Anatomy I Muse lecture 1 2430 Fall 2012. Introduction Anatomy and physiology affect your life...
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Transcript of Anatomy I Muse lecture 1 2430 Fall 2012. Introduction Anatomy and physiology affect your life...
Anatomy I
Muse lecture 12430 Fall 2012
Introduction
Anatomy and physiology affect your life everyday Anatomy is the oldest medical science
1600 B.C.
Physiology is the study of function Biochemistry Biology Chemistry Genetics
Introduction
Study strategies crucial for success Attend all lectures, labs, and study sessions Read your lecture and laboratory assignments before
going to class or lab Devote a block of time each day to your A&P course Set up a study schedule and stick to it Do not procrastinate! Approach the information in different ways Develop the skill of memorization, and practice it
regularly As soon as you experience difficulty with the course,
seek assistance
Introduction
Learning Outcomes Illustrations and
Photos Pronunciation Guides Checkpoint Questions The A&P Top 100 Tips & Tricks Clinical Notes Chain Link Icons
End-of-Chapter Study and Review Materials
Systems Overview Section
System in Perspective Summaries
Colored Tabs End-of-Book
Reference Sections
Important features of the textbook
Introduction
Supplements The InterActive Physiology® (IP) CD MyA&P™ Martini’s Atlas of the Human Body Get Ready for A&P! A&P Applications Manual Study Guide
Full descriptions in preface of textbook
Structure and Function
Anatomy Describes the structures of the body
What they are made of Where they are located Associated structures
Physiology Is the study of
Functions of anatomical structures Individual and cooperative functions
Anatomy and Physiology Integrated
Anatomy Gross anatomy, or macroscopic anatomy,
examines large, visible structures Surface anatomy: exterior features
Regional anatomy: body areas
Systemic anatomy: groups of organs working together
Developmental anatomy: from conception to death
Clinical anatomy: medical specialties
Anatomy and Physiology Integrated
Anatomy
Microscopic anatomy examines cells and
molecules
Cytology: study of cells and their structures
• cyt- = cell
Histology: study of tissues and their structures
Levels of Organization
The Chemical (or Molecular) Level Atoms are the smallest chemical units Molecules are a group of atoms working together
The Cellular Level Cells are a group of atoms, molecules, and organelles
working together
The Tissue Level Tissues are a group of similar cells working together
The Organ Level An organ is a group of different tissues working
together
Levels of Organization
The Organ System Level Organ systems are a group of organs working
together Humans have 11 organ systems
The Organism Level A human is an organism
Levels of Organization
FIGURE 1–1 Levels of Organization.
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Homeostasis
Homeostasis: all body systems working
together to maintain a stable internal
environment
Systems respond to external and internal
changes to function within a normal range
(body temperature, fluid balance)
Homeostasis
Mechanisms of Regulation
Autoregulation (intrinsic)
Automatic response in a cell, tissue, or organ to some
environmental change
Extrinsic regulation
Responses controlled by nervous and endocrine systems
Homeostasis
Receptor
Receives the stimulus
Control center
Processes the signal and sends instructions
Effector
Carries out instructions
FIGURE 1–3 The Control of Room Temperature.
Homeostasis
Negative and Positive Feedback
FIGURE 1–4 Negative Feedback in the Control of Body Temperature.
Negative and Positive Feedback
The Role of Positive Feedback
The response of the effector increases
change of the stimulus
Body is moved away from homeostasis
Normal range is lost
Used to speed up processes
Negative and Positive Feedback
FIGURE 1–5 Positive Feedback: Blood Clotting.
Stimulusproduceschange invariable.
Receptordetectschange.
Input: Informationsent along afferentpathway to controlcenter.
Output:Information sent alongefferent pathway toeffector.
Responseof effectorfeeds backto reducethe effect ofstimulusand returnsvariable tohomeostaticlevel.
Receptor Effector
ControlCenter
BALANCE
Afferentpathway
Efferentpathway
IMBALANCE
IMBALANCE
1
2
34
5
Figure 1.4
Anatomical Terminology
Superficial Anatomy
Anatomical position: hands at sides, palms
forward
Supine: lying down, face up
Prone: lying down, face down
Anatomical Terminology
Superficial Anatomy Anatomical Landmarks
References to palpable structures
Anatomical Regions Body regions
Abdominopelvic quadrants
Abdominopelvic regions
Anatomical Directions Reference terms based on subject
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Anterior
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Anterior
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Posterior
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Posterior
Anatomical Terminology
Anatomical Terminology
Figure 1.7a
Cervical
(a) Anterior/Ventral
Pubic(genital)
Cephalic
FrontalOrbitalNasalOralMental
Thoracic
AxillaryMammarySternal
Abdominal
Umbilical
Pelvic
Inguinal(groin)
Upper limb
AcromialBrachial (arm)AntecubitalAntebrachial (forearm)
Carpal (wrist)
Manus (hand)
PalmarPollexDigital
Lower limb
Coxal (hip)Femoral (thigh)
PatellarCrural (leg)Fibular or peroneal
Pedal (foot)
Tarsal (ankle)MetatarsalDigitalHallux
Thorax
Abdomen
Back (Dorsum)
Anatomical Terminology
FIGURE 1–7 Abdominopelvic Regions.
Anatomical Terminology
FIGURE 1–7 Abdominopelvic Relationships.
Anatomical Terminology
FIGURE 1–8 Directional References. An Anterior View.
Anatomical Terminology
Anatomical Terminology
Sectional Anatomy Planes and sections
Plane: a three-dimensional axis
Section: a slice parallel to a plane
Used to visualize internal organization and structure
Important in radiological techniques– MRI
– PET
– CT
Anatomical Terminology
FIGURE 1–9 Sectional Planes.
Anatomical Terminology
Body Cavities
FIGURE 1–10 Relationships Among the Subdivisions of the Ventral Body Cavity.
Body Cavities
Serous membranes
Line body cavities and cover organs
Consist of parietal layer and visceral layer
Parietal layer — lines cavity
Visceral layer — covers organ
Body Cavities
The Thoracic Cavity Separated into regions
Right and left pleural cavities– contain right and left lungs
Mediastinum– upper portion filled with blood vessels, trachea,
esophagus, and thymus
– lower portion contains pericardial cavity
» the heart is located within the pericardial cavity
Body Cavities
FIGURE 1–11 The Ventral Body Cavity and Its Subdivisions.
Body Cavities
FIGURE 1–11 The Ventral Body Cavity and Its Subdivisions.
Body Cavities
FIGURE 1–11 The Ventral Body Cavity and Its Subdivisions.
Body Cavities
The Abdominopelvic Cavity
Peritoneal cavity — chamber within
abdominopelvic cavity
Parietal peritoneum lines the internal body wall
Visceral peritoneum covers the organs
Chapter 3Cells
• vary in size• possess distinctive shapes• measured in micrometers
An Introduction to Cells
Sex cells (germ cells)
Reproductive cells
Male sperm
Female oocyte (a cell that develops into an egg)
Somatic cells (soma = body)
All body cells except sex cells
Cell Membrane
The Plasma Membrane
Cell Membrane
The proteins are divided into two categories: integral and peripheral. The integral proteins form the majority of membrane proteins. They
penetrate and are embedded in the bilayer, bound to the non polar tail regions.
The transmembrane proteins span the bilayer completely and may form channels (pores) for transport of substances across the membrane.
Integral proteins also may lie partly submerged in one side or the other. They have several functions.
– Some integral proteins serve as cell surface enzymes.– Integral proteins bound to carbohydrates may form
receptor sites for chemical messages from other cells, such as endo crine glands.
– Some also function as markers, or antigens, which identify cell types.
The peripheral proteins are loosely bound to the membrane surface and can be easily removed from it. Their functions are not as well known as those of integral proteins. They may be involved in structural support and changes in membrane shape during cell division or cell movement.
Intercellular Junctions
Tight junctions• close space between cells• located among cells that form linings
Desmosomes• form “spot welds” between cells• located among outer skin cells
Gap junctions• tubular channels between cells• located in cardiac muscle cells
The cytoplasm contains a complex network of structural components
Microfilaments Structure
Microfilaments are solid thread-like cylinders made of protein and found in a variety of sites within the cell.
Function Microfilaments are responsible for contractility of cells,
which is a property of all cells but is especially well developed in muscle cells.
Contractility is responsible for cell locomotion and movements associated with phagocytosis, pinocytosis, and cell division.
Cell Adhesion Molecules
• guide cells on the move
• selectin – allows white blood cells to “anchor”
• integrin – guides white blood cells through capillary walls
• important for growth of embryonic tissue
• important for growth of nerve cells
Structural Components
Microtubules Structure
Microtubules are hollow tubes present everywhere in the cytoplasm in all cells.
They are composed of protein tubulin molecules. Function
Microtubules contribute to the cytoskeleton, or supporting elements, of the cell.
They also are involved in cell division, cell movements, and the transport of materials from one area of the cell to another.
Microfilaments and microtubules• thin rods and tubules• support cytoplasm• allows for movement of organelles
Cytoplasmic Organelles
Inclusions
• temporary nutrients and pigments
Movements Into and Out of the Cell
Passive (Physical) Processes• require no cellular energy• simple diffusion•facilitated diffusion• osmosis• filtration
Active (Physiological) Processes• require cellular energy• active transport• endocytosis• exocytosis• transcytosis
Simple Diffusion
• movement of substances from regions of higher concentration to regions of lower concentration• oxygen, carbon dioxide and lipid-soluble substances
Osmosis
• movement of water through a selectively permeable membrane from regions of higher concentration to regions of lower concentration• water moves toward a higher concentration of solutes
Osmosis
Osmotic Pressure – ability of osmosis to generate enough pressure to move a volume of water
Osmotic pressure increases as the concentration of nonpermeable solutes increases
• hypertonic – higher osmotic pressure• hypotonic – lower osmotic pressure• isotonic – same osmotic pressure
Facilitated Diffusion
In facilitated diffusion, the carrier substance combines with the solute molecules to form a solute-carrier complex, which is soluble in the lipid-bilayer, and thus transports the solute across the membrane.
Once on the other side, the solute is released. The carrier breaks away from the complex, returns to the exterior of the membrane, and repeats the process. The carriers exhibit specificity; i.e. they are highly selective in
distinguishing between closely related molecules. Facilitated diffusion can be inhibited by competitive and
noncompetitive inhibitor molecules, which closely resemble the solute molecules.
The rate of passage of a solute through facilitated diffusion depends on: its concentration difference on both sides of the membrane the number of carrier molecules available how rapidly the solute-carrier complex formation takes place.
Filtration
• smaller molecules are forced through porous membranes• hydrostatic pressure important in the body• molecules leaving blood capillaries
Active Transport
• carrier molecules transport substances across a membrane from regions of lower concentration to regions of higher concentration• sugars, amino acids, sodium ions, potassium ions, etc.
Endocytosis
Transcytosis
• endocytosis followed by exocytosis• transports a substance rapidly through a cell• HIV crossing a cell layer
Exocytosis• reverse of endocytosis• substances in a vesicle fuse with cell membrane• contents released outside the cell• release of neurotransmitters from nerve cells
Nucleus
Structure The nuclear envelope consists of a double membrane separated by the
perinuclear space. The inner membrane is smooth. The outer membrane often contains
ribosomes and is continuous with the surrounding ER. The inner and outer membranes fuse at irregular intervals around the
nucleus to form nuclear pores, which allow for exchange of materials between the nucleus and the cytoplasm.
Chromatin appears as irregular clumps or granules material dispersed throughout the nucleus.
Chromatin is composed of coiled strands of DNA bound to basic proteins called histones, varying amounts of RNA, and other nonhistone proteins and enzyme systems.
In a dividing cell, the chromatin is condensed and coiled into discrete units, the chromosomes. Human cells contain 23 pairs of chromosomes.
The nucleoplasm is the matrix that surrounds the chromatin. It is composed of proteins, metabolites, and ions.
The nucleolus is a spherical structure composed of RNA and protein. The size of the nucleolus and the number present vary in different cell types. It is missing in cells that do not synthesize protein, such as spermatozoa. It is the site of ribosome production
Ribosomes
Structure Ribosomes are small granules composed of ribosomal RNA and
almost 80 different proteins. They occur as individual granules or in clusters called
polyribosomes. They may be free in the cytoplasm (free ribosomes) or attached
to the membranes of the endoplasmic reticulum. Function
Ribosomes are the site of protein synthesis. Free ribosomes are involved in the synthesis of proteins for the
cell’s own use; for example, in the renewal of enzymes and membranes.
Attached ribosomes are the site of synthesis of proteins that are secretory products to be released from the cell.
Golgi Apparatus
Function The Golgi apparatus is the site of accumulation, concentration,
packaging, and chemical modification of the secretory products synthesized on the rough ER. The transport vesicles pinch off from the ER and carry the secretions to
the Golgi apparatus, where the secretions fuse with its cisternae. The large condensing vacuoles concentrate the secretion and package
them to become secretory granules. Secretory granules, which are large, densely packed, membrane-
bounded structures, unload their contents via exocytosis upon nervous or hormonal stimulation.
The Golgi apparatus also chemically modifies the molecules synthesized in the ER for incorporation into the plasma membrane. It adds fatty acid residues to certain proteins to convert them to lipoproteins, and it synthesizes and attaches carbohydrate side chains to proteins to form glvcoproteins.
The Golgi apparatus processes proteins that function intracellularly, such as the lysosome enzymes.
The cell cycle and mitosis
The cell cycle, in cells that are capable of dividing, refers to the events in a cell’s life span in the period between the time it was formed by cell division to the beginning of the next cell division.
The greatest portion of the cycle (about 90%) is devoted to growth and synthesis, called interphase, with a smaller portion devoted to nuclear and cell division, or mitosis.
The Cell Cycle
Stem and Progenitor Cells
The End