bio resp

1
7/28/2019 bio resp http://slidepdf.com/reader/full/bio-resp 1/1 RESPIRATION In general: Air enters through nose, pharynx, larynx (voicebox), trachea, 2 bronchi, bronchioles and into alveoli where oxygen is exchanged for CO2 in the blood. ------- Trachea (windpipe) is in front of the esophagus. // from each alveolus, oxygen diffuses into a capillary where it is picked up by RBC. The RBC release carbon dioxide which diffuse into alveolus and is expelled upon exhalation. ------- ->During inspiration, diaphragm contracts (moves down), rib cage expands and rib muscles contract. *intercostals muscle (rib muscles) also help to expand chest cavity ->During exhalation, diaphragm relaxes (moves up), rib cage gets smaller, rib muscle relax ------- Since microtubules are found in cilia and ciliated cells are found in the respiration tract (and the fallopian tubes and ependymal cells of the spinal cord) a problem in microtubule production might result in a problem in breathing (or fertility of circulation of csf) ------- Hemoglobin: there are 4 polypeptide subunits (each with cofactor called heme group that has an iron atom at the center) and each iron atom binds one molecule of oxygen. Thus, 1 hemoglobin can carry 4 oxygen molecules. It has cooperativity. It loads oxygen in lungs and unloads in other parts of body ------- As oxygen pressure increases, the oxygen saturation of hemoglobin increases sigmoidally. ------- Oxygen dissociation curve is shifted to the right by an increase in carbon dioxide pressure, hydrogen ion concentration or temperature. Shift to right means lowering of hemoglobins affinity for oxygen. The shift due to pH change is called the Bohr shift. 2,3-DPG (found in RBC) also shifts curve to right. ------- Carbon monoxide has more than 200x affinity for hemoglobin than does oxygen but shifts curve to left. Oxygen can be administrated to displace the CO from hemoglobin. ------- Carbon dioxide is carried by blood in three ways: 1) physical solution 2) bicarbonate ion 3) carbamino compounds (combined with hemoglobin and other proteins) *Most is bicarbonate And bicarbonate ion formation is governed by enzyme carbonic anhydrase: Co2+H20 -> HCO3- + H+ Carbonic anhydrase is inside the RBC and not in the plasma so when co2 is absorbed in the lungs, bicarbonate ion diffuses into the cell. To balance the electrostatic forces, chlorine moves out of the cell via chloride shift ------- The greater the pressure of carbon dioxide, the greater the blood content of carbon dioxide. When hemoglobin becomes saturated with oxygen, its capacity to hold carbon dioxide is reduced. This is called the Haldane effect. This effect facilitates transfer or carbon dioxide from blood to lungs and from tissues to blood.

Transcript of bio resp

Page 1: bio resp

7/28/2019 bio resp

http://slidepdf.com/reader/full/bio-resp 1/1

RESPIRATION

In general: Air enters through nose, pharynx, larynx (voicebox), trachea, 2

bronchi, bronchioles and into alveoli where oxygen is exchanged for CO2 in

the blood.

-------

Trachea (windpipe) is in front of the esophagus. // from each alveolus,oxygen diffuses into a capillary where it is picked up by RBC. The RBC

release carbon dioxide which diffuse into alveolus and is expelled upon

exhalation.

-------

->During inspiration, diaphragm contracts (moves down), rib cage expands

and rib muscles contract. *intercostals muscle (rib muscles) also help to

expand chest cavity

->During exhalation, diaphragm relaxes (moves up), rib cage gets smaller,

rib muscle relax

-------

Since microtubules are found in cilia and ciliated cells are found in therespiration tract (and the fallopian tubes and ependymal cells of the spinal

cord) a problem in microtubule production might result in a problem in

breathing (or fertility of circulation of csf)

-------

Hemoglobin: there are 4 polypeptide subunits (each with cofactor called

heme group that has an iron atom at the center) and each iron atom binds

one molecule of oxygen. Thus, 1 hemoglobin can carry 4 oxygen molecules.

It has cooperativity. It loads oxygen in lungs and unloads in other parts of 

body

-------

As oxygen pressure increases, the oxygen saturation of hemoglobin

increases sigmoidally.

-------

Oxygen dissociation curve is shifted to the right by an increase in carbon

dioxide pressure, hydrogen ion concentration or temperature. Shift to

right means lowering of hemoglobin’s affinity for oxygen. The shift due to

pH change is called the Bohr shift. 2,3-DPG (found in RBC) also shifts curve

to right.

-------

Carbon monoxide has more than 200x affinity for hemoglobin than does

oxygen but shifts curve to left. Oxygen can be administrated to displace

the CO from hemoglobin.

-------

Carbon dioxide is carried by blood in three ways: 1) physical solution 2)

bicarbonate ion 3) carbamino compounds (combined with hemoglobin andother proteins)

*Most is bicarbonate

And bicarbonate ion formation is governed by enzyme carbonic anhydrase:

Co2+H20 -> HCO3- + H+

Carbonic anhydrase is inside the RBC and not in the plasma so when co2 is

absorbed in the lungs, bicarbonate ion diffuses into the cell. To balance the

electrostatic forces, chlorine moves out of the cell via chloride shift

-------

The greater the pressure of carbon dioxide, the greater the blood contentof carbon dioxide. When hemoglobin becomes saturated with oxygen, its

capacity to hold carbon dioxide is reduced. This is called the Haldane effect.

This effect facilitates transfer or carbon dioxide from blood to lungs and

from tissues to blood.