Changes

Jump to navigation Jump to search
Line 146: Line 146:  
In mammals, two types of adipose tissue exist: white adipose tissue (WAT) and brown adipose tissue (BAT).
 
In mammals, two types of adipose tissue exist: white adipose tissue (WAT) and brown adipose tissue (BAT).
   −
[[File:adipose.jpeg|300px]]
+
[[File:adipose.jpeg|200px]]
 
'''Adipose tissue with fat cells'''
 
'''Adipose tissue with fat cells'''
   −
[[File:adipose.jpg|300px]]
+
[[File:adipose.jpg|350px]]
 
'''Figure showing the location of adipose tissue below epidermis'''
 
'''Figure showing the location of adipose tissue below epidermis'''
   Line 195: Line 195:  
The haversian canals of adjoining haversian systems are interconnected by transverse canals called '''volkmann's canal'''.
 
The haversian canals of adjoining haversian systems are interconnected by transverse canals called '''volkmann's canal'''.
   −
[[File:Haversian.jpg|300px]]
+
[[File:Haversian.jpg|350px]]
 
'''Haversian systems'''
 
'''Haversian systems'''
   −
[[File:compact_spongy_bone.jpg|300px]]
+
[[File:compact_spongy_bone.jpg|350px]]
 
'''Cross section of long bone showing both spongy and compact osseous tissue'''
 
'''Cross section of long bone showing both spongy and compact osseous tissue'''
   Line 208: Line 208:  
In vertebrates, it is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume),and contains dissipated proteins, glucose, mineral ions, hormones, carbon dioxide, and blood cells themselves. Albumin is the main protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are mainly '''red blood cells''' (also called RBCs or erythrocytes) and '''white blood cells''', including leukocytes and '''platelets'''.<br>
 
In vertebrates, it is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume),and contains dissipated proteins, glucose, mineral ions, hormones, carbon dioxide, and blood cells themselves. Albumin is the main protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are mainly '''red blood cells''' (also called RBCs or erythrocytes) and '''white blood cells''', including leukocytes and '''platelets'''.<br>
 
The most abundant cells in vertebrate blood are '''red blood cells'''. These contain hemoglobin, an iron-containing protein, which facilitates transportation of oxygen. In contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as bicarbonate ion. Red blood cells are the body's oxygen transport systems. They are not true cells, as they do not have a nuclei or organelles.Their life span is 100-120 days. Their color ranges from bright red to dark red, depending on how much oxygen they are carrying. In the lungs, the oxygen binds to hemoglobin, a protein with four iron-containing sites for oxygen to bind to. Hemoglobin is also what gives the cells their red color.The number of RBC varies from 4.5 to 5,5 million cells/cubic mm of blood.<br>
 
The most abundant cells in vertebrate blood are '''red blood cells'''. These contain hemoglobin, an iron-containing protein, which facilitates transportation of oxygen. In contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as bicarbonate ion. Red blood cells are the body's oxygen transport systems. They are not true cells, as they do not have a nuclei or organelles.Their life span is 100-120 days. Their color ranges from bright red to dark red, depending on how much oxygen they are carrying. In the lungs, the oxygen binds to hemoglobin, a protein with four iron-containing sites for oxygen to bind to. Hemoglobin is also what gives the cells their red color.The number of RBC varies from 4.5 to 5,5 million cells/cubic mm of blood.<br>
 +
 +
[[File:RBC.jpeg|300px]]
 +
'''Red blood cells'''
 +
 
'''White blood cells''', or leukocytes, are the defense army within the blood tissue. They are the only true cells in the blood and are not limited to the blood stream. When called to defeat an infection or to dispose of a dead cell, they can squeeze through openings in the vessel walls. There, they can move through amoeboid action, meaning that they sprout cytoplasmic extensions that can move them. Leukocytes, along with platelets, usually make up less than 1% of blood.Their number varies from 6000 to 10000 cells/cubic mm of blood.<br>
 
'''White blood cells''', or leukocytes, are the defense army within the blood tissue. They are the only true cells in the blood and are not limited to the blood stream. When called to defeat an infection or to dispose of a dead cell, they can squeeze through openings in the vessel walls. There, they can move through amoeboid action, meaning that they sprout cytoplasmic extensions that can move them. Leukocytes, along with platelets, usually make up less than 1% of blood.Their number varies from 6000 to 10000 cells/cubic mm of blood.<br>
 +
 +
[[File:Red and white BC.jpg|300px]]
 +
'''White blood cells and RBC'''
    
Platelets are actually cell fragments that help in blood clotting. When a tear occurs in the blood vessels, platelets stick to the exposed collagen at the site of injury. They produce fibrous protein that traps other blood cells in a clot that stops blood from flowing and helps to prevent excess blood loss. Some platelets also secrete substances that signal other platelets to the break, substances that constrict blood vessels, or substances that promote an inflammatory response. Once the clot is formed, the platelets contract and pull the opening back together, thus healing the break.They are about 2,50,000 platelets in 1cc of blood.<br>
 
Platelets are actually cell fragments that help in blood clotting. When a tear occurs in the blood vessels, platelets stick to the exposed collagen at the site of injury. They produce fibrous protein that traps other blood cells in a clot that stops blood from flowing and helps to prevent excess blood loss. Some platelets also secrete substances that signal other platelets to the break, substances that constrict blood vessels, or substances that promote an inflammatory response. Once the clot is formed, the platelets contract and pull the opening back together, thus healing the break.They are about 2,50,000 platelets in 1cc of blood.<br>
 +
 +
[[File:platelet.jpg|300px]]
 +
'''RBC,WBC and platelets'''
    
Most of the blood cells contained in blood tissue don't last very long. Red blood cells only last about 100-120 days before they are disassembled, recycled, and disposed of. Platelets last about 10 days if they do not need to clot blood. The bone marrow makes and releases blood cells into the blood on a regular basis to replace old blood cells. Thus, the tissue is constantly being restored.<br>
 
Most of the blood cells contained in blood tissue don't last very long. Red blood cells only last about 100-120 days before they are disassembled, recycled, and disposed of. Platelets last about 10 days if they do not need to clot blood. The bone marrow makes and releases blood cells into the blood on a regular basis to replace old blood cells. Thus, the tissue is constantly being restored.<br>
Line 222: Line 232:  
Lymph nodes make immune cells that help the body fight infection. They also filter the lymph fluid and remove foreign material such as bacteria and cancer cells. When bacteria are recognized in the lymph fluid, the lymph nodes make more infection-fighting white blood cells, which causes the nodes to swell. The swollen nodes are sometimes felt in the neck, under the arms, and groin.<br>
 
Lymph nodes make immune cells that help the body fight infection. They also filter the lymph fluid and remove foreign material such as bacteria and cancer cells. When bacteria are recognized in the lymph fluid, the lymph nodes make more infection-fighting white blood cells, which causes the nodes to swell. The swollen nodes are sometimes felt in the neck, under the arms, and groin.<br>
 
The lymphatic system includes the tonsils, adenoids, spleen, and thymus.
 
The lymphatic system includes the tonsils, adenoids, spleen, and thymus.
 +
 +
[[File:Lymph-Capillaries.jpg|300px]]
    
===Activities===
 
===Activities===
494

edits

Navigation menu