Biology, 9th ed, Sylvia Mader Chapter 33 Chapter 33 Animal Organization & Homeostasis Animal Organization & Homeostasis

Types of Epithelial Tissues in the Vertebrates

Outline Tissue Types Organs Organ Systems Homeostasis Epithelial Connective Muscular Nervous Organs Organ Systems Homeostasis Negative Feedback Positive Feedback

Levels of Organization Tissue - Group of similar cells performing a similar function Organ - Group of tissues performing a specialized function Organ System - Collection of several organs functioning together Organism - A collection of organ systems

Four major vertebrate tissue types Types of Tissues Four major vertebrate tissue types Epithelial Connective Muscular Nervous

Types of Epithelial Tissues in the Vertebrates

Three types of epithelial tissues: Forms a continuous layer over body surfaces Lines inner cavities Forms glands Exocrine glands - Secrete products into ducts or cavities Endocrine glands - Secrete products directly into the bloodstream Covers abdominal organs Three types of epithelial tissues: Squamous – Flat cells Cuboidal - Cube-shaped cells Columnar – Pillar-shaped cells

Connective tissues consist of: Fibroblast cells A matrix containing collagen and elastic fibers Loose fibrous connective tissue Allows organs to expand Dense fibrous connective tissue Strong connective tissue Tendons Ligaments

Diagram of Fibrous Connective Tissue

Connective Tissue Adipose Tissue Cartilage Insulates the body and provides padding Cartilage Classified according to type of collagen and elastic fibers found in the matrix Cartilage cells (chondrocytes), lie in small chambers (lacunae) in the matrix

Connective Tissue Examples

Connective Tissue Compact Bone Matrix is inorganic salts deposited around protein fibers Bone cells (osteocytes) are located in lacunae Lacunae arranged in concentric circles within osteons around tiny tubes (central canals)

Transports nutrients and oxygen to cells Blood Actually a connective tissue in which cells are embedded in a liquid matrix (plasma) Red blood cells - erythrocytes White blood cells - leukocytes Transports nutrients and oxygen to cells Removes carbon dioxide and other wastes

Blood, a Liquid Tissue

Contractile cells containing actin and myosin filaments Muscular Tissue Contractile cells containing actin and myosin filaments Cells are called muscle fibers Skeletal Muscle Voluntary - Long, striated fibers Smooth Muscle Involuntary - No striations Cardiac Muscle Striated, but mostly involuntary Bound by intercalated disks

Muscular Tissue

Nervous Tissue Nervous Tissue: neurons-specialized for the transmission of nerve impulses. Made up of dendrites, a cell body, and an axon Dendrites (like antennae) receive signals from sensory receptors. Cell body contains the nucleus and organelles. Axons conduct a nerve impulse away from the cell body. Myelin-white matter Unmyelinated fibers, cell bodies, and dendrites-grey matter A nerve is a bundle of axons bound together by connective tissue. Neuroglia support and nourish neurons

Neurons

Nervous Tissue Nervous system regulates body response to stimuli and has three main functions Sensory input Sensory (afferent) carrying impulses from the body to the CNS Transmit info to the spinal cord Data integration Spinal cord and brain integrate Decision is made regarding appropriate response Motor output-(efferent) Response is transmitted to effector (gland or muscle) Effector initiates actual response

Neurons are not in direct contact with one Neurons are not in direct contact with one another instead, a synapse separates them. Neurons communicate with other neurons by releasing chemical signals called neurotransmitters across a tiny gap.

Types of Neuroglial Cells Astrocytes CNS mop up excess ions, etc induce synapse formation stimulate formation of tight junction between cells that make up the walls of capillaries. (Blood-brain barrier) Schwann Cells peripheral nervous system myelinating cell Oligodendrocytes CNS myelinating cell Ependyma CNS ciliated line central canal of spinal cord line ventricles of brain Regulate the production of CSF Microglia CNS phagocytic cell

Types of Neuroglial Cells

Integumentary system-Skin and derivatives Biology, 9th ed, Sylvia Mader Integumentary system-Skin and derivatives Chapter 33 Animal Organization & Homeostasis Functions of skin: Largest organ in the body Covers and protects underlying body regions Regulate body temperature Contains sensory receptor- touch, pressure Vital in maintaining homeostasis Epidermis - Outer, thinner region Stratified squamous epithelium-lacks blood vessels As new cells enlarge, older cells are pushed outward, become keratinized, and are sloughed off Melanocytes produce melanin (pigment) Nails grow from specialized epidermal cells 15% of the body’s weight.

Dermis - Deeper and thicker than epidermis Regions of Skin Dermis - Deeper and thicker than epidermis Fibrous connective tissue containing elastic and collagen fibers Contains: Hair follicles Sebaceous glands-secrete sebum Receptors-specialized nerve endings Nerve fibers Blood vessels Subcutaneous Layer - Loose connective tissue and adipose tissue located below dermis

Human Skin Anatomy

Body Cavities Organ Systems Dorsal cavity / posterior (toward the back) Contains the cranial cavity and the vertebral cavity The brain is in the cranial cavity, and The spinal cord is in the vertebral cavity Ventral cavity/ anterior (toward the front) is divided by the diaphragm into The thoracic cavity (includes heart and lungs) and The abdominal cavity (most other internal organs) The pelvic cavity

Mammalian Body Cavities

The organ systems of the human body contribute to Homeostasis The digestive system Takes in and digests food Provides nutrient molecules that re-place used nutrients The respiratory system Adds oxygen to the blood Removes carbon dioxide The organ systems of the human body contribute to homeostasis

Homeostasis The liver and the kidneys The kidneys Store excess glucose as glycogen-regulates blood glucose Later, glycogen is broken down to replace the glucose used The hormone insulin regulates blood glucose levels The kidneys Under hormonal control as they excrete wastes and salts Regulate pH

Negative Feedback Homeostatic Control Partially controlled by hormones Ultimately controlled by the nervous system Negative Feedback is the primary homeostatic mechanism that keeps a variable close to a set point Sensor detects change in the internal environment; Regulatory Center activates an effector Effector reverses the changes

Regulation of Body Temperature

Positive Feedback During positive feedback, an event increases the likelihood of another event-a change occurs in one direction Childbirth Process Positive Feedback Does not result in equilibrium Does not occur as often as negative feedback

Review Tissue Types Organs Organ Systems Homeostasis Epithelial Connective Muscular Nervous Organs Organ Systems Homeostasis Negative Feedback Positive Feedback

Biology, 9th ed, Sylvia Mader Chapter 33 Ending Slide Chapter 33 Animal Organization & Homeostasis Animal Organization & Homeostasis