unit 2

endocrine vs exocrine gland

endo: releases hormone into blood vessels

exo: releases compounds (NOT HORMONES) into ducts

3 classes of hormones and characteristics
-solubility, derived from, and when synthesized?

biogenic amine:
water soluble(except thyroid), derived from AA, made in advance

protein:
water soluble, AA chains, made in advance

steroid:
lipid soluble, from cholesterol, synthesized on demand

3 types of stimuli that cause hormone secretion:

humoral: altered levels of ions or nutrients

neuronal: action potentials

hormonal: from another tropic hormone (TRH, GIH)

what is the master hormone regulator? (and its nuclei)

hypothalamus!

uses paraventricular and supraoptic nuclei

anterior pituitary gland:

is also called?

uses what system and describe pathway?

adenohypophysis: mostly gland cells (adeno)

uses hypophyseal portal system
1) hypothalamus secretes RH and IH secreted into capillary bed
2) travel through portal veins in infundibulum
3) exit capillary bed and bind to anterior pituitary cells
4) secrete hormones from anterior

posterior pituitary gland:

is also called?

uses what system and describe pathway?

called neurohypophysis: mostly axons and terminals

1) hormones (oxytocin and ADH) are made in hypothal
2) transported down tract to posterior where they are stored
3) released by AP

describe similarities and differences between the 2 hormones released by the posterior pituitary

released from?
actions?

-both small peptide hormones- GCPRs
-both stored in axon terminals

ASOP

ADH/vasopressin is released from the supraoptic nuclei of hypothalamus. causes increase water reabsorption and thirst

oxytocin is released from paraventricular nuclei of hypothal and causes increase in smooth muscle contraction in mammary gland ducts

describe growth hormone pathway:

GH-releasing or GH-inhibiting (somatostatin) binds to GPCRs on somatotroph cells

direct effect on adipose, liver, muscle. increases lipolysis, gluconeogenesis, and AA uptake

indirect effect on somatic cells through IGF by liver

overall GH effect

increase blood glucose levels for brain and other tissues

describe prolactin pathway

1) hypothalamus releases PRH and PIH (dopamine)
2) normally OFF - feeding inhibits PIH and increases milk production

describe luteinizing hormone (LH) and follicle stimulating hormone (FSH) pathway

1) hypothalamus releases gonadotropin releasing hormone (GnRH)

2) in females LH triggers ovulation and FSH triggers gametes and E2 production

2a) in males LH stimulates testosterone and FSH triggers gametes

describe the anatomy and function of the thyroid follicles

function: produce thyroid hormones

anatomy: follicle cells produce thyroid hormone and store in central colloids. parafollicular cells make calcitonin.

describe the TH pathway

hypothalamus releases TRH

anterior pituitary releases TSH

thyroid follicles produce THs

structure of THs

AA core and iodine atoms

describe TH synthesis in follicles

1) iodide ion and TG brought into colloid

2) iodide ion goes to iodine and attaches to TG

3) I+TG enter follicle cell via endocytosis and is converted to T3+T4 by enzymes

4) released

3 main categories of TH effects

1. metabolic and thermoregulation

   1. set basal metabolic rate (BMR)

2. promote growth and development

3. works with sympathetic system

Hypothyroidism has excessive ____

give symptoms and example of disease

TSH

Hashimoto’s: antibodies destroy thyroid

goiter

Hyperthyroidism has excessive ____

give symptoms and example of disease

THs

Grave’s: antibodies activate TSH

treat with radioactive I

3 hormones that control Ca balance

INCREASES BLOOD Ca

1. Parathyroid hormone (PTH): from parathyroid

   1. increases osteoclast activity and Ca release

2. Calcitriol (D3)

   1. PTH increases calcitriol synthesis

   2. calcitriol increases Ca absorption in intestine
      
      DECREASES BLOOD Ca

3. Calcitonin

   1. inhibits osteoclast activity

   2. important in pregnancy

layers of adrenal gland + what they secrete

• adrenal cortex

  • zona glomerulosa:

    • aldosterone regulated by RAAS

  • zona fasciculata + zona reticularia

    • produce cortisol + androgen regulated by HPA

• adrenal medulla : epi and norepi

describe the cortisol pathway

1. hypothalamus releases CRH

2. anterior pituitary releases B-lipotropin and adrenocorticotrophs

3. stimulates corticotrophs secrete cortisol

cortisol actions

• inc metabolic

• inc vascular tone

• anti-inflammatory

Addison’s

steroid deficit

describe regions of pancreas

exocrine pancreas: acinar cells produce digestive enzymes

endocrine pancreas: Islets of Langerhans cells produce hormones

Describe the different pancreatic islets cells:

alpha: secrete glucagon

beta: secrete insulin

what does glucagon do to liver?

increases glyconeogenesis (get glucose from glycogen), gluconeogenesis (make glucose), and lipolysis

what does insulin do to adipose and resting skeletal? (fasting vs fed)

fasting: no insulin, no GLUT4 in membrane

fed: glucose uptake by signaling cell to insert GLUT4 transporters via exocytosis into membrane

what does insulin do to liver? (fasting vs fed)

fasting: no insulin, glucose leaves via GLUT2 down gradient

fed: glucose enters via GLUT2 on gradient

what type of epithelium does epidermis have?

keratinized stratified squamous epithelium

5 skin functions

PVETS

protection
vitamin D synthesis
excretion
thermoreg
sensation

Layers of THIN SKIN epidermis

CGSB (COME GET SUN BURNT)

corneum: dead keratinocytes and glycolipids

granulosum: flattened cells

spinosum: keratinocutes connected to desmosomes

basale: closest to blood supply, youngest

What does thick skin have?

stratum lucidum layer: thin clear band cut off from nutrients

(CLGSB) come lets get sun burnt

what are skin layers held together by?

desmosomes (cell/cell) and hemidesmosomes (cells to basal lamina)

layers of dermis

20% papillary- loose connective

80% reticular- dense irregular connective, blood vessels, sweat and sebaceous

epidermal ridges are from

dermal papillae indent

flexure lines are

dermal folds that occur near a joint

cleavage lines are

gaps in dermis collagen

what determines skin color?

melanin, carotene, hemoglobin

Describe the different glands:
sebaceous
eccrine sweat
apocrine sweat

sebaceous: oil gland, creates sebum, HOLOCRINE SECRETION
eccrine sweat: duct extends to surface, merocrine secretion
apocrine sweat: duct empties into follicle, merocrine secretion

what is erythemia?

fever, hypertension, inflammation

what is the ABCDE rule for skin cancer?

Asymmetry: two sides dont match

Border irregularity: indented borders

Color: several colors

Diameter: larger than 6mm

Evolution: changes over time

1st line of defense: protective chemicals

lysozyme; breaks down bacterial cell walls

defensins and dermicidin: antimicrobial

mucin: forms mucus

Rank most to least % total WBCs

neut> lymph>mono>eosino>baso

never let monkeys eat bananas

neutrophils:

1st reponse to injury destroys invaders, high levels indicate bacterial infection

eosinophils:

attracted to foreign compounds that react with antibodies, high levels indicate allergy

basophils:

release histamine and heparin in damaged tissue

inflammation and allergy response

monocyte

leaves circulation to become macrophage

what cells are considered phagocytes?

neutrophils, macrophages, dendritic cells, B lymphocytes

what happens if a bacteria has a capsule?

needs to be coated with opsonin (antibody or complement) before being recognized

NK cells + mechanism

eosinophils and some lymphocytes

less picky about target cells; activated by abnormal signals

perforins, granzymes, pro inflammatory chemicals

what are the four signs of inflammation?

redness, heat, swelling, pain

2 stages of inflammation

1. basophils and mast cells secrete histamine and prostaglandins

2. phagocyte mobilization

   1. margination; adhesion mols interact

   2. diapedesis; neutrophils leave capillaries

   3. chemotaxis; neutrophils follow chemicals

describe interferons

1. virus invades

2. interferon gene turns on

3. cell 1 produces interferon mols

4. released by exocytosis and binds cell 2

5. cell 2 turns on antiviral genes and blocks viral reproduction

what do complement proteins do

• opsoniztion

• enhance inflammation

• insert MAC (membrane attack complex) and induce cell lysis

what is released by damaged cells during fever

pyrogens

what are antigens

foreign substance that generates antibody response

• has immunogenicity and reactivity

describe the development, maturation and activation of B lymphocytes

development: red bone marrow

maturation: in bone marrow
immunocompetence; makes one antigen receptor (antibody)
self tolerance; unresponsive to self antigens

activation: encounters antigen and help from T cell
HUMORAL IMMUNITY
antigen binds, forms clones, clones differentiate into plasma cells (make antibodies) and memory B cells that go dormant

describe difference between active and passive immunity

active: b lymphocytes used via pathogen or dead vax

passive: antibodies from mother or mono/polyclonals

how do antibodies enhance humoral attack?

NAPCA

nasty antibodies puncture cut antigens

neutralization
agglutination
precipitation
complement
activation

describe the development, maturation and activation of T lymphocytes

development: created in red bone marrow

maturation: T cell moves to thymus gland to mature
immunocompetence: recognizes self MHC (POSITIVE SELECTION)
self tolerance: die if they bind self antigen (NEGATIVE SELECTION)

activation: cell mediated immunity!
activation requires MHC/antigen and costimulation

describe the two different activated t lymphocytes
what type of MHCs?
What do they become?
what do they do?

CD4:
interacts with Class II MHCs, ANTIGEN PRESENTIN CELSL
becomes helper T cells and memory T cells
release cytokines and activate B cells and cytotoxic c cells

CD8:
interacts with Class I MHCs, on nucleated human cells
become cytotoxic T cells and memory T cells
release perforins and granzymes
work with NK cells

describe primary v secondary response of cell mediated immunity

primary: naive lymphocytes activated
secondary: memory cells from primary activated

what happens when interstitial pressure is greater than lymphatic?

fluid flows into lymphatic capillaries

what do follicles in lymphoid tissue indicate

B cells, humoral immunity,

no follicles in thymus (t cells)

function and structure of spleen:

function: lymphocyte proliferation, blood filtering

structure: white pulp (lymphocytes) and red pulp (RBC destruction)

function and flow of lymph of lymph nodes:

function: filter lymph, activate immune system

flow: lymph enters through afferent
flows through cortex and follicles
screened by lymphocytes and phagocytes
flows out efferent

examples of MALTs

peyeres patches, tonsils, appendix