AP - CT Types - Chapter 4

Areolar Connective Tissue Overview

• least specialized tissue and universal packing tissue

• gel-like matrix with all 3 fibers (elastic, reticular, collagen) and many types of cells

• its viscosity absorbs shocks

Areolar CT Function

• wraps and cushions organs

• phagocytic cells defend against pathogens

• provides support and allows movement

Where is areolar CT located?

• dermis of the skin

• lines the digestive and respiratory tracts

• between muscles and around joints

type

areolar tissue image

Adipose Tissue Overview

• provides padding/packing around structures, insulator, absorbs shocks

• adipocytes are metabolically active and deflate/inflate in response to lipid use

• balloon like cell appearance

White Fat vs Brown Fat

white fat = pale, yellow; energy storage, insulation, hormone production

brown fat = deep, rich, brown; vascularized, upper body fat, only in young children

Adipose Tissue Function

• insulates, provides packing/cushion, provides reserve energy storage

Where is adipose tissue located?

• hypodermis

• sides, buttocks

• around eyes

• breasts

type

adipose tissue image

What type of CT is adipose tissue? (1)

Loose CT (1)

Reticular Tissue Overview

• thin reticular fibers in 3-D network

• resist forces (interwoven), stabilize positions of structures

• cells are present; reticular fibers are darkly stained and look like squiggly lines

Reticular Tissue Function

• makes supportive internal framework, supports other cell types (WBC, mast cells, macrophages)

Where is reticular tissue found?

• liver

• kidney

• spleen

• bone marrow

type

reticular tissue image

What type of CT is reticular tissue? (2)

Loose CT (2)

What are the three types of loose CT?

1. areolar

2. adipose

3. reticular

Dense Regular CT Overview

• wavy bundles of collagen running in the same direction(great resistance to tension)

• fibroblasts are present, but no other cells

• poorly vascularized

Dense Regular CT Function

• attaches muscles to bones, bone to bone, etc.

• withstands great pulling force (parallel collagen fibers)

Where is dense regular CT located?

• tendons

• ligaments

type

dense regular CT image

Dense Irregular CT Overview

• same structure as regular CT (fibroblasts & collagen fibers) but collagen fibers are thicker and are arranged without pattern

• helps withstand force from different directions

Dense Irregular CT Function

• gives strength to resist tension in many directions

• helps prevent over expansion of organs/structural strength

Where is dense irregular CT located?

• fibrous capsules of joints/organs

• dermis of skin

type

dense irregular CT image

Elastic CT Overview

• elastic fibers present (in abundance over collagen fibers)

• allow extension and recoil

• composed of fibroblasts and elastic fibers

Elastic CT Function

• gives tissue ability to extend and recoil (organs pulsating)

• stabilizes vertebrae and penis positions

Where is elastic CT located?

• large artery walls (aorta)

• bronchial tubes (breathing)

• penis

• between vertebrae

type

elastic CT image

Cartilage Overview

• differs bc chondrocyte is the only cell present

• avascular so cells use diffusion through perichondrium

• injuries heal slowly

Chondrocytes are found in small openings called ______.

lacunae

What is the CT membrane that surrounds the cartilage mass?

the perichondrium

What are the 3 main elements of cartilage?

1. special cells

2. ECM

3. collagen fibers

Chondroblasts are ________ cells that grow into __________.

• immature

• chondrocytes

Chondroblasts Characteristics

• found under perichondrium near outer surface

• secrete ECM

• become entrapped and mature into chondrocytes

Chondrocytes Characteristics

• mature chondroblasts

• divide and cluster to make lacunae

ECM Characteristics

Made up of

1. aggrecans = proteoglycan

2. water = 75% of ECM

3. collagen + more

What are the 3 types of cartilage?

1. Hyaline

2. Elastic

3. Fibrous

Hyaline Cartilage Overview

• most prevalent type

• lower collagen amount gives translucent appearance

Hyaline Cartilage Function

• gives stiff, somewhat flexible support and reinforcement

• reduces friction between bony surfaces

• resilient cushion/resists compression

Where is hyaline cartilage found?

• embryonic skeleton

• tips of ribs

• sternum

• trachea

• nose/nasal septum

• ends of bones at joints

type

hyaline cartilage image

Elastic Cartilage Overview

• few collagen fibers but abundance of fine elastic fibers

• high degree of flexibility

Elastic Cartilage Function

• maintains shape of structure but gives lots of flexibility

• provides support

Where is elastic cartilage found?

• external ear (pinna)

• epiglottis

type

elastic cartilage image

Fibrocartilage Overview

• little ground substance, high abundance of interwoven collagen fibers (very durable and tough)

• resists compression

Fibrocartilage Function

• tensile strength absorbs compression

• prevents bone-to-bone contact

Where is fibrocartilage located?

• intervertebral discs

• pubic bones

• disc of knee joint

type

fibrocartilage image

Interstitial growth grows cartilage from ________. Chondrocytes divide and daughter cells make ________. Its important in __________.

• within

• ECM

• development

type

interstitial growth image

Appositional growth adds new layers to the _________. Cells differentiate into chondroblasts and secrete new _______. As new ECM enlarges, more chondroblasts are encased and mature into __________. This grows the amount of cartilage.

• surface

• ECM

• chondrocytes

What are the 3 main functions of cartilage?

1. supportive framework for airways

2. forms articular surfaces of bone

3. is a template for the skeleton

type

appositional growth image

Osseus Tissue Overview

• supports and protects body structures

• matrix is similar to cartilage but is more rigid/harder bc of calcium salts and more collagen fibers

• vascularized

__________ make organic part of matrix.

Osteoblasts

__________ reside in the lacunae.

Osteocytes

Bone units that are concentric rings with the central canal containing blood vessels.

Osteons

Osseus Tissue Function

• hematopoiesis

• lipid/mineral storage

• support

• protection

Hematopoiesis

formation of blood cells from stem cells in bone marrow

Lipid/mineral storage

bone holds adipose tissue and calcium in its crystals

type

osseus tissue image

Fluid CT Function

• transport respiratory gases, nutrients, waste, etc.

Where is fluid CT located?

• contained in blood vessels

What are elements in the blood?

• RBCs = transport O2

• WBCs = monocytes, lymphocytes, neutrophils, etc.

• Platelets = blood clotting

What are the 3 types of muscle tissue?

1. skeletal

2. cardiac

3. smooth

Skeletal Muscle Tissue Overview

• long, cylindrical, multinucleated cells with striations die to actin and myosin fibers

• produce voluntary movement

Skeletal Muscle Tissue Function

• moves/stabilizes skeleton

• generates heat

• facial expression

Where is skeletal muscle tissue located?

• in skeletal muscles attached to bones

type

skeletal muscle tissue image

Cardiac Muscle Tissue Overview

• centrally positioned nucleus, branching, striation, intercalated discs join cells together

• connected via desmosomes and gap junctions which aid ion movement and synchronization between cells

• limited repair ability

• pacemaker cells set their own rate (striated involuntary muscle)

Cardiac Muscle Tissue Function + Location

• contraction propels blood for circulation

• walls of heart

type

cardiac muscle tissue image

Smooth Muscle Tissue Overview

• short, spindle-shaped, tapering ends, single nucleus

• can regenerate after injury

• actin/myosin have different arrangement = NO STRIATIONS

• contract on their own (involuntary control) through gap junction coordination

Smooth Muscle Tissue Function

• propels substances/objects through internal passages

Where is smooth tissue located?

• walls of hollow internal organs (bladder, intestines, reproductive tract)

type

smooth muscle tissue image

Nervous Tissue Overview

• specialized for propagating electrical impulses for communication

• mostly found in brain and spinal cord

• 2 cells (neurons and neuroglia)

• limited ability to repair

Neurons are the ________ cells in the body.

longest

Neurons have ________ : branching ends that receive info, and ______: tails that communicate to other cells. This part is also called a nerve fiber

• dendrites

• axons

Nervous Tissue Function

• transmit electrical impulses to/from sensory receptors

type

nervous tissue image