Tissues No, 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 tissue Embryonic (mesenchyme) Connective tissue proper ○ Includes all mature connective tissue except bone, cartilage and blood. ○ Loose CT: areolar, adipose and reticular Reticular- liver, lymph nodes, marrow and spleen Adipose- 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; immunity Cartilage ○ 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: epiglottis Bone (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 Striated Packaged by connective tissue sheets. Attached to bone Contract 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 types Neurons- 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)