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Cancellous bone looks like a sponge under the microscope and contains empty spaces between trabeculae, or arches of bone proper. It is lighter than compact bone and found in the interior of some bones and at the end of long bones. Compact bone is solid and has greater structural strength.

Fluid connective tissue

Blood and lymph are fluid connective tissues. Cells circulate in a liquid extracellular matrix. The formed elements circulating in blood are all derived from hematopoietic stem cells located in bone marrow ( [link] ). Erythrocytes, red blood cells, transport oxygen and some carbon dioxide. Leukocytes, white blood cells, are responsible for defending against potentially harmful microorganisms or molecules. Platelets are cell fragments involved in blood clotting. Some white blood cells have the ability to cross the endothelial layer that lines blood vessels and enter adjacent tissues. Nutrients, salts, and wastes are dissolved in the liquid matrix and transported through the body.

Lymph contains a liquid matrix and white blood cells. Lymphatic capillaries are extremely permeable, allowing larger molecules and excess fluid from interstitial spaces to enter the lymphatic vessels. Lymph drains into blood vessels, delivering molecules to the blood that could not otherwise directly enter the bloodstream. In this way, specialized lymphatic capillaries transport absorbed fats away from the intestine and deliver these molecules to the blood.

Blood: a fluid connective tissue

This micrograph of a blood smear shows a group of red blood cells and a single white blood cell. The red cells are small discs which have a slight depression at their centers with no nuclei present. The white blood cell is larger and more darkly stained and has a large, prominent nucleus that is also darkly stained.
Blood is a fluid connective tissue containing erythrocytes and various types of leukocytes that circulate in a liquid extracellular matrix. LM × 1600. (Micrograph provided by the Regents of University of Michigan Medical School © 2012)

View the University of Michigan Webscope at (External Link) to explore the tissue sample in greater detail.

Visit this link to test your connective tissue knowledge with this 10-question quiz. Can you name the 10 tissue types shown in the histology slides?

Chapter review

Connective tissue is a heterogeneous tissue with many cell shapes and tissue architecture. Structurally, all connective tissues contain cells that are embedded in an extracellular matrix stabilized by proteins. The chemical nature and physical layout of the extracellular matrix and proteins vary enormously among tissues, reflecting the variety of functions that connective tissue fulfills in the body. Connective tissues separate and cushion organs, protecting them from shifting or traumatic injury. Connect tissues provide support and assist movement, store and transport energy molecules, protect against infections, and contribute to temperature homeostasis.

Many different cells contribute to the formation of connective tissues. They originate in the mesodermal germ layer and differentiate from mesenchyme and hematopoietic tissue in the bone marrow. Fibroblasts are the most abundant and secrete many protein fibers, adipocytes specialize in fat storage, hematopoietic cells from the bone marrow give rise to all the blood cells, chondrocytes form cartilage, and osteocytes form bone. The extracellular matrix contains fluid, proteins, polysaccharide derivatives, and, in the case of bone, mineral crystals. Protein fibers fall into three major groups: collagen fibers that are thick, strong, flexible, and resist stretch; reticular fibers that are thin and form a supportive mesh; and elastin fibers that are thin and elastic.

The major types of connective tissue are connective tissue proper, supportive tissue, and fluid tissue. Loose connective tissue proper includes adipose tissue, areolar tissue, and reticular tissue. These serve to hold organs and other tissues in place and, in the case of adipose tissue, isolate and store energy reserves. The matrix is the most abundant feature for loose tissue although adipose tissue does not have much extracellular matrix. Dense connective tissue proper is richer in fibers and may be regular, with fibers oriented in parallel as in ligaments and tendons, or irregular, with fibers oriented in several directions. Organ capsules (collagenous type) and walls of arteries (elastic type) contain dense irregular connective tissue. Cartilage and bone are supportive tissue. Cartilage contains chondrocytes and is somewhat flexible. Hyaline cartilage is smooth and clear, covers joints, and is found in the growing portion of bones. Fibrocartilage is tough because of extra collagen fibers and forms, among other things, the intervertebral discs. Elastic cartilage can stretch and recoil to its original shape because of its high content of elastic fibers. The matrix contains very few blood vessels. Bones are made of a rigid, mineralized matrix containing calcium salts, crystals, and osteocytes lodged in lacunae. Bone tissue is highly vascularized. Cancellous bone is spongy and less solid than compact bone. Fluid tissue, for example blood and lymph, is characterized by a liquid matrix and no supporting fibers.

Visit this link to test your connective tissue knowledge with this 10-question quiz. Can you name the 10 tissue types shown in the histology slides?

Click at the bottom of the quiz for the answers.

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Questions & Answers

what is brain
raja Reply
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body
Bind
nice
Anumel
what are the functions of the liver
Emorut Reply
detoxification formation of blood in the fetus blood reservoir regulations of the body temperature
ibrahim
regulation of the body temperature in the sense that the liver reduce some of the activities so has to maintain the amount of heat generations in the body
ibrahim
detoxification of blood
marzia
1. Regulate blood clotting. 2. Detoxify harmful substances. 3. Stores and release glucose when necessary. 4. Produce certain proteins for blood plasma. 5. Produce bile which helps in fat metabolism. 6. It stores iron needed for erythropoiesis and also helps in haemolysis
Adoma
It regulate blood clotting by producing clotting factors like vitamin k
Adoma
metaboilism produce bile
Tahir
production of heat
Aradhana
prevents shortages by storing vitamins minerals and sugar
Dr
haemolysis
Bind
what Is food chain & food web
sani
explain the advantages and disadvantages of learning anatomy using systemic and regional. help please😫🙏🙏💓
Enock Reply
hello which is the longer tater
Daniel Reply
the inflammation of spinal cord is called
Francis Reply
TM partial transver myelitis
Ayan
Transverse myelitis
Amit
transverse mylitis
Gopi
T M means transeverse myelitis
Ayan
TM
babita
Example of irregular bones in the upper limb
Daniel
What is myelitis
Fatima
what is anatomy
Bruce Reply
is the study of human structure or various parts of the body
Adoma
What is the chordae tendineae and where is located? Where is the Aorta located?
Sovilace Reply
What is the meaning of aponuerosis
Veronica Reply
a sheet of pearly white fibrous tissue that takes the place of a tendon in flat muscles having a wide area of attachment.
Hassan
example of epitheliam tissue
Nirob Reply
what is systemic anatomy
Friday Reply
it's a study of organ structure
Amarachi
definition of anatomy and physiology
Kapil Reply
in anatomy we study about structure of human body........ in physiology we study about function
Zahid
Explain the anatomy
Junaid
structure of heart
Anusha
explain biology
saviour
biology is the science of life. biologists study the structure, function, growth, origin, evolution and distribution of living organisms.
Kadence
how is albino affected
Ujam Reply
what are the important stuff in the papillary layer
Ujam
Melanie's is responsible for the change in the color of the skin
Ujam
what happened when they are badly severed
Ujam
what happened when they are badly severed
Ujam
Examples of glial cells?
Nesh Reply
glial cell s help in the attractive foces of motion in the cellular network
Ujam
What is glial cell?
Esther
what is gland
Nirob
a gland is a group of cells or group of similar cells that secretes substances
Veronica
what is homeostasis
Laura Reply
homeostasis- The ability to maintain relatively stable internal conditions even though the outside world changes continuously. i,e, maintaining normal values in your body such as Adequate blood levels,blood pressure, heart activity and blood pressure.
Williams
thank you
Laura
Give atleast three reasons to study anatomy and physiology
George Reply
It helps to know about the body structure properly and administer proper care for the patient
Opeyemi

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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