Lab 4 - Connective and Muscle Tissues Study Guide

Lab 4: Connective and Muscle Tissues

Connective Tissue (Part 1)

• Connective tissue is the most abundant, widespread, and varied tissue type in the body.
• It has a wide variety of functions.

Connective Tissue - Chapter 4 Reference

• A: Cells (very few)
  • Fibroblasts and others
• B: Extracellular Matrix (ECM, a lot of it)
  • 1. Ground Substance
    • Proteoglycans
    • Water
  • 2. Fibers:
    • 2a) Collagen
    • 2b) Elastic
    • 2c) Reticular
• Connective Tissue is Vascular
  • Exceptions:
    • Cartilage is avascular
    • Dense regular CT is low in vascularity

Connective Tissue Proper

• All mature connective tissues belong to the Connective Tissue Proper class except bone, cartilage, and blood.
• These can be broken into loose connective or dense connective tissues.

Connective Tissue Proper: Loose

• Areolar connective tissue
  • Gel-like matrix with all three connective tissue fibers
  • Contains Fibroblasts, macrophages, mast cells, and some white blood cells
  • Wraps and cushions organs
  • Widely distributed throughout the body
• Adipose connective tissue
  • Matrix similar to areolar connective tissue with closely packed adipocytes
  • Reserves food stores, insulates against heat loss, and supports and protects
  • Found under skin, around kidneys, within abdomen, and in breasts
  • Local fat deposits serve nutrient needs of highly active organs
• Reticular connective tissue
  • Loose ground substance with reticular fibers
  • Reticular cells lie in a fiber network
  • Forms a soft internal skeleton, or stroma, that supports other cell types
  • Found in lymph nodes, bone marrow, and the spleen

Loose Connective Tissue Proper: Areolar

• Description: Gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells, and some white blood cells.
• Function: Wraps and cushions organs; macrophages phagocytize bacteria; plays important role in inflammation; holds and conveys tissue fluid.
• Location: Widely distributed under epithelia of body, e.g., forms lamina propria of mucous membranes; packages organs; surrounds capillaries.
• Contains:
  • Epithelium
  • Lamina propria
  • Elastic fibers
  • Collagen fibers
  • Fibroblast nuclei

Loose Connective Tissue Proper: Adipose

• Description: Matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet.
• Function: Provides reserve food fuel; insulates against heat loss; supports and protects organs.
• Location: Under skin; around kidneys and eyeballs; within abdomen; in breasts.
• Contains:
  • Nuclei of fat cells
  • Vacuole containing fat droplet

Loose Connective Tissue Proper: Reticular

• Description: Network of reticular fibers in a typical loose ground substance; reticular cells lie on the network.
• Function: Fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages.
• Location: Lymphoid organs (lymph nodes, bone marrow, and spleen).
• Contains:
  • Spleen
  • White blood (lymphocyte) cell
  • Reticular fibers
  • Mast cells

Connective Tissue Types

• Areolar CT
  • Ground substance
  • Elastic fibers
  • Collagen fibers
• Reticular CT
  • Reticular fibers

Connective Tissue Proper: Dense

• Dense Regular
  • Parallel collagen fibers with a few elastic fibers
  • Major cell type is fibroblasts
  • Attaches muscles to bone or to other muscles, and bone to bone
  • Found in tendons, ligaments, and aponeuroses
• Dense Irregular
  • Irregularly arranged collagen fibers with some elastic fibers
  • Major cell type is fibroblasts
  • Withstands tension in many directions providing structural strength
  • Found in the dermis, submucosa of the digestive tract, and fibrous organ capsules

Connective Tissue Proper: Dense Regular

• Description: Primarily parallel collagen fibers; a few elastin fibers; major cell type is the fibroblast.
• Function: Attaches muscles to bones or to muscles; attaches bones to bones; withstands great tensile stress when pulling force is applied in one direction.
• Location: Tendons, most ligaments, aponeuroses.
• Contains:
  • Shoulder joint
  • Ligament
  • Tendon
  • Collagen fibers
  • Nuclei of fibroblasts

Connective Tissue Proper: Dense Irregular

• Description: Primarily irregularly arranged collagen fibers; some elastic fibers; major cell type is the fibroblast.
• Function: Able to withstand tension exerted in many directions; provides structural strength.
• Location: Dermis of the skin; submucosa of digestive tract; fibrous capsules of organs and of joints.
• Contains:
  • Fibrous joint capsule
  • Nuclei of fibroblasts
  • Collagen fibers

Connective Tissue (Dense)

• Dense regular CT
• Dense irregular CT

Connective Tissue: Blood

• Red and white cells in a fluid matrix (plasma)
• Contained within blood vessels
• Functions in the transport of respiratory gases, nutrients, and wastes

Connective Tissue: Blood

• Description: Red and white blood cells in a fluid matrix (plasma).
• Function: Transport of respiratory gases, nutrients, wastes, and other substances.
• Location: Contained within blood vessels.
• Contains:
  • Neutrophil
  • Red blood cells
  • Lymphocyte

Connective Tissue Hints

• Blood (CT)
• Reticular CT
• Blood is full of round blood cells
• Reticular CT is also full of round blood cells… plus reticular fibers (but no lacunae)

Connective Tissue: Cartilage

• Hyaline cartilage
  • Amorphous, firm matrix with imperceptible network of collagen fibers
  • Chondrocytes lie in lacunae
  • Supports, reinforces, cushions, and resists compression
  • Forms the costal cartilage
  • Found in embryonic skeleton, the end of long bones, nose, trachea, and larynx

Connective Tissue: Hyaline Cartilage

• Description: Amorphous but firm matrix; collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae.
• Function: Supports and reinforces; has resilient cushioning properties; resists compressive stress.
• Location: Forms most of the embryonic skeleton; covers the ends of long bones in joint cavities; forms costal cartilages of the ribs; cartilages of the nose, trachea, and larynx.
• Contains:
  • Chondrocyte in lacuna
  • Costal cartilages
  • Matrix

Connective Tissue: Bone (Osseous Tissue)

• Hard, calcified matrix with collagen fibers found in bone
• Osteocytes are found in lacunae and are well vascularized
• Supports, protects, and provides levers for muscular action
• Stores calcium, minerals, and fat
• Marrow inside bones is the site of hematopoiesis

Connective Tissue: Bone (Osseous Tissue)

• Description: Hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae. Very well vascularized.
• Function: Bone supports and protects (by enclosing); provides levers for the muscles to act on; stores calcium and other minerals and fat; marrow inside bones is the site for blood cell formation (hematopoiesis).
• Location: Bones
• Contains:
  • Osteocytes in lacunae

Macroscopic Anatomy of Bone

• Structures in the bone:
  • Artery with capillaries
  • Vein
  • Nerve fiber
  • Collagen fibers
  • Central (Haversian) canal
  • Lamellae
  • Osteon (Haversian system)
  • Circumferential lamellae
  • Nerve
  • Vein
  • Artery
  • Canaliculi
  • Osteocyte in a lacuna
  • Compact bone
  • Spongy bone
  • Perforating (Volkmann's) canal
  • Endosteum lining bony canals and covering trabeculae
  • Perforating (Sharpey's) fibers
  • Periosteal blood vessel
  • Periosteum
  • Lacunae
  • Interstitial lamella Lacuna (with osteocyte)

Compact Bone

• canaliculi – spaces for cytoplasmic extensions of osteocytes
• osteocyte
• lamella(e) (circular)
• lacuna(e) in matrix for osteocyte
• Haversian Canal (central)
  • lines cell layer space vein nerve artery
• HAVERSIAN SYSTEM (OSTEON) MODEL OF COMPACT BONE

Bone & Cartilage

• Bone
• Cartilage - hyaline

A&P Lab Activity - Tissues

• Connective Tissue
• Body
• Organ
• Tissue
• Cell

Muscle Tissue (Part 2)

• Human Smooth Muscle

Muscle Tissue

• Nearly half of the body's mass
• Transforms chemical energy (ATP) to directed mechanical energy à exerts force
• Three types:
  • Skeletal
  • Cardiac
  • Smooth

Skeletal Muscle

• Location: attached to bone or skin
• Function: Voluntary, can be contracted at will
  • controlled by conscious area of brain
  • wrapped in connective tissue to form organs called skeletal muscles
• Cells:
  • very long (length of entire muscle)
  • multinucleate, cylindrical, striated cells, does not have typical cells.
  • referred to as muscle fiber cells

Cardiac Muscle

• Location: heart
• Function: Involuntary. heart beats by itself at rest.
  • increase or decrease in beats is controlled by nerves & hormones.
  • Intercalated discs (interlocking plasma membranes of adjacent cells) support synchronized contraction
• Cells: striated, long, branching uninucleate cells; does not have typical cells.

Cardiac Muscle Video

• Human cardiac muscle cells generated from stem cells beating in a dish.
• https://www.youtube.com/watch?v=WLtJTywFpol
• CARDIAC MUSCLE
  • Intercalated discs

Smooth (visceral) Muscle

• Location: In walls of hollow organs
  • stomach, urinary bladder, blood vessels, and airways
• Function: Involuntary.
  • does not require a conscious thought for contraction.
  • controlled by involuntary centers in the brain.
• Cells: non-striated (smooth) spindle-shaped cells. Individual smooth muscle cells

Smooth Muscle Hint

• look for this cell pattern
• If you zoomed in to just this area, it would look a lot like dense reg. CT

Tricky: Connective Tissue vs. Muscle

• Smooth muscle
• Dense regular CT (not connective tissue!)
• If you zoom in to closely, differentiating between these two will be difficult!

Tricky: Connective Tissue vs. Muscle (zoomed out)

• Dense regular CT
• Smooth muscle

Smooth Muscle Examples

• Artery Wall
  • Lumen
  • Connective tissue
  • Smooth muscle
  • Simple columnar epithelium
• Wall Of Intestine

Muscle Tissue Control

• Skeletal Muscle
  • Voluntary Control
• Cardiac Muscle
  • Involuntary Control
• Smooth Muscle
  • Involuntary Control

Muscle Tissue Comparison

• Skeletal muscle
• Cardiac muscle
• One skeletal muscle cell
• One cardiac muscle cell
• Intercalated disks

Muscle Tissue Nuclei

• Skeletal Muscle
• Smooth Muscle
• Cardiac Muscle

Comparison of Skeletal, Cardiac, and Smooth Muscle

Muscle Tissue Activity

• A&P Lab Activity - Tissues

The Integument (Part 3)

• Human Scalp:
  • stratum corneum
  • stratum granulosum
  • epidermis
  • stratum spinosum
  • stratum basale
  • dermis

Skin Structure

• Hair shaft
• Epidermis
• Papillary layer
• Dermis
• Reticular layer
• Hypodermis (subcutaneous tissue; not part of skin)
• Dermal papillae
• Subpapillary plexus
• Sweat pore
• Cutaneous plexus
• Adipose tissue
• Nervous structures
  • Sensory nerve fiber with free nerve endings
  • Lamellar corpuscle
  • Hair follicle receptor (root hair plexus)
• Appendages of skin
  • Eccrine sweat gland
  • Arrector pili muscle
  • Sebaceous (oil) gland
  • Hair follicle
  • Hair root

Epidermis Functions

• Making new skin cells
• Giving skin its color
• Protecting your body
• Contains:
  • Keratinocytes
  • Stratum corneum
  • Stratum lucidum
  • Stratum granulosum
  • Stratum spinosum
  • Melanocyte
  • Stratum basale
  • Basement membrane
  • Dermis

Skin Color

• Three pigments contribute to skin color:
  • Melanin
  • Carotene
  • Hemoglobin

Melanin

• Blocks UV from sunlight
• Two forms:
  • Reddish-yellow to brownish-black
  • Color differences due to amount and form
• Produced in melanocytes
  • Same relative number in all people
  • Melanin granules are transferred to keratinocytes to form "pigment shields" for nuclei
• Freckles and pigmented moles
  • Local accumulations of melanin
• Sun exposure stimulates melanin production

Carotene

• Yellow to orange pigment
• From food, mainly vegetables
• Accumulates in stratum corneum and hypodermis
• Most obvious in palms and soles
• Can be converted to vitamin A for vision and epidermal health
• Yellowish-tinge of some asians – carotene and melanin variations

Hemoglobin

• Pinkish hue of fair skin
• Relatively low levels of melanin, carotene
• allows hemoglobin from blood to be primary colorant
• Harlequin syndrome
  • Due to autonomic nerve damage on opposing side, capillary dilation in dermis is restricted

Skin Cancer

• Most skin tumors are benign (not cancerous) and do not metastasize (spread)
• Risk factors:
  • Overexposure to UV radiation
  • Frequent irritation of skin
• Some skin lotions contain enzymes that can repair damaged DNA
• Three major types of skin cancer:
  • Basal cell carcinoma
  • Squamous cell carcinoma
  • Melanoma

UV Radiation and Skin Protection

• Biggest threat to skin is excessive sun exposure
• UVB rays
• UVA rays
• UV penetration into the layers of the skin
• Skin without protection
  • Epidermis
  • Dermis
  • Hypodermis
• Sunscreen
  • Filter reflects UV radiation

Basal Cell Carcinoma

• Least malignant; most common
• Stratum basale cells proliferate and slowly invade dermis and hypodermis
• Cured by surgical excision in 99% of cases

Squamous Cell Carcinoma

• Second most common type
• Involves keratinocytes of stratum spinosum
• Usually scaly reddened papule on scalp, ears, lower lip, and hands
• Does metastasize
• Good prognosis if treated by radiation therapy or removed surgically

Melanoma

• Cancer of melanocytes
• Most dangerous
• Highly metastatic and resistant to chemotherapy
• Treated by wide surgical excision accompanied by immunotherapy
• Key to survival is early detection – ABCD rule
  • A: asymmetry; the two sides of the pigmented area do not match
  • B: border irregularity; exhibits indentations
  • C: color; contains several (black, brown, tan, sometimes red or blue)
  • D: diameter; larger than 6 mm (size of pencil eraser)
  • E: Evolving; changes in size, shape, color

Warning Signs of Melanoma

• A: ASYMMETRY
  • One half unlike the other half.
• B: BORDER
  • Irregular, scalloped, or poorly defined border.
• C: COLOR
  • Varied from one area to another; shades of tan and brown, black; sometimes white, red, or blue.
• D: DIAMETER
  • While melanomas are usually greater than 6mm (the size of a pencil eraser) when diagnosed, they can be smaller.
• E: EVOLVING
  • A mole or skin lesion that looks different from the rest or is changing size, shape, or color.

ABCDE Test for Melanoma

• A: Asymmetry
• B: Border
• C: Color
• D: Diameter 6mm
• E: Evolving

ABCDE Rule for Early Detection

• A is for Asymmetry
  • If you draw a line through the middle of the mole, the halves of a melanoma won't match in size.
• B is for Border
  • The edges of an early melanoma tend to be uneven, crusty, or notched.
• C is for Color
  • Healthy moles are uniform in color. A variety of colors, especially white and/or blue, is bad.
• D is for Diameter
  • Melanomas are usually larger in diameter than a pencil eraser, although they can be smaller.
• E is for Evolving
  • When a mole changes in size, shape, or color, or begins to bleed or scab, this points to danger.

Melanoma Development

• Stages of Melanoma
  • Stage 0
  • Stage I
    • Ia
    • Ib
  • Stage II
    • IIa
    • IIb
    • IIc
  • Stage III
    • IIIa
    • IIIb
    • IIIc
      • Micrometastases in 3 lymph nodes
      • Micrometastases in 4+ lymph nodes
      • Metastatic deposits in lymph notes & vessles
  • Stage IV
    • Bone Metastasis
    • Liver Metastasis
    • Brain Metastasis
    • Lung Metastasis
    • Intestine Metastasis
    • Bloodstream Metastasis
• Epidermis
• Dermis
• Hypodermis
• Primary Melanoma

Dermis Functions

• Making sweat
• Helping you feel things
• Growing hair
• Making oil
• Bringing blood to your skin

Sebaceous Gland

• Dermal connective tissue
• Hair in hair follicle
• Sebaceous gland duct
• Sebaceous gland
• Eccrine gland
• Secretory cells
• Sweat pore

Layers of the Dermis: Papillary Layer

• Areolar connective tissue with collagen and elastic fibers and blood vessels
• Loose tissue
• Phagocytes can patrol for microorganisms
• Dermal papillae
  • Superficial peglike projections

Layers of the Dermis: Reticular Layer

• ~80% of dermal thickness
• Dense fibrous connective tissue
• Elastic fibers provide stretch-recoil properties
• Collagen fibers
  • Provide strength and resiliency
  • Bind water
• Cleavage lines because most collagen fibers parallel to skin surface
  • Externally invisible
  • Important to surgeons
  • Incisions parallel to cleavage lines gap less and heal more readily

Cleavage Lines

• Dermal modifications result in characteristic skin markings.
• Cleavage lines in the reticular dermis
• An incision made across the cleavage lines is more likely to gape, increasing healing time, and result in increased scar tissue.
• An incision made parallel to the cleavage lines results in less gaping, faster healing, and less scar tissue.
• BEST lines run coronally on the scalp; additional relaxation of tension can be achieved by galeal scoring in the coronal plane
• BEST Lines on the mid-cheek follow RSTL due to the SMAS layer, however principle of cheek neurovascular zones must be followed
• BEST lines run vertically on the neck, following the direction of the Platysma muscle fibres
• Biodynamic Excisional Skin Tension (lines)

Subcutaneous Fat

• Attaching the dermis to your muscles and bones
• Helping the blood vessels and nerve cells
• Controlling your body temperature:
• Storing your fat

Skin Structure Review

• Epidermis
  • St. Corneum
  • St. Granulosum
  • St. Spinosum
  • St. Basale
• Dermis (irregular dense connective tissue)
  • Papilllary Dermis
  • Reticular Dermis
• Hypodermis
• Sweat gland
• Sebaceous gland
• Hair follicle
• Arrector pili muscle

Skin Anatomy Review

• hair shaft
• stratum corneum
• dermal papilla
• Meissner’s corpuscle (touch)
• blood vessels
• sebaceous gland
• arrector pili muscle
• sweat gland
• hair follicle
• Pacinian corpuscle (deep pressure)
• adipose tissue (usually in subcutaneous area)
• dermis
• epidermis

Required Terms and Structures

• Connective Tissue Proper: Loose
  • Areolar CT (Gel-like matrix with all three connective tissue fibers)
  • Adipose CT (Matrix similar to areolar connective tissue with closely packed adipocytes – lipid storage)
  • Reticular CT (Loose ground substance with reticular fibers)
• Connective Tissue Proper: Dense
  • Dense Regular CT (tendons, ligaments)
  • Dense Irregular CT (dermis, submucosa of the digestive tract, and fibrous organ capsules)
• Other Connective Tissues
  • Hyaline Cartilage (ex/ tracheal ring)
  • Bone
    • Osteon (compact bone section)
  • Blood (liquid matrix = plasma)
• Muscle Tissues
  • Smooth muscle
  • Cardiac muscle
  • Skeletal muscle
• Integument
  • Epidermis
    • Stratum corneum
    • Stratum lucidum
    • Stratum granulosum
    • Stratum spinosum
    • Stratum basale
  • Dermis
    • Dermal papillae
    • Cleavage lines
    • Papillary layer of dermis
    • Reticular layer of dermis
    • Eccrine sweat gland
    • Apocrine sweat gland
    • Sebaceous gland
    • Sebum
    • Arrector pili muscle
    • Hair follicle
    • Hair shaft
    • Sensory receptors
  • Hypodermis
    • Subcutaneous fat