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Lifecycle of erythrocytes

Production of erythrocytes in the marrow occurs at the staggering rate of more than 2 million cells per second. For this production to occur, a number of raw materials must be present in adequate amounts. These include the same nutrients that are essential to the production and maintenance of any cell, such as glucose, lipids, and amino acids. However, erythrocyte production also requires several trace elements: iron, copper, zinc, and several types of B vitamins.

Erythrocytes live up to 120 days in the circulation, after which the worn-out cells are removed by a type of phagocytic cell called a macrophage    , located primarily within the bone marrow, liver, and spleen. The components of the degraded erythrocytes’ hemoglobin are further processed, with some being retained by the body and others being released in the urine and feces.

The breakdown pigments formed from the destruction of hemoglobin can be seen in a variety of situations. At the site of an injury, biliverdin from damaged RBCs produces some of the dramatic colors associated with bruising. With a failing liver, bilirubin cannot be removed effectively from circulation and causes the body to assume a yellowish tinge associated with jaundice. Stercobilins within the feces produce the typical brown color associated with this waste. And the yellow of urine is associated with the urobilins.

Disorders of erythrocytes

The size, shape, and number of erythrocytes, and the number of hemoglobin molecules can have a major impact on a person’s health. When the number of RBCs or hemoglobin is deficient, the general condition is called anemia    . There are more than 400 types of anemia and more than 3.5 million Americans suffer from this condition. Anemia can be broken down into three major groups: those caused by blood loss, those caused by faulty or decreased RBC production, and those caused by excessive destruction of RBCs. The effects of the various anemias are widespread, because reduced numbers of RBCs or hemoglobin will result in lower levels of oxygen being delivered to body tissues. Since oxygen is required for tissue functioning, anemia produces fatigue, lethargy, and an increased risk for infection. An oxygen deficit in the brain impairs the ability to think clearly, and may prompt headaches and irritability. Lack of oxygen leaves the patient short of breath, even as the heart and lungs work harder in response to the deficit.

Anemias caused by faulty or decreased RBC production include sickle cell anemia, iron deficiency anemia, vitamin deficiency anemia, and diseases of the bone marrow and stem cells.

  • A characteristic change in the shape of erythrocytes is seen in sickle cell disease    (also referred to as sickle cell anemia). A genetic disorder, it is caused by production of an abnormal type of hemoglobin, called hemoglobin S, which delivers less oxygen to tissues and causes erythrocytes to assume a sickle (or crescent) shape, especially at low oxygen concentrations ( [link] ). These abnormally shaped cells can then become lodged in narrow capillaries because they are unable to fold in on themselves to squeeze through, blocking blood flow to tissues and causing a variety of serious problems from painful joints to delayed growth and even blindness and cerebrovascular accidents (strokes). Sickle cell anemia is a genetic condition particularly found in individuals of African descent.

Questions & Answers

what is the meaning of extended family
Shellyann Reply
extended family is two are more nuclear family living together under one roof
Nordalee
what is genetic engineering
Ebot Reply
good day please what is a cell?
Colota Reply
cell is the basic unit of all living things/organism
Hassan
differenciate b/w cilia and flagellum
Abshira
Cilia: 1. They are smaller in number. 2. Cilia usually occur throughout or major part of the surface of a cell. 3. They beat oar like and in a co-ordinated rhythm 4. Cilia help in locomotion, feeding, circulation, etc.. 5. Example: Paramecium
iti
Flagella: 1. They are larger in size. ADVERTISEMENTS: 2. Flagella are commonly found at one end of the cell. 3. The flagella beat whip-like and independently. 4. Flagella help in locomotion. 5. Example: Euglena
iti
smallest structural and functional unit of an organism!
zidane
cell is the basic unit of all living things
Lukman
what is homeostasis
alex Reply
the ability of an organism to maintain stable internal environment, even when the external environment changes
Bee
what's the function of the hypothalamus
Agyekum
what is homeostasis
Edward Reply
constant maintenance of internal body temperature
Agyekum
What is the function of the Pituitary Gland?
WeNdlovu
how can homeostasis be maintained?
alex
pituitary gland also known as the master gland secretes hormones which triggers other gland to secretes their hormones
Agyekum
what's the full meaning of DNA and RNA
Deborah Reply
DNA is Deoxyribonucleic acid and RNA means Ribonucleic acid
Christian
sha is mitochondria?
Sparrow Reply
what is biology
Femi Reply
biology is the study which deals with the study of the biological components or animal and plants.
Juhi
biology is the study of life.
Roger
biology is the branch of science which deals with study of two parts 1.botany&2zoology these is known as biology....
Chetan
biology is the study of human beings ...
Chetan
Biology is a branch of science that deals with the study of nature
Agyekum
biology is the science of living organism
Abshira
biology is the branch of science that deals with study of living organisms
Lukman
what is neculer cell?
is it nuclear cell?
iti
asthma occur in which part of the body organ?
Festus Reply
what is hemoglobin
Lucky Reply
a protein that carries oxygen, it is found within red blood cells
EmmyOrangePeel
Apart from endocrinology, what other alternative should be done to a D/m client
Deborah Reply
good day please what is excretion
Blaise Reply
excretion is the process by which metabolic wastes and other none-useful materials are eliminated from an organism.
Petrene
its the process of eliminating or removal of metabolic waste and non useful materials from an organ.
eyong
Its the removal of metabolic waste product from the body
Boo
it is the removal from the body of living organisms, toxic waste products of metabolism which if allowed to accurate can cost harm to the body..
Renzo
how are protons formed?
Brian Reply
What is isotopes?
Brian
isotopes is a phenomenon in which atoms of the same element has the same atomic number but different mass number due to a difference in their neutron number or relative abundance in the earth crust
Efosa
give me more mcqs there r just two mcqs
Salma Reply
Define the term Disease in one paragraph.
Sutanya Reply
Disease is any disorders that counteract with the normal performance of the immune system.
Agyekum
what is cell?
Colota
Cell is the basic unit of life It is the building block of an organism
Agyekum
do agree with me that if someone needs to truely be a biologist he should be mathematician physicist & chemist in oreder to acheive the level #biologist
Assila
what is a protoplasm?
Colota
colourless living part of the cell
Jenny
what is protoplasm made up of?
Jack

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Source:  OpenStax, Human biology. OpenStax CNX. Dec 01, 2015 Download for free at http://legacy.cnx.org/content/col11903/1.3
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