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


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


FIGURE 1–1 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.


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


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


Superficial Anatomy Anatomical Landmarks

References to palpable structures

Anatomical Regions Body regions

Abdominopelvic quadrants

Abdominopelvic regions

Anatomical Directions Reference terms based on subject


FIGURE 1–6 Anatomical Landmarks. Anterior


FIGURE 1–6 Anatomical Landmarks. Posterior

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)


FIGURE 1–7 Abdominopelvic Regions.


FIGURE 1–7 Abdominopelvic Relationships.


FIGURE 1–8 Directional References. An Anterior View.


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


FIGURE 1–9 Sectional Planes.

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

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

anatomy i muse lecture 1 2430 fall 2012. introduction anatomy and physiology affect your life...

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