Transcript Chapter 2

Chapter 2
The Human Body in
Health and Disease
Chapter 2 Objectives
• Define and decipher common terms associated with
the structural organization of the body
• Identify the body cavities and list the organs
contained within those cavities
• Locate and name the anatomical divisions of the
back
• List and define terms related to positions, direction
and planes of the body
• Analyze unfamiliar terms using knowledge of word
roots, suffixes and prefixes
Branches of Science that Study the
Human Body
Anatomy – studies the structure of the body
Physiology – studies the normal functions of the
structures of the human body
Biology – the study of all forms of life and living things
Embryology
– the study of the origin and development of an organism
– Covers from 2nd to 8th week after conception, the
embryonic stage
– After 8 weeks, the developing organism is known as a fetus
• Histology – the study of the structure, composition
and functions of tissues
• Cytology – the study of the anatomy, physiology,
pathology, and chemistry of the cell
• Pathology – the study of the nature and cause of
diseases that involve changes in structure and
function.
• Epidemiology – study of outbreaks of disease within
a population group
Anatomic Reference Systems
• Describe the location and functions of body
parts using:
– Body planes
– Body directions
– Body cavities
– Structural units (ex. A cell, a tissue, an organ)
Anatomic Position
•
•
•
•
Body Erect
Arms at side
Palms forward
Head and neck forward
So…what’s up with page 30?
Body Planes
Imaginary horizontal and vertical lines used to divide the body
Vertical plane – an up and down line that is a right
angle to the horizon
• Midsagittal plane –also known as the midline, divides the
body into equal left and right sides
• Sagittal plane – divides the body into left and right
portions
• Frontal plane – divides the body into anterior (front) and
posterior (back) portions. Also known as the coronal
plane
Horizontal plane – a flat crosswise plane, such
as the horizon
• Transverse plane – a horizontal plane that
divides the body into superior (upper) and
inferior (lower) portions. Can be at the waist
or at any other level across the body
Directional Terms
Used for the most precise descriptions possible
Ventral
Anterior
Superior
Cephalic
Proximal
Medial
Dorsal
Posterior
Inferior
Caudal
Distal
Lateral
Let’s Put it All Together
Major Body Cavities
There are 2 major body cavities (spaces) that
contain and protect internal organs
1) Dorsal cavity – located along the back of the head
and body and contains:
»Cranial cavity – located in skull protects
the brain
»Spinal cavity – located in the spinal
column . Surround and protects the spinal
cord
2) Ventral Cavity – located along the front of
the body and contains:
»Thoracic cavity – AKA chest or thorax,
surrounds and protects the heart and lungs
Note: the diaphragm is a muscle used in
breathing that divides the thoracic cavities!
»Abdominal cavity – contains primarily the
major organs of digestion and is often just
referred to as the abdomen
»Pelvic cavity – the space formed by the hip
bones and contains the reproductive and
excretory organs
Major Body Cavities
Regions of the Thorax & Abdomen
descriptive system that divides the lower part of the
thorax and abdominopelvic area into 9 parts
Quadrants of the Abdomen
The Peritoneum
a multi-layered membrane that protects and holds the organs in
place within the abdominal cavity
• Parietal Peritoneum – the outer layer that lines the
interior of the abdominal wall
• Visceral Peritoneum – the inner layer that surrounds
the organs of the abdominal cavity
• Mesentery – fused double layer of the parietal
peritoneum that attaches sections of the intestines
to the abdominal wall
• Retroperitoneal – means located behind the
peritoneum
• Peritonitis – inflammation of the peritoneum
Levels of Structural Organization (6)
1.
Chemical level – atoms combine to form molecules
2. Cellular level – molecules combine to form cells
3. Tissue level – groups of similar cells that have a
common function
4. Organ level – at least 2 tissues combined (usually 4)
that perform a specific function
5. Organ system level – consists of multiple organs working
closely together to accomplish a
common purpose
6. Organismal level – the result of all structural levels
working together
6. Organismal Level
Cytology
• The study of the formation, structure, and
function of cells, including:
– Chromosomes
– DNA
– Genetics
• Cells- the basic structural and functional unit
of the body. When cells are specialized and
grouped together, they form tissues.
The Structure of Cells
Cell membrane – the
tissue that surrounds and
protects the contents of the
cell and separates it from
the external environment
Cytoplasm – the material
within the cell membrane
that contains and suspends
the organelles
Nucleus – the control center of the cell and is involved in cell
division
Stem Cells
• unspecialized cells that are able to renew
themselves for long periods of time by cell
division
• in contrast, specialized cells (liver cells, muscle
cells, etc..) have a shorter life span
• May be transformed into a specialized cell (ex.
Pancreatic cell that is capable of producing
insulin)
Adult Stem Cells – undifferentiated, and can
potentially be transplanted from one person to
another (bone marrow transplant) but matching must
be very close to prevent rejection
Embryonic Stem Cells
• Undifferentiated cells, can grow rapidly and indefinitely in
a lab and could potentially provide a source for adult
muscle, liver, bone, or blood cells.
• More primitive than adult stem cells which means there
does not need to be a donor/recipient match – there is
little risk for rejection
• Come from cord blood found in the umbilical cord and
placenta of new born infants.
• Can be harvested at the time of birth without danger to
mother or child and kept frozen until needed for treatment
purposes.
• Can also be obtained from extra embryos produced by in
vitro fertilization with the informed consent of the donor
couple.
Genetics
The study of how genes are transferred from parents to
their children and the role of genes in health and disease
• Gene – fundamental physical and functional unit of
heredity. This is what determines whether you will
have blue eyes or brown, curly hair or strait
• Dominant gene – when inherited the offspring will
display that genetic condition or trait
• Recessive gene – if inherited from both parents,
offspring will have the condition or trait. Ex. Sickle cell
disease. If inherited from only one parent the child will
not display the condition or trait but will carry trait and
can still pass it to their offspring
Remember: inside each cell there are 23
chromosomes made up of DNA molecules that
contain the body’s genes.
When there is a genetic mutation there is a
change in the sequence of a DNA molecule. This
can sometimes be caused by exposure to radiation
or environmental pollution.
A genetic disorder, on the other hand, is a pathological
condition caused by an absent or defective gene. Some
examples of genetic disorders are:
• Cystic fibrosis
• Down syndrome
• Hemophilia
• Huntington’s disease
• Muscular dystrophy
• Phenylketonuria
• Tay-Sachs disease
Histology
• The study of tissues, which are composed
of groups of similar cells that join together to
perform specific functions, including:
– Stem Cells
– Epithelial Tissues
– Connective Tissues
– Muscle Tissue
Epithelial Tissues
form a protective covering for all the internal and
external surfaces of the body and also form glands
• Epithelium- specialized epithelial tissue that
forms the epidermis of the skin and the surface
layer of the mucous membranes.
Epi- means _____________________
• Endothelium – specialized epithelial tissue that
lines the blood and lymph vessels, body cavities,
glands and organs
Endo- means _____________________
Connective tissues
4 types that support and connect organs and other
body tissues
1. Dense connective tissue: form the joints and
framework of the body. Ex: bone and cartilage
2. Adipose tissue: provides protective padding,
insulation, and support. Also known as fat
3. Loose connective tissue: surrounds various
organs and supports both nerve cells and blood
vessels
4. Liquid connective tissue: transport nutrients and
waste products. Ex: blood and lymph
• Muscle tissue – contains cells with the special
ability to contract and relax
More to come in chapter 4!
• Nervous tissue – contains cells with the
specialized ability to react to stimuli and to
conduct electrical impulses
More to come in chapter 10!
Tissue Formation = -plasia
Incomplete Tissue Formation
Aplasia – the defective development, or the
congenital absence or an organ or a tissue
Hypoplasia – the incomplete development of an
organ or tissue usually due to a deficiency in the
number of cells
Example: Spina bifida
Spina bifida is a
congenital disorder
(birth defect) in which
the backbone and
spinal canal do not
close before birth.
Abnormal Tissue Formation
Anaplasia – the change in the structure of cells
and their orientation to each other
Dysplasia – abnormal development or growth of
cells, tissues, or organs
Hyperplasia – the enlargement of an organ or
tissue because of an increase in the number of
cells in the tissue
Hypertrophy - a general increase in the bulk of
a body part or organ that is due to an increase in
the size, but not the number of cells in the
tissue
Here’s another way to look at it….
Anaplastic alphabet – Letter structure is unrecognizable
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Dysplastic alphabet – abnormal development of letters but
you can still recognize them
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Hyperplastic alphabet – same letters just more of them
AABCDDEFGGHIJKLLLMNOPQRRSTUVWWXYYZZZZZ
Hypertrophic alphabet – same letters just larger letters
ABCDEFGHIJKLMNOPQRSTUV
WXYZ
Hyperplasia =
increase in the
number of cells
Hypertrophy =
increase in the size
of the cells
Glands
• Specialized cells that secrete material used
elsewhere in the body, including:
Exocrine Glands – secrete substances that lead to other
organs or outside the body. Ex. Sweat glands
Endocrine Glands – produce hormones that are secreted
directly into the bloodstream, do not have ducts. Ex.
Thyroid gland
More to come later…
Disease Transmission
A communicable disease is any condition that
can be spread from one person to another. There
are several ways this can happen….
Indirect contact transmission- you catch the
disease by coming into contact with a
contaminated surface
Bloodborne transmission
disease is spread through
contact with blood or
other body fluids that are
contaminated with blood.
Ex. HIV
Airborne transmission
occurs through contact
with contaminated
respiratory droplets
spread by a cough or
sneeze. Ex. TB, flu, cold
Food-borne and waterborne transmission - also
known as fecal-oral transmission, is caused by
eating or drinking contaminated food or water
that has not been properly treated to remove
contamination or kill pathogens that are present
Vector-borne transmission – disease spread by the
bite of a vector (insect or animal) that is capable of
spreading disease
Rabies
Lyme disease
Rocky Mountain
Spotted Fever
West Nile
Malaria
Outbreaks of Diseases
• Endemic – the ongoing presence of a disease
within a population, group, or area. Ex. The
common cold
• Epidemic – a sudden and widespread outbreak
of disease within a specific population group or
area. Ex. A sudden widespread outbreak of the
flu
• Pandemic –an outbreak of a disease occurring
over a large geographic area, possibly worldwide.
Ex. AIDS
Types of Diseases
• Functional disorder- produces symptoms for
which no physiological or anatomical cause
can be identified. Ex: panic attack
• Iatrogenic illness – an unfavorable response
due to prescribed medical treatment. Ex:
severe burns after radiation therapy
• Idiopathic disorder – an illness without a
known cause
Types of Diseases
• Infectious disease – an illness caused by a
living pathogenic organism such as bacteria or
viruses
• Nosocomial infection – a disease acquired in a
hospital or clinical setting. Ex: ventilator
acquired pneumonia, MRSA
• Organic disorder – produces symptoms
caused by a detectable physical change in the
body. Ex. The rash associated with chicken
pox is caused by a virus