Anatomy 2
Introduction
Dr. Michael P. Gillespie
Chapter 1
An Introduction to the Human Body
Definitions
Anatomy – Deals with the structure of body parts – their forms and relationships.
Physiology – Deals with the functions of body parts – what they do and how they do it.
Dissection – The careful cutting apart of body parts to see their relationships.
Levels of Body Organization
Chemical level Cellular level Tissue level Organ level System level Organism
Chemical Level
Atoms – smallest units of matter that participate in chemical reactions.
Molecules – two or more atoms joined together.
Elements In Living Things
11 main elements comprise living things. C, H, O, P, K, I N, S, Ca, Fe, and Mg. CHOPKINS CaFé, Mighty Good!
Cellular Level
Molecules combine to form cells. Cells are the basic structural and functional
units of an organism. Cells are the smallest living units in the
human body. Cells are made up of organelles.
Tissues
Tissues are groups of cells and the materials surrounding them that work together to perform a particular function.
4 basic types of tissues in the human body: Epithelial tissue Connective tissue Muscle tissue Nervous tissue
Organs
Organs are composed of two or more tissues that work together to perform specific functions.
They usually have recognizable shapes.
System Level
A system consists of related organs that have a common function.
Sometimes an organ is part of more than one system.
There are eleven systems in the human body.
Organ Systems
Integumentary System Muscular System Skeletal System Nervous System Endocrine System Lymphatic and
Immune System
Cardiovascular System Respiratory System Digestive System Urinary System Reproductive Systems
Integumentary System
Components – Skin, hair, nails, sweat glands, oil glands.
Functions – Protects the body; helps regulate body temperature; eliminates wastes; makes vitamin D; detects sensations such as touch, pain, warmth, and cold.
Muscular System
Components – Muscles, tendons. Functions – Produces body movements, such
as walking; stabilizes body position (posture); generates heat.
Skeletal System
Components – Bones, joints, associated cartilages.
Functions – Supports and protects the body; aids body movements; houses cells that produce blood cells; stores minerals and lipids.
Nervous System
Components – Brain, spinal cord, nerves, special sense organs (I.e. eyes and ear).
Functions – Generates action potentials (nerve impulses) to regulate body activities; detects changes in the body’s internal and external environments, interprets these changes, and responds causing muscular contractions or glandular secretions.
Endocrine System
Components – Hormone producing glands and hormone producing cells.
Functions – Regulates body activities by releasing hormones (chemical messengers) which are transported in the blood from an endocrine gland or tissue to a target organ.
Lymphatic and Immune System
Components – Lymphatic fluid and vessels; spleen, thymus, lymph nodes, tonsils.
Functions – Returns proteins and fluids to blood; carries lipids from gastrointestinal tract to blood; includes structures that generate lymphocytes (to protect against disease-causing organisms).
Cardiovascular System
Components – Blood, heart, and blood vessels.
Functions – Heart pumps blood through vessels; blood carries oxygen and nutrients to cells and carbon dioxide and wastes away from cells; regulates acid-base balance, temperature, and water content of body fluids; components defend against disease.
Respiratory System
Components – Lungs, air passageways such as the pharynx (throat), larynx (voice box), trachea (windpipe), and bronchial tubes.
Functions – Transfers oxygen from inhaled air to blood and carbon-dioxide from blood to exhaled air; regulates acid-base balance, air flowing out through vocal cords produces sounds.
Digestive System
Components – Mouth, esophagus, stomach, small and large intestines, and anus (organs of GI tract); salivary glands, liver, gallbladder, pancreas (accessory organs).
Functions – Physical and chemical breakdown of food; absorbs nutrients, eliminates solid wastes.
Urinary System
Components – Kidneys, ureters, urinary bladder, urethra.
Functions – Produces, stores, and eliminates urine; eliminates wastes; regulates volume and chemical composition of blood; maintains acid-base balance; maintains mineral balance; helps regulate production of red blood cells.
Reproductive Systems
Components – Gonads (testes in males, ovaries in females), associated organs (uterine tubes, uterus, and vagina in females and epididymis, ductus deferens, and penis in males).
Functions – Gonads produce gametes (sperm or oocytes); gonads release hormones.
Non-invasive techniques to assess body structure and function
Inspection – the examiner observes the body for any changes that deviate from normal.
Palpation – the examiner feels the body with the surface of the hands.
Non-invasive techniques to assess body structure and function
Auscultation – the examiner listens to the body sounds to evaluate functioning of certain organs, often using a stethoscope to amplify the sounds.
Percussion – the examiner taps on the body surface with fingertips and listens to the resulting echo.
Basic Life Processes
Metabolism Responsiveness Movement Growth Differentiation Reproduction
Metabolism
The sum of all the chemical processes that occur in the body. Catabolism – The breaking down of complex
chemical substances into simpler ones. Anabolism – The building up of complex
chemical substances from simpler ones.
Responsiveness
The body’s ability to detect and respond to changes in its internal and external environment.
Movement
Motion of the whole body. Motion of individual organs. Motion of Single cells. Motion of structures inside cells.
Growth
Growth is an increase in body size that results from an increase in the size of existing cells, the number of cells, or both.
A tissue can increase in size due to an increase in the amount of material between cells (I.e. bone tissue).
Differentiation
Differentiation is a process a cell undergoes to develop from an unspecialized to a specialized state.
Each type of cell has a specialized structure and function.
Stem cells can divide and give rise to progeny that undergo differentiation.
Reproduction
The formation of new cells for tissue growth, repair or replacement.
The formation of new cells for the production of a new individual organism (through fertilization of an ovum by a sperm cell.
Anatomical Terminology
Body Positions Regional Names Directional Terms Planes and Sections Body Cavities
Body Positions
Anatomical Position The subject stands erect facing the observer, with
the head level and the eyes facing forward. The feet are flat on the floor and directed forward, and the arms are at the sides with the palms turned forward.
Prone – body lying face down. Supine – body lying face up.
Prone & Supine
Regional Names
Regions can be identified externally. Principal regions:
Head (cephalic) Neck (cervical) Trunk Upper limb Lower limb
Directional Terms
Superior (cephalic or cranial) and inferior (caudal). Anterior (ventral) and posterior (dorsal). Medial and lateral. Intermediate Ipsilateral and contralateral. Proximal and distal. Superficial and deep.
Planes and Sections
Sagittal Plane – vertical plane – divides body into right and left.
Midsaggital or median plane – equal parts Parasaggital plane – unequal parts Frontal or coronal – divides body into anterior and
posterior parts Transverse plane – divides body into superior and inferior
parts Oblique plane – angle Section – one flat surface or a 3-D structure
Body Cavities
Spaces within the body that help protect, separate, and support internal organs.
Two major cavities are the dorsal and ventral body cavities.
Dorsal Body Cavity
Located near the dorsal (posterior) surface of the body.
Subdividions Cranial cavity Vertebral (spinal) canal
Meninges
Ventral Body Cavity
Located near the ventral (anterior) aspect of the body.
Subdivisions Thoracic cavity Abdominopelvic cavity
Diaphragm Viscera
Thoracic Cavity
Subdivisions Pericardial Cavity Pleural cavities mediastinum
Abdominopelvic cavity
Subdivisions Abdominal Cavity Pelvic Cavity
Thoracic and Abdominal Cavity Membranes
Serous membrane Pleura Pericardium Peritoneum
Abdominopelvic Regions and Quadrants
The nine-region designation is used for anatomical studies, whereas the quadrant designation is used to locate the site of pain, tumor, or some other abnormality.
Abdominopelvic Regions
Right Hypochondriac Region Epigastric Region Left Hypochondriac Region Right Lumbar Region Umbilical Region Left Lumbar Region Right Inguinal (Iliac) Region Hypogastric (Pubic Region) Left Inguinal (Iliac) Region Subcostal line, transtubercular line, midclavicular lines
Abdominopelvic Quadrants
Right Upper Quadrant (RUQ) Left Upper Quadrant (LUQ) Right Lower Quadrant (RLQ) Left Lower Quadrant (LLQ) Horizontal lines passes through umbilicus
Homeostasis
The French physiologist Claude Bernard proposed that cells live in a relatively constant internal environment -“le milieu interieur”- despite changes in the organisms’ external environment.
The American physiologist Walter Bradford Cannon coined the term homeostasis to describe this constancy.
Homeostasis Continued…
Homeo = sameness; Stasis = standing still. The condition of equilibrium in the body’s
internal environment. Various regulatory processes in the body
maintain this condition. Dynamic condition.
Body Fluids
An important aspect of homeostasis is maintaining the volume and composition of body fluids.
Intracellular fluid ICF – intra = inside. Extracellular fluid ECF = extra = outside. Various substances are dissolved in the water
of ICF and ECF.
Dissolved Substances
Oxygen Nutrients Proteins Ions
Interstitial Fluid
The extracellular fluid that fills the narrow spaces between cells of tissues is known as interstitial fluid.
Inter = between. For cells to function properly, the
composition of the surrounding fluid must be precisely regulated.
Types of Interstitial Fluid
Blood plasma = ECF within blood vessels Lymph = ECF within lymphatic vessels Cerebrospinal fluid = ECF around the brain
and spinal cord Synovial fluid = ECF in the joints Aqueous humor and vitreous body = ECF in
the eyes
Internal Environment
Interstitial fluid surrounds all of the body’s cells and is therefore referred to as the “internal environment” of the body.
Exchange of Materials
Substances move back and forth between the interstitial fluid and the blood plasma.
This exchange occurs at the blood capillaries. The exchange occurs as a result of diffusion
(passive transport) and active transport. Movement of substances occurs in both
directions across capillary walls.
Diffusion
Diffusion or passive transport is the movement of substances from a region of higher concentration to a region of lower concentration.
Diffusion
Substances move down their concentration gradient.
Factors Influencing Diffusion
Steepness of the concentration gradient. Temperature. Mass of the diffusing substance. Surface area. Diffusion distance.
Active Transport
In active transport, substances move from a region of lower concentration to a region of higher concentration. This requires energy in the form of ATP.
Disturbance of Homeostasis
Homeostasis is constantly being disturbed. External disruptions. Internal disruptions. Regulatory systems bring the body back into
balance. Nervous system – nerve impulses – typically cause
rapid changes. Endocrine system – hormones – work slowly.
Feedback Systems
A cycle of events in which the body is continually monitored, evaluated, changed, remonitored, reevaluated, and so on.
Each monitored variable is a controlled condition.
Stimulus – a disruption that changes a controlled condition.
3 Components of a Feedback System
Receptor Control center Effector
Receptor
A body structure that monitors changes in a controlled condition and sends input to a control center.
Input is in the form of nerve impulses or chemical signals.
Control Center
The control center sets the acceptable range of values for a controlled condition.
The control center evaluates input from receptors. The control center generates output commands as
needed. Output – nerve impulses, hormones, chemical
signals.
Effector
A body structure that receives output from the control center.
Produces a response or effect that changes the controlled condition.
Feedback Loop
The system “feeds back” to change the controlled condition in some way.
Feedback systems can produce either negative feedback or positive feedback.
Negative Feedback Systems
If the response reverses the original stimulus, the system is operating by negative feedback.
Positive Feedback Systems
If the response enhances or intensifies the original stimulus, the system is operating by positive feedback.
Homeostatic Imbalances
As long as the body’s controlled conditions stay within certain narrow limits, body cells function efficiently and the body stays healthy. Homeostasis is maintained.
If homeostatic imbalance is moderate, a disorder or disease may occur; If it is severe, death may result.
Homeostatic Imbalances Continued…
Disorder – any derangement or abnormality of function.
Disease – a more specific term for an illness characterized by a specific set of signs and symptoms. Local disease. Systemic disease.
Homeostatic Imbalances Continued…
Symptoms – subjective changes in body functions that are not apparent to an observer. Headache, nausea, anxiety.
Signs – objective changes that a clinician can observe and measure. Anatomical – swelling, rash. Physiological – fever, high BP, paralysis.
Epidemiology
The science that deals with why, when, and where diseases occur and how they are transmitted to individuals.
Epi- upon. Demi - people.
Pharmacology
The science that deals with the effects and uses of drugs.
Pharmac = drug.
Diagnosis
The science and skill of distinguishing one disorder or disease from another.
Dia – through. -Gnosis – knowledge. Working diagnosis.
Information Utilized to Obtain a Diagnosis
The patient’s signs and symptoms Medical history (S.O.A.P. Notes, review of
systems, personal history, family history, medicines taken, etc.)
Physical examination (inspection, palpation, auscultation, percussion, vital signs)
Laboratory tests