Lecture Outline - Chapter 3

3.1 Types of Tissues (p. 60)
	1.	Epithelial Tissue Covers (p. 60, Fig. 3.2)
		a.	A tissue is made up of a group of similar cells that function together in the body. Humans have four basic types of tissues.
		b.	Epithelial tissue consists of tightly packed cells, attached to a basement membrane, that line body cavities or surfaces opening to the outside. It is named according to the shape of its cells.
		c.	Epithelial tissues are specialized for protection, absorption, and secretion. Examples include: squamous epithelium, cuboidal epithelium, and columnar epithelium.
		d.	Epithelium can be stratified or simple. Pseudostratified epithelium appears layered but is not.
		e.	Gland cells can be found within epithelium lining a cavity. 
		f.	Junctions Help Communication (p. 62, Fig. 3.3)
			i.	Tight junctions form an impermeable barrier between cells.
			ii.	Gap junctions allow exchange through pores between cells.
			iii.	Adhesion junctions are formed by intercellular filaments.
	2.	Connective Tissue Connects (p. 62, Fig. 3.4)
		a.	Connective tissue supports, protects, provides frameworks, fills spaces, stores fat, and produces blood cells.
			i.	A matrix that varies from solid to fluid separates connective tissue cells.
			ii.	The matrix contains three types of fibers: strong collagen fibers; stretchy, elastin- containing elastic fibers; and supportive reticular fibers also composed of collagen.
		b.	Loose Connective Tissue Supports (p. 62)
			i.	Loose connective tissue binds structures together and can be found between epithelial layers.
			ii.	Fibroblasts are suspended in a jellylike matrix containing both collagen and elastic fibers.
			iii.	Adipose tissue is a type of loose connective tissue that stores fat.
		c.	Fibrous Connective Tissue Binds (p. 62)
			Fibrous connective tissue contains many collagen fibers and can be found in tendons and ligaments, which heal slowly because of their poor blood supply.
		d.	Cartilage Is Flexible (p. 63)
			i.	Cartilage cells lie within small chambers called lacunae within the gel-like matrix.
			ii.	Hyaline cartilage, found at the ends of long bones and in the fetal skeleton, contains very fine collagen fibers.
			iii.	Elastic cartilage has elastic fibers and is found in the outer ear.
			iv.	Fibrocartilage contains strong collagen fibers that aid in shock absorption between vertebrae and within knees.
		e.	Bone Is Rigid (p. 63)
			i.	Bone is a rigid connective tissue with an inorganic matrix of inorganic salts and collagen fibers.
			ii.	Compact bone makes up the shaft of a long bone.
			iii.	Bone cells called osteocytes reside in lacunae within the matrix.
			iv.	Spongy bone is strong yet decreases the weight of the skeleton.
		f.	Blood Has a Liquid Matrix (p. 64, Fig. 3.5, Table 3.1)
			i.	Blood is a connective tissue in which a fluid matrix called plasma separates cells.
			ii.	Blood transports nutrients, wastes, and gases to body cells.
			iii.	Red blood cells contain hemoglobin and transport oxygen.
			iv.	White blood cells help fight infections in the body.
			v.	Platelets (cell fragments) assist in blood clotting.
	3.	Muscular Tissue Contracts (p. 65, Fig. 3.6)
		a.	Muscular tissue is composed of cells called muscle fibers that contain filaments of actin and myosin. Three types of muscle exist.
		b.	Skeletal, or voluntary, muscle is striated and multinucleate.
		c.	Smooth muscle lacks striations, is involuntary, and occurs in the digestive system and internal organs. Its cells are tapered and uninucleate. 
		d.	Cardiac muscle is striated and found in the heart. Its cells are quadrangular with a single nucleus and connect to adjacent cells with intercalated disks.
	4.	Nervous Tissue Conducts Impulses (p. 66, Fig. 3.7)
		a.	Nerve cells, or neurons, contain dendrites, a cell body, and a single axon. 
		b.	Neuroglial cells are helper cells that support and protect neurons.
3.2 Skin As an Organ (p. 66)
	1.	Skin Has Layers (p. 66, Fig. 3.8)
		a.	The epidermis is made up of stratified squamous epithelium that is produced at the base of the epidermis and that pushes older, keratinized cells outward. Melanocytes within this layer produce melanin. 
		b.	The dermis is fibrous connective tissue with collagen and elastic fibers. Hair follicles in the dermis produce hair shafts. Each follicle has a sebaceous gland that produces lubricating sebum. 
		c.	The subcutaneous layer is made up of loose connective tissue, including adipose tissue.
	2.	Skin Cancer on the Increase (p. 67)
		a.	Fair-skinned people who sunburn easily are especially at risk of developing malignant melanoma, a deadly form of skin cancer.
		b.	Basal cell carcinoma and squamous cell carcinoma are on the increase in anyone who is exposed to the sun's ultraviolet rays.
			ECOLOGY FOCUS: Ozone Depletion Threatens the Biosphere (p. 68, Fig. 3A)
			i.	Stratospheric ozone has declined for several years now at increasing rates.
			ii.	The decline in ozone is caused by chlorofluorocarbons (CFCs).
			iii.	CFC molecules strip oxygen atoms from thousands of molecules of ozone.
3.3 Body Cavities and Their Membranes (p. 69, Fig. 3.9)
	1.	During embryonic development, a large central cavity, called a coelom, develops into the thoracic and abdominal cavities. The dorsal cavity contains the cranial cavity and vertebral column.
	2.	Membranes Line and Cover (p. 69)
		a.	Body membranes are made of epithelial connective tissues that line cavities and the internal spaces of organs opening to the outside.
		b.	Mucous membranes line the digestive, urinary, respiratory, and reproductive systems and are characterized by goblet cells.
		c.	Serous membranes line body cavities and secrete a lubricating serous fluid. Examples include the pleural membranes and the peritoneum.
		d.	Synovial membranes line joint cavities and secrete a lubricating synovial fluid.
		e.	Meninges are membranes within the dorsal cavity and are composed only of connective tissue. They protect the brain and spinal cord.
3.4 Studying Organ Systems (p. 70)
	1.	Maintenance of the Body (p. 70)
		The varying activities of five systems (circulatory, respiratory, digestive, lymphatic, and urinary) contribute to the homeostasis of tissue fluid.
	2.	Integumentary System (p. 70) 
		The skin is called the integumentary system because it is comprised of a number of organs. 
	3.	Support and Movement (p. 70)
		The skeletal and muscular systems support the body and allow movement.
	4.	Integration and Coordination (p. 70)
		The nervous system and endocrine system regulate and coordinate the activities of the various body systems.
	5.	Reproduction and Development (p. 70)The reproductive systems help to propagate the human species.
3.5 Homeostasis (p. 72, Fig. 3.10)
	1.	Homeostasis refers to the maintenance of constant internal body conditions. 
	2.	Most body systems contribute to homeostasis of the body.
	3.	How the Nervous and Endocrine Systems Coordinate (p. 73, Fig. 3.11)
		a.	The endocrine system helps maintain homeostasis through hormone production.
		b.	The nervous system exerts control over the body, including the endocrine system, by nervous impulse.
		c.	Many homeostatic mechanisms in the body operate by negative feedback. 
	4.	How Body Temperature Is Regulated (p. 74, Fig. 3.12)
		a.	The hypothalamus regulates body temperature.
		b.	When body temperature drops below normal, impulses are sent to restrict the flow of blood to the extremities. Shivering causes muscle contractions to warm the body.
		c.	When body temperatures rise above normal, sweating is induced, and more blood flows through superficial vessels.