Connective Tissue Quiz

Connective Tissue

• Connective tissue binds structures, provides a framework and support for organs and the body, stores fat, transports substances, protects against disease, and helps repair tissue damage.
• It is found throughout the body.
• Characterized by an abundance of intercellular matrix with few cells.
• Connective tissue is able to reproduce, but not as quickly as epithelial cells.
• Most connective tissues have a good blood supply, but some do not.
• Originates from the middle germ layer (mesoderm).
• Cells do not rest on a basement membrane.

Classification of Connective Tissue

• Connective tissue (CT) is classified according to the type of ground substance into:
  • CT Proper
  • Skeletal CT
  • Vascular CT

Connective Tissue Proper

• Types of CT proper:
  • Areolar connective tissue
  • Fibrous connective tissue
  • Elastic connective tissue
  • Reticular connective tissue
  • Mucous connective tissue
  • Adipose connective tissue

Skeletal Connective Tissue

• Skeletal connective tissue is a type of connective tissue that forms the internal skeleton, supporting the body and attaching to muscles.
• The internal skeletal system consists of rigid (bone) or semi-rigid (cartilage) structures.
  • Bone: rigid, mineralized, and ossified structures connected by ligaments and connected to the muscular system via tendons.
  • Cartilage: semi-rigid, not ossified structures, supporting the human ear and nose.
• Sharks are composed entirely of cartilage and do not have calcified bones.

Cartilage

• Cartilage is a type of dense connective tissue composed of collagen fibers and/or elastin fibers + cartilage cells (chondrocytes).
• Found in joints, rib cage, ear, nose, and bronchial tubes.
• Types of cartilage include:
  • Elastic cartilage
  • Hyaline cartilage
  • Fibrocartilage

Hyaline Cartilage

• Contains fibers scattered throughout the matrix, which looks glassy.
• Has a clear ground substance with chondrocytes in lacunae.
• Essential for endochondral development of bone.
• Found in the trachea.

Elastic Cartilage

• Similar to hyaline cartilage but contains elastic fibers (elastin) throughout the matrix.
• Found in the ear (pinna) and auditory (Eustachian) tubes, larynx, and epiglottis.
• Keeps these tubes permanently open.

Fibrocartilage

• Very fibrous.
• Found between the vertebrae of the spinal column.
• Also includes calcified cartilage, with calcium salts deposited.
• Found in the xiphisternum of the toad.

Bone

• Bones are rigid connective organs making up the skeleton of vertebrates.
• Primarily composed of osseous tissue (bone tissue) that gives rigidity.
• Functions of bones include:
  • Protection of internal organs (e.g., skull protecting the brain, ribs protecting the heart and lungs)
  • Providing shape and support to the body
  • Blood production: marrow located in the medullary cavity of long bones and cancellous bone produces blood vessels in a process called hematopoiesis
  • Mineral storage: bones store minerals important for the body, mostly calcium and phosphorus.
  • Movement: musculoskeletal system (bones, skeletal muscles, tendons, ligaments, and joints) function together to generate and transfer forces so the body can move.
  • Acid-base balance: bones buffer blood against excessive pH changes by absorbing or releasing alkaline salts
  • Detoxification: bones store heavy metals and foreign elements, removing them from the blood and reducing their effects on other tissues and releasing them for excretion
  • Sound transduction: bones are crucial for mechanical aspects of hearing

Types of Bones

• Compact bone
• Trabecular (spongy) bone

Compact Bone

• The hard outer layer of bones, composed of compact bone tissues with minimal gaps and spaces.
• Gives bones their smooth, white, and solid appearance.
• Makes up 80% of the total bone mass in an adult skeleton.
• Also called dense bone or cortical bone.

Trabecular (Spongy) Bone

• Fills the interior of bones.
• Consists of a network of rod- and plate-like elements called cancellous or spongy bone.
• Lighter and allows room for blood vessels and marrow.
• Accounts for the remaining 20% of total bone mass but has a much larger surface area than compact bone.

Cavities in Bone

• Haversian canals
• Marrow cavities
• Lacunae

Vascular (Fluid) Connective Tissue

• Includes blood and lymph.

Blood

• A connective tissue originating from bones.
• Composed of a fluid called plasma with several cell types suspended in it.
• Cellular constituents include:
  • Red blood cells (erythrocytes): carry respiratory gases and give blood its red color.
  • White blood cells (leukocytes): fight disease.
  • Platelets (thrombocytes): cell fragments important for blood clotting.
• Functions of blood:
  • Supply of oxygen to tissues.
  • Supply of nutrients (glucose, amino acids, fatty acids).
  • Removal of waste (carbon dioxide, urea, lactic acid).
  • Immunological function (circulation of white cells and detection of foreign material by antibodies).
  • Coagulation (self-repair mechanism).
  • Messenger functions (transport of hormones and signaling of tissue damage).
  • Regulating of body pH.
  • Regulating of core body temperature

Blood Structure

• Cellular components (45%):
  • Erythrocytes (red blood cells)
  • Leukocytes (white blood cells)
  • Thrombocytes (platelets)
• Plasma (55%)
• Erythrocytes (R.B.Cs): 4.7 – 6.1 million (male), 4.2 – 5.4 million (female) - lack nucleus in mammals. Contain hemoglobin
• Leukocytes (W.B.Cs): 4,000 – 11,000. Part of immune system destroying and removing cells. Attack pathogens.
• Thrombocytes (platelets): 200,000 – 500,000. Responsible for blood clotting. Change fibrinogen into fibrin.

Blood Plasma

• A fluid medium appearing golden-yellow in color; about 92% water and 8% blood plasma proteins (serum albumin, blood clotting factors, immunoglobulins/antibodies, hormones, etc.)
• Serum is plasma from which clotting proteins have been removed. Important proteins in serum are albumin, and immunoglobulins.

Lymph

• A complex network of lymph nodes, lymph ducts, lymphatic tissues, lymphatic capillaries and lymph vessels.
• Produces and transports lymph fluid from tissues to the circulatory system.
• A major component of the immune system.
• Functions:
  • Removal of excess fluids from body tissues.
  • Absorption of fatty acids and transport of fat to the circulatory system.
  • Production of immune cells such as lymphocytes and monocytes.