questions 579-648

Describe a red blood cell
Answer: a disc- shaped cell, lacking a nucleus, that is packed with the oxygen carrying molecule hemoglobin.

Describe the life cycle of a red blood cell
Answer: in their early stages they have nuclei then they become less and less active when they become less active the spleen and the liver removes them.

List two sources of iron that can be used for the synthesis of hemoglobin
Answer:

Describe a blood platelet, and explain its functions.
Answer: not complete cells, they arise from very large cells in the red bone marrow called megakaryocytes.

Distinguish between low- density lipoprotein and high density lipoprotein
Answer: low- density lipoproteins have a relatively high concentration of cholesterol high density have a relatively high concentration of protein and lower concentration of lipids.

List the major leading to the formation of a blood clot.
Answer: first release of biochemicals from broken blood vessels or damaged tissue triggers extrinsic clothing mechanism the stimulates the intrinsic clotting mechansim.

Explain why a person with blood type AB is sometimes called a universal recipient
Answer: because they lack both anti- A and anti- B antibodies they can receive a transfusion of blood of any other type.

Explain why a person with blood type O is sometimes called a universal donor
Answer: it lacks antigens A and B this means it can be transfused into persons with any kind of blood.

647-648

Describe the pericardium
Answer: the pericardium encloses the heart and the closer end of the blood vessels in which it is attached.

Identify and describe the locations of the chambers and the valves of the heart.
Answer: four hollow chambers, two on the left, two on the right. The upper chambers are called the atria the lower are called the ventricles.

The tricuspid valve is between the right atrium and the right ventricle it allows blood to move from the atrium into the ventricle and prevents it from moving backwards the bicuspid valve prevents the blood from flowing back into the left atrium from the ventricle it is located on the left.
Trace the path of the blood through the heart
Answer: enters through right atrium continues towards the right ventricle moves through the pulmonary valve and into the capillaries goes through pulmonary veins and heads out through the left atrium, next they head to the left ventricle .

Explain the origin of heart sounds: heart sounds come from vibrations in heart tissue when blood moves through.

pg. 818

1. Describe the general functions of the respiratory system
Answer: provides oxygen for the internal environment and excretes carbon dioxide.

3. Explain how the nose and nasal cavity filter incoming air.
Amswer: the hairs of the nostrils prevent large particles carried in the air from entering the nose.

5. Distinguish between the pharynx and the larynx
Answer: pharynx is the passageway for food and air. The larynx is also a passageway for air moving in and out of the trachea the larynx is inferior to the pharynx.

list the successive branches of the bronchiol tree, from the primary bronchi to the alveoli.
Answer: starts with the right and left primary bronchi later it divides into secondary bronchi (lobar). next it divides into tertiary bronchi (segmental) next they turn into intralobular bronchioles the next branch is the terminal bronchioles after there are the respiratory bronchioles after there are the alveolar ducts then there are the alveolar sacs finally there are the alveoli.

define suffactant, and explain its function: surfuctant is a mixture of lipoproteins which is secreted into alveolar air spaces it helps you breathe by making it easier for the alveoli to inflate.

compare the mechanisms of coughing and sneezing and explain the function of each:
Answer: coughing and sneezing are similar in the fact that they both clear passageways of foreign objects. coughs force air upwards from the upper respiratory tracts.

explain the function of yawning.
Answer: yawning is used to help ventilate alveoli, it allows the blood to receive more oxygen.

Define hyperventilation and explain how it affect the respiratory center:
Answer: hyperventilation lowers the blood carbon dioxide concentration below normal. After it takes longer for carbon dioxide to reach normal levels

Describe how oxygen is transported in blood:
Answer:oxygen travels through the blood bound to hemoglobin, it later dissolves and mixes with hemoglobin.

List three factors that increase release of oxygen from the blood.
Answer: oxyhemoglobin increases the release of oxygen as the blood ph decreases. Also increase in temperature, increase in carbon dioxide acidity.