Lecture 3: Connective Tissue

Question 1

Overview

Answer 1

• widely distributed in the body
• cells are not stacked tightly, they are spaced well apart
• supporting tissue composed of cells embedded within a matrix that varies in consistency from fluid to crystals
• cells are responsible for synthesis and maintenance of the extracellular fluid
  examples: cartilage, bone, ligaments, blood, and adipose tissue

Question 2

connective tissue subtypes: 3 types

Answer 2

structural, defensive, and sequestering

Question 3

structural connective tissue

Answer 3

fibroblast, cartilage, bone

Question 4

defensive connective tissue

Answer 4

macrophages, lymphocytes

Question 5

sequestering connective tissue

Answer 5

adipose tissue, red blood cells

Question 6

fibroblasts

Answer 6

most common connective tissue within vertebrate bodies
flat, irregular, branching cells
secretes structurally strong proteins into matrix between cells; most commonly COLLAGEN
-fibroblasts also secrete elastin

Question 7

Elastin

Answer 7

fibrous tissue that is the principal component of the lungs

Question 8

Areolar (loose) Connective Tissue (ACT)

Answer 8

• found throughout the body wherever protective cushioning and flexibility are needed
• ie. blood vessels are surrounded by a sheath of ACT; permits the vessels to move and yet protects them
• also present beneath the skin, attaching it to underlying muscles

Question 9

Dense Regular CT

Answer 9

present in tendons, connecting muscle to bone, and in ligaments, connecting bone to bone

Question 10

Dense Irregular CT

Answer 10

present in dermis (living part) of the skin

• arranged in thick mat
• tanned to make leather, also present in arterial walls

Question 11

Cartilage: 3 types

Answer 11

firmer and flexible tissue that does not stretch, yet not as hard as bone

• laid down along lines of stress; cells=chondrocytes
• 3 types: hyaline, elastic, and fibrocartilage

Question 12

hyaline cartilage

Answer 12

• glass-like covering of bones within joints
• forms a smooth surface that reduces friction so one bone easily glides over another
• found at ends of long bones

Question 13

elastic cartilage

Answer 13

mixture of cartilage substances and elastic fibers

-found in external ear

Question 14

fibrocartilage

Answer 14

cartilage and collagen

-interverteral discs are made of fibrocartilage

Question 15

Bone

Answer 15

special form of cartilage where the collagen fibers are coated with a calcium phosphate salt
-bone forming cells are osteoblasts and osteoid tissue, that calcify to form bone

Question 16

harvesian canals

Answer 16

channels surrounded by lamellae, which contain blood vessels and nerve cells

Question 17

lamellae

Answer 17

bone laid down in concentric layer

Question 18

spongy or cancellous bone

Answer 18

lines the medullary cavity

Question 19

compact bone

Answer 19

surrounds the spongy bone and collagen fibers are laid down in a pattern far denser than the interior framework

Question 20

Blood

Answer 20

connective tissue consisting of microscopically visible elements: erythrocytes, leukocytes, and platelets/thrombocytes, all suspended in intercellular fluid called plasma
plasma>erythrocytes>leukocytes

Question 21

plasma

Answer 21

complex fluid in which blood cells and thrombocytes circulate

• 93% water, 7% solutes, including proteins, inorganic solutes, nonprotein oranic substances (glucose, glycerol, and fatty acids)
• hormones, enzymes, vitamins, and pigments
• cell waste products (urea, uric acid)
• amino acids

Question 22

serum

Answer 22

supernatant yellow fluid that is expressed out when blood coagulates
-serum is used for prevention and treatment of diseases because it contains the antibody fraction of the blood

Question 23

Blood cell types

Answer 23

red blood cells/erythrocytes, white blood cells/leukoccytes, and platelets/thrombocytes

Question 24

RBC

Answer 24

transport gases

• flat discs with a central depression
• contain pigment called hemoglobin, which associates and dissociates with O2 and CO2

Question 25

WBC, 2 types

Answer 25

``` granular leukocytes (granulocytes), and Agranular leukocytes (agranulocytes) -both are the defense against invading bacteria and other foreign substances ```

Question 26

Granulocytes: 3 subtypes

Answer 26

neutrophils, eosinophils, and basophils

Question 27

Neutrophils

Answer 27

first line of defense against bacteria | -very motile phagocytic

Question 28

eosinophil

Answer 28

detoxification of foreign proteins and substances - less motile phagocytic - found in lungs mammary glands, and small intestine

Question 29

Basophil

Answer 29

- inflammatory response | - cytoplasmic granules contain heparin (anticoagulant) and histamine (vasodilator) outside blood

Question 30

Agranulocytes: 2 types

Answer 30

-monocytes and lymphocytes

Question 31

Monocytes

Answer 31

- largest leukocytes | - precursor of macrophage; defend against microorganisms and chemicals

Question 32

lymphocytes

Answer 32

B-lymph=antibody-user | T-lymph=celllular immune response

Question 33

Adipose tissue aka fat

Answer 33

forms when connective tissue cells take up fat for storage as inclusions within the cytoplasm of cells -most fat of animal body is white in color, may be yellow due to presence of carotene in feed

Question 34

brown fat

Answer 34

- present in hibernating and young animals | - generates heat to protect young mammals and awakening hibernating mammals from extreme cold

Question 35

Smooth muscle:

Answer 35

involuntary, visceral, and unstriated - spindle shaped cells that contain one centrally located nucleus per cell - found in the walls of digestive tract, blood vessels, urinary and reporductive organs - contract more slowly than striated muscles and respond to a variety of stimuli

Question 36

Striated muscle

Answer 36

voluntary, skeletal - long fibres: striations, many peripherally located nuclei; posses cell membrane=sarcolemma - each striated muscle has its own nerve supply: all or none law - striated muscle tissue + some connective tissue makes up the flesh of meat producing animals

Question 37

Cardiac muscle

Answer 37

- involuntary, striated - modified muscle cells called Purkinje's fibres conduct impulse within the heat - intercalated discs increase the speed of electrical transmission between muscle fibres

Question 38

Nerve cells consist of

Answer 38

dendrites, conducting impulses towards cell body - nerve cell body - nucleus - axons, conducting impulses away from cell body