Anatomy and Physiology PDF

ANAPHY REV. PRELIM Anatomy is the study of the structure and shape of PATHOPHYSIOLOGY the body and its parts and their relationships to one is the study of the effects of the disease. another....

ANAPHY REV. PRELIM Anatomy is the study of the structure and shape of PATHOPHYSIOLOGY the body and its parts and their relationships to one is the study of the effects of the disease. another. Relationship: Branches of Anatomy Anatomy and physiology are closely linked, as Gross Anatomy the structure of the body determines its - Studying large, easily observable structures. functions. Each part of the body has a specific role in the overall operation of the body. For example, Microscopic Anatomy/ Microanatomy the structure of the lungs allows them to exchange - study of body structures that are too small to be gases and provide oxygen to the body. This intimate seen with the naked eye. relationship between anatomy and physiology is important to understand for meaningful learning. - the study of anatomic structures using microscope. Levels of Structural Organization. divided into two (2) branches: 1. Chemical Level - is the very basic level, includes the atoms and molecules. Cytology – the study of origin, structure, function and pathology of cells.  Atom smallest units of matter that participate in chemical reactions and, Histology – study of tissues  Molecule, 2 or more joined together. Systemic Anatomy 2. Cellular Level - molecules combine to form, - an approach to anatomic study organized by an cell, among the many cells in your body are muscle organ system. cells, nerve cells and epithelial cells. Regional Anatomy  Cell - basic and structural units of organism. - an approach to anatomic studies based on regions, 3. Tissue Level - Tissue is a group of cells that emphasizing the relationships of various systemic work together to perform a particular function. structures. Types of tissue; Epithelial tissue - covers body surface, lines Physiology is the study of how the body and its hollow organs. parts work or function. Connective tissue - connects, supports and Branches of Anatomy protects body organs. CELL PHYSIOLOGY Muscular tissue - contracts to make body parts move It is the study of the function of the cell. Nervous tissue - carries information from one SPECIAL PHYSIOLOGY place to another through nerve impulses. this is the study of the function of specific organs. 4. Organ Level - different type of tissue are SYSTEMIC PHYSIOLOGY joined together. It includes all the aspects of the functions of the - organs are structures that are composed of 2 or body systems. more different types of tissues; they have specific functions and usually have recognizable shapes. (e.g. stomach, heart, Liver, lungs) 5. System Level - consists of related organ with Endocrine System common action (e.g. digestive system, respiratory Components: hormone producing glands and system). hormone producing cells in several other organs 6. Organismal Level - an organism, any living Functions: regulates body activities by releasing individual. All parts of the human body hormones (chemical messengers transported in functioning together. blood form from endocrine glands or tissue to target organs) Cardiovascular System Components: Blood, heart and blood vessels Functions: Heart pumps blood through blood vessels: blood carries oxygen and nutrients to calls and carbon dioxide and wastes away from cells and help regulate acid-base balance, temperature, water content of body fluids; blood components helps defend against disease and repair damaged The 11 major system of the human body blood vessels. Integumentary system. Lymphatic system and Immunity Components: skin and assoclated structures such Components: Lymphatic fluid and vessels; as hair, fingernails and toenails, sweat glands and spleen, thymus, lymph nodes and tonsils. oil glands. Functions: Returns proteins and fluid to blood; Function: protects body, helps regulate body carries lipids from gatrointestinal tract to blood, temperature, helps make vitamin D, detects rentains sites of maturation and proliferation of sensation such as pain, cold, warmth and touch B cells and T cells that protect against disease Skeletal system. causing microbes Components: bones and joints and associated Respiratory system cartilage Components: Lungs, pharynx, larynx, trachea Function; supports and protects body, provide and bronchial tubes surface area for muscle attachments, aids body Functions: Transfers oxygen from inhaled air to movement. blood and carbon dioxide from blood to exhaled Muscular system. air; helps regulate acid base balance of body fluids. Components: skeletal muscle tissue Digestive system Functions: participates in body movements such as walking and produce heat Components: Organs of gastroinstinal tract, along tube that includes the mouth, phar inx Nervous system (throat) espohagus, stomach, small and large Components: brain and spinal cord, nerve and instestines and anus. Accessory organs that assists special sense organs. in digestion such as salivary glands, liver, gallbladder and pancreas. Functions: detects changes in body’s internal and external environments, interprets changes. Functions: Achieves physical and chemical Maintaining Life breakdown of food, absorbs nutrients and NECESSARY LIFE FUNCTIONS eliminates solid wastes.  Maintaining boundaries Urinary System  Movement Components: Kidneys, ureters, urinary bladder  Responsiveness and urethra  Digestion Functions: Produces, stores and eliminates urine,  Metabolism eliminates waste and regulates volume and  Excretion chemical composition of blood; helps maintain the  Reproduction acid base balance of body fluids  Growth Male Reproductive System & Female SURVIVAL NEEDS Reproductive System  nutrients Overall function of the reproductive system is  Oxygen production of offspring.  Water and appropriate terperature and atmospheric pressure Testes produce sperm and male sex hormone; ducts and glands aid in delivery of viable sperm to HOMEOSTASIS the female reproductive tract. - Describes the body’s ability to maintain relatively Ovaries produce eggs and female sex hormones; stable internal conditions even though the outside remaining structures serve as sites for fertilization world is continuously changing. and development of the fetus. Mammary glands of female breasts produce milk to nourish the Homeo = the same ; newborn. stasis = standing still Necessary Life Functions HOMEOSTATIC CONTROL MECHANISM The human body performs necessary life functions Receptor; it is some type of sensor that monitors to maintain well-being, including maintaining and responds to changes in the environment. It boundaries, movement, responding to responds to such changes called STIMULI, environmental changes, obtaining and digesting nutrients, carrying out metabolism, eliminating Control center: determine the level et which a waste, reproducing, and growing. Organ systems in variabie is to be maintained, analyzes the the body work together to support these functions. information it receives and then determines the Detailed descriptions of the organ systems are appropriate response or course of action. provided on pages 26-29 and in Figure 1.2 for Effector: which provides the means for the control reference. center’s response (output) to the stimulas. Maintaining Boundaries Information flows from the control senter to the effector along the efferent pathway. The result of Living organisms must maintain boundaries, with the response then feedback to influence the stimulus cells surrounded by membranes to separate internal either POSITIVE FEEDBACK or NEGATIVE and external environments. The integumentary FEEDBACK. system, or skin, protects the body from dehydration, pathogens, and external hazards NEGATIVE FEEDBACK MECHANISM - The net effect of the response to the stimulus is to shut off the original stimulus or reduce its intensity POSITIVE FEEDBACK MECHANISM condenses to "The ears are lateral to the nose" in anatomical terminology. Learning and using - It tend to increase the original disturbance and anatomical terminology saves words and is much to push the variable farther from its original clearer. Several terms are group in pairs that value have opposite meanings. ANATOMICAL POSITION Planes and Section The anatomical position is the standard position Planes Imaginary flat surfaces that passes used to describe body parts and position. through body parts DIRECTIONAL TERMS Directional terms in anatomy help describe the location of body structures in relation to each other. For example, "The ears are located on each side of the head, to the right and left of the nose" Body Cavities Body cavities are spaces within the body that help protect, separate and support internal organs. Abdominopelvic Regions and Quadrants 2 horizontal and 2 vertical lines, aligned like tic Anatomy of the Cell tac toe grid, partition this cavity into 9 All cells have three main regions or parts: Abdominopelvic regions  nucleus 9 Abdominopelvic regions  cytoplasm 1. Right  Plasma/Cell membrane hypochondriac Nucleus 2. Epigastric 3. Left  “headquarters,” or the control center, and the hypochondriac. gene-containing 4. Right lumbar  The genetic material, or deoxyribonucleic 5. Umbilical acid (DNA), is much like a blueprint that 6. LefT lumbar contains all the instructions needed for 7. Right inguinal (iliac) building the whole body. it is most often oval or 8. Hypogastric (pubic) spherical, the shape of the nucleus usually 9. Left Inguinal (iliac) conforms to the shape of the cell.  The nucleus has three recognizable regions or structures: the nuclear envelope, nucleoli, and 2nd method is much simpler and divides the chromatin. abdominopelvic cavity into quadrants Nuclear Envelope  The nucleus is bounded by a double membrane barrier called the nuclear envelope, or nuclear membrane  the two layers of the nuclear envelope fuse, and nuclear pores penetrate the fused regions.  It allows some substance to pass through CELLS L2  nuclear membrane encloses a jellylike fluid called nucleoplasm in which other nuclear Cells; Overview of the Cellular Basis of Life elements are suspended. Since the late 1800s, cell research has been Nucleoli exceptionally fruitful and provided us with four concepts collectively known as the cell theory  The nucleus contains one or more small, dark staining, essentially round bodies called 1. A cell is the basic structural and functional nucleoli unit of living organisms.  Nucleoli are sites where cell structures called 2. The activity of an organism depends on the ribosomes are assembled. collective activities of its cells.  Most ribosomes eventually migrate into the 3. According to the principle of complementarity, cytoplasm where they serve as the actual sites the biochemical activities of cells are dictated by of protein synthesis. their shape or form and by the relative number Chromatin of their specific subcellular structures  When a cell is not dividing, its DNA is 4. Continuity of life has a cellular basis. combined with protein and forms a loose network of bumpy threads called chromatin that is scattered throughout the nucleus  When a cell is dividing to form two daughter Cytoplasm cells, the chromatin threads coil and condense to  Cytoplasm is the cellular material outside the form dense, rodlike bodies called chromosomes nucleus and inside the plasma membrane much the way a stretched spring becomes  It is the site of most cellular activities the shorter and thicker when allowed to relax cytoplasm as the “factory area” of the cell The Plasma Membrane it has three major elements;  The flexible plasma membrane is a fragile, 1. Cytosol transparent barrier that contains the cell 2. Organelles contents and separates them from the 3. Inclusions surrounding environment. Cytoplasmic Organelles The Fluid Mosaic Model  Literally “little organs”, are specialized  The structure of the plasma membrane consists cellular compartments each performing its own of two lipid (fat) layers arranged "tail to tail" job to maintain the life of the cell. in which protein molecules float.  Many organelles are bounded by a membrane  Most of the lipid portion phospholipids but a like the plasma membrane. substantial amount of cholesterol is found in  These membrane boundaries allow organelles plasma membranes too. to maintain an internal environment quite Hydrophilic Head different from that of the surrounding cytosol. Hydrophobic Tail Mitochondria The polar “heads’ of the lollipop-shaped  are usually depicted as tiny, and sausage- phospholipid molecules shaped organelles are hydrophilic (“water  The mitochondrial wall consists of a double loving”) and are attracted membrane, equal to two plasma membranes, to water, the main component of both the placed side by side, intracellular and extracellular fluids and so they  The outer membrane is smooth and featureless, lie on both the inner and outer surfaces of the but the inner membrane has shelflike membrane. protrusions called cristae. The nonpolar "tails," being hydrophobic (“water Mitochondria hating”) avoid water and line up in the center (interior) of the membrane.  Enzymes dissolved in the fluid within the mitochondria, as well as enzymes that form part The hydrophobic makeup of the membrane interior of the cristae membranes, carry out the reactions makes the plasma membrane relatively in which oxygen is used to break down foods. impermeable to most water-soluble molectiles. The  As the foods are broken down, energy is cholesterol helps keep the membrane fluid. The released. Much of this energy escapes as heat proteins scattered in the lipid bilayer are responsible but some is captured and used for ATP for most of the specialized functions of this molecules. membrane. Some proteins are enzymes.  ATP provides the energy for all cellular work, Many of the proteins producing from the cell and every living cell requires a constant supply exterior are receptors for hormones or other of ATP for its many activities chemical messengers or are binding sites for  The mitochondria supply most of this ATP, they anchoring the cell. are the “powerhouses” of the cell. Ribosomes Golgi Apparatus  The tiny, bilobed, dark bodies made of proteins  appears as a stack of flattened and one variety of RNA called ribosomal RNA.  membranous sacs, associated with swarms of  Ribosomes are the actual sites of protein tiny vesicles synthesis in the cell. Some ribosomes float free  generally found close to the rucleus and is the in the cytoplasm, where they manufacture principal “traffic director” for cellular proteins, proteins that function in the cytoplasm.  Its major function is to modify and package  Others attach to membranes, and the whole proteins (sent to it by the rough ER via ribosome-membrane combination is called the transport vesicles) in specific ways, depending rough endoplasmic reticulum on their final destination. Endoplasmic Reticulum Lysosomes  “network within the cytoplasm” (ER) is a  appear in different sizes, are membranous system of fluid-filled cisterns (tubules, or ‘bags” containing powerful digestive enzymes canals) that coil and twist through the  Lysosomal enzymes are capable of digesting cytoplasm. worn-out or non-usable cell structures and  It accounts for about half of a cell’s most foreign substances that enter the cell membranes.  Lysosomes function as the cell’s demolition  It serves as a mini-circulatory system for the sites. cell because it provides a network of channels for carrying substances (primarily proteins Peroxisomes from one part of the cell to another.)  are membranous sacs containing powerful There are 2 forms of ER: Smooth and Rough ER oxidase enzymes that use molecular oxygen (02) to detoxify several harmful or poisonous Rough ER substances, including alcohol.  The most important function is to "disarm"  It is studded with ribosomes dangerous free radicals  essentially all the building materials of cellular  Free radicals are highly reactive chemicals with membranes are formed either in it or on it, you unpaired electrons that can scramble the can think of the rough ER as the cell's structure of proteins and nucleic acids. membrane factory  Free radicals are normal byproducts of cellular  The proteins made on its ribosomes migrate metabolism, but if ellowed to accumulate, they into the tubules of the rough ER, where they can have devastating effects on cells. fold into their functional three-dimensional shapes and then are dispatched to other areas of Cytoskeleton the cell in transport vesicles.  An elaborate network of protein structures- Smooth ER extends throughout the cytoplasm  communicates with the rough variety  acts as a cell's "bones and muscles" by furnishing an internal frame work that  it plays no role in protein synthesis. determines cell shape, supports other  it functions in lipid metabolism (cholesterol and organelles and provides the machinery for fat synthesis and breakdown), and intracellular transport and various types of detoxification of drugs and pesticides. cellular movements  is made up of microtubules, intermediate filaments, and microfilamert Centrioles plasma membrane in basically two ways: Passively and Actively.  lie close to the nucleus. It is rod-shaped bodies  In passive processes, substances are that lie at right angles to each other; internally transported across the membrane without any they are made up of a pinwheel array of fine energy input from the cell. microtubules.  In active processes, the cell provides the  Centrioles are best known for their role in metabolic energy (ATP) that drives the generating microtubules, and during cell transport process. division, the centrioles direct the formation of the mitotic spindle Passive Processes: Cilia and Flagella Diffusion  Cilia are whiplike cellular extensions that move  Diffusion is the process by which molecules substances along the cell surface. There are (and ions) move away from a region where usually many of them projecting from the they are more concentrated (ore numerous) exposed cell surface. to a region where they are less concentrated  Flagella projections formed by the centrioles (fewer of them). are substantially longer. The only example of a  as the molecules move about randomly at flagellated cell in the human body is the sperm, high speeds, they collide and change which has a single propulsive flagellum called direction with each collision. The overal its tail. effect of this erratic movement is that molecules move. down their concentration Cell Physiology graficient, and the greater the difference in  a solution is a homogeneous mixture of two or concentration between the two areas, the more components faster diffusion occurs,  substance present in the largest amount-in a  Diffusion. Particles in solution move solution is called the solvent (or dissolving continuously and collide constantly with medium). Water is the body's chief solvent. other particles. As a result, particles tend to  Components or substances present in smaller move away from areas where they are most amounts are called solutes. highly concentrated and to become evenly  intracellular fluid (collectively, the distributed, as illustrated by the diffusion of nucleoplasm and the cytosol) is a solution dye molecules in a beaker of water. containing small mounts of gases (oxygen and The hydrophobic core of the plasma membrane is a carbon dioxide), nutrients, and salts, dissolved physical barrier to diffusion, However, molecules in water. will diffuse through the plasma membrane if any of  interstitial fluid, the fluid that continuously the following are true: bathes the exterior of our cells. It contains thousands of ingredients, including nutrients 1. The molecules are small enough to pass through (amino acids, sugars, fatty acids, vitamins), the membrane's pores (channels formed by regulatory substances such as hormones and membrane proteins). neurotrensmitters, salts, and waste products, 2. The molecules are lipid-soluble,  The plasma membrane is a selectively permeable barrier. 3. The molecules are assisted by a membrane  Selective permeability means that a barrier carrier. allows some substances to pass through it while excluding others. Thus, it allows nutrients to enter the cell but keeps many undesirable substances out substances move through the CELL DIVISION TISSUE L3 BODY TISSUE Tissue  a group of cells that are similar in structure and function.  similar in structure and function are called tissues. The four primary tissue types: 1. Epithelium Connective Tissue 2. connective tissue 3. nervous tissue  connects body parts 4. Muscle tissue  It is found everywhere in the body. it is the most abundant and widely distributed of the Epithelial Tissue tissue types.  Connective tissues perform many functions, but  Epithelial tissue, or epithelium, they are primarily involved in protecting,  is the lining, covering, and glandular tissue of supporting, and binding together other body the body. tissues  Glandular epithelium forms various glands in the body. Types of Connective Tissue  Covering and lining epithelium covers all  Bone, sometimes called osseous tissue, is free bodies, surfaces and contains versatile composed of osteocytes (bone cells) sitting in cells. cavities called lacunas Epithelial functions incluide:  bone has an exceptional ability to protect and support other body organs (for example, the 1. Protection skull protects the brain 2. Absorption  Cartilage is less hard and more flexible than bone, its major cell type is chondrocytes 3. Filtration (cartilage cells). It is found in only a few places 4. secretion in the body.  Most widespread is hyaline cartilage which Classification Of Epithelium has abundant collager fibers hidden by a rubbery The classifications by cell arrangement (layers): matrix with a glassy, blue-white appearance  It forms the supporting structures of the larynx, 1. simple epithelium (one layer of dells) or voice box, taches the ribs to the breastbone, 2. stratified epithelium (more than one cell layer). and covers the ends of many bones, where they form joints The second describes the shape of its cells:  Although hyaline cartilage is the most abundant 1. There are squamous cells, flattened like fish type of cartilage in the body, there are others: scales  Highly compressible fibrocartilage forms the 2. cuboidal cells, which are cube-shaped like cushion like disks between the vertebrae of dice, the spinal column 3. columnar cells, shaped like columns.  Elastic cartilage is found in structures with elasticity, For example, it supports the external ear Types of Connective Tissue These muscles, which can be controlled voluntarily form the flesh of the body  Dense Connective Tissue, also called dense fibrous tissue, collagen fibers are the main The cells of skeletal muscle are long, cylindrical, matrix element multinucleate, and they have obvious striations.  forms strong, ropelike structures such as Because skeletal muscl cells are elongated to tendons and ligaments. Tendons attach provide an long axis for contraction, they are of skeletal muscle: to bones; ligaments connect en called muscle fiber. bores to bones at joints. Ligaments are stretcher and contain more elastic filers than do tendons.  Cardiac Muscle it contracts, the heart acts as a  Loose Connective Tissue softer and have pump and propels blood through the blood more cells and fewer fibers than any other vessels. connective tiSsue type except blood.  cardiac muscle has stilations relatively short  Areolar Tissue, the most Widely distributed  cardiac cells are uninucleate connective tissue variety in the body, is a soft,  Cardiac muscle is under involuntary control pliable "cobwebby" tissue that body organs it  Smooth (visceral) muscle is so called because wraps. no striations are visible. The individual cells  It functions as a universal packing tissue and have a single nucleus. connective tissue "glue" because it helps to  found in the walls of hollow organs such as the hold the internal organs together and in their stomach, uterus, and blood vessels. proper position.  Smooth muscle is under involuntary control  Adipose Tissue, is commonly called fat.  Adipose tissue forms the subcutaneous tissue Nervous Tissue beneath the skin, where it insulates the body  Nervous cell are called neurons, All neurons and protects it from bumps and extremes of receive and conduct electrochemical impulses both heat and cold. from one part of the body to another; thus,  Adipose tissue also protects some organs irritability and conductivity are their two major individually-the kidney: are surrounded by a functional characteristics. capsule of fat, and adipose tissue cushions the  Their cytoplasm is drawn out into long eyeballs in their sockets. processes, as much a 3 feet or more in the leg,  There are also fat "depots" in the body, such as which allows a single neuron to conduct an the hips and breasts impulse over long distances in the body.  Blood, or vascular tissue, is considered a  A special group of supporting cells called connective tissue. because it consists of blood neuroglia insulate, support, and protect the cells surrounded by a nonliving, fluid matrix delicate neurons in the structures of the nervous called blood plasma. system - the brain, spinal cord, and nerves.  Blood is the transport vehicle for the cardiovascular system, carrying nutrients, wastes, respiratory gases, and many other substances throughout the body. Types of Muscle Tissue  Skeletal muscle tissue is packaged by connective tissue sheets into organs called skeletal muscles, which are attached to the skeleton. Pulmonary Ventilation  Costal breathing - Breathing primarily using the intercostal muscles to expand and contract  In pulmonary ventilation, air flows between the the rib cage. atmosphere and the alveoli of the lungs Also called: Chest breathing because of alternating pressure differences  Diaphragmatic breathing - breathing created by contraction and relaxation of primarily using the diaphragm, a dome-shaped respiratory muscles muscle below the lungs.  Inhalation  Exhalation Also called: Belly breathing or deep breathing LUNG VOL & CAPACITIES Other Factors Affecting Pulmonary Ventilation Control Respiration.  Surface tension - inwardly directed force in the Exercise and the Respiratory System. alveoli which must be overcome to expand the lungs during each inspiration The respiratory and cardiovascular systems make  Elastic recoil - Decreases the size of the alveoli adiustments in response to both the intensit and during expiration duration of exercise  Compliance - Ease with which the lungs and  As cardiac output rises, the jood flow to the thoracic wall can be expanded. lungs, termed pulmonary perfusion, increases as well  The O, diffusing Capacity may increase Breathing Patterns and Respiratory threefold during maximal exercise so there is a Movements greater surface area available for O, diffusion  Eupnea - Normal, easy, and quiet breathing. Aging and the Respiratory System Also called: Quiet respiration  Aging results in decreased:  Apnea - Temporary cessation of breathing.  Vital capacity Types: Obstructive apnea: Caused by blockage of  Blood O, level the airway.  Alveolar macrophage activity  Ciliary action of respiratory epithelia Central apnea: Caused by a failure of the brain to signal the muscles to breathe. Consequently, elderly people are more susceptible  Dyspnea - Difficulty or labored breathing. to pneumonia, bronchitis, emphysema, and other Also called: Shortness of breath issues  Tachvpnea - Rapid breathing. Breathing and Respiratorion Surface Anatomy of the Nose  Respiration is the exchange of gases between the atmosphere, blood, and cells 1. Root  The combination of 3 processes is required 2. Apex for respiration to occur 1. Ventilation (breathing) 3. Bridge 2. External (pulmonary) respiration 4. External naris 3. Internal (tissue) respiration  The cardiovascular system assists the Pharynx respiratory system by transporting gases The pharynx Structures of the Respiratory System functions as a passageway for air and food, provides a resonating chamber for speech sounds, Structurally, the components and houses the tonsils, which participate in of the respiratory system are immunological reactions against foreign invaders divided into 2 parts: Regions of the pharynx 1. Upper respiratory system Nasopharynx - yellow 2. Lower respiratory Oropharynx - blue system Laryngopharynx - red Functionally, the components of the respiratory Larynx system are divided into 2 zones:  The larynx (voice 1. Conducting zone box) is a passageway 2. Respiratory zone that connects the pharynx and trachea  The larynx contains vocal folds, which produce Respiratory System Anatomy sound when they vibrate The upper respiratory system consists of the Bronchi nose, pharynx, and associated structures The lower respiratory system consists of the  At the superior border of the 5th thoracic vertebrae, the trachea branches into a right larynx, trachea, bronchi, and lungs primary bronchus o which enters the right lung Cartilaginous Framework of the Nose and a left primary bronchus which enters the left lung  The external portion of the nose is made of  Upon entering the lungs the primary bronchi cartilage and skin and is lined with mucous further divide to form smaller and smaller membrane diameter branches Internal Anatomy of the Nose  The terminal bronchioles are the end of the conducting zone  The bony framework of the nose is formed by the frontal, nasal, and maxillary bones BRANCHING OF BRONCHIAL TREE 1. Trachea 2. Main bronchi 3. Lobar bronchi 4. Segmental bronchi 5. Bronchioles  6. Terminal bronchioles Lungs  The lungs are paired organs in the thoracic cavity  The lungs are enclosed and protected by the pleural membrane Alveoli  When the conducting zone ends at the terminal bronchioles, the respiratory zone begins  The respiratory zone terminates at the alveoli, the "air sacs" found within the lungs. MICROSCOPIC AIRWAYS 1. RESPIRATORY 2. BRONCHIOLES 3. ALVEOLAR DUCTS 4. ALVEOLAR SACS 5. ALVEOLI Blood Supply to the Lungs  Blood enters the lungs via the pulmonary arteries (pulmonary circulation) and the bronchial arteries (systemic circulation)  Blood exits the lungs via the pulmonary veins and the bronchial veins  Ventilation-perfusion coupling  Vasoconstriction' in response to hypoxia diverts blood from poorly ventilated areas to well ventilated areas  The laryngeal skeleton has nine cartilages: the thyroid cartilage, cricoid cartilage, epiglottis, arytenoid cartilage, corniculate cartilage, and cuneiform cartilage.