Anatomy and Physiology Lecture Reviewer PDF

MCC 102A - ANATOMY AND PHYSIOLOGY REVIEWER LECTURE BRIONES | BSN 1 - N | 1st Semester | A.Y. 2024-2025 “Every move you make, and every new day that you live to see, ➔ Subcategories of Anatomy is the result of a collection of systems working together to ◆ Regional ana...

MCC 102A - ANATOMY AND PHYSIOLOGY REVIEWER LECTURE BRIONES | BSN 1 - N | 1st Semester | A.Y. 2024-2025 “Every move you make, and every new day that you live to see, ➔ Subcategories of Anatomy is the result of a collection of systems working together to ◆ Regional anatomy, systemic anatomy, function properly.” histology, cytology, and others. CHAPTER 2 PHYSIOLOGY: HOW PARTS FUNCTION INTRODUCTION TO THE HUMAN BODY FUNCTION FOLLOWS FORM ★ Anatomy ★ The function of a cell or an organ or a whole organism ○ All about what your body is. always reflects its form. ○ The scientific study of the body’s structures. ○ Ex. Blood flows in one direction through your ○ The study of the structure and relationships heart simply because its valves prevent it from between body parts and their interrelation. flowing backwards. ★ Physiology STRUCTURE AND FUNCTION ○ About what it does. Structure and function are closely related. ○ The study of the function of the human body. ○ Structure determines function Helps to understand the chemistry Changes in protein shape can change their function. and physics of the anatomical Human pelvis evolved to support abdominal and structures of the body and how they thoracic organs. work. Branching structures in living organisms increase ○ Categories of physiology surface area for molecular absorption and exchange. Neurophysiology PHOSPHORYLATION CAUSES CHANGES IN PROTEIN SHAPE Cardiovascular physiology Renal physiology This illustrates how form is related to function. ○ This connects health, medicine, and science in Adding a phosphate group to a protein changes the a way that studies how the human body shape of the protein. acquaints itself to physical activity, stress, and Common form of molecular regulation. diseases. BRANCHING STRUCTURES IN NATURE Ex. Study how our plasma membrane Branching maximizes surface area. transports nutrients, how the heart ○ E.g., Respiratory tubes increase surface area pumps blood into and out of the available for gas exchange. heart. Branching increases the speed of molecular transport. ★ Microscopic Anatomy EVOLUTION AND HUMAN VARIATION ○ Some structures are very small and can only Evolution be observed and analyzed with the assistance ○ Caused by random changes in gene of a microscope. expression that occur from generation to ○ Further classified into cytology (study of generation. human blood cells) and histology (study of Leads to variation among a species. tissues). ○ Becomes more frequent when the variation ★ Gross Anatomy (Macroscopic) offers an advantage. ○ Larger structures can readily be seen, ○ Variation is less likely to be seen in traits that manipulated, measured and weighed. affect the ability to reproduce. ○ Body parts or body structures that we can Anatomical variation occurs more frequently than easily observe using the naked eye. represented in most texts. ○ Gross anatomy is further classified into ○ Does not affect the function. regional anatomy, systemic anatomy, and ○ For example, the number of pulmonary veins surface anatomy. and lumbar vertebrae can vary from person to 2 GENERAL APPROACH OF ANATOMISTS TO STUDY THE BODY’S person. STRUCTURES PHYSIOLOGICAL VARIATION 1. Regional Anatomy More diverse and widespread than anatomical ○ A study of different structures in a particular variation. region. Affects function of an organ, organ system, or 2. Systemic Anatomy organism. ○ A study of human structures, the system by Physiological variation can be based on age or gender. system. 1  Necessitates diversity when health studies are It maintains body parameters within conducted. their normal range. FLOW Positive feedback occurs when the original stimulus is The movement of a substance or molecule. enhanced or increased. Dependent on a gradient. ○ Positive feedback Intensifies a change in the ○ Examples of gradients in nature. body’s physiological condition rather than Electrical, pressure, and reversing it. concentration gradients. CONTROL OF BLOOD SUGAR LEVELS ○ Flow is directly proportional to the size of a Negative feedback loop to control blood sugar levels: gradient. ○ A decrease in blood sugar levels leads to Resistance opposes or stops flow. release of glucagon from the pancreas. ○ Flow is inversely proportional to resistance. ○ Glucagon will then promote an increase in An increase in resistance will blood sugar levels. decrease flow. MAINTAINING BLOOD SUGAR LEVELS NEAR A SETPOINT ANATOMY OF FLOW Physiological processes help maintain blood sugar Gradients determine the direction of flow. levels near a setpoint. ○ Molecules flow down their concentration Eating increases blood sugar levels and insulin is gradients. secreted to lower them. ○ Pressure gradients move food, blood, and air Fasting decreases blood sugar levels and glucagon is through the body. secreted to increase them. HOMEOSTASIS POSITIVE FEEDBACK LOOP INVOLVED IN CHILDBIRTH ★ Everyone’s ultimate cause of death is the extreme and Childbirth involves a positive feedback loop. irreversible loss of homeostasis. Stretching of the cervix leads to release of oxytocin. ★ The real result of such an injury–the actual cause of Oxytocin strengthens contractions of the uterus. death–is the loss of homeostasis. Cervix stretches more as labor continues. ★ The dynamic stability of the body's internal HIERARCHY OF ORGANIZATION environment. STRUCTURAL ORGANIZATION OF THE HUMAN BODY ○ The body's parameters, or variables, are kept near a normal setpoint. pH, temperature, blood pressure, oxygen levels, nutrient levels, and electrolyte levels are constantly monitored. ○ Receptors monitor and send information to a control center. ○ Control center determines if changes are necessary. ○ Changes made by effectors keep parameters, 1. Chemical → atoms (smallest unit of an element that or variables, near setpoint. cannot be divided) ★ For example, body temperature homeostasis: ○ At its simplest level, the body is composed of ○ Sensors in the skin detect increase in atoms. The most common elements in living temperature. organisms are carbon, hydrogen, oxygen, ○ Control center receives sensory information to nitrogen, phosphorus, and sulfur. maintain body temperature setpoint (37°C). ○ Atoms → Molecule → Compounds ○ Control center communicates with the effector ○ Molecule (collection of atoms) to change body temperature (e.g., sweating). Most significant molecule in the body FEEDBACK LOOPS = DNA (Deoxyribonucleic acid) The method of control for many variables of the human 2. Cellular → cell (collection of molecules) body. ○ Smallest independently functioning unit of all Most variables are controlled through negative living things. feedback. ○ All life depends on the many chemical ○ The body's response is to decrease the original activities of cells. stimulus. ○ Some of the basic functions of a cell are: ○ Negative feedback is a mechanism that growth, metabolism, irritability and reverses a deviation from the setpoint. reproduction. 2 3. Tissue (collection of cells) → a group of many cells 5. Endocrine System that work together to perform all functions of life (like ○ Secretes the hormones that regulate many muscles and membranes) bodily processes ○ Tissue is made up of many similar cells that ○ Responsible for making and release of perform a specific function. The various tissues hormones of the body are divided into four groups. 6. Lymphatic System ○ Epithelial Tissue - Found in the outer layer of ○ Responsible for immunity of the body skin, lining of organs, blood and lymph vessels ○ Regulates fluid balance in the body and body cavities. ○ It houses immune cells that defend the body ○ Connective Tissue - Connects and supports from pathogens, and white blood cells that most parts of the body. They constitute most protect the body from infections and diseases of the skin, bone and tendons. 7. Integumentary System ○ Muscle Tissue - Produces movement through ○ Creates a barrier that protects the body from its ability to contract. This constitutes skeletal, pathogens and fluid loss smooth and cardiac muscles. ○ Responsible for covering and protection of the ○ Nerve Tissue - Found in the brain, spinal cord body against foreign invaders and nerves. It responds to various types of ○ Sensory reception stimuli and transmits nerve impulses. 8. Cardiovascular System (circulatory) ○ → when two or more tissue types combine, ○ Responsible for the distribution of oxygen, they form; nutrients, hormones, and waste products 4. Organs (collection of tissues) → a structure of the throughout the body body that is composed of two or more tissue types; ○ Contributes to temperature regulation each organ performs one or more specific 9. Reproductive system physiological functions. ○ Responsible for the creation of new human ○ For example: Stomach is made of all types of organisms. It produces and exchanges tissues. → organs work together to get things gametes. It houses the embryo / fetus until done, forming; birth (female) 5. Organ system (collection of organs) → a group of ○ Lactation, produces milk to nourish offspring organs that work together to perform major functions. (female) ○ Ex. The liver, stomach, and intestines of your ○ Produces and releases egg and sperm cells digestive system, all unite to take your food 10. Urinary system (excretory) from plate to pooper. ○ Responsible for the excretion of waste from the 6. The body → organism (collection of organ systems) blood. It contributes to blood pressure and pH ○ The various organs of the body form the entire homeostasis organism. 11. Digestive system (gastrointestinal) ORGAN SYSTEMS OF THE HUMAN BODY ○ Breaks down food, absorbs nutrients into the body, extraction of nutrients, and eliminating MEET MRS. NELI CRUD waste 1. Muscular System ANATOMICAL TERMINOLOGY ○ Responsible for the movement of the body ○ Contributes to body temperature homeostasis The language of anatomy will probably be unfamiliar to 2. Respiratory System you at first. But once you have understood the basic ○ Provides surface area for the diffusion of word roots, combining word forms, prefixes and suffixes, oxygen and carbon dioxide with the blood you will find that anatomical terminologies are not as ○ Responsible for helping maintain acid-base difficult as you first imagined. balance and the exchange of gasses between LANGUAGE OF ANATOMY the blood and atmosphere Proper anatomical terminology to describe body ○ Responsible for the gas exchange between O2 regions, orientation and direction, and body planes. and CO2 Exact terms are used for: 3. Skeletal System ○ Position ○ Supports and protects the body ○ Direction ○ Framework of the body ○ Regions ○ It stores calcium and phosphorus ○ Structures 4. Nervous System ANATOMICAL POSITION ○ Responsible for control of the entire body Anatomical positions are universally accepted as the system to promote homeostasis / balance starting points for positional references to the body. ○ Connects the brain to every part of the body In anatomical position; ○ Acts as the sensor for homeostasis 3  ○ The body is standing upright (standing / erect the nose. / orthostatic) ○ The feet are parallel and shoulder-width apart Proximal Toward (nearer) the trunk of ○ Toes point forward the body or the attached end ○ Upper limbs are held out to each side with the of a limb. The shoulder is palms facing forward proximal to the wrist. Distal Away (farther) from the trunk of the body or the attached end of a limb. The wrist is distal to the forearm. Superficial Nearer the surface of the body. The ribs are superficial to the heart. Deep Farther from the surface of If the subject is lying down with face up, it is referred to the body. The heart is deeper as Supine. to the ribs. If the subject is lying face down, it is referred to as Prone. Peripheral Away from the central axis of the body. Peripheral nerves radiate away from the brain and spinal cord. DEFINITIONS FROM THE PHYSICAL BOOK TERM DEFINITION & EXAMPLE DIRECTIONAL TERMS Standardized terms of reference are used when Superior (cranial) Describes a position above or anatomists describe the location of the body part. higher than another part of Relative means the location of one part of the body is the body proper. always described in relation to another part of the The neck is superior to the body. shoulders. TERM DEFINITION & EXAMPLE Inferior (caudal) Describes a position below or Superior (cranial) Toward the head. The leg is lower than another part of superior to the foot. the body. The pelvis is inferior to the abdomen. Inferior (caudal) Toward the feet. The foot is inferior to the leg. Anterior (ventral) Describes the front (belly) of the body. The toes are Anterior (ventral) Toward the front part of the anterior to the foot. body. The nose is anterior to the ears. Posterior (dorsal) Describes the back of the body. The spine is posterior Posterior (dorsal) Towards the back of the to the stomach. body. The ears are posterior to the nose. Medial Describes the middle or direction toward the middle Medial Towards the midline of the of the body. The hallux is the body. The nose is medial to most medial toe. the eyes. Lateral Describes a structure toward Lateral Away from the midline of the the side of the body. The body. The eyes are lateral to thumb (pollex) is lateral to 4  2. CERVICAL the digits. ○ Pertaining to the neck region ○ Down to the thoracic. The area between the Proximal Describes a position on a neck and the abdomen supported by the ribs, limb that is nearer to the sternum, and costal cartilages point of attachment or the 3. THORACIC trunk of the body. The ○ Found in the thoracic region is sternal *middle brachium is proximal to the of the breast*, the breast bone area, axillary antebrachium. or armpit, and pectoral relating to or occurring in the chest Distal Describes a position in a limb 4. ABDOMINAL that is farther from the point ○ This is the anterior body trunk inferior to the of attachment or the trunk of rips the body. The crus is distal to ○ Found in the abdominal region is the umbilical the femur. pertaining to the navel Superficial Describes a position closer to 5. PELVIC the surface of the body. The ○ The area overlying the pelvis anteriorly skin is superficial to the ○ Inguinal (groin) are where the thigh meets the bones. body trunk 6. PUBIC (GENITAL) Deep Deep Describes a position ○ This pertains to the genital region farther from the surface of BODY LANDMARKS (CAN BE FOUND ON THE LIMBS) the body. The brain is deep to 1. UPPER LIMB the skull. ○ Acromial or the point of the shoulder ○ Deltoid is the curve of the shoulder formed by large deltoid muscles ○ Brachial or arm ○ Antecubital is the anterior surface of the elbow ○ Antebrachial or the forearm ○ Carpal pertaining to the wrist 2. MANUS (HAND) ○ Digital pertaining to the fingers 3. LOWER LIMB ○ Coxal or the hip ○ Femoral pertaining to the thigh that both applies to the anterior and posterior ○ Patellar for the anterior knee ○ Crural for the anterior leg or the sheen ○ Fibular is the lateral part of the leg 4. PEDAL (FOOT) ○ Tarsel for the ankle region EXAMPLE ○ Digital pertaining to the toes 1. 5TH digit Medial to the hand. POSTERIOR BODY LANDMARKS 2. Brain is Superior to the heart. 1. CEPHALIC 3. Thumb is Lateral to the hand. ○ Occipital is the posterior surface of the head or base of the skull ANATOMICAL POSITION AND REGIONAL TERMS 2. CERVICAL ANTERIOR BODY LANDMARKS ○ Posterior portion of the neck region 1. CEPHALIC 3. BACK (DORSAL) ○ Frontal for the forehead ○ Scapular is the shoulder blade region ○ Orbital for the eye area ○ Vertebral pertaining to the area of the spinal ○ Nasal for the nose area column ○ Buccal for the cheeks area ○ Lumbar is the area of the back between the ○ Oral for the mouth ribs and the hips or also known as the loin ○ Mental for the chin ○ Sacral is the area between the hips at the base of the spine 5  ○ Gluteal or the buttock area 4. UPPER LIMB ○ Acromial pertaining to the points of the shoulder ○ Brachial for the arm ○ Olecranal for the posterior surface of the elbow ○ Antebrachial for the forearm 5. MANUS (HAND) ○ Digital pertaining to the fingers 6. LOWER LIMB ○ Femoral or the thigh ○ Popliteal is the posterior knee area ○ Sural is the posterior surface of the leg/ calf ○ Fibular is the lateral part of the leg 7. PEDAL (FOOT) ○ Calcaneal pertaining to the heel of the foot ○ Plantar pertaining to the sole of the foot TWO DIMENSIONAL PLANES (actually on the inferior body surface) Planes and sections can illustrate the same structures, SECTIONS AND PLANES but from different perspectives. Sections through the human body can be used to It is important to understand the plane or section being investigate internal anatomy. presented. ○ Section is a slice of three-dimensional This information can be used to build a 3-D structure that has been cut. understanding of body structures. Plane is an imaginary section through the body. ORGANIZATION AND COMPARTMENTALIZATION OF THE HUMAN ○ Plane is an imaginary slice through the body BODY used in imaging. Body planes are imaginary surfaces or plane lines that Internal compartments organize the body's internal divide the body into sections. This helps for further space identification of specific areas. ○ Separated by membranes 1. Sagittal plane Referred to as cavities ○ Divide the body into right and left sides. Posterior, or dorsal, body cavity ○ Mid sagittal plane or median plane - Divides ○ Consists of cranial and spinal (or vertebral) body into equal left and right halves / directly cavities down the middle of the body. Anterior body cavity ○ Para sagittal plane - Divides body into ○ Consists of thoracic and abdominopelvic unequal left and right. cavities 2. Frontal plane (coronal) BODY CAVITIES ○ Divides the body into anterior (front) and The cavities of the body house the internal organs, posterior (rear) portions / sections. which are commonly referred to as the viscera. The two ○ Mid coronal or mid frontal - Divides the body main body cavities are the larger ventral (anterior) and into two halves (anterior and posterior) that the smaller, dorsal (posterior) body cavity. cuts through both shoulders. The ventral body cavity constitutes the thoracic cavity ○ Often referred to as a coronal plane. (“Corona” and the abdominopelvic body cavity. is Latin for “crown.”) ○ The Thoracic cavity houses lungs and heart. It 3. Transverse plane is protected by the rib cage & associated ○ Divides the body into upper and lower portions musculature and the sternum anteriorly. It / sections. consists of the right and left pleural cavities 4. Oblique plane and mediastinum (the portion of tissues and ○ Divides the body obliquely into upper and organs that separates the left and right lung). lower sections. ○ Abdominopelvic Cavity extends from the diaphragm inferior to the floor of the pelvis. It is divided into superior abdominal and inferior pelvic cavity by imaginary line passing at upper pelvis. ○ Abdominal cavity contains the stomach, intestine, liver, spleen and gallbladder. 6  ○ The pelvic cavity contains the urinary bladder, Cavity between the layers contains serous fluid. rectum, and portions of the reproductive Each of the body's three serous cavities has its own organs. associated membrane. The dorsal body cavity ○ The pleura is the serous membrane that ○ It constitutes the cephalic cavity containing surrounds the lungs in the pleural cavity. the brain and the vertebral canal containing ○ The peritoneum is the serous membrane that the spinal cord. surrounds several organs in the abdominopelvic cavity. SUBDIVISIONS OF THE POSTERIOR AND ANTERIOR CAVITIES ○ The pericardium is the serous membrane that surrounds the heart in the pericardial cavity. LAYERS OF THE SEROUS MEMBRANE Serous membrane layers develop as the organ develops into the membrane. This is similar to the way that an underinflated balloon forms two separate layers around a fist. ABDOMINOPELVIC CAVITY (PERITONEAL CAVITY) The abdominopelvic cavities can be divided into (A) nine regions or (B) four quadrants. ABDOMINOPELVIC CAVITY REGIONS ➔ Divides the abdominopelvic cavity into separate regions by four planes 1. Hypochondriac region POSTERIOR BODY CAVITY AND SUBDIVISIONS ○ Flank the epigastric region and contains the Posterior body cavity (dorsal) lower ribs ○ Cranial cavity ○ Right hypochondriac region constraints the Brain liver, right kidney, gallbladder and the large / ○ Spinal cavity (vertebral) Spinal cord, beginning of spinal small intestine nerves ○ Left hypochondriac region contains the liver’s ANTERIOR BODY CAVITY AND SUBDIVISIONS tip,stomach, pancreas, left kidney, spleen and Thoracic cavity he large / small intestine ○ Pleural cavity 2. Epigastric region Lungs ○ Located superior to the umbilical region ○ Mediastinum ○ Contains the liver, stomach, spleen, Thymus duodenum, adrenal glands, and pancreas Esophagus Trachea 3. Lumbar region Pericardial cavity ○ Lie lateral to the umbilical region and spinal Heart column, between the bottom ribs and the hip Abdominopelvic cavity bones ○ Abdominal cavity ○ Right lumbar region contains the ascending Stomach colon, small intestine and the right kidney Spleen ○ Left lumbar region contains the descending Liver Small intestine colon, small intestines and left kidney Pelvic cavity 4. Umbilical region ○ Urinary bladder ○ Center most region ○ Ovaries ○ Deep two surrounding the umbilicus SEROUS MEMBRANES OF THE ANTERIOR BODY CAVITY ○ Contains the duodenum, small intestine and Serous membranes are sheets of tissue that cover organs in the transverse colon anterior body cavity. 5. Iliac region Reduce rubbing and friction as internal organs move. ○ Lateral to the hypogastric region Serous membranes have two layers. ○ Parietal layer lines the wall of the body cavity. ○ Right iliac region constraints the appendix, ○ Visceral layer lies directly on the surface of the secum, ascending colon, and the small organ. intestine 7  ○ Left iliac region contains the sigmoid colon, side notes descending colon, and the small intestine X-Rays 6. Hypogastric region Medical imaging provides an internal view of the human body. It aids in diagnosing disease. Best used to ○ Inferior to the umbilical region view teeth and bone. ○ Contains the bladder, sigmoid colon, small Computed Tomography (CT) intestine and the reproductive organs Tomography refers to imaging by planes. A noninvasive imaging technique that uses computers to analyze several cross-sectional X-rays in order to reveal minute details about structures in the body. X-rays and CT scans are capable of damaging cells and initiating changes that can lead to cancer. Magnetic Resonance Imaging (MRI) Uses radio signals emitted by internal structures to provide very precise details and It’s expensive. Positron Emission Tomography (PET) Uses small amounts of radiation to detect metabolic activity. Useful in diagnosing cancers, heart disease, and strokes. Ultrasonography Uses sound waves to yield a real time image of internal anatomy. Used in sensitive situations like pregnancy. ABDOMINOPELVIC CAVITY QUADRANTS CHAPTER 4 ➔ Quadrants are named based on their location in THE CELLULAR LEVEL OF ORGANIZATION relation to the anatomical position: THE CELL MEMBRANE AND ITS INVOLVEMENT IN TRANSPORT 1. Right Upper Quadrant (RUQ) ○ Contains the liver, right kidney, gallbladder, CELL THEORY portion of the colon and pancreas Cells are the building blocks of all organisms. 2. Left Upper Quadrant (LUQ) All cells come from the division of preexisting cells. ○ Contains the stomach, left kidney, spleen, Cells are the smallest units that perform all vital portion of the colon and pancreas physiological functions. 3. Right Lower Quadrant (RLQ) Each cell maintains homeostasis at the cellular level. Cytology is a branch of cell biology. ○ Contains the appendix, colon, small intestine , ○ The study of cells ureter, and major artery and vein to the right ○ Sex cells (germ cells or reproductive cells) leg Male sperm 4. Left Lower Quadrant (LLQ) Female oocytes (cells that develop ○ Contains the colon, small intestine, ureter, and into ova) major artery and vein to the left leg ○ Somatic cells 5. Midline All body cells except sex cells ○ Contains the aorta, pancreas, small intestine, bladder and the spine STRUCTURE OF THE CELL MEMBRANE Separates the cell's internal environment from the external environment. Regulates the movement of materials into and out of the cell. Composed of phospholipids, cholesterol, carbohydrates, and proteins. Flexible, dynamic structure. PLASMA (CELL) MEMBRANE Extracellular fluid (interstitial fluid) ○ A watery medium that surrounds the cell. Plasma membrane separates cytoplasm from the 8  ○ Transmembrane, or integral, proteins extracellular fluid. Span the entire width of the cell Functions of the plasma membrane. membrane. ○ Physical isolation ○ Peripheral proteins Barrier Do not span the membrane. ○ Regulation of exchange with the Attached to the interior or exterior of environment the membrane. Ions and nutrients enter ○ Glycoproteins = proteins that have Wastes eliminated and cellular carbohydrate molecules attached. products released Aid in cell recognition ○ Sensitivity to the environment ○ Glycocalyx is formed by numerous Chemical signals glycoproteins. ○ Structural support Only present in some cells. Anchors cells and tissues Can serve as receptors for hormones and a means to bind to other cells. PHOSPHOLIPIDS Helps break down nutrients. Major structural component of the cell membrane. TRANSPORT ACROSS THE CELL MEMBRANE Amphipathic molecules Cell membrane is selectively permeable. ○ Hydrophilic ("water-loving") ○ Allows only small, nonpolar molecules to pass ○ Hydrophobic ("water-fearing") freely. Arranged into a bilayer (two layers) Molecules that are able to pass will flow across the ○ Phosphate heads face internal and external membrane if there is a gradient. environments. ○ Flow occurs from high to low concentration ○ Fatty acid tails create hydrophobic regions unless prevented by resistance. within the bilayer. PHOSPHOLIPID STRUCTURE DIFFUSION AND OSMOSIS Amphipathic molecule The plasma (cell) membrane is a barrier, but ○ Hydrophilic head contains a phosphate group ○ Nutrients must get in and is attracted to water. ○ Products and wastes must get out ○ Hydrophobic tails are nonpolar and repelled Permeability determines what moves in and out of a by water. cell, and a membrane that Organized into a bilayer to form biological membranes. ○ Lets nothing in or out is impermeable ○ Lets anything pass is freely permeable ○ Restricts movement is selectively PLASMA (CELL) MEMBRANE permeable Phospholipid bilayer Plasma membrane is selectively permeable ○ Hydrophilic heads ○ Allows some materials to move freely Face outward on both sides, ○ Restricts other materials towards watery environment. ○ Hydrophobic fatty-acid tails Inside membrane PASSIVE TRANSPORT Barrier to ions and water-soluble Movement does not require energy. compounds Requires a concentration gradient. Two forms: CELL MEMBRANE STRUCTURE 1. Simple diffusion: molecules move from higher to lower concentration without the use of membrane proteins. Selectively permeable barrier 2. Facilitated diffusion: molecules move from higher to Composed mainly of phospholipid bilayer lower concentration through membrane proteins. Intracellular fluid (ICF) inside of cell ➔ Everyday examples of diffusion: Perfume diffuses ○ Also called cytosol. across a room, sugar molecules dissolve in coffee, and Extracellular fluid (ECF) outside of cell dye diffuses through water. Proteins also associate with cell membrane SIMPLE DIFFUSION ACROSS A CELL MEMBRANE MEMBRANE PROTEINS Small, nonpolar molecules can pass through the cell membrane. Proteins associated with cell membranes add Diffusion continues until a net equilibrium is reached. functionality. Diffusion occurs faster at higher temperatures. ○ Serve as channel proteins, receptors, enzymes, and in cell-cell recognition. 9  DIFFUSION AND OSMOSIS (CONT.) solute concentration in a solution Diffusion ○ Net movement of a substance from area of EFFECT OF TONICITY ON CELLS higher concentration to area of lower concentration An isotonic solution has equal water concentration ○ Ions and molecules are constantly in across the cell membrane. motion ○ Cell functions normally A hypertonic solution contains more solutes in the environment. ○ Cell shrinks A hypotonic solution contains fewer solutes in the environment. ○ Cell swells and may burst DIFFUSION AND OSMOSIS (CONT.) Tonicity describes how a solution affects cells ○ Depends on the nature of the solutes ○ Isotonic solution (iso-= same, tonos = tension) Does not cause osmotic flow OSMOSIS ○ Hypotonic solution (hypo—below) The movement of water across the cell membrane. Lower solute concentration than Water moves from areas of lower solute to higher solute the cell concentration. ○ Hypertonic solution (hyper—above) Hypotonic solution–less solute outside of the cell. Higher solute concentration than ○ Water enters cells when they are in hypotonic the cell solutions. ➔ Osmolarity and tonicity Hypertonic solution–more solute outside of the cell. ○ A cell in an isotonic solution ○ Water will leave cells in hypertonic solutions. Stays the same size and shape WATER MOLECULE CONCENTRATION ○ A cell in a hypotonic solution Osmosis depends on the ratio of solute molecules to Gains water water. May rupture (hemolysis) Water will move from areas of lower solute ○ A cell in a hypertonic solution concentration to areas of higher solute concentration. Loses water and shrinks OSMOSIS ACROSS A MEMBRANE (crenation) Water moves across a semipermeable membrane toward the area with a higher solute concentration (i.e., lower water concentration). SOLUTION COMPARISONS Isosmotic solutions have equal concentrations of solute. A hyperosmotic solution contains more solute by comparison. A hypoosmotic solution contains less solute by comparison. Tonicity describes the osmolarity of the ECF compared to the cytosol of the cell. DIFFUSION AND OSMOSIS (CONT.) Osmosis ○ Diffusion of water across a selectively permeable membrane ACTIVE TRANSPORT ○ Water molecules move from a high to a low Requires energy to move molecules against their concentration concentration gradient. Osmolarity (osmotic concentration) is the total 10  ○ From areas of lower concentration to areas of EXOCYTOSIS higher concentration. The process of a cell exporting material, or cell Primary active transport—uses ATP as an energy secretion. source. Vesicle fuses with cell membrane. Secondary active transport—uses electrochemical Contents are released from the cell. gradients as an energy source. Hormones and digestive enzymes secreted this way. ○ Symporters—secondary active transporters that move two molecules in the same CARRIERS AND VESICLES (CONT.) direction Exocytosis (exo—outside) ○ Antiporters—move two molecules in opposite ○ Granules or droplets are released from the directions cell as a vesicle fuses to plasma membrane SODIUM-POTASSIUM PUMP Common example of primary active transport. Uses ATP to move 3 sodium ions out of the cell and 2 potassium ions into the cell, against their concentration gradients. ENDOCYTOSIS A form of active transport Uses the cell membrane to engulf materials. Cell membrane pinches off to form a vesicle and material enters the cell. FORMS OF ENDOCYTOSIS 1. Phagocytosis: extends the cell membrane to bring in large molecules. 2. Pinocytosis: membrane invagination brings in small amounts of fluid containing dissolved substances. 3. Receptor-mediated endocytosis: more selective ○ Ligand binds to membrane receptors for cellular entry. THE CYTOPLASM AND CELLULAR ORGANELLES INTERNAL COMPONENTS OF CELLS Major components of the inside of cells include: ○ Cytoplasm - the fluid-like interior of cells including its compartments and organelles. ○ Organelles - membrane-bound structures that perform specific functions. ○ Cytosol - the gel-like substance within the cytoplasm. Contains organelles and molecules needed by cells. CARRIERS AND VESICLES ○ Lysosomes - are organelles that digest Endocytosis unneeded cellular components, such as ○ Pinocytosis damaged organelle. Endosomes "drink" extracellular fluid ORGANELLES WITHIN THE CYTOPLASM ○ Phagocytosis Organelles Cytoplasmic extensions called Nonmembranous organelles pseudopodia (pseudo—false, ○ No membrane podon = foot) ○ Direct contact with cytosol Large objects are engulfed in ○ Include the cytoskeleton, centrioles, phagosomes ribosomes, proteasomes, microvilli, cilia, and flagella 11  Membranous organelles ○ Isolated from cytosol by a plasma membrane ○ Endoplasmic reticulum (ER), the Golgi apparatus, lysosomes, peroxisomes, and mitochondria Cytoskeleton ○ Structural proteins for shape and strength Microfilaments Intermediate filaments Microtubules Microvilli ○ Increase surface area for absorption ○ Attach to cytoskeleton Centrioles ○ Form spindle apparatus during cell division ○ Centrosome—cytoplasm next to the nucleus that surrounds centrioles Cilia (singular, cilium) ○ Slender extensions of plasma membrane ENDOPLASMIC RETICULUM (ER) ○ Move fluids across the cell surface Flagellum is whip-like extension of cell membrane Series of channels continuous with the nuclear Ribosomes—organelles that synthesize proteins membrane; provides passages for synthesis, ○ Composed of small and large ribosomal transportation and storage. subunits ○ Rough ER—contains ribosomes Contain ribosomal RNA (rRNA) Involved in protein synthesis ○ Free ribosomes in cytoplasm ○ Smooth ER—lacks ribosomes Manufacture proteins that enter Involved in lipid synthesis cytosol directly ○ Fixed ribosomes are attached to ER ORGANELLES WITHIN THE CYTOPLASM (CONT.) Manufacture proteins that enter ER Endoplasmic reticulum (ER) for packaging ○ Contains storage chambers known as Proteasomes cisternae ○ Organelles that contain enzymes Functions: (proteases) 1. Synthesis of proteins, carbohydrates, and ○ Disassemble damaged proteins for lipids recycling 2. Storage of synthesized molecules and Five types of membranous organelles materials 1. Endoplasmic reticulum (ER) 3. Transport of materials within the ER 2. Golgi apparatus 4. Detoxification of drugs or toxins 3. Lysosomes Smooth endoplasmic reticulum (SER) 4. Peroxisomes ○ No attached ribosomes 5. Mitochondria ○ Synthesizes Phospholipids and cholesterol (for membranes) Steroid hormones (for reproductive system) Rough endoplasmic reticulum (RER) ○ Surface covered with ribosomes Active in protein synthesis Encloses products in transport vesicles for delivery to Golgi apparatus 12  MEMBRANOUS ORGANELLES FOR DETOXIFICATION AND ENERGY PRODUCTION GOLGI APPARATUS Lysosomes–membrane–bound vesicles that contain The Golgi Apparatus-series of flattened sacs. digestive enzymes. ○ Responsible for sorting and modifying ○ Used to break down wastes within the cell. products from rough ER for transport. Peroxisomes–contain enzymes used to produce Cis-face receives products for modification. hydrogen peroxide. Trans-face releases products after modification. ○ Used for detoxification and lipid metabolism. Mitochondria–site of aerobic respiration. ORGANELLES WITHIN THE CYTOPLASM (CONT.) ○ Responsible for nutrient breakdown and ATP Golgi apparatus (Golgi complex) production. ○ Vesicles enter forming face and exit maturing face ORGANELLES WITHIN THE CYTOPLASM (CONT.) Functions: Lysosomes 1. Modifies and packages secretions ○ Powerful enzyme-containing vesicles ○ Such as hormones or enzymes, for produced by Golgi apparatus release from cell ○ Function to destroy bacteria, break down 2. Renews or modifies the plasma membrane molecules, and recycle damaged 3. Packages special enzymes within vesicles organelles (lysosomes) for use in the cytoplasm Autolysis ○ Self-destruction of damaged or inactive cells Lysosome membranes break down Digestive enzymes released Cell is destroyed Cellular materials are recycled Peroxisomes ○ Small, enzyme-containing vesicles Produced by division of existing peroxisomes Break down organic compounds such as fatty acids Mitochondria ○ Smooth outer membrane ○ Inner membrane has numerous folds 13  (cristae) Cristae surround fluid contents (matrix) ○ Take chemical energy from food (glucose) Produce the energy molecule ATP MITOCHONDRIA Energy transformer of the cell. Lined by 2 bilayers; ○ Outer membrane DYNAMIC NATURE OF THE CYTOSKELETON ○ Inner membrane is folded into cristae More numerous in muscle and nerves. Cytoskeleton is not fixed. Cytoskeletal components form and can move depending on needs of the cell. Helps move molecules and structures around the interior of the cell. CELL SURFACE SPECIALIZATIONS Microvilli help increase surface area of the cell. Cilia aid in movement of the cell or movement across the surface of the cell. Flagella are long appendages used for movement. THE NUCLEUS AND DNA ORGANIZATION OF THE NUCLEUS Nucleus houses the DNA of the cell. Most human cells have a single nucleus. Nucleus is surrounded by a nuclear envelope. CYTOSKELETON ○ Nuclear pores allow small molecules to move Made up of fibrous proteins that provide structural into and out of the nucleus. support for cells. Nucleolus within nucleus is involved in ribosome Organizes cytoplasm production. Aids in separation during cellular division. Composed of protein filaments that provide support: 1. Microtubules—made of tubulin CELL NUCLEUS 2. Intermediate filaments—made of keratin Nucleus 3. Microfilaments—made of actin ○ Largest organelle ○ The cell's control center Nuclear envelope ○ Double membrane around the nucleus Perinuclear space ○ Between the two layers of the nuclear envelope Nuclear pores ○ Communication passages in nuclear envelope 14  Chromatin is packaged during replication to form chromosomes. CELL NUCLEUS (CONT.) Information storage in the nucleus Genetic code ○ Chemical language of DNA instructions Sequence of bases (A, T, C, G) ○ Triplet code Gene ○ DNA instructions for one protein ○ Functional unit of heredity PROTEIN SYNTHESIS Protein Synthesis within the Cell DNA contains the genetic code of the cell. Genetic code provides the instructions to produce cellular proteins. CELL NUCLEUS (CONT.) Protein production begins in the nucleus and ends in Contents of the nucleus the cytoplasm. Nuclear matrix in the nucleoplasm Genes are transcribed into messenger RNA (mRNA). ○ Support filaments ○ Gene is a segment of DNA that codes for a Nucleoli protein. ○ Nuclear organelles mRNA is then translated into proteins. ○ Synthesize RNA and assemble ribosomal subunits ○ Made of RNA, enzymes, and histones PROTEIN SYNTHESIS Nucleosome—DNA coiled around histones Assembling of functional polypeptides in the ○ Loosely coiled into chromatin in cytoplasm non-dividing cells Gene activation ○ Tightly coiled chromosomes form before ○ Uncoiling DNA and temporarily removing division histones Transcription ○ Synthesis of RNA from DNA template NUCLEIC ACIDS FOUND IN HUMAN CELLS ○ All RNA, including messenger RNA (mRNA), Nucleic acids found in a healthy human cell include is formed through transcription of DNA DNA, mRNA, tRNA, and rRNA: ○ DNA is storage form of genome ○ mRNA is used in translation of proteins MAKING PROTEINS FROM DNA ○ tRNA moves amino acids during translation Proteome is a cell's full complement of proteins. ○ RNA is structural component of ribosomes Genes contain information necessary to make proteins. NUCLEOTIDE BASES OF DNA DNA is transcribed to mRNA. DNA has a double-helix structure formed by hydrogen mRNA is then translated to proteins. bonds between nucleotide bases. TRANSCRIPTION The four nucleotide bases of DNA are: Process of creating a strand of messenger RNA (mRNA) 1. Adenine (A) from a DNA template. 2. Thymine (T) Occurs within the nucleus of the cell. 3. Cytosine (C) and Complementary mRNA is made from a gene of one 4. Guanine (G) strand of DNA. Adenine forms a double bond with thymine. mRNA will leave the nucleus for translation. Cytosine forms a triple bond with guanine. FROM DNA TO RNA: TRANSCRIPTION ORGANIZATIONS OF DNA THE PROCESS OF TRANSCRIPTION DNA strands are wrapped around histone proteins for Three stages of transcription: organization. 1. Initiation - DNA strands are separated and RNA Chromatin is the loose form of DNA. polymerase begins to synthesize complementary RNA molecules. 15  2. Elongation - RNA polymerase continues to add 3. Amino acids are delivered by transfer RNA (tRNA) nucleotides to growing strands. 4. A tRNA anticodon binds to a complementary mRNA 3. Termination - RNA polymerase reaches the end of the codon gene and mRNA transcript is released. 5. Enzymes join amino acids with peptide bonds 6. At stop codon, components separate PROTEIN SYNTHESIS (CONT.) Process of transcription 1. RNA polymerase binding 2. RNA polymerase nucleotide linking ○ Begins at "start" signal in promoter region ○ Reads DNA code ○ Binds nucleotides to form mRNA in three-base sequences known as codons 3. Detachment of mRNA ○ Enzyme and mRNA strand detach from DNA at "stop" signal ➔ RNA processing ○ mRNA is "edited" before leaving nucleus CREATING A MATURE (mRNA) TRANSCRIPT Before leaving the nucleus, the mRNA transcript is modified. DNA contains regions that do not code for amino acids. ○ Called introns. Regions that code for amino acids are called exons. Introns must be removed before mRNA leaves the nucleus. TRANSLATION CELL REPLICATION Process of creating a protein from a mRNA template. THE CELL CYCLE Occurs in the cytoplasm of the cell. Three phases: Interphase, mitosis, and cytokinesis. Carried out by ribosomes. The cell spends most of its time in interphase. ○ Ribosomal RNA (rRNA) - component of Interphase is split into: ribosomes. 1. G1 phase—cell grows, makes proteins, and Each three nucleotide sequences of mRNA is a codon. carries out cellular functions Ribosomes read codons. 2. S phase—cell replicates its DNA Transfer RNA (tRNA) brings amino acids to ribosomes. 3. G2 phase—cell prepares for mitosis ○ tRNA contains anticodons that match specific mRNA codons. CELL LIFE CYCLE Amino acids are linked by peptide bonds to form Cell division is a form of cellular reproduction proteins. ○ A single cell divides to produce two FROM RNA TO PROTEIN: TRANSLATION daughter cells 1. Initiation - ribosome subunits attach to start codon of At the end of a cell's life span, it undergoes mRNA transcript. genetically controlled death called apoptosis 2. Elongation - tRNA molecules are attracted to the Interphase ribosome and deliver the corresponding amino acids to ○ Nondividing period in which somatic cells the growing polypeptide. spend the majority of their lives 3. Termination - translation continues until the ribosome Mitosis reaches a "stop" codon that ends the process. ○ Duplication of chromosomes in the nucleus and their separation into two identical sets ○ A continuous process consisting of several PROTEIN SYNTHESIS (CONT.) stages: prophase, metaphase, anaphase, Process of translation and telophase 1. After leaving nucleus, mRNA binds to ribosomal Cytokinesis subunits in cytoplasm ○ Division of the cytoplasm 2. Each mRNA codon translates to one amino acid Produces two daughter cells 16 CELLULAR REPLICATION Cellular replication occurs as the parent cell divides to form two daughter cells: ○ Mitosis occurs in somatic cells Daughter cells are identical to parent cells. Cells contain 46 chromosomes or the diploid number. ○ Meiosis occurs for reproductive cells Resulting cells have half the amount of genetic material from one parent and half from the other parent. Cells contain 23 chromosomes or the haploid number. DNA REPLICATION The process of copying DNA CELL LIFE CYCLE (CONT.) Occurs during the S phase of the cell cycle Mitotic rate Three phases: ○ Rate of cell division 1. Initiation: the DNA strands are separated by Slower mitotic rate means longer helicase cell life 2. Elongation: the DNA polymerase synthesizes a Cell division requires energy (ATP) new strand 3. Termination: the DNA replication stops Chromatin—the linear form of DNA. CELL DIVISION AND CANCER Condensed into chromosomes during replication. Tumor (neoplasm) Replicated copy is called a sister chromatid. ○ Mass produced by abnormal cell growth Sister chromatids are attached at a centromere. and division Chromatids separate during mitosis. ○ Benign tumor ○ Make sure each daughter cell has a complete Contained, not life threatening copy of DNA. unless large PHASES OF NUCLEIC ACID PROCESSES ○ Malignant tumor Spreads into surrounding tissues Transcription, translation, and replication are each (invasion) divided into 3 steps: Cancer results from abnormal proliferation of cells ○ Initiation ○ Caused by mutations in genes involved ○ Elongation with cell growth ○ Termination Modified genes are called MITOSIS oncogenes Cell replication consists of four major phases, followed ○ Mutagens are agents that cause mutations by cytokinesis: ○ Carcinogens, including many mutagens, 1. Prophase: Chromatin condenses into chromosomes are cancer—causing agents and the centrioles migrate to opposite sides of the cell. ○ Metastasis is the spread of cancer to other 2. Metaphase: Chromatids align in the middle of the cell. areas 3. Anaphase: Chromatids separate-and move toward the Begins with invasion of tissues opposite sides of the cell. surrounding tumor 4. Telophase: Nucleoli and nuclear membranes start to form, and chromosomes return to chromatin form 5. Cytokinesis: Cleavage furrow divides cell into two distinct cells. 17  CHAPTER 5 THE TISSUE LEVEL OF ORGANIZATION TYPES AND COMPONENTS OF TISSUES Tissue ○ Used to describe a group of cells functioning together in the body. Histology ○ The microscopic study of tissue appearance,