HAPII Final

Inflammation

Nonspecific response to tissue injury that is marked by redness, heat, swelling, and pain

Innate immunity

Inherited immunity, contains the first and second lines of defense

Mechanical barriers

First line of defense in the immune system; innate. Includes the skin and mucous membranes, which prevent the entrance of pathogens

Chemical (surface) barriers

Second line of defense in the immune system, innate. Include phagocytes, NKCs, inflammation, antimicrobial proteins, and fever

Defensins

Peptides produced by neutrophils

Collectins

Proteins that protect against bacteria, yeast, and some viruses

Interferons (IFN)

Immune modulating proteins secreted by virus-infected cells

Complement system

consists of >30 blood proteins in blood (inactive form). Activation enhances inflammation and directly destroys bacteria and enhances both innate and adaptive defenses

Natural Killer Cells (NKCs)

A small population of lymphocytes that defend against viruses and cancer cells by secreting cytolytic
substances called perforins that lyse cell membrane and kill by apoptosis

Phagocytes

Ingest and digest foreign invaders, include neutrophils and macrophages

Adaptive immunity

the third line of specific defense mechanisms that respond to particular foreign antigens, recognizing 'non-self' antigens from 'self', and building a targeted response to eliminate the specific antigen. It involves immunological memory, allowing for a faster response upon re-exposure, and is carried out by lymphocytes and macrophages. There are two types of adaptive defenses: the Cellular immune response (performed by immune cells) and the Humoral immune response (performed by antibodies).

MHC Class I

Found on all nucleated cell surfaces except for RBCs, allows T cells to bind

B cells

Activated by CD4 cells and differentiate into plasma cells or memory cells

Plasma cells

Secrete specific antibodies at rate of 2000 molecules per second for 4 to 5 days, then die

Antibodies

Circulate in blood or lymph; bind to antigens, marking them for destruction

Memory cells

Provide immunological memory and mount an immediate response to future exposures to same antigen

Vaccines

Contain pathogens that are dead or attenuated, forces the primary response to be started without the side effects of the infection, booster vaccinations enhance the secondary response

Lymph nodes

Contain macrophages that filter lymph

Spleen

Filters blood and destroys and recycles RBCs

Lacteals

Lymph capillaries in the small intestines that assist in fat absorption

Thoracic duct

Drains the majority of the lymph from the lymph system, left side of body

Right lymphatic duct

The second major lymph collecting duct that serves the region around the right arm/chest

Edema

Occurs when the lymph flow of interstitial fluid is blocked

Hemoglobin

Transports oxygen

Granulocytes

Leukocytes that contain visible cytoplasmic granules, include neutrophils (60-70%), eosinophils (0.5-1%), and basophils (2-4%). Granules have proteolytic enzymes that help break down pathogens and bacteria

RBC antigens

Presence (clumping)/absence (no clumping) when exposed to an antibody used to classify blood cells into groups

Agglutinogens

Antigen that triggers a response

agglutinins

Antibody that acts against foreign agglutinogens

agglutination

the clumping of particles, such as bacteria or red blood cells, suspended in a liquid, typically caused by antibodies binding to antigens

Amino acid-based (water soluble EXCEPT T3/4) hormones

Act via G protein second messenger systems; cAMP and PIP2-Calcium

Lipid-soluble hormones

Enter cell to act

Glucagon

Increases blood glucose levels by targeting the liver to release stored glucose

Melatonin

Regulates sleep cycle

Antidiuretic hormone

Increases kidney water reabsorption and retention, can be weakened by alcohol

Atrial natriuretic peptide

• increases urinary sodium excretion

  • Reduces blood volume and promotes vasodilation

  • Lowers blood pressure

Endocrine signalling

• Signalling mechanisms: Chemical

• Primary chemical signal: Hormones

• Distance traveled: Long or short

• Response time: Fast or slow

• Environment targeted: Internal

Exocrine (nervous) signalling

• Signalling mechanisms: Chemical/electrical

• Primary chemical signal: Neurotransmitters

• Distance traveled: Always short

• Response time: Always fast

• Environment targeted: Internal and external

Carbonic acid-bicarbonate buffer system

resists changes in pH by removing excess H+ ions through a reversible reaction that combines H+ with HCO3- to form H2CO3, which then dissociates into CO2 and H2O.

Left side of the heart

• Fully oxygenated blood arrives from lungs via pulmonary veins

• Blood sent to all organs of the body via aorta

Right side of the heart

• Oxygen-poor blood arrives from inferior and superior venae cavae

• Blood sent to lungs via pulmonary trunk

SA node

Modified cardiocytes that serves as the pacemaker of the heart that initiates each heartbeat and determines heart rate

P wave

• SA node fires, atria depolarize and contract

• Atrial systole begins 100 ms after SA signal

QRS complex

• Ventricular depolarization

• Complex shape of spike due to different thickness and shape of the two ventricles

ST segment

• Ventricular systole

• Corresponds to plateau in myocardial action potential

T wave

Ventricular repolarization and relaxation

Tunica media

Regulates vessel diameter

Precapillary sphincters

Regulate capillary flow

How does blood pressure change the further you get from the heart?

Decreases

Veins

Low pressure vessels that have valves to assist blood flow

Vasodilation

Increases blood flow

Pulmonary edema

Caused by left sided heart failure

What drives gas exchange?

Pressure gradients

Inspiration sequence of events

• Inspiratory muscles contract (diaphragm descends; ribcage rises)

• Thoracic cavity volume increases

• Lungs are stretched; intrapulmonary volume increases

• Intrapulmonary pressure drops (to -1 mmHg)

• Air (gases) flows into lungs down its pressure gradient until intrapulmonary pressure is 0 (equal to atmospheric pressure)

Expiration sequence of events

• Inspiratory muscles relax (diaphragm rises; rib cage descends due to recoil of costal cartilages)

• Thoracic cavity volume decreases

• Elastic lungs recoil passively; intrapulmonary volume decreases

• Intrapulmonary pressure rises (to +1 mmHg)

• Air (gases) flow out of lungs down its pressure gradient until intrapulmonary pressure is 0.

Air tends to flow in what way with pressure?

High → low

Three ways CO2 is transported

• 7-10% dissolved in plasma as CO2

• 20% bound to hemoglobin

  • Referred to as carbaminohemoglobin

• 70% transported as bicarbonate ions (HCO3-) in plasma

  • Bicarbonate

    • CO2 + H20 → carbonic acid (H2CO3) which quickly dissociates into bicarbonate (HCO3-) and H+

Carbonic anhydrase

Enzyme that reverses bicarbonate reaction

Acidosis

Increase in CO2, decrease in pH

Alkalosis

Decrease in CO2, increase in pH

Surfactant

Thin fluid layer that aids in diffusion and keeps alveoli from collapsing

Type I alveolar cells

Single layer of simple squamous epithelium covered with capillaries that forms the alveolar wall

Type II alveolar cells

Scattered cuboidal cells that secrete surfactant

pO2 in arterial blood

100 mmHg

pCO2 in arterial blood

40 mmHg

pO2 in systemic veins

40 mmHg

pCO2 in systemic veins

46 mmHg

Where is most body water contained?

Intracellular

Intracellular fluid (ICF) compartment

fluid inside cells that accounts for 2/3 of total body fluid

Extracellular fluid (ECF) compartment

• Fluid in two main ECF compartments outside the cells

  • = 1/3 of total body fluid:

    • Plasma: 3 L (separate of the IF, found in blood vessels)

    • Interstitial fluid (IF): 12 L in spaces between cells

      • Also considered part of IF: Lymph, CSF, humors of the eye, synovial fluid, serous fluid, and gastrointestinal secretions

Electrolytes

• Dissociate into ions in water

  • Examples: Inorganic salts, all acids and bases, some proteins

  • Ions conduct electrical current

  • Greater osmotic power than nonelectrolytes

    • Greater ability to cause fluid shifts due to ability to dissociate into two or more ions

Nonelectrolytes

• Most are organic molecules

  • Do not dissociate (dissolve) in water

  • Examples: glucose, lipids, creatinine, and urea

    • No charged particles are created

Dehydration

Causes cells to shrink

Salivary amylase

• Desires a neutral environment (pH 6.5-7)

• Starts working in the mouth and continues to work in the stomach until it is inactivated (acid deactivates it)

• Digests starches

Parietal cells

Secrete HCL and Intrinsic factor (required for B12 absorption)

Cholecystokinin (CKK)

Stimulates gallbladder contraction, pancreatic enzyme secretion

What kind of diet should an individual who is missing their gallbladder be on?

Low-fat

Glomerular filtration

Produces cell-free and protein-free filtrate

Tubular reabsorption

Selectively returns 99% of substances from filtrate back to blood in renal tubules and collecting ducts

Tubular secretion

Selectively moves substances (wastes) from blood to filtrate in renal tubules and collecting ducts

Proximal convoluted tubule

Site of most reabsorption

Glomerular hydrostatic pressure

Drives filtration

Aldosterone

Increases Na reabsorption and potassium secretion

Countercurrent multiplier

Concentrates urine

Micturition reflex

Triggered by bladder stretch

Seminiferous tubules

Site of sperm production

Epididymis

Site of sperm maturation

Leydig cells

Secrete testosterone, contain receptor proteins for LH

Sertoli cells

• Blood-testes barrier

  • Tight junctions form blood testis barrier

  • Prevents autoimmune destruction of haploid sperm

  • Prevents sperm antigens from escaping into blood

    • Would cause activation of immune system

Ovulation

FSH causes the follicle to grow large and thin-walled, and triggers a LH surge. This causes the wall of the follicle to rupture and release an egg

Progesterone

Maintains endometrium, high during luteal phase

Menstruation

Caused by hormone levels dropping

Fertilization

Occurs in uterine tubes

Inhibin

Regulates FSH

Prolactin

Milk production

Oxytocin

Uterine contractions

Sperm

Determines genetic sex based on which chromosomes are carried (XX or XY)

Testosterone

• Male secondary sex characteristics

  • Pubic, axillary, facial hair

  • Growth of chest hair; deepening of voice

  • Skin thickens and becomes oily

  • Bones grow, increase in density

  • Skeletal muscles increase in size and mass

  • Boosts BMR

  • Basis of sex drive in males