CHAPTER 1

Organization of the Human Body

The Study of anatomy and physiology has paralleled the development of cultures, religion, and technology.

Ancient civilizations such as the Maya and Incas are believed to have preformed surgeries

Imhotep, 2500 BC: recorded some of the earliest information on surgery

Aristotle, 500 BC: founder of comparative anatomy Herophilus, 500 BC: “father of anatomy” described

the diagnostic value of the pulseErasistratos, 500 BC: contributed to the

understanding of the anatomy of the brain, and noted the difference between motor and sensory nerves

History of Anatomy and Physiology

Galen, year 0: “First Great Anatomist”, his writings remained unchallenged for 1500 years. Conformed his anatomic findings to theological principles

Andreas Vesalius, 1500: “Father of Modern Anatomy”, corrected Galen’s mistakes. Dissected human cadavers

Ambroise Pare’, 1500: “Greatest Surgeon of the 16th century”, first to ligate vessels to control bleeding after amputations

Terms

Anatomy: is the study of the structure and morphology of the body and its systems.

Physiology: is the study of the functions of the cells, tissues, and organs of the body

Pathophysiology: – is the study of disease and disorder of the human body. (Knowledge of anatomy and physiology is essential to understand these disorders.

Anatomic Position

When a person is in anatomic position, the body is erect and facing forward with arms supinated at the side and palms of the hands and feet facing forward.

Supine- face up, palms upProne- face down, palms down

Anatomic Position

Directional Terms

Superior – toward the headInferior – toward the feet

Anterior – frontPosterior – back

Directional Terms cont.

Medial – toward the midline of the bodyLateral - toward the side of the body

Proximal – nearest the point of origin of one of its parts

Distal - away from the point of origin

Superficial- nearer the surfaceDeep- farther away from the surface

Geometric Planes

Geometric Planes

The body is sectioned into imaginary geometric planes: Saggital - divides the body or parts into right and

left sides Midsaggital (median plane)– divides the body into

equal right and left sides Transverse (horizontal plane)- divides the body or

parts into upper and lower portions Coronal (frontal plane)- divides the body or parts into

anterior and posterior portions Cross section – a transverse cut that is at angles to

the long axis of the organ

Saggital

Transverse

Coronal

Reference Points

Reference points are used to identify key anatomic landmarks Epicondyle Condyle Foramen Fossa Trocanter Triangle of Calot Hesselbach’s triangle Trigone of bladder Ligament of Treitz Hepatic flexure Splenic flexure

Quadrants

When making clinical diagnoses surgeons frequently use quadrants to indicate the area of bodily pain

RUQ – right upper quadrant RLQ – right lower quadrant

LUQ – left upper quadrantLLQ – left lower quadrant

Quadrants

Nine Regions

Two saggital planes and two transverse planes divide the abdomen into nine regions Right Hypochondrium Left Hypochondrium Epigastrium Right Lumbar Left lumbar Umbilical Right iliac Left iliac Hypogastrium

Nine Regions

Major Body Cavities

The body is divided into two major cavities: Dorsal Cavity – Posterior division of the

body. further subdivided into the cranial cavity and the spinal cavity

Ventral Cavity – Anterior division of the body. further subdivided into the thoracic and abdominopelvic cavities

Body Cavities

Body Cavities

Cranial cavity: contains the brain Spinal Cavity: contains the spinal cord The membranes that line the cranial and spinal cavities are called the

meninges

Thoracic cavity: further subdivided into the… mediastinum: esophagus , thymus gland, trachea Pericardial cavity: contains the heart (within its pericardial sac) Pleural cavities: contains the lungs

Abdominopelvic cavity: also called the peritoneal cavity is further subdivided into the…

Abdominal cavity: contains the stomach, liver, gallbladder, spleen, pancreas, small intestines, and colon

Pelvic cavity: sigmoid colon, rectum, bladder, and internal reproductive organs

Diaphragm

Separates the thoracic cavity from the abdominopelvic cavity

Is the most important muscle in breathing

Peritoneum

The peritoneum is a serous membrane that lines the abdominal cavity Parietal peritoneum: lines the wall of the

abdominoplevic cavity Visceral peritoneum: covers the organs in the

abdominopelvic cavity Peritoneal space: small space between the two

layers, contains serous fluid and reduces friction

Mesentery

Mesentery: a fold of peritoneum that invests the intestines and attaches them to the posterior abdominal wall

Omentum : a double fold of peritoneum that is divided into the greater omentum and the lesser omentum Greater omentum: attaches to the greater curvature

of the stomach and hangs loosely downward covering the intestines

Attaches to the lesser curvature of the stomach and duodenum

Organization of the Human Body

The levels of organization progress from the least complex (chemical level) to the most complex (organism level)

Atoms and molecules are referred to as the chemical level

Organization of the Human Body

Cells are the smallest living units of structure and function in our body

Tissues are an organization of many similar cells

Organs are an organization of several different kinds of tissues

Organization of the Human Body

Systems are varying numbers and kinds of organs working together to perform complex functions

The body is a unified and complex assembly of interactive components

Body Systems

A group of organs arranged to perform a more complex function There are 11 major organ systems in the human body:

1. Integumentary2. Skeletal3. Muscular4. Nervous5. Endocrine6. Circulatory (cardiovascular & peripheral vascular) 7. Lymphatic 8. Digestive 9. Respiratory 10. Genitourinary11. Reproductive

Integumentary system

Largest organ system which Includes:•Skin•Sweat glands •Sebaceous glands•Hair •Nails

Functions: •First line of defense •Protects underlying tissues and structures•Insulates •Regulation of body temperature •Cutaneous sensation •Detects Pressure •Contains sweat & sebaceous glands •Synthesis of Vitamin D •Absorption sigh for topical medications

Skeletal System

Includes: •Skeleton•Ligaments •Tendons •Cartilage

Function:•Support•Providing basic body shape •Aids in movement of the body•Sight of hematopoeisis in red bone marrow •Stores fat in Yellow bone marrow •Protects internal organs •Tendons attach muscle to bone •Ligaments attach bone to bone •Cartilage allows articulation and attachment of bones to other bones

Muscular System

Includes: •Skeletal muscle (Voluntary/striated muscle)•Smooth muscle (involuntary/non striated muscle)•Cardiac muscle

Function:•Movement •Maintains body posture •Heat production •Aids flow of blood through the body•Pushes food through the gastrointestinal tract (GI) by way of parastalsis

Nervous system

Includes:•Brain •Spinal cord•Cranial nerves •Peripheral nerves

Functions:•Memory•Special senses •Receives and interprets sensory information from internal and external stimuli•Sends motor impulses

Nervous System cont.

CNS (Central nervous system): Consists of the brain and spinal cord

PNS (Peripheral nervous system): Comprises the nerves *SNS (Somatic Nervous system): Cranial nerves connected the brain to the skin and skeletal muscle

and initiate voluntary movements and responses *ANS (Autonomic Nervous system): Cranial and spinal nerves connect the brain to visceral organs initiate

involuntary responses *Sympathetic: “fight or flight”*Parasympathetic: Calms the body, conserves energy, restores homeostatic balance

Visceral: Internal organs

Endocrine system

Includes:•Pituitary gland (Master gland)•Thyroid gland •Parathyroid gland•Pancreas•Thymus gland•Adrenal glands•Testes•Ovaries

Functions:•Secretes hormones that affect metabolism and many functions

of the bodyTarget tissue: group of cells to be affected by a particular hormone

The endocrine system works closely with the nervous system.The nervous system provides rapid response while the endocrine system Provides slower response, but longer lasting results

Circulatory system

Includes:•Cardiovascular system: Heart, coronary arteries, aorta, pulmonary arteries and veins, superior and inferior vena cava•Peripheral vascular system: All arteries, veins and capillaries outside of the heart

Functions:•Heart pumps to circulate blood•Blood transports oxygen to body cells•Blood transports waste for elimination•Blood transports hormones •Helps maintain normal body temperature

Lymphatic system

Includes:Lymph fluidLymph vessels Lymph nodes SpleenThymus

Functions: Lymphatic system also called the Immune systemFilters out microorganism and foreign body substancesMaintains fluid levels in interstitial spaces to prevent EdemaAbsorption of fat in the intestinal tract

Edema: accumulation of excess fluid in interstitial spaces Lymphocytes: cells of the lymphatic system

Digestive system

Includes: •Mouth •Teeth •Tongue•Salivary glands •Pharynx•Esophagus•Stomach

•Liver•Gallbladder•Biliary duct system•Pancreas •Small intestine •Colon

Function:•Mechanical and chemical breakdown of food into simpler forms that can be used by body cells a energy•Transports food out of the body

Respiratory system

Includes:•Nasal cavity•Pharynx (throat)•Larynx (voice box)•Trachea (wind pipe)•Lungs•Bronchi•Bronchioles •Alveoli

Function:•Exchange of oxygen and carbon dioxide between the blood and inhaled air

Genitourinary system

Includes:•Kidneys•Ureters •Urinary bladder•Urethra

Functions:•Maintains water & electrolyte balance •Filters blood removing waste •Elimination of waste and excess fluid through formation of urine

Female Reproductive System

Includes:•Ovaries•Fallopian tubes•Uterus•Vagina•Clitoris•External genitalia (vulva)•Breast

Functions:•Production of ova•Transportation of fertilized ova into uterus •Support developing embryo •Delivery of fetus•Milk production •Menstruation if ova is not fertilized •Formation of sex characteristics

Male Reproductive system

Includes: Scrotum Testes Epididymis Vas deferens Seminal vesicles Prostate gland Bulbourethral glands Urethra Penis

Function: Production of spermatozoa Responsible for transporting the spermatozoa into the female

reproductive tract

Homeostasis !!!!

Homeostasis: is the coordination of all the various functions of the body to maintain a normal internal environment.