Chapter 4 Membranes, Nervous and Muscle Tissue Advanced Biology Chapter 4 Membranes, Nervous and Muscle Tissue

Epithelial Membranes Continuous multicellular sheet, composed of 2 primary tissue types Epithelium bound to underlying CT

Cutaneous Mucous Serous

Skin

Keratinized stratified squamous (epidermis) attached to Dense Irr Keratinized stratified squamous (epidermis) attached to Dense Irr. CT (Dermis)

Body Cavities open to exterior (Dig, resp, urogenital)

Lamina Propria – Loose CT

In closed ventral body cavity

Parietal Layer – lines cavity wall Visceral layer – covers outer surface of organs

Lubrication – reduce friction Prevents organs from sticking to cavity walls

Nervous Tissue Nervous System Brain Spinal Cord Nerves

Highly specialized nerve cells that generate and conduct nerve impulses

Support Insulate Protect

Neurons Supporting cells

Brain Spinal Cord Nerves

Transmit electrical signals

Muscle Tissue Highly cellular, well vascularized

Muscle fibers

Bring about movement or contraction Actin Myosin

Skeletal Cardiac Smooth

Long, cylindrical, multinucleated cells Obvious striations (lines)

Attached to bones Occasionally to skin

Voluntary movement Facial Expression Locomotion

Branching, “striated”, generally uninucleate cells that interdigitate (Interlock) at specialized junctions

Walls of heart

As it contracts, it propels blood into circulation Involuntary control

Spindle shaped cells w/ central nuclei Cells arranged closely to form sheets, no striations

Walls of hollow organs

Propels substances or objects along internal passageways

Tissue Repair Stimulates body’s inflammatory and immune responses

Non-specific – develops quickly

Eliminate harmful agent Prevent further injury Restore tissue to a healthy condition

Very Specific – Takes more time

Steps of Tissue Repair Histamine is released and other inflammatory chemicals

Capillaries are dilated – DIAPEDESIS Allows MAC’s, WBC’s, Clotting factors out of Blood Stream

This isolates Bacteria or Toxin Part exposed dries out – SCAB

Any leftover fluid is phagocytized by MAC’s

Restore Blood Supply

Pink Tissue – thin, permeable capillaries bud from intact capillaries Starts new capillary bed, can bleed easy

Fibroblasts build new tissue

Regeneration/Fibrosis

Proliferation of fibrous CT – SCAR

Factors Affecting Repair Tissue Injured Type of injury and immediate care given to site Nutrition

Adequacy of blood supply State of health Age

Epithelial, bone, fibrous CT - *** Smooth muscle, Dense Reg. Tissue - **

Skeletal muscle, cartilage

Cardiac Nervous

In urinary bladder, heart or other muscular organs – function is hampered Could cause abnormal flow patterns

Heart Failure Not as flexible or as elastic

Developmental Aspects Endoderm Mesoderm Ectoderm

Specialize into all 4 tissue types

Endo – Epithelial, mucousal membranes

Meso – Epithelial, endothelium, mesothelium, muscle, CT

Ecto – Epithelial, epidermis, nervous

Primary tissues, all major organs in place

Epithelia thins, more easily breached Collagen drops, tissue repair less effective

Bone, muscle, nervous tissue – atrophy