KINE 1P99 Midterm 2

t or f - CO2 is eliminated because it breaks down into carbonic acid which can build up and make the body acidic

true

the movement of CO2 is respiration is __

passive

venous return

return of blood back up to heart

non respiratory functions of respiratory system

• Humidifies and warms the inspired air

• Enhances venous return

• Maintains normal acid-base balance by expelling CO2

• Enables speech and other vocalizations

• Sense of smell

• defend against inhaled foreign matter

inspired particles adhere to ___ in respiratory tract

mucous

“mucous escalator”

when foreign matter enters tract, cilia trap it and bring it back up and it is let out as spit or when you cough

____ are also secreted into the mucous

antibodies

the oxygen transport system is also called

cardiorespiratory system

cardiorespiratory system is responsible for (2)

Responsible for:

• delivery of oxygen and nutrients to working muscles

• removal of carbon dioxide and waste products from the working muscles

nasal passages - external and internal nares or nostrils

external - self explanatory

internal - two openings posteriorly, connect nose and pharnyx

path of air in nasal passages

air enters the external nostrils, then the internal nostrils and then the nasopharynx

pharynx - define it and state how long it is 

Pharynx: Also called the throat • A tube, approx. 13cm long

explain the 3 portions of the of the pharynx

Nasopharynx: At the back of the nose area

Orophanynx: At the back of the mouth area

Laryngopharynx: Connects with the esophagus posteriorly and with the larynx anteriorly

larynx (voice box) - define it

short passageway that connects the pharynx with the trachea

the larynx walls are supported by 

cartilage 

respiratory tract - trachea (windpipe): define it, state how long it is, state whether it is anterior or posterior to esophagus 

rigid tube, 12 cm long, anterior 

trachea is lined with mucous producing ___ ____

goblet cells

tracheostomy is done why

Tracheostomy done if an object gets stuck in the trachea or if breathing support is needed

explain how trachea branches and branches…

trachea branches into primary left and right bronchi 

primary branches into secondary bronchi 

secondary branches into tertiary 

tertiary bronchi branches into bronchioles 

bronchioles branches into terminal bronchioles 

terminal bronchioles branches into respiratory bronchioles  

____ are sensitive to certain hormones and local chemicals

bronchioles

the bronchioles divide into alveolar ducts, and these alveolar ducts end in __ ___

alveolar sacs

what are alveolar sacs

clusters of thin-walled, inflatable grape-like sacs (alveoli)

how many alveoli in lungs

about 300 mil

t or f - only 0.6 um separates air in the alveoli from blood in the capillaries which surround alveoli

false - 0.5

Approximately ___ ml CO2 /min leaves the blood and enters the alveoli

200

During heavy exercise, by how much can O2 transfer across the alveolar membrane increase?

25 times more O2 is transferred across the alveolar membrane (6.25 L/min or 6250 ml/min)

mass of lung

about 1.3kg

what takes up most of the chest cavity

lungs

how does pressure get generated in chest wall (just understand)

The chest wall contains muscles that can increase or decrease the volume inside the rib cage…the volume changes generate the pressures that causes airflow (breathing)

Internal Intercostal muscles - where do they lay, what are they innervated by

• lie between the ribs

• innervated by intercostal nerves

External intercostal muscles

• lie over the internal intercostal muscles

• innervated by intercostal nerves

intrapleural pressure is exerted outside the ___ but in the ___ ____

lungs, thoracic cavity

Increasing the volume in the lungs ___ the pressure (inhale) 

decreases

Decreasing the volume in the lungs __ the pressure (exhale)

increases

the diaphragm in quiet inspiration (just understand)

The diaphragm:

• Innervated by the phrenic nerve

• At rest = dome shaped

• When it contracts, it flattens and descends

• Increasing the vertical dimension of the thoracic cavity

• Accounts for 50-75% of the enlargement of the thoracic cavity during quiet breathing

the external intercostal muscles in quiet inspiration - where do they lie, and what does contracting it do

The external intercostal muscles:

• Between ribs

• Contraction enlarges the thoracic cavity in the lateral and anteroposterior dimensions

muscles involved in deep inspiration

• diaphragm 

• external intercostal muscles 

• the accessory muscles (sternocleidomastoids, scalenes: in the neck, raise the sternum, elevate the first 2 ribs) 

• in deep inspiration instead of relaxing when you exhale, you contract which makes you breathe harder 

how do abs and internal intercostal muscles contribute to forced expiration

• Abdominal muscles (push the abdominal contents in and the diaphragm up)

•Internal intercostal muscles (pull the ribs downandin)

finer point #1 why do the lungs expand when the chest expands

think of two glass flat circles with water between them. Water resists being pulled apart. This is the same as the intrapleural fluid which holds the pleural surfaces together. Therefore, when thoracic cavity expands lungs also expand

finer point #1 continued why do the lungs expand when the chest expands

the transmural pressure gradient.

• intrapleural pressure is less than intra alveolar pressure

• like a -4mmHg vacuum in the intrapleural space

• the lungs get sucked outward toward the chest wall

finer point #2

Normally, the pleural space is closed, and no air enters. What would

happen if it were exposed to the atmosphere (as in a puncture

wound) and air was allowed in?

Pneumothorax:

• The atmospheric and intrapleural pressure would equilibrate

• The vacuum sucking the lungs outward would be lost

• Lung collapse

F = ΔP/R

Where,

F = airflow rate

ΔP = Pressure gradient (intra-alveolar and atmospheric)

R = Resistance of the airways (determined by radius

__ nervous system controls

contraction of smooth muscle in walls of

bronchioles (changes the radius

autonomic

parasympathetic associated with

acetylcholine which causes bronchoconstriction

sympathetic associated with

norepinephrine and epinephrine which causes bronchodilation

– Measures the volume of air breathed in and out

A spirometer consists of an air-filled drum

floating in a water-filled chamber (old school)

modern spirometers

Modern spirometers are digital, but the same

basic idea…they measures the volume (and

rate) of air breathed in and ou

Inspiratory Capacity (IC)

• The maximum volume of air that can

be inspired at the end of a normal quiet

expiration (IC = IRV + TV)

Average value = approx 3500mL

Functional Residual Capacity (FRC)

• The volume of air in the lungs at the end of a normal passive expiration

(FRC = ERV + RV)

Average value = approx 2200mL

vital capacity (VC)

The maximum volume of air that can be moved out during a single breath

following a maximal inspiration (inspire maximally, then expire maximally) (VC

= IRV + TV + ERV)

Average value = approx 4500m

Total Lung Capacity (TLC)

• The maximum volume of air that the lungs can hold at the end of maximum

inspiration

• (TLC = VC + RV)

Average value = approx 5700mL

usually, FEV1 (forced expiratory vol in one second) is __% of VC

80

pulmonary ventilation

vol of air breathed in and out in one min

alveolar ventilation

vol of air exchanged between atmosphere and alveoli per min, more important that pulmonary ventilation

The whole thing minus the useless part = alveolar ventilation

useless part its useless because it did not make it all the way down to alveoli

imagine you are taking shallow rapid breaths, nothing gets down to your alveoli which is why its useless

(this is why alveolar ventilation is more important)

anatomic dead space

useless air that didnt make it all the way down to alveoli

external resp

exch of gas betw. lungs n blood

internal resp

exh. gas betw. blood n body cells

Oxygen and carbon dioxide will flow

down their pressure gradients (from an

area of __ pressure to an area of __

pressure)

high, low 

Oxygen is carried in the blood in two ways:

1. A small amount dissolves in the blood

plasma (1.5 %)

WHY?

 Oxygen is poorly soluble in fluids, so only a

small amount is carried this way, but…

 This small amount is very important! It

determines the PO2

Carbon Dioxide Transport

CO2 is transported to the lungs in one of

three forms:

1. 10% is dissolved in blood plasma

2. 30% binds to Hb (once bound this is

called carbamino hemoglobin)

3. 60% binds with water to become

bicarbonate (HCO3)

Can a poor diet negatively affect lung function??

Yes!...Beware of processed meats containing nitrites

how much more likely is someone with lower level spinal cord injury to die of pneumonia

250x

Protection: blood protects against foreign microbes and toxins through its WBC, but another function is…

protection from fluid loss due to damaged vessels and tissues via clotting mechanism

true or false - hematocrit is mostly red blood cells (but also includes white blood cells and platelets < 1%)

true

plasma is 

the remainder of total blood volume 

what does colloid osmotic pressure do

prevents excess fluid from leaving capillaries

the main contributor to water balance between blood and tissues is

albumins

which globulins (alpha beta or gamma) are involved in the blood clotting process

alpha and beta 

what are the 3 groups of plasma proteins

• albumins

• globulins

• fibrinogen

about how many RBCs per mL of blood

5 billion

t or f - RBC have very stiff membrane (the diameter can reduce from 8μm to 3μm as it squeezes through narrow capillaries) 

false - flexible 

t or f RBC Thinness of cell enables oxygen to diffuse rapidly between the exterior and innermost regions of the cell

true

what do RBC transport

O, CO2 and H+

haemoglobin only found only in ___

RBC

each rbc contains about ___ million hemoglobin molecules

280

each heme group is bond to one of the ___

polypeptides 

primary role of haemoglobin is to carry oxygen, but it also combines

• carbon dioxide

• carbon monoxide

• nitric oxide

• acidic hydrogen ion (H+) of ionized carbonic acid

haemoglobin transport co2 from ___ back to the ___

tissues, lungs

Approximately __% of CO2 produced by tissues combines with hemoglobin which is then released from the lungs to the atmosphere

30

t or f - haemoglobin can also buffer pH changes in blood by binding with free H+ produced by carbonic acid

true

Erythropoiesis occurs in ___ ___ ___ (sternum, ribs, long bones)

red bone marrow 

describe leukocytes in terms of colour and size

colourless (lack haemoglobin), somewhat larger than erythrocytes

the # of wbc needed in circulation depends on __ ___

defense needed 

leukocytes are also made of their ___ and a variety of ____ proteins

derivatives, plasma

wbc with granules are called

granulocytes

what are granules

sacs containing digestive enzymes or other chemical substances 

major function of eosinophils

phagocytosis of parasites (worms)

which leukocyte is most poorly understood

basophils

histamine is important in ____ reactions

allergic

major function of basophils

chemotactic factor production

major functions of monocytes (4)

phagocytosis, antigen presentation, cytokine production, cytotoxicity

monocytes emerge from ____ ___ while still immature and circulate for how long before settling down in various tissues in the body?

bone marrow, a day or two 

main function of Lymphocytes

provide immune defense against targets for which they are specifically programmed

t or f- T lymphocytes do not produce antibodies

true

Disk-shaped cellular fragments with granules are called 

thrombocytes (platelets)

They prevent fluid loss when  blood vessels are damaged via blood clotting

platelets

• The opposing endothelial surfaces adhere to each other 

• This slows the flow of blood through the broken vessel

vascular spasm

in platelet aggregation, platelets release ____ like ADP that cause the platelets to ___ to each other

chemicals, stick

the released chemicals by platelets stimulate the release of ____ and ___ ___ from normal endothelium which inhibits platelet ____. This causes ____ and blood ____

prostacyclin, nitric oxide, aggregation, vasoconstriction, coagulation

clot formation (just understand)

1. clot formation is the transformation of blood from a liquid into a solid gel

2. lots of steps but ultimately,