of the liver
Connective tissue divides these lobes from each other and they take on a hexagon shape - poorly defined in humans - 193Portal triadsEach lobule contains 6 portal triads, one at each corner, and each triad contains a vein and artery and a bile duct.
Branches from each of the arteries and veins delivers blood to the hepatic sinusoids of adjacent liver lobules - 194SinusoidsBlood vessels that do not have a basement membrane and they resemble large fenestrated capillaries
- 195Blood supply to the liverBlood enters lobules via branches of hepatic arteries and portal veins
Arterial blood - oxygenates hepatic cells
Portal blood - inspected and filtered by Kupffer cells
Nutrients for storage - enter hepatic cells
Some detox occurs in hepatic cells
To central vein --> hepatic veins --> vena cava - 196Blood flow and the sinusoidsBlood enters the sinusoids, and about 1/3 is oxygenated blood from the main hepatic artery. The rest is deoxygenated venous blood from the hepatic portal vein coming from the digestive tract.
As blood flows through the sinusoids, the solute and nutrient levels are regulated and molecules are absorbed or secreted
Central Vein collects the blood from the sinusoids. All the central veins from all the lobules merge to form hepatic veins which empty into the inferior vena cava. - 197Sinusoids are lined with what type of specialized macrophages?Kupffer cells
- 198Role of Kupffer cellsEngulf pathogens, cellular debris and damaged blood cells through phagocytosis
- 199Functions of the liverDetoxification by liver cells
Bile synthesis and secretion (~ 1 pint of bile per day) - bile is stored in the gall bladder
Liver metabolism - role in metabolizing proteins, fats, and carbohydrates
Storage of substances - iron, some vitamins
Production of important plasma proteins - 200Excessive ethanol consumptionToxic to the liver
Can cause morphological changes - extensive fibrosis, inflammation, cell damage
Fatty liver
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- Anatomy Flashcards on Anatomy Test 3, created by Lily James on 25/03/2022.
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