A&P Test 3

what is blood

fluid component of cardiovascular system

functions of blood

• transport (gases, nutrients, wastes, and hormones)

• regulates pH and ion composition of interstitial fluids

• restricting fluid loss at injury site (clotting)

• defense (white blood cells provide immune function)

• temperature (redistribute heat)

erythrocytes

• red blood cells

• carry oxygen and carbon dioxide

leukocytes

• white blood cells

• immune response

platelets

cell fragments that help with clotting

hemocytoblast

immature blood cell that can become a RBC or WBC

blood sampling

• powerful diagnostic tool

• can collect blood from any vessel for analysis

• veins are preferred - low pressure

• arterial puncture needed to examine blood gasses

whole blood composition

• plasma (46-63 %)

• formed elements (38-54 %)

plasma composition

• water (92%)

• plasma proteins (7%)

• other solutes (1%)

hemopoiesis

• production of blood

• 1. pluripotent stem cell (hemocytoblast)

• 2. colony forming units

• 3. precursor cells

• 4. mature cells

erythropoiesis

• red blood cell production

• ~3-5 days

• requires iron, B12, folic acid

• nucleus is ejected for function

• high turn over rate

• life span ~120

erythropoiesis steps

1. stem cell - hematopoietic stem cell

2. committed cell - proerythroblast

3. ribosome synthesis

4. hemoglobin accumulation

5. ejection of nucleus

red blood cells

• most abundant formed element

• shaped like bi-concave disc

• high surface area/volume (lots of area for gas exchange)

• slightly flexible (squeeze thru capillaries)

• no organelles

• obtains coloration from hemoglobin

hemoglobin

• contains heme

• folded protein with 4 subunits

• site that holds oxygen

oxyhemoglobin

• bound to oxygen

• bright red

deoxyhemoglobin

• after oxygen has been delivered

• dark red

anemia

• low number of RBCs

• low Hb content

• symptoms: lethargy, weakness

• reduces O2 transport - body weakens

polycythemia

• too many RBCs

• blood is too thick and cannot move through vessels easily

blood loss anemia

• loss of RBCs due to hemorrhage

• can be caused by NSAIDS

  • cause stomach and GI bleeding

  • inhibits clotting

  • RBC production is hampered

iron deficiency anemia

• most common

• not enough iron to make heme molecules

• body can’t make Hb

• no way to carry O2

pernicious anemia

• vitamin B12 deficiency

• B12 is needed for erythropoiesis

• either low B12 in diet or not able to absorb B12 in digestive system

sickle cell anemia

• caused by point mutation

• defective beta chain in Hb molecules

• Hb molecules stick together after releasing O2

• causes RBCs to become rigid, fragile, and sickle shaped

• RBCs get hooked and stuck together causing blockage of blood vessels

• die faster than normal RBCs

what is erythropoiesis stimulated by

• erythropoietin

  • increases when environmental O2 is low (hypoxemia)

• androgens (ie. testosterone)

blood doping

• enhancing athletic performance due to increased O2 supply to muscles

• taking EPO/testosterone can increase blood viscosity and hematocrit up to 65%

• removing blood while training then reinfusing RBCs before a competition

order of abundance for leukocytes

• Never Let Monkeys Eat Bananas

• neutrophils, lymphocytes, monocytes, eosinophils, basophils

granulocytes

• neutrophils, eosinophils, basophils

• have granules

neutrophils

• most abundant

• phagocytosis of bacteria

• release antimicrobial chemicals

• have 2-3 lobes in nucleus

eosinophils

• phagocytosis of antigen-antibody complex and allergens

• release chemicals to kill parasitic worms

• stain reddish

basinophils

• rare

• secrete histamine (vasodilator)

• secrete heparin (anticoagulant)

• important for immune response to work

• stain bluish

agranulocytes

• lymphocytes

• monocytes

• absence of granules

lymphocytes

• second most abundant WBC

• role in specific immunity

• secrete antibodies

• coordinate other immune cells

• immune memory

• seen a lot in viral infections

• big nucleus

monocytes

• differentiate into macrophages

• phagocytosis

• slow but numerous

• very large cells

platelets

• fragments of megakaryocytes

• function in clotting

• create a plug

• initiate a signaling cascade

• platelets form when cytoplasm of megakaryocytes break

thrombopoiesis

production of platelets

process of stopping blood or bleeding (hemostasis)

1. vascular spasm/phase

2. platelet phase

3. coagulation phase

vascular phase

• vessel spasms

• endothelial cells contract and release endothelin

• endothelin signals for smooth muscle to contract and for endothelial cells to divide and repair

• endothelial cells become sticky

platelet phase

• form platelet plug

  • 1. adhesion - platelets stick to endothelial cells

  • 2. aggregation - platelets stick to eachother (15 seconds after injury)

• platelets release chemical signals to stimulate clotting process

  • ADP - low energy, not enough phosphate

  • PDGF - platelet derived growth factor

coagulation phase

• requires clotting factors

  • Ca2+

  • 13 proteins working in a cascade

  • vitamin K

• end result is fibrin

  • seals injury site

• begins 30 seconds after injury

• can take 8-18 minutes to complete

• bleeding usually stops in 1-4 minutes

functions of respiratory system

• gas exchange

  • oxygen to blood

  • CO2 from blood to atmosphere

• moving air

• protection

  • guards respiratory membranes from dry/cold air and inhaled pathogens or debris

• communication

• olfaction (smells)

ventilation

air transport

respiration

gas exchange

conducting zone of respiratory system

• site of ventilation

• cleanse, humidify, warm air

• nose to terminal bronchioles

respiratory zone of respiratory system

• site of respiration

• exchange CO2 and O2

• respiratory bronchioles to alveoli

nasal cavity

• superior portion

  • ethmoid and sphenoid bones

• inferior portion

  • hard bone and soft palates (muscle)

• midline nasal septum

• inside of nostrils are covered with hair to filter debris

• nasal conchae

  • circulates air to warm and humidify

paranasal sinuses

• in frontal, ethmoid, sphenoid, and maxillary bones

• lighten skull

• secrete mucus

• help to warm and moisten air

pharynx

• muscular tube

• connects nasal cavity and mouth to larynx and esophogus

• three regions

nasopharynx

• uvula closes off and provides passage for air only

• first section of pharynx

oropharynx

• second section of pharynx

• for air and food

laryngopharynx

• third section of pharynx

• epiglottis closes off and provides passage for air only

glottis

opening connecting pharynx to larynx

epiglottis

• covers glottis

• prevents food from entering airway

larynx

• attaches to hyoid bone

• continuous with trachea

• airway

• routes air and food into proper channels

• voice production

what are the 9 cartilages of the larynx

1. thyroid cartilage (hyaline)

2. cricoid cartilage (hyaline)

3. paired arytenoid (hyaline)

4. paired cuneiform and corniculate cartilages (elastic)

5. epiglottis (elastic cartilage)

vocal ligaments

• contain elastic fibers

• form core of vocal folds (true vocal cords)

• glottis is opening between vocal folds

• folds vibrate to produce sound as air moves from lungs to external environment

vestibular folds

• superior to vocal folds

• no part in sound production

• help to close glottis during swallowing

trachea

• within mediastinum

• wall with 3 layers

mucosa

• ciliated epithelium with goblet cells

submucosa

• connective tissue with seromucous glands

adventitia

• connective tissue

• encasing C-shaped rings of hyaline cartilage

mucus escalator

• respiratory mucosa lines conducting zones

• cells produce mucus to catch particles

• cilia sweep particles toward pharynx

• found in trachea, bronchi, and bronchioles

alveolar defense

• alveolar macrophages

• aka dust cells

• eat dust

nasal filtration

• nasal cavity lined with hairs

• filters out large particles

• nasal conchae

  • boney ridges that stir air

primary bronchi

• trachea bifurcates into right and left primary bronchi

• primary bronchi enter lungs and branch profusely

• enter hilum of one lung

• right bronchus is wider, shorter, more vertical

lobar bronchi (secondary)

• primary bronchus branch into secondary bronchus

• 3 on right

• 2 on left

• each lobar bronchus supplies one lobe of the lungs

segmental bronchi (tertiary)

• lobar bronchi branch into tertiary bronchi

• cartilage rings becomes plates

• divide repeatedly

bronchioles

• tertiary bronchi branch into bronchioles

• little bronchi

• smaller than 1 mm in diameter

• terminal and respiratory bronchioles

terminal bronchioles

• end conducting zone

• smallest bronchiole

respiratory bronchioles

• begin respiratory zone

• connect to alveoli

alveoli

• tiny air sacs

• site of respiration (gas exchange)

• collectively make up respiratory membrane (150 million/lung)

• 1 capillary wraps around each alveolus

alveolar sacs

• clusters of alveoli

respiratory membrane/surfactant

• 2 cells thick

• alveolar surfaces are thin and moist

• surfactant prevents sticking

• detergent breaks surface tension of water

• allows alveoli to inflate

• produced by pneumocyte II

• reduce surface tension

• gas exchange

right lung

• 3 lobes

  • superior

  • inferior

  • middle

• 2 fissures

  • horizontal

  • oblique

left lung

• 2 lobes

  • superior

  • inferior

• 1 fissure

  • oblique

• cardiac notch

pleurae

• thin, double layered serosa

• encases pleural cavity

parietal pleura

• on thoracic wall, diaphragm, and between lungs

• wraps body wall

visceral pleura

• external lung surface

• wraps lungs

pleural cavity

• potential space

• filled with pleural fluid

• lubrication and surface tension - assist with expansion and recoil

boyle’s law

• inverse relationship between pressure and volume

• increase in volume, decrease in pressure

• decrease in volume, increase in pressure

• chest volume increases, alveolar pressure falls, air flows in

• chest volume decreases, alveolar pressure rises, air flows out

inhalation

• diaphragm contracts and rib cage elevates

• volume of thoracic cavity increases

• pressure of thoracic cavity decreases

• air flows into lungs

exhalation

• rib cage returns to original position and diaphragm relaxes

• volume of thoracic cavity decreases

• pressure of thoracic cavity increases

• air moves out of lungs

normal quiet breathing (tidal) muscles

• inspiration (active)

  • diaphragm and external intercostals contract

• expiration (passive)

  • diaphragm and external intercostals relax

forced inspiration muscles

• accessory muscles - scalene, sternocleidomastoid, pectoralis minor contrat

• diaphragm and intercostals contract

forced expiration muscles

• active process

• abdominal muscles and internal intercostals contract

tidal volume (TV)

~500 mL

inspiratory reserve volume

• amount of air that can be forcefully inhaled after a normal tidal volume inspiration

• ~3100 - 1900 mL

expiratory reserve volume

• amount of air that can be forcefully exhaled after a normal tidal volume expiration

• ~1200-700 mL

residual volume

• amount of air left in lungs after a forced expiration

• ~1200 - 1100 mL

pneumothorax

• collapsed lung

• hole in parietal pleura allows pleural cavity to fill with air

• no longer potential space

• air flows in

• lung recoils and collapses

• alveoli can’t open

• pressure in pleural cavity is too great

dalton’s law

• sum of all partial pressures of gasses gives us the total pressure

• high altitudes, partial pressure decreases

• low altitudes, partial pressure increases

pressure gradient of gas movement

1. inspired air moves into alveoli; PO2 decreases as it mixes with air and water vapor

2. alveoli diffuse O2 into blood

3. pulmonary veins bring oxygenated blood back to heart and into body

4. O2 diffuses into the tissues

5. blood leaves tissues, returns back to heart, and is pumped to lungs to be oxygenated

inspired air

• PO2 - 160 mmHg

• PCO2 - 0.3 mmHg

alveoli

• PO2- 104 mmHg

• PCO2 - 40 mmHg

blood leaving lungs and entering tissue capillaries

• PO2- 100 mmHg

• PCO2 - 40 mmHg

tissues

• PO2 - less than 40 mmHg

• PCO2 - higher than 45 mmHg

blood leaving tissues and entering lungs

• PO2 - 40 mmHg

• PCO2 - 45 mmHg

ventilation-perfusion coupling

• match of ventilation and perfusion is necessary for optimal gas exchange

ventilation (V)

• amount of gas reaching alveoli that can participate in gas exchange

• need to make sure airways are wide enough to allow right amount of air flow in and out

perfusion (Q)

• blood flow reaching alveoli that can participate in gas exchange

• need to make sure capillary beds have blood flowing through them quickly enough to pick up oxygen and unload carbon dioxide

PO2 controls

• perfusion

• changes arteriolar diameter

• alveolar O2 is high, arterioles dilate

• alveolar O2 is low, arterioles constrict

• direct blood to go to alveoli to get O2

PCO2 controls

• ventilation

• changes bronchiolar diameter

• alveolar CO2 is high, bronchioles dilate

• alveolar CO2 is low, bronchioles constrict

• allows for more rapid elimination of CO2