Lab Endocrine, Hemotology, Heart, Flashcards
What are the endocrine system organs? 9
Pineal Gland
Hypothalamus
Pituitary gland
Thyroid gland
Parathyroid glands (on dorsal aspect of thyroid gland)
Thymus
Adrenal glands
Pancreas
Gonads
• Ovary (female)
• Testis (male)
Endocrine System Functions
Endocrine system controls and integrates:
• Reproduction
• Growth and development
• Maintenance of electrolyte, water, and nutrient balance of blood
• Regulation of cellular metabolism and energy balance
• Mobilization of body defenses
Androgens general class of hormones that the reproductive system releases
Testes-testosterone (males)
Estrogen-females
Progesterone (steroid hormone
2 main releasing hormones that stimulate the release of the top 2
FSH-follicle stimulate hormone
LH-luteinizing hormone
Growth Hormone
Skeletal muscle-integration of collage and more bone formation and bone cells to grow
Increases dna synthesis
Increases amt of amino acids to build more structure in cells
Glucose production
Volume of the blood-adrenal gland and kidneys (aldosterone)
2 types of glands(secrete)
Exocrine-produce NON-hormonal substances (examples: sweat, saliva)
Have ducts to carry secretion to membrane surface
Endocrine-
• Produce hormones
• Lack ducts
Steroid Hormones Direct Gene Activation Mechanism
Receptor-Hormone Complex
(relatively uncharged and can pass through the lipid by layer) into the cytoplasm of the cell
Synthesized from cholesterol (lipid soluble)
Long 1/2 life
Gonad and adrenalcortical hormones
- hormone diffuses through the plasma membrane and binds an intracellular receptor.
- The receptor- hormone complex enters the nucleus.
- The receptor- hormone complex binds a specific DNA region.
- Binding initiates transcription of the gene to mRNA.
- The mRNA directs protein synthesis.
Amino Acid hormones Extracellular Receptors on the plasma membrane
Charged and can’t cross the lipid by layer (plasma membrane)
- Hormone(1stmessenger) binds to receptor (embedded in the membrane) changes the shape to accept the hormone
- Receptor activates G protein (Gs). That are on the cytoplasm side of the receptor and swaps a GDP for GTP (basically ATP)
- Gprotein activates adenylate cyclase. (Which will allow for the ATP to be chewed up and converted to cyclic AMP)
- Adenylate cyclase converts ATP to cAMP (2nd messenger). The second messenger system is activated at this point (activate one molecule from inactive to active and so forth down the line until the protein can activate transcription)
Pituitary Gland (2 lobes)
Anterior (front towards face)
Posterior (back towards back of the head)
Anterior-Adenohypophysis Glandular Tissue
Posterior-Neurohypophysis Nueral Tissue -directly connected to the hypothalamus
Posterior Pituitary Lobe
Neural tissue
hypothalamic- hypophyseal tract
Produces Oxytocin & Antidiuretic Hormone (ADH) through axon terminals into the capillaries
Synthesis of these two occur in the hypothalamus
In supraoptic nuclei & Paraventricular
Anterior Pituitary Lobe-glandular tissue
Hyphyseal portal system
Nuerosecretary cells
Activate target cells via cAMP 2nd messenger system
GH and PRL are NOT tropin hormones but the rest are
Oxytocin
Posterior Pituitary & Hypothalamic Hormones
• Strong stimulant of uterine contractions released during childbirth
• Also acts as hormonal trigger for milk ejection
• Both are positive feedback mechanisms
• Acts as neurotransmitter in brain
• Uses PIP2-calcium second messenger system
Antidiuretic hormone (ADH)
Posterior Pituitary & Hypothalamic Hormones
• Hypothalamus contains osmoreceptors that monitor solute concentrations
• If concentration too high, posterior pituitary triggered to secrete ADH
• Targets kidney tubules to reabsorb more water to inhibit or prevent urine formation
• Release also triggered by pain, low blood pressure, and drugs
• Inhibited by alcohol, diuretics
• High concentrations cause vasoconstriction, so also called vasopressin
Anterior Pituitary Lobe-glandular tissue
Secretes 6 hormones (all peptides)
- Growth Hormone
- Thyroid-stimulatinghormone(TSH)(tropic)
- Adrenocorticotropichormone(ACTH)(tropic)
- Follicle-stimulatinghormone(FSH)(tropic)
- Luteinizinghormone(LH)(tropic)
- Prolactin(PRL)
Tropic means that these hormones are primary action of the secretion of another hormone
Example: tsh releases T3,T4
FSH LH-reproductive testosterone, progesterone, estrogen
ACTH-hormones released from adrenal gland, glucocorticoids, androgens
Anterior Pituitary Hormones
• Growth hormone (GH)
• Also called somatotropin as it is produced by somatotropic cells
• Has direct actions on metabolism and indirect growth-promoting actions
• Direct actions on metabolism
• Glucose-sparing actions decrease rate of cellular glucose uptake and metabolism (anti-
insulin effects)
• Triggers liver to break down glycogen into glucose
• Increases blood levels of fatty acids for use as fuel and encourages cellular protein synthesis
• Indirect actions on growth:
• GH triggers liver, skeletal muscle, and bone to produce insulin-like growth factors (IGF’s)
• IGFs then stimulate:
•CellularuptakeofnutrientsusedtosynthesizeDNAandproteinsneededforcelldivision
• Formationofcollagenanddepositionofbonematrix
• GH stimulates most cells to enlarge and divide, but major targets are bone and skeletal muscle
Hunger hormone
Ghrelin
Also stimulates GH
• Growth hormone–releasinghormone(GHRH)
stimulatesGHrelease
TriggeredbylowbloodGHorglucose,orhighaminoacidlevels
• Growthhormone–inhibitinghormone(GHIH)
(somatostatin)inhibitsrelease •TriggeredbyincreaseinGHandIGFlevels
Thyroid Gland Anatomy
has two lobes connected by an isthmus (small connecting stalk) and is in the lower part of the neck just inferior the larynx.
The thyroid gland
• It is “butterfly” in morphology, having 1 parathyroid gland embedded in each “wing” posterior to the trachea
Thyroid Gland Cellular Anatomy
• Follicles: hollow sphere of epithelial follicular cells that produce glycoprotein thyroglobulin
• Colloid: fluid of follicle lumen containing thyroglobulin plus iodine and is precursor to thyroid hormone
• Parafollicular cells: produce hormone calcitonin (antagonist to parathyroid hormone) helps decrease the amount of calcium floating around in the blood via osteoclasts
Thyroid Hormone (TH)
• Bodyʼs major metabolic hormone
• Found in two forms
• T4 (thyroxine): major form that consists of two tyrosine molecules with four bound iodine atoms
• T3 (triiodothyronine): form that has two tyrosines with three bound iodine atoms and must be converted to T4 at tissue level
• Both are iodine-containing amine hormones
Which of the following types of hormones find to intracellular receptors, which act on the DNA to increase transcription?
Gonadal and Adrenocorticotropic
Steroid Hormones
Which of the following hormones are transported down the axons of the hypothalamic-hypophyseal tract to the posterior lobe of the pituitary gland?
Oxytocin
Antidiuretic Hormone
Which of the following hormones triggers liver, skeletal muscle and bone to produce insulin0like growth factors which then stimulates cellular uptake of nutrients which are used to synthesize DNA and proteins needed for cell division? It also stimulates most cells to enlarge and divide but major targets are bone and skeletal muscle.
Growth Hormone
The Parathyroid Glands counteract the parafollicular (c-cells)
Function to:
• Stimulate osteoclasts to digest bone matrix and release Ca2+ to blood
• Enhances reabsorption of Ca2+ and secretion of phosphate (PO43-) by kidneys
• Promotes activation of vitamin D by kidneys, which leads to increased absorption of Ca2+ by intestinal mucosa
Adrenal Gland
• Paired, pyramid-shaped organs atop kidneys Also referred to as suprarenal glands
• Structurally and functionally it is two glands in one
• Adrenal cortex: three layers of glandular tissue that synthesize and secrete several different hormones
• Adrenal medulla: nervous tissue that is part of sympathetic nervous system
Which cells release a hormone which is responsible for inhibiting osteoclast activity, inhibiting the release of calcium from the bone matrix and stimulates calcium uptake and its incorporation into bone matrix?
Parafollicular cells
Adrenal Cortex
• This area of adrenal gland produces over 24 different hormones collectively called corticosteroids
• Steroid hormones are not stored in cells
• Rate of release depends on rate of synthesis
• Three layers of cortical cells produce the different corticosteroids
1. Zonaglomerulosa—Mineralocorticoids (Aldosterone-regulate blood volume and pressure)
2. Zonafasciculata—Glucocorticoids (cortisol; more direct influences on metabolism)
3. Zonareticularis—Gonadocorticoids (androgens-testosterone, estrogen
Microscopic Structure of the Adrenal Gland zones
Adrenal Medulla
• Medullary chromaffin cells synthesize catecholamines epinephrine (80%) and norepinephrine (20%) **very quick response *fight or flight
• Effects of catecholamines:
• Vasoconstriction
• Increased heart rate
• Increased blood glucose levels
• Blood diverted to brain, heart, and skeletal muscle
• Both hormones have basically same effects, but:
• Epinephrine is more a stimulator of metabolic activities
• Example: bronchial dilation, and blood flow to skeletal muscles and heart
• Norepinephrine has more of an influence on peripheral vasoconstriction and blood pressure
• Responses to stressors are brief, unlike adrenal cortical hormones
Pineal Gland
• Small gland hanging from roof of third ventricle
• Pinealocytes secrete melatonin, derived from serotonin
• Melatonin may affect:
• Timing of sexual maturation and puberty
• Day/night cycles
• Physiological processes that show rhythmic variations (body temperature, sleep, appetite)
• Production of antioxidant and detoxification molecules in cells
Pancreas
• Triangular gland located retroperitoneal, posterior to the stomach
• Has both exocrine and endocrine cells
• Acinar cells (exocrine) produce enzyme-rich juice for digestion
• Pancreatic islets (islets of Langerhans) contain endocrine cells
• Alpha (a) cells produce glucagon (hyperglycemic hormone)
• Beta (b) cells produce insulin (hypoglycemic hormone)
Anatomy of the Pancreas
4 Pancreatic Regions:
- Head
• Head Proper
• Uncinate Process - Neck
- Body
- Tail
Photomicrograph of Differentially Stained Pancreatic Tissue
Acinar cells are exocrine
Blood Components
• Adults have between 4-6 liters of blood in circulation
• Liquid connective tissue: cells and extracellular matrix
• Matrix=Plasma (clear light-yellow fluid)
• Formed elements:
1. Erythrocytes (RBCs)
2. Platelets
3. Leukocytes (WBCs)
Plasma 47-63%
WBCs & Platelets<1%
RBCs 37-52%
*RBCs are the 37-52% of the total volume=Hematocrit
Blood Plasma: Nitrogenous Wastes
Toxic end products of metabolism
Blood Plasma: Electrolytes
Sodium is 90% of the plasma cations (+)
↑salt intake ->↑Na in plasma ->↑H2O ->↑BP
Erythropoiesis: Formation of Red Blood Cells
Erythrocytes or Red Blood Cells (RBCs)
Functions:
- Pick up O2 from the lungs and deliver it to the tissues
- Pick up CO2 from the tissues and unload in the lungs
• Most abundant formed elements of the blood
• Discoidal cell with a biconcave shape a thick rim and a thin sunken center
• No nucleus or organelles (lost during maturation)
• Rely on anaerobic fermentation to produce ATP (lack of mitochondria)
Structure of Hemoglobin
• RBCs are dedicated to respiratory gas transport
• Hemoglobin binds reversibly with oxygen
• Normal values: Males 13–18g/100ml;
Females: 12–16 g/100ml
• Hemoglobin consists of red heme pigment
bound to the protein globin
• Globin is composed of four polypeptide chains
• Two alpha and two beta chains
• A heme pigment is bonded to each globin chain
• Gives blood red color
• Each heme’s central iron atom binds one O2
Erythrocytes: Microscopic View
Reticulocytes
• Immature RBCs
• Named for the temporary network (reticulum) composed of ribosome clusters (polyribosome)
• Reticulocyte disintegrate the polyribosome in ~2 days
• Reticulocytes account for 1-2% of all erythrocytes in the blood of healthy people
• Reticulocyte count indicates the rate of RBC formation
Sickle cell disease
• Hereditary hemoglobin defects (recessive allele)
• Most common in people of African and Mediterranean descent
• Sickle-cell hemoglobin HbS, differs from normal HbA
in the β chain: Glutamic acid->Valine
• Only 1 amino acid is wrong in a globin beta chain of
146 amino acids
• RBCs become crescent shaped when O2 levels are low
• Misshaped RBCs rupture easily and block small vessels
• Results in poor O2 delivery and pain
Blood types
• Blood types A, B, AB and O->ABO blood group
• Determined by the presence/absence of A and B antigens in the RBCs
• Blood types and transfusion compatibility are a matter of interactions between plasma proteins and erythrocytes
• 1900 – Karl Landsteiner discovered blood types
• Blood types are based on large molecules->Antigens and Antibodies
Antigen: complex molecules such as proteins, glycoproteins and glycolipids that are genetically unique to each individual (except identical twins)
• They are found on the surface of all cells and enable the body to distinguish its own cells from foreign matter
ABO Blood Groups
• Plasma membrane: Outer surface glycolipids-> determine blood type
• When the body detects a foreign antigen immune response is antigen, and triggered, and antibodies are formed:
WBCs->B lymphocytes-> Plasma cells->Gamma Globulins -> antibodies
Antibodies bind to Antigens to mark them for destruction!
The ABO Blood Group
Antibodies (agglutinins) of the ABO blood group appear 2-8 months after birth and reach maximum concentrations between 8-10 years of age
Anti A (alpha agglutinin) =Antibody against Antigen A
Anti B (beta agglutinin) =Antibody against Antigen B
• Anti-A is present in the people with type O or type B blood • Anti-B is present in the people with type O or type A blood
Agglutination
Donor/Recipient Flow Chart
Blood Typing of ABO Blood Types
What is this patient’s Blood Type?
Rh(-) mom and Rh(+) baby
• Agglutinated RBCs hemolyze and the baby is born with severe anemia: Hemolytic Disease of the newborn (Erythroblastosis fetalis)
• About 1 in 10 cases of ABO incompatibility occur between mother and baby
Prevention: 28-32 weeks and at birth
RhoGAM: Rh immune globulin can be administered; it will bind to the fetal RBC antigens so they cannot stimulate her
immune system to produce Anti-D
Hemolytic disease of the newborn
• Babies are born severely anemic-> young RBCs enter the circulation (erythroblasts: Erythroblastosis fetalis)
• Hemolyzed RBCs release Hb->Heme-> bilirubin -> Kernicterus (brain damage)
• Can be treated with phototherapy (UV light) to degrade bilirubin
• For severe cases there is an exchange transfusion to replace the infant,s Rh (+) blood with Rh (-)
Leukocytes or White Blood Cells (WBCs)
• Least abundant formed elements in the blood
• Spend a few hours in the bloodstream and enter then to the tissues (diapedesis)
• Leukocytes do have organelles->protein synthesis in order to function
• Proteins are packed into lysosomes: appear like cytoplasmic granules
Types of WBCs
They are 5 kinds of WBCs and are distinguished from one another by their granules:
• Nonspecific granules (Agranulocytes)
1. Monocytes
2. Lymphocytes
• Specific granules (Granulocytes)
1. Eosinophils (eosin – Wright’s stain)
2. Basophils (methylene blue – Wright’s stain)
3. Neutrophils (don’t stain intensely with either stain)
Neutrophils
• Granulocyte: fine reddish granules (cytoplasm)
• Most abundant->60-70% of the circulating WBCs
• Nucleus: 3-5 lobes connected by strands
Polymorphonuclear leukocytes (PMNs)
• Band cells: immature Neutrophils
• Function: response to bacterial infection
• Neutrophilia->neutrophil count elevation
Eosinophils
• Granulocyte: abundant red to orange granules
• Only 2-4% of the WBC total (not many in the
blood)
• Abundant in the mucous membranes
• Nucleus: 2 large lobes connected
• Eosinophilia: in allergies, parasitic infections, collagen diseases and diseases of the spleen and central nervous system
Basophils
• Granulocyte: dark violet granules
• Rarest of WBCs: less than 0.5%
• Nucleus: S or U shaped
• Secrete:
1. Histamine (vasodilation)
2. Heparin (anticoagulant)
3. Chemical signals that attract Eosinophils and Neutrophils to the area
Lymphocytes
• Agranulocytes
• 2nd most abundant, 25-33% of WBCs
• Nucleus: round, ovoid and slightly dimpled on one side
• Stains dark violet, uniform
• Small (blood), medium & large (connective tissue)
• “Present” antigens for other cells to kill them
• Secrete antibodies
• Immune memory
Monocytes
• Agranulocyte
• Largest WBC, 2-3x the size of the RBC; 3-8% of WBCs
• Nucleus: large, kidney shape
• Abundant cytoplasm with fine granules
• Monocyte count rises in inflammation and viral infections
• In the blood they are called monocytes->Macrophages in the tissues
• Highly phagocytic cells and antigen-presenting cells
Leukocyte Disorders
Normal leukocyte value: 5,000- 10,000 WBCs/μL
Leukopenia is below 5,000 WBCs/μL
Leukocytosis is above 10,000 WBCs/μL
• Infection
• Allergy
• Dehydration
• Emotional disturbances
A differential WBC count is more useful since it identifies each WBC
Leukemia
Cancer of Hemopoietic tissues that produces too much WBCs (immature cells)
Classification: Acute or chronic
• Myeloid Leukemia
• Uncontrolled granulocyte production (basophils, eosinophils, neutrophils)
• Lymphoid Leukemia
• Uncontrolled Lymphocyte or monocyte production
