TissuesNo, not that kind!

BODY TISSUES!!!

4 Main Types

Epithelial

Connective

Muscle

Nervous

Epithelial Tissues

2 main types:1. Covering and Lining- includes mucosa, skin and serosae (moist membranes found in closed ventral body cavities.) Ex: pleura, pericardium, peritoneum

2. Glandular- endocrine and exocrine

Connective Tissues Most abundant of the primary

tissues. Most widely distributed, and varied

type. It includes fibrous tissues, fat,

cartilage, bone, bone marrow, and blood.

often bind other organs together, hold organs in place, cushion them, and fill space.

Characteristics: Common origin (mesenchyme) Varied degrees of vascularity Matrix- major component of connective

tissue○ Nonliving○ Allows connective tissue to bear weight,

withstand great tension and endure trauma.

Types of Connective tissueEmbryonic (mesenchyme)Connective tissue proper

○ Includes all mature connective tissue except bone, cartilage and blood.

○ Loose CT: areolar, adipose and reticularReticular- liver, lymph nodes, marrow and spleenAdipose- fat in breasts, around eyes and kidneys

and under skin.- Provides reserve food fuel, insulates against heat

loss.Areaolar- packages organs, surrounds capillaries

- Cushions organs, macrophages phagocytize bacteria, holds and transports tissue fluid

Types of Connective Tissue, Cont.○ Dense CT

Elastic- provides durability with stretch- Walls of aorta, vocal cords, ligaments that

connect vertebrae, parts of trachea and bronchi.

Irregular- provides structural strength- Dermis, fascia, fibrous capsules of joints,

etc.Regular- attaches muscles to bones and

bones to bones- Tendons, ligaments and aponeuroses

Types of Connective Tissue, Cont.Blood- transport of gases, nutrients and waists;

immunityCartilage

○ Hyaline cartilage: forms most of the embryonic skeleton, covers ends of long bones, costal cartilage of ribs, cartilage of nose trachea and larynx.

○ Fibrocartilage: intervertebral discs, pubic symphysis, discs of knee joint

○ Elastic cartilage: epiglottisBone (osseous tissue)

○ Very vascular. Has hard, calcified matrix w/ collagen.○ Provides support and structure, calcium storage,

and hematopoiesis.

Muscle Tissues Highly cellular Well vascularized Responsible for body

movement

Types of Muscle Tissue: Voluntary: (skeletal)

Long, cylindrical cells with many nuclei

StriatedPackaged by

connective tissue sheets.

Attached to boneContract to pull on

bone or skin.

Involuntary: (cardiac and smooth)Cardiac

○ found only in heart.Smooth

○ has no visible external striation.

○ Spindle-shaped with one central nucleus.

○ Found in walls of hollow organs.

○ Propels substances through organs by contracting and relaxing.

Nervous Tissues Found in brain,

spinal cord and nerves.

2 major cell typesNeurons- branching

or stellate cells that generate & conduct nerve impulses.

Neuroglial cells-nonconducting cells that support, insulate and protect neurons.

Tissue Repair

Most types of repair involve both regeneration and fibrosis.Regeneration- replacement of destroyed

tissue by proliferation of the same type of cell.

Fibrosis- proliferation of fibrous connective tissue. (scarring)