Slide 6 Flashcards
What is atherosclerosis?
blocked artery due to plaque buildup causing abnormal blood flow or blocking it
What happens if the coronary artery is blocked?
heart attack
What are catheters for?
for coronary artery
they expand the stent to compress the plaque so that there is a widening artery
What is the blood composed of?
formed elements
- erythrocytes
- platelets
- leukocytes
plasma 55%
- plasma protein
- water
- other solutes
these percentages can change with disease
What is the role of albumin?
synthesized by the liver
contribute to colloid osmotic pressure of plasma
carry many substance
What are globulins for?
synthesized in the liver and lymphoid tissue
act as clotting factors
enzymes
antibodies
carrier for substances
What is fibrinogen for?
source is the liver
forms fibrin threads for blood clot
What is transferrin for?
from the liver and other tissues
iron transport
Why is liver disease associated with edema?
liver disease is dysfunctional
edema: fluid accumulation in the interstitial fluid due to leaky capillaries
less circulation protein synthesis = even less water retention by osmosis
What are the formed elements composed of?
RBCs
WBCs
granulocytes:
monocytes
lymphocytes
agranulocytes:
basophils
neutrophils
eosinophils
Platelets
Describe the structure and function of RBC. What is the spectrin molecule look like and its function?
structure: biconcave disk
flexibility
SPECTRIN cytoskeleton create this unique shape of RBCs by binding to the membrane and gives them elastic strength under deformation
it is two intertwined polypeptide chains
contains hemoglobin composed of four protein chains [globins], each heme has one iron = give the red colour
What happens during RBC differenciation?
takes 4 days to mature
hematopoietic stem cells [hemocytoblast] -> proerythroblasts - mitotic divisions -> basophilic erythroblasts - differentiation -> polychromatic erythroblasts [produce hemoglobin] - lose their nuclei-> reticulocytes
What is aplastic anemia?
serious form of anemia
What is leukopenia?
reduction of WBC leaving a person with many infections
What is thrombocytopenia?
reduce production of platelets leaving a person at high risk for hemorrhage
What does erythropoiesis do?
- when low oxygen levels detected by kidneys
- releases erythropoietin
- red bone marrow receives signal to make more RBCs = increased erythropoiesis so increased number of RBCs
- when levels are normalized, kidneys stop release of EPO
Why would athletes train at high altitudes?
at high altitudes, there is lower oxygen availability
therefore more production of erythropoietin and more erythropoiesis so they have more red blood cells for more oxygen carrying capacity [ get used to low oxygen supply, will perform better at a higher oxygen supply]
What is the process of RBC breakdown?
macrophage cells in the liver and spleen phagocytose the aged/abnormal/fragmented RBCs
they breakdown hemoglobin = amino acids used for energy or synthesis of new protein
iron is recycled by returning to bone marrow for synthesis of new hemoglobin
bilirubin brought to the liver where it is excreted into the intestine as bile
Describe iron homeostasis and metabolism.
iron comes from the diet binds to transferrin where it is transported to the bone marrow for the synthesis of new RBC. It is added to heme and heme combines with protoporphyrin to make a RBC. It then circulates for 120 days and becomes mature where a macrophage engulfs it in the liver or spleen. Once digested, it partitions the bilirubin for excretion by sending it back to the liver then to intestine into the bile out of the body. The iron is recycled by storing it in the ferritin stores of the liver or brought back to the bone marrows for synthesis of more RBCs.
What separate layers can be seen if the blood is allowed to stand or centrifuged?
hematocrit, buffy coat and RBC [ measured by PCV~ 42-45%]
anemia: reduced PCV
polycythemia: increase PCV
Which WBC is the most abundant?
neutrophils: highly mobile and phagocytic
can diapedesis: migrate out of blood vessel to enter tissues
have granules that contain lysozyme for destruction of bacterial cells
eosinophils: line the respoatory and digestive tract, weak phagocytes but provide protection against infections against parasitic warms and allergic reactions, release anti inflammatory
basophils: motile and diapedesis, contain histamine [inflammatory chemical] and heparin [anticoagulant]
Differenciate agrnulocytes.
lymphocytes: smallest have B and T –> produced in the thymus
T cells direct attack infect/cancerous cells, B cells produce antibodies to specific antigens
monocytes: largest type of leukocyte, mobile and highly phagocytic to ingest bacteria and cancerous cells
What is the function of platelets?
circulate in the blood, small, pale bodies, irregular spindled shapes
properties: agglutinations, adhesiveness and aggregation
- during hemostasis (stoppage of blood flow)but
- if injury is too much=blood clotting mechanism is activated for blood coagulation
they form from megakaryocyte fragments on the edge
What are megakaryocytes?
giant cells with many DNA copies in the nucleus
Describe the platelet plug formation.
- collagen exposed, binds and activates platelets
- release platelet factors
- factors attract more platelets
- platelets aggregate into the platelet plug
What is the blood clotting mechanism?
release clotting fators from injured tissues and sticky platelets
series of chemical reactions that form thrombin
formation of fibrin and traps clood cells to form aclot
What happens if there is damage to the blood vessel wall?
- vasoconstriction
- platelet and coagulation cascade aggregate into a loose platelet plug = hemostasis
- clot is reinforced by platelet plug
How do we know when to breath?
sensory input: pons receive signals form chemo receptors to medullary rhythmicity area relay information to respiratory muscles to drive breathing
cerebral cortex = can override automatic control of breathing
What do the respiratory function include?
- external respiration
- transport of gases by blood
- internal respiration
- regulation of respiration
How is the respiratory system divided?
upper respiratory tract: from larynx to nasal cavity
lower respiratory tract: from trachea to diaphragm,/bronchus
accessory structures
What are the muscles of inspiration?
intercostals (external or internal)
What muscles are for expiration?
abdominal muscles
List the structures from out to in.
trachea - primary bronchi - bronchials- alveolar sacs - alveoli - pulmonary arterioles and veins
Describe key features of the nose=upper respiratory division
lined with hair: filters air
turbinates: provides large mucus covered surface over which air travels to moisten it
mucus acts to trap particles before air enters respiratory system
What is the cause of cleft palate?
cleft palate = palatine bones fails to unitecan be genetic or non genetic = mutant gene trisomy 13, teratogenic, corticosteroids, etc.
48% reduction by folic acid
What are the 3 divisions of pharynx (throat)
nasopharynx
oropharynx
laryngopharynx
What are some lower respiratory tract or accessory structures?
lower respiratory tract: organs in the thorax, trachea, bronchial tree and lungs
accessory structure: oral cavity, rub cage, diaphragm
Describe the trachea and the bronchi.
trachea: windpipe - connects the larynx to the bronchi
open airway to the lungs so obstruction can cause death
smooth muscle is embedded cartilage C rings
ciliated epithelium [columnar] to move mucus to pharynx
bronchi: epithelial, smooth muscle and connective tissue
goblet cells and ciliated cells and hyaline cartilage as well
Describe the alveoli
each alveolus is ventialed, bronchioles subdivided into alveolar ducts then to the alveolar sac and then alveoli in each sac connected by PORES OF KOHN
What is the respiratory membrane made of? Differentiate type 1 and type 2 alveolar cells
alveolar epithelium, capillary endothelium and joined basement membranes
type 1 alveolar cells: form alveolar wall {single layer}
type 2 cells produce SURFACTANT that reduces surface tensions and coats the inside of alveolus
How does the respiratory cycle work?
inspiration: taking air into the lungs - active phase of ventilation because muscles contract (diaphragm moves down and thoracic cavity increases in volume so the pressure in the alveoli decreases resulting in air flow into the lungs [flows from high atmospheric pressure to low aleovlar pressure]
Expiration is the process letting air out, it is relaxation of the diaphragm and elastric recoil of tissue decrease the thoracic volume which increase the alveolar pressure = expiration so air moves from low to high pressure outside
What are the two pressure gradients to consider during breathing?
- pressure within the alveoli of lungs [lower than atmospheric pressure - produces inspiration]
[pressure of the alveoli of lungs is ghier than atmospheric pressure - produces expiration] - pressure gradients establish by change in the size of the thoracic cavity as a result of contraction or relaxation of muscles
Describe the diaphragm in two different states.
at rest: relaxed, thoracic volume decreases
contracted: thoracic volume increases
What are the three important ventilation pressures?
atmospheric pressure - outside
alveolar pressure - intrapulmonary pressure
intrapleural pressure - between the parietal pleura [outer membrane] and visceral pleura [membrane around the lungs]
What is the concept of compliance?
ability of pulmonary tissues to stretch so inspiration is possible [filling of the lungs with air requires stretching]
What is the main agent of expiration?
due to elastic recoil = when diaphragm relaxes
What is surfactant?
lipoprotein formed from protein and phospholipid secretions of type 2 cells in the wall of the alveolus
it reduces surface tension and prevents alveolar collapse during exhalation = it acts to decrease the attraction between water molecules [causes a shrivelled alveolus due to strong water bonds that don’t break easily] and are interspersed between water molecules
What are alveolar macrophages?
primary phagocytes of the innate immune system clear the air space secrete lysozyme phagocytoses eliminate small daily normal microbes
What are the factors that determine the amount of oxygen diffusion into the blood
- total functional surface area of the respiratory membrane
- respiratory volume
- alveolar ventilation
capillary bed = large surfaces and thin layer so each RBC is close to alveolar
What is the negative feedback loop control of respiration?
in response to high plasma CO2:
- increased cell respiration during exercise = rise in CO2 in plasma detected by chemoreceptors in carotid sinus and aorta
- feedback information is relayed to which send correction signals to the effectors
- effector muscle increase alternate contraction and relaxation so respiratory rate increases and the rate of CO2 is lossed form the body so CO2 drops accordingly and the plasma CO2 is brought back to the set point value.
Where are the sensors that influence breathing?
nervous system provides feedback to the rhythmicity area
- chemoreceptors in medulla [PCO2 increased- faster breathing, decreased - slower breathing]
- peripheral chemoreceptors in carotid and aortic bodies and central chemoreceptors [decrease in pH, less CO2 = slowed breathing]
- arterial O2 blood has minimal influence
cerebral cortex influence breathing by increase or decreasing rate and strength of respirations
What are some respiratory pathologies? (laboured breathing)
chronic bronchitits: air tubes narrows due to swollen or excessive mucous production = inflammation of alveoli and epithelium and glands
asthma: edema (swelling) of respiratory mucosa and excessive mucous production obstruct airways = inflated alveoli
emphysema: alveoli walls are torn and unrepairable so alveoli fuses into large space but cannot inflate properly
