CH 4b: Connective, Muscle, Nervous

Connective tissue

tissue with usually more matrix than cell volume; of ten specialized to support, bind, and protect organs

Connective tissue GEN LOC

tendons and ligaments, cartilage and bone, blood and lymph

Connective tissue GEN FUNCTION

binding organs, support physical protection, immune protection, movement, storage, heat production, transport

Common characteristics of connective tissue

Common origin, degrees of vascularity, extracellular matrix

Structural elements of connective tissue

Ground substance, connective tissue fibers, connective tissue cells

Ground substance

unstructured material fills space between cells and contain fibers

Ground substance COMPONENTS

interstitial fluid, cell adhesion proteins, proteoglycans

Interstitial fluid

consist large amount of lfuid, fibers embedded in ground substance making it less pliable and hinder diffusion; nutrients and other dissolved substances diffuse between blood capillaries and cells

Cell adhesion protein

proteins that serve mainly as connective tissue GLUE for connective tissue cells to attach extracellular matrix

Proteoglycan

GAG form protein core fibers of bottle brush, intertwined and trap water forming substance that vary from fluid to viscous gel

Connective tissue fibers

proteins that provide support

Connective tissue fibers TYPES

collagen, elastic, reticular fibers

Collagen fibers

tought and flexible (white fibers of tendons and ligaments) STRONGEST AND MOST ABUNDANT AMONG OTHERS

Elastic Fibers

stretch and recoil (elastin protein is abundant in lungs)

Reticular Fibers

thin collagen fibers (framework of spleen and lymph nodes)

Connective tissue cells

immature (-blast), mature form (-cyte)

Adipocytes

aka adipose/fat cells, store energy as fat

White Blood Cells

aka WBCs/leukocytes, concerned with tissue response to injury

Mast cell

typically cluster along blood vessels, detect foreing microorganisms and initiate local inflammatory responses

Mast cell - Heparin

anticoagulant chemcial that prevent blood clotting in bloodstream

Mast cell - Histamine

substance that makes capillaries leaky

Types of connective tissue

connective tissue proper, cartilage, bone, blood

Connective tissue proper

loose connective tissue, dense connective tissue

Loose connective tissue

areolar, adipose, reticular

Dense connective tissue

regular, irregular, elastic

Areolar Connective tissue

gel-like matrix with all 3 fiber types cells; fibroblasts, macrophages, mast cells and some white blood cells

Areolar Connective Tissue FUNCTION

wrap and cushion organs, macrophage phagocytize bacteria; play in inflammation; hold and convey tissue fluid

Areolar Connective Tissue LOCATION

widely distributed under epithelia of body; forms laminated propria of mucous membranes; packages organs; surrounds capillaries

Brown Adipose Tissue

burn energy to generate heat using lipid fuels

White Adipose Tissue

stores energy, nutrient

Adipose Tissue

matrix as in areolar, but very sparse; closely packed adipocytes (fat cells), have nucleus pushed to the side by large fat droplet

Adipose Tissue FUNCTION

provide reserve food fuel; insulate against heat loss; support and protect organs

Adipose Tissue LOCATION

under skin in hypodermis; around kidneys and eyeballs; within abdomen; in breasts

Reticular Connective Tissue

network of reticular fibers in typical loose ground substance forming delicate network along fibroblasts - reticular cells

Reticular Connective Tissue FUNCTION

fibers form soft internal skeleton (stroma) supporting other cell types like white blood cells, mast cells, and macrophages

Reticular Connective Tissue LOCATION

lymphoid organs (lymph nodes, bone marrow, and spleen)

Dense Connective Tissue

Dense regular connective tisue, irregular connective tissue, and elastic connective tissue. aka fibrous connective tissues

Dense Regular Connective Tissue

primarily parallel collagen fibers; few elastic fibers; major cell type - fibroblast

Dense Regular Connective Tissue FUNCTION

attaches muscles to bones or muscles; attaches bones to bones withstand great tensile stress when pulling force is applied in one direction

Dense Regular Connective Tissue LOCATION

tendons, most ligaments, aponeuroses

Dense Irregular Connective Tissue

primarily irregularly arranged collagen fibers; some elastic fibers; major cell type - fibroblast

Dense Irregular Connective Tissue FUNCTION

able to withstand tension exerted in many directions; provide strucutral strength

Dense Irregular Connective Tissue LOCATION

fibrous capsules of organs and joints; dermis of skin; submucosa of digestive tract

Elastic Connective Tissue

dense regular connective tissue containing a high proportion of elastic fibers

Elastic Connective Tissue FUNCTION

allows recoil of tissue following stretching; maintain pulsatile flow of blood thorugh arteries; aid passive recoil of lungs following inspiration

Elastic Connective Tissue LOCATION

walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes

Cartilage

Hyaline cartilage, elastic cartilage, fibrocartilage

Hyaline Cartilage

amorphous but firm matrix; collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie lin lacunae

Hyaline Cartilage FUNCTION

supports and reinforces; has resilient cushioning properties; resists compressive stress

Hyaline Cartilage LOCATION

form most of embryonic skeleton; cover ends of long bones in joint cavities; form costal cartilages of the ribs; cartilages of the nose, trachea, and larynx

Elastic Cartilage

similar to hyaline cartilage, more elastic fibers in matrix

Elastic Cartilage FUNCTION

maintain the shape of a structure while allowing great flexibility

Elastic Cartilage LOCATION

supports external ear (pinna); epiglottis

Fibrocartilage

matrix similar to but less firm than that in hyaline cartilage; thick collagen fibers predominate

Fibrocartilage FUNCTION

tensile strength with the ability to absorb compressive shock

Fibrocartilage LOCATION

intervertebral discs; pubic symphysis; discs of knee joint

Bone

hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae; very well vascularized

Bone FUNCTION

supports and protects (by enclosing); provide levers for muscles to act on; store calcium and other minerals and fat; marrow inside bones is the site for blood cell formation (hematopoiesis)

Bone LOCATION

ostensibly, concentric rings of bony matrix (lamellae), surrounding central canals containing blood vessels and nerves serving the bone

Blood

red and white blood cells in a fluid matrix (plasma); erythrocytes and platelets are also seen

Blood FUNCTION

transport of respiratory gases, nutrients, wastes and other substances

Blood LOCATION

contained within blood vessels

Muscle Tissue

well-vascularized and responsible for most body movements

Types of Muscle Tissue

Skeletal muscle, Cardiac muscle, Smooth muscle

Skeletal Muscle

VOLUNTARY MUSCLE - long, cylindrical, multinucleate cells; obvious striations

Skeletal Muscle FUNCTION

voluntary movement; locomotion; manipulation of the environment; facial expression; voluntary control

Skeletal Muscle LOCATION

skeletal muscle attached to bones or ocassionally to skin

Cardiac Muscle

INVOLUNTARY MUSCLE - branching striated, generally uninucleate cells that interdigitate at specialized junctions (intercalated discs)

Intercalated Discs

branching cells that fit together tightly at unique junctions

Cardiac Muscle FUNCTION

as it contracts, it propels blood into circulation; involuntary control

Cardiac Muscle LOCATION

walls of heart

Smooth Muscle

spindle-shaped cells with central nuclei; no striations; cells arranged closely to form sheets

Smooth Muscle FUNCTION

propel substances or objects; squeeze substances through organs alternately contracting and relaxing

Smooth Muscle LOCATION

mostly walls of hollow organs other than heart; digestive and urinary tract organs, uterus, and blood vessels)

Nervous Tissue

neurons are branching cells; cell process may be quite long extend form nucleus-containing cell body; aslo contributing to nervous tissue are non irritable supporting cells

Nervous Tissue FUNCTION

transmit electrical signals from sensory receptors and to effectors (muscles and glands) which control their activity

Nervous Tissue LOCATION

brain, spinal cord, and nerves

Neurons

transmit information, highly specialized nerve cells that generate and conduct nerve impulses

Dendrite process

respond to stimuli

Axon process

transmit electrical impulses over substantial distances within body

Glial cells (neuroglia)

non-conducting cells that support, insulate, and protect delicate neurons

Covering and lining membranes

continuous multicellular sheets composed of 2 primary tissue types: epithelium bound to underlying connective tissue proper

Cutaneous membrane TISSUE TYPE

keratinized stratified squamous epithelium (epidermis) firmly attached to thick layer of connective tissue (dermis)

Cutaneous membrane D/LOCATION

cover body surface and exposed to air and dry membrane; skin

Mucous membrane D/LOCATION

line passageways to openings; hollow organs of digestive, respiratory and urogenital tracts; wet or moist membranes bathed by secretions or (in urinary mucosa) urine; adapt to absorption and secretion; secret copious amounts of lubricating mucus, not urinary tract

Mucous membrane TISSUE TYPES

stratified squamous or simple columnar epithelia

Serous membrane D/LOCATION

moist membrane found in closed ventral body cavities, cells add slippery molecule hyaluronic acid filtering capillaries in associated connective tissue

Serous membrane TISSUE TYPES

visceral layer, parietal layer; simple squamous epithelium (mesothelium)