copyright ©2012 delmar, cengage learning. all rights reserved. chapter 23 anatomic descriptors and...
TRANSCRIPT
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Chapter 23
Anatomic Descriptors and Fundamental Body Structure
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Anatomical Position
• A body is said to be in the anatomical position when the patient is standing erect, with the arms down at the sides, and the palms of the hands facing forward
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Appropriate Terminology forAnatomical Directions
• To describe exact location when charting, the body is divided by imaginary lines
• One line divides the body into right and left
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Terms
• Medial– Toward the midline
• Proximal– Nearest the point of attachment
• Distal– Farthest from the point of attachment
• Lateral– Away from the midline
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Appropriate Terminology forAnatomical Directions
• Another line divides the body into upper and lower halves
• Finally, a line divides the body into front and back
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Terms
• Anterior– Toward the front
• Frontal– Toward the front
• Ventral– Toward the front or belly side
• Superior– Above the transverse plane
• Cranial– Toward the head
• Inferior– Below the transverse
plane• Caudal
– Toward the tail or feet• Posterior
– Toward the back
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Body Cavities and Major Organs
• The body is divided into two main cavities:1.Anterior or ventral
• Cavity toward the belly side that contains the head, chest, and major abdominal organs
2.Posterior or dorsal • Cavity toward the back that contains the brain and
spinal cord
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Body Cavities
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Diaphragm
• Diaphragm– A large dome-shaped muscle that separates the
thoracic cavity from the abdominal cavity
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Organs of the Abdomen
• The abdomen contains the:– Stomach– Small intestine– Most of the large intestine– Liver– Spleen– Pancreas– Gallbladder
The Regions of the Abdomen
• Because of its size, the abdomen is first divided into four areas called quadrants.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Regions of the Abdomen
• The abdomen is then divided into 9 regions for purposes of identification and reference.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Basic Characteristics of a Cell
• The cell is the basic building block of the human body:– Cells need nutrients and oxygen to survive.– Cells perform specific functions.– Cells produce heat and energy.– Cells can give off waste products.– Some cells can reproduce themselves.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Basic Characteristics of a Cell
• Organelles are minute bodies within the cytoplasm:
– Nucleus– Mitochondria– Ribosomes– Centriole
• Some organelles physically separate the chemical reactions that are not compatible.
• Organelles also control the time when reactions take place.
Endoplasmic reticulum Golgi apparatus Lysosomes
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Basic Characteristics of a Cell
• Chromosomes– Located within the nucleus, each human has 23
pairs of chromosomes that store the hereditary material passed from one generation to the next
– 22 pairs are identical.– The 23rd pair are the sex chromosomes:
• XY = male• XX = female
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Basic Characteristics of a Cell
• Cytoplasm– Fluid that makes up the cell
• Cell membrane– Separates the cell from the surrounding
environment• Cytoplasm
– Semisolid fluid within the membrane where chemical reactions, such as respiration, occur
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
What Happens When Mutations Occur
• DNA that is lost, rearranged, or paired in error results in a change in the genetic code called a mutation.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Six Ways Molecules Pass Through Cell Membranes
1.Diffusion– Gas, solids, or liquids are distributed evenly
through a medium.
2.Osmosis– Diffusion of water or another solvent through a
selectively permeable membrane
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Six Ways Molecules Pass Through Cell Membranes
3.Filtration– Movement of solutes and water across a
semipermeable membrane– Filtration occurs as a result of force such as gravity
or blood pressure.
4.Active transport– Molecules move across a membrane from an area
of low concentration to an area of high concentration.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Six Ways Molecules Pass Through Cell Membranes
5.Phagocytosis– White blood cells become phagocytes and engulf
bacteria, cell fragments, or damaged cells.
6.Pinocytosis– Cells engulf large molecules of liquid materials;
cell drinking
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Patterns of Inheritance andHow They Affect a Trait
• A trait is a recognizable result of the effect of a gene or a group of genes– 3 patterns of inheritance can produce these traits
1. Dominant genes: produce the trait2. Recessive genes: produce the trait if both parents
have the same mutation3. X-linked: traits that are sex linked
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Genetic and Congenital Disorders
• These disorders can result from improper sex cell division at the time of fertilization, from the inheritance of altered genes, or as the result of environmental factors or poisons.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Cleft Lip and Cleft Palate
• Cleft lip– A structural defect is present in the upper lip
caused by failure of the soft or bony tissues to unite during the 8th to 12th week of gestation.
• Cleft palate– A structural defect is present in the roof of the
mouth caused by failure of the soft or bony tissues to unite during the 8th to 12th week of gestation.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Color Vision Deficiency
• Inaccurately called “colorblindness” – most people see some colors.
• The most common problem is an inability to distinguish between red and green.
• There is no treatment to correct the problem; people must learn to compensate.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Cystic Fibrosis
• Affects multiple systems; a generalized dysfunction of the exocrine glands.
• 30,000 people affected in the U.S.; median age of survival is 37 years.
• All states require infant screening to identify cystic fibrosis before leaving the hospital.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Down Syndrome
• A genetic syndrome caused by improper cell division• Occurs in about 1 in every 1,000 births, depending
on the mother’s age• The result is an extra chromosome 21.• Down syndrome has several physical characteristics,
e.g., slanting eyes, large tongue, pug nose, and a small head.
• Mental retardation occurs in all cases and there is some degree of growth restriction.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Dwarfism
• Condition that results in an abnormally undersized person.
• About 200 conditions that result in dwarfism; achondroplastic dwarfism accounts for 70% of cases.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Klinefelter’s Syndrome
• Sex-linked disorder where there is one or more extra X chromosomes; affects 1 in every 600 males.
• At puberty, the penis and testicles fail to mature and there is little body hair.
• Breasts may enlarge and long legs with a short, obese trunk are noted.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Spina Bifida
• A structural malformation of the spine• The posterior portion of the spinal tissues fails
to close during the first 3 months of pregnancy.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Talipes
• A structural deformity of one or both feet• Commonly called clubfoot• There may be varying degrees of inward,
outward, downward, or upward turning of one or both feet.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Turner’s Syndrome
• Sex-linked defect that affects about 1 in every 10,000 females.
• Only 45 chromosomes are present because the sex cells failed to divide correctly.
• Ovaries fail to develop.• The chest is wide and there is poor breast
development and underdevelopment of the genitalia.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Body System Interaction
• Because the body is so dependent on multiple systems to function, when diseases and disorders develop, often multiple systems are involved.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Discoveries in Genetics
• The Human Genome Project identified a 3 billion letter code of human DNA, which is the chemical sequence containing the basic information for building and running a human body.
• This sequence determines every human characteristic from eye color to vulnerability to disease.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Genetic Techniques
• Polymerase Chain Reaction• DNA Fingerprinting• Genetic Counseling• Gene Therapy• Genetic Engineering• Stem Cell Research
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Cell to Tissue Progression
• When cells of the same type group together for a common purpose, they form a tissue.
• Tissue has four main classifications and is 60% to 99% water.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Four Main Types of Body Tissue
1.Epithelial tissue– Forms the body’s glands, covers the surface of the
body, and lines the body cavities
2.Connective tissue– Connects tissues together to form the organs and
body parts
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Four Main Types of Body Tissue
3.Nerve tissue– The basic structural unit of this tissue is the
neuron, which serves as the body’s communication network.
– These neurons are made up of a nerve cell body and fibers that resemble tree branches to bring impulses toward the cell and carry impulses away from the cell.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Four Main Types of Body Tissue
– Sensory neurons in the skin or sensory organs send impulses to the brain and spinal cord.
– Interneurons carry impulses to another neuron.– Motor neurons receive an impulse and send a
message, which causes a reaction.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Four Main Types of Body Tissue
4.Muscle tissue– Designed to contract on stimulation– Involuntary action occurs without control or
conscious awareness, such as the heartbeat and respirations.
– Tissues controlled at will by brain impulses are called voluntary muscle tissue.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Body Organs
• The organs are made up of two or more types of tissues working together to perform a specific body function.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
Body Systems
• The human body is made up of 10 body systems and the organs of each are discussed in the unit that relates to that particular body system.
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The Body Systems
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The 10 Body Systems
Integumentary– Skin
Muscular system– Muscles
Skeletal system– Bones and joints
Nervous system– Brain and spine
Endocrine system– 9 glands
Copyright ©2012 Delmar, Cengage Learning. All rights reserved.
The 10 Body Systems
Circulatory system – Heart and blood vessels
Respiratory system– Mouth, nose, and lungs
Digestive system– Intestines
Urinary system– Bladder, kidneys, ureters, and urethra
Reproductive– Sex organs