Anatomy and Physiology 1 Chapter 4 Outline Tissues and Membranes 1 Tissue group of cells with similar structure and function o 4 major groups epithelial, connective, muscle, nerve Epithelial tissue (Fig 4-1, 2, 3, Table 4-1) o Coverings (outer surface) or linings (inside surface) o No capillaries get nutrients from connective tissue below o Classification based on: Cell type Shape Squamous flat Cuboidal cube shaped Columnar tall and narrow Number of layers Simple one layer Stratified many layers o Simple squamous epithelium smooth, thin, and flat Alveoli, capillaries allow gas and fluid exchange o Stratified squamous epithelium many layers of mostly flat cells (lower cells are rounded) Mitosis occurs in the lower cells Keratinizing epithelium Epidermis Nonkeratinizing Mucous membranes Oral cavity, esophagus, vagina, etc o Transitional epithelium stratified epithelium with varied shapes of layers Urinary bladder cells flatten as bladder fills o Simple cuboidal epithelium single layer cube-shaped Secretion and absorption Glandular epithelium secretion Thyroid, saliva glands Reabsorption in kidney tubules (microvilli) o Simple columnar epithelium single layer taller than they are wide Secretion and absorption Stomach o secretes gastric juices (HCl and pepsin), mucus Small intestine o Secretes digestive enzymes, mucus (goblet cells unicellular gland) o Absorption via Microvilli o Ciliated epithelium columnar cells with cilia Nasal cavities, larynx, trachea, bronchials Sweep mucus trapped debris Fallopian tubes Sweep egg
2 Glands cells or organs that secrete something o Unicellular or multicellular o Unicellular one cell Goblet cells respiratory and digestive tracts Secrete mucus o Multicellular similar or dissimilar cells that combine secretions 2 types Exocrine and endocrine Exocrine have ducts Salivary, sweat, gastric, pancreas (both endo & exo) digestive enzymes into duodenum Endocrine ductless Secrete directly into the blood or interstitial fluid Secrete hormones Thyroid, adrenals, pituitary, pancreas insulin and glucagons into blood Connective tissue (Table 4-2) blood, areolar (loose), adipose, fibrous, elastic, bone, cartilage o Matrix and cells o Matrix structural network or solution of nonliving intercellular material Plasma, calcium salts, collagen, etc. o Blood (Fig 4-4 A) Cells WBCs, RBCs, platelets Matrix plasma Hemopoietic tissue blood forming In red bone marrow and lymphatics (spleen and lymph nodes) Marrow RBCs, 5 types of WBCs, and platelets Lymphatics 2 types of WBCs RBCs carry O 2 on hemoglobin WBCs destroy pathogens and provide immunity Platelets clotting o Areolar (also called loose) (Fig 4-4 B) Cells Fibroblasts Produce protein fibers Matrix 2 types of fibers collagen (strong, inelastic) elastin (elastic) Found beneath all epithelial tissue that have openings to the environment and the dermis of the skin Contain WBCs to fight infection in this sub-surface layer o Adipose (Fig 4-4 C) Cells adipocytes store fat Matrix (very small amount) fluid and collagen fibers Mostly subcutaneous in areolar connective tissue Also around kidneys and eyes for protection o Fibrous (Fig 4-5 A) Cells fibroblasts Matrix collagen Outer walls of arteries (high pressure), tendons, ligaments parallel fibers Poor blood supply slow healing Dermis and fascia randomly arranged Good blood supply
o Elastic Cells fibroblasts Matrix mostly elastin In walls of large arteries allows them to stretch and recoil In alveoli stretch during inhalation then contract to push air out Some ligaments o Bone (Fig 4-5 C) Cells osteocytes Matrix calcium salts and collagen Arranged into haversian systems Skeletal support, organ protection, red bone marrow in femur head, pelvis, sternum produce blood cells Good blood supply fast healing o Cartilage (Fig 4-5 B) Cells chondrocytes Matrix protein Joint surfaces decreases friction (smooth) External ear, nose, trachea structural support IVDs shock absorption, allows movement No capillaries nutrients by diffusion slow healing Muscle tissue (Table 4-3) skeletal, smooth, cardiac o Skeletal (aka striated or voluntary) Cells (Fig 4-6 A) Cylindrical Several nuclei in each Striated (striped) contractile proteins Attach to bone to move the skeleton Each cell has its own motor nerve ending can be controlled voluntarily Produce heat to maintain body temperature Review of names Skeletal location Striated appearance Voluntary function o Smooth (aka involuntary or visceral) Cells (Fig 4-6 B) Tapered ends Single nuclei No striations In many visceral organs Involuntary work on their own GI tract peristalsis Blood vessels dilate to maintain blood pressure Iris constricts or dilates the pupil Review of names Visceral location Smooth appearance Involuntary function 3
4 o Cardiac Cells (Fig 4-6 C) Branched Single nucleus Small striations Forms the myocardium (heart muscle) the walls of the chambers of the heart Pumps blood Electrical impulses produced in the heart cause cells to contract in unison Nervous tissue (Table 4-4) o Neurons generate and carry electrochemical impulses o Has a direct role in almost every body function o 2 structural divisions CNS brain and spinal cord Neurons and neuroglial cells PNS peripheral nerves Neurons and Schwann cells (produce myelin sheath) o Neuron structure Cell body contains organelles Axons process that carries impulses away from the cell body Only one Dendrites processes that carry impulses toward the cell body May have several o Electrochemical impulses Electrical impulses travel along the cell membrane Converted to chemical impulses (neurotransmitters) at the synapse (place where axon of one neuron meets the dendrite of another) Membranes epithelial (serous & mucous) and connective tissue membranes o Epithelial serous and mucous (Fig 4-8) Secrete fluids Serous membranes simple squamous epithelium that line closed body cavities and cover organs in these cavities Secrete serous fluid prevents friction Types of serous membranes o Parietal pleura lines thoracic cavity o Visceral pleura covers lungs o Parietal pericardium lines the fibrous pericardium o Visceral pericardium (epicardium) covers the heart o Peritoneum lines abdominal cavity o Visceral peritoneum (mesentery) covers abdominal organs
Mucous membranes line body tracts that have openings to the outside Respiratory, digestive, urinary, and reproductive tracts Secrete mucus keeps cells wet, lubricates, traps dust and bacteria Epithelium (mucosa) varies o Esophagus and vagina stratified squamous o Trachea ciliated o Stomach columnar o Connective tissue membranes made of connective tissue Covered in Organ Systems (Table 4-5) Superficial fascia between skin and muscles Periosteum covers bone, anchors tendons and ligaments to bone Perichondrium covers cartilage Synovial lines synovial joint cavities, secretes synovial fluid Deep fascia covers skeletal muscles, anchors tendons to muscle Meninges cover the brain and spinal cord Fibrous pericardium forms a sac around the heart, lined by parietal pericardium 5