Ch. 21 Animal Physiology

Organization of animal bodies

cell—> tissue—> organ—> organ system

The four tissues

1.) Connective

2.) Epithelial

3.) Muscle

4.) Nervous

Connective Tissue

Composed of cells interspersed throughout a matrix; provides structure and support, anchors cells, and regulates communication between cells.

Epithelial Tissue

Composed of cells that cover and line most surfaces of animal bodies; forms the skin and the lining of the lungs, digestive tract, and blood vessels.

Muscle Tissue

Composed of cells that can contract; generates movement, pumps fluid, and moves substances.

Nervous Tissue

Composed of specialized cells that send and receive electrical signals; stores and transmits information.

Connective Tissue

The most abundant type of tissue in most animals; a collection of cells embedded within an extracellular matrix, usually containing collagen, that holds the cells together and gives shape, structure, and support to other body tissues.

Epithelial Tissue

A very thin, sheetlike tissue that covers most of the exterior and interior surfaces of an animal’s body; acts as a barrier between the inside and outside of an organism.

Skeletal Muscle

Generates most of the movement seen in animals; under both conscious and unconscious control.

Cardiac Muscle

Muscle in the heart that pumps blood through the body; under unconscious control.

Smooth Muscle

Generates slow, rhythmic contractions that can gradually move food or other substances through the body or alter blood pressure; under unconscious control.

Nervous Tissue

Specialized to store and transmit information; consists of neurons, which can receive and transmit a signal, and glial cells, which assist and provide nutrients for neurons.

Digestive System

Disassembles and absorbs food so the body can acquire the nutrients it needs to function.

Circulatory System

Transports nutrients and respiratory gases to the tissues and eliminates wastes from the tissues.

Respiratory System

Provides a site for gas exchange between the external environment and an organism's circulatory system.

Nervous System

Acts as the control center of the body and interprets, stores, and transmits information, using electrical impulses and chemical signals.

Endocrine System

Regulates body activities by releasing hormones that travel through vessels in the circulatory system to reach target cells.

Reproductive System (Male)

Produces sperm and delivers them to the female reproductive system, where fertilization may occur.

Reproductive System (Female)

Produces eggs and provides an environment that can nurture a developing embryo and fetus, if fertilization occurs.

Immune and Lymphatic System

Attacks pathogens that threaten the body and plays a supporting role in circulation by recycling fluid that leaks from the circulatory system.

Urinary/Excretory System

Purifies the blood by filtering out wastes and transports wastes out of the body.

Integumentary System

Provides protection by forming a barrier between the inside and outside of an organism and can aid in the secretion and transport of molecules.

Skeletal System

Supports and protects the body and internal organs, manufactures blood cells, and provides a surface for muscle attachment, creating a foundation for movement.

Muscular System

Generates force through contraction, which enables movement of the body and of blood, food, and other substances throughout the body.

Homeostasis Imbalance

Failure to maintain a consistent internal physical and chemical environment.

Homeostasis

Animals maintain this; they keep a variety of internal physiological variables within a relatively constant range.

Negative Feedback

Sensors detect a change in the internal environment and trigger effectors to oppose the change.

Positive Feedback

Oppose homeostasis by increasing change in the same direction.

Endotherms

Animals that generate body heat internally.

Ectotherms

Animals that get their heat primarily from the environment.

Thermoregulation

Control of body temperature.

Osmoregulation

The regulation of water balance by controlling concentrations of dissolved solutes that influence osmosis.

Osmoregulators

Maintain fluids and solute concentrations within narrow ranges by using osmoregulatory structures.

Kidneys

Regulate water balance in body fluids, while producing urine.

Nephron

The fundamental unit of the human kidney.

Filtration

Blood pressure forces water and small molecules out of the capillaries in the glomerulus. The filtrate accumulates in Bowman's capsule.

Reabsorption

As the filtrate moves from Bowman's capsule through the long tubule of the nephron, most of the water and dissolved solutes are reabsorbed.

Excretion

The collecting duct merges with the collecting ducts from other nephrons and empties into the urinary bladder.