Physiology Exam 4

Immsune system function

• protect against infection by microbes

• Isolate and remove non-microbial foreign substances

• Destroy cancer cells that are in the body (immune surveillance)

• distinguish between self and non self cells

Innate Immunity

• nonspecific immune system

• bodily surfaces, inflammation pathway, complement system, phagocytes (neutrophils, monocytes, macrophages)

Adaptive Immunity

• specific immunity that systemily travels through body continuously

• has memory (B cells)

• late responders due to recognition of specific antigen

Immune system cells

• leukocytes or white blood cells

• 5 main types:

Neutrophils, Eosinophils, Basophils (granular)

Monocytes, Lymphocytes (agranular)

Role of Hematopoietic Stem cells or HSC

• origination of leukocytes

• monocytes → macrophage

• lymphocytes → B lymphocyte and T lymphocyte

How does innate immunity recognize pathogens

• Pathogen associated molecular patterns on the pathogen

• recognized by pathogen recognizing receptors on toll like receptors that project out of a phagocytic cell

Events occur in inflammation pathway

• local non specific resposne

1. entry of microbe

2. activation of the compliment system

3. Mast cell triggered to release cytokine Histamine which triggers near by capillary to vasodialate

4. Extravasion of more phagocytic cells from capillary occur

Main types of phagocyte

• neutrophils and macrophages

Cardinal signal of inflammation

• fever

• macrophages release endogenous pyrogen in response to bacterial molecules

• signal to hypothalamus to raise body temp

what is an interferon

• cytokine release by infected cells that tell neighboring cells to resist the infection

• stop virus from spreading

what is an antigen

• foreign molecule capable of triggering an immune response

what are the lymphoid organs

• primary: site of maturation (thymus and bone marrow)

• secondary: some of encounter and activation (groin, armpit, neck)

what is colonel selection theory

• each lymphocyte is specific for a pathogen

• exposure to a pathogen results in production of clones

• creates memory B cells with receptors specific for antigen or Plasma B cells that secrte antibodies to TAG pathogen

How do B cells activate

• specific B cell receptor that bind to specific antigen

• once binded differentiate into plasma cells and memory cells

Function of antibodies

• bind to antigen to inactivate toxins or virus

• link microbe to macrophages or neutrophils

• stimulate other cells

Types of T cells

• Cytotoxic killer T cells: destroy host cells with CD8+ receptor

• Helper T cells: modulate activities of there Immunity cells with CD4+ receptors

• Supressor T cells: regulatory and dampen response

Types of antigen presenting cells

• macrophages

• B cells

• Dentrictic cells

Activation of T cells

• antigen has to be complexed with own bodies properties before a T cell receptor can bind to antigen

Helper T cell antigen presentation

• antigen presenting cell engulf antigen

• antoen binds to MHC class II

• MHC class II with antigen and CD4+ receptor on T cell form complex

• T cell can then bring antigen to B cells to promote the creation of plasma or memory cells

OR

• T cells will release cytokine interleukin 2 to promos the production of cytotoxickiller T cells

Cytotoxic killer T cell antigen presentign

• a target cell will bind antigen to MHC class I receptor

• CD8 recpetor and MHC class I will form a complex and is further activated by Helper T cell cytokine

• Killer T cell will then secret performs and granzymes to induce lysis of target cells

Active Immunity Primary réponse

• when exposed to microbe the body will generate effector and memory cells

Active immunity secondary response

• if pathogen enters body again memory cells will provide a larger rapid response

Passive immunity

• borrowing of antibodies or transferring to provide immediate protection

Autoimmune disease

• immune system tolerant to self preventing immune system from attacking owns tissue

• creates B cells that produce antibodies that bind to self antigens

• cytotoxic killer T cells will then bind and kill own cells

Immunodeficiency

• not enough immune defense in body

• infects and killer helper T cells whihc cause a diminished B and cytotoxic killer T cell function

• HIV and AIDS is acquired

Hypersensityivy

• immune réponse to enviornemtnal antigens

• allergen binds to B cells → B cell will make plasma cells producing IgE antibody → bind to Mast cell with realize histamine and cause excitatory reaction

Natural Killer cells

• part of innate immunity that recognizes malignant cells or infected cells and kills how cytotoxic killer T cells do

Lymphocytes

• provide immunological surveillance agianst cancer cells

• cytotoxic killer T cells

Tumor cells

• evade immune surveillance by suppressing immunity

Lymphocyte

• malignant lymphocytes especially B cells

Leukemia

• malignancies of white blood cells in bone marrow

Myeloma

• malignancy of plasma cells found in bone marrow

functions of the kidney

• regulate H2O and electrolyte balance, help maintain proper acid-base balance in body, eliminate waste of bodily metabolism and foreign compounds, gluconeogenesis, hormone secretion (renin, EPO, Vitamin D)

components of the kidney

• renal corpuscle

• tubule

Basic renal processes

1. glomerular filtration (renal corpuscle → Bowmans capsule)

2. tubular reabsorption ( tubule → capillary)

3. Tubular secretion (capillary → tubule)

4. excretion

Filtration barriers in glomerular filtration

1. glomerular capillary endothelium (very fenistreated a lot can pass)

2. basement membrane (tight to repel proteins from entering)

3. podocytes that split diaphragm between foot processes

How is GFR regulated

• SNS works to impact the afferent and efferent arterioles

• Vasodialation = Low SNS = high GFR

• Vasoconstriction = High SNS = low GFR

Tubular reabsorption

• very selective and variable

• rates are high for water, ions, and nutrients

• low rates for waste products

Mechanism of tubular reabsorption

• diffusion due to tubule interstitial concentration gradients

• mediated transport of glucose and AA by Na+ reabsorption (secondary active transport)

• Na+ kept low in the cell by the Na/K ATP pump

• limited due to saturation of transporters or transport maximum

Renal Clearance

• kidneys removing excess ions and wastes from blood through filtration and secretion

• Paired with GFR → high GFR + low reabsorption = high clearance

• completely reabsorption = no to little clearance

Substances usually undergoing tubular secretion

• H+

• K+

• organic ions

Sodium and water balance

• Gains of Na+ by ingestion loss via skin, GI urine

• major control point is the urine loss

• Na is freely filterable at glomerulus → cardiovascular baroreceptors and Na+ reabsorption by kidneys are control point

• Lower GFR = decrease amount of Na+ secretion (due to SNS on arterioles) when body Na levels are low

RAAS control of Na+ reabsorption

• stimulates Na reabsorption and acts on collecting ducts

• renin released by JGA cells on the afferent arteriole → release when baroreceptors aren’t firing, SNS is low, and there is little Na in filtrate (Macula Densa cells)

Renal control of H2O

• ADH secretion by stimulus of baroreceptors (reduction of firing) and osmorecptors (increase firing)

Acid Base Balance

• Kidneys maintain blood pH b reabsorbing bicarbonate and secreting H+

• Alkalosis (high pH): secret less H and reabsorb less bicarbonate

• Acidosis (low pH): secret more H and reabsorb more bicarbonate

Micturation muscles

• detrusor muscle: PNS

• internal urethera sphincter: SNS

• external urethra sphincter: somatic motor neuron

digestive tract functions

• mobility

• secretion

• digestion

• absorption

gastric emptying

• amount of chyme in stomach

• high fat amounts in SI delays

• High acid in SI slows

• High osmolarity of chyme or SI slows

• Too much chyme in SI (dissension) slows

functions of liver

• first organ to receive absorbed nutrients (hepatic portal vein)

• produces plasma proteins

• removes bilirubin

• manufactures bile salts

• alcohol metabolism

• store nutrients

• Reeves toxins

Digestive mobility and secretion regulation

• intreluminal content

• ANS smooth muscle function

• intrinsic nerve plexus

• extrinsic nerve

• hormones

Regulation of secretion (luminal stimuli_

• mechanoreptors: dissension of wall

• osmorecptors: osmolarity of chyme

• chemoreceptors: acidity of chyme

Regulation of Gi function (enteric ns)

• long reflex: receptors detect stimulus → CNS detects smell, sight, or thought of food → efferent impulse at local nerve plexus

• short reflex: stimulus detected by afferent impulse → sent to local nerve plexus → smooth muscle contraction or gland section from effector response

Phases of gastric secretion

• cephalic phase: receptors in head stimulated by senses

• gastric phase: food reaches the stomach, protein increases this

• intestinal phase: intestinal tract stimuli

X inactivation

• females XX chromosome experiences the dosage effect

• one X chromosome will secret more chemical than the other turning the other X chromosome into a Barr Body

Secondary male reproductive

• epididymis

• vas defers

• ejaculatory duct

• urethra

functions of female reproductive tract

• produce ova

• reception of sperm

• transport sperm and ova

• maintain developing fetus

• form placenta

• give birth to baby

• nourish infant after birth

what do sertori cells secrete

• inhibit and start spermogenesis

• triggered by FSH

What do leydig cells secrete

• testosterone triggered by LH

What do granulosa cells secret

• estrogen triggered by FSH

• also secret inhibin

What do theca cells secret

• androgens by LH

Menstrual phase of uterine cycle

• release uterine prostaglandin

• cause vasoconstriction of endometrial vessels and death of cells

Prolifreative phase of uterine cycle

• new growing follicles influence endometrium cells to proliferate

Secretory phase utrine cycle

• concurrent with corpus luteum

• progesterone stimulates endometrial glands to secrete glycogen

Whattype of transport does tubular reabsorption use

• trasepitheal transport

• secondary active transport

What type of transport does tubular secretion use

• diffusion down concentration gradient

What is the basic renal process for water and sodium reabsorption

• Na is freely filtered at glomerus

• almost all Na and water reabsorbed with no secretion

how is renal sodium regulated by baroreceptors

• decrease firing of baroreceptors = more SNS = vasoconstriction in afferent arteriole of glomerulus = lower GFR = less Na excreted