Chapter 6 Flashcards
Human Anatomy and Physiology
Anatomy: the study of body structures and
the relation of one part to another
Physiology: the study of how the body
works and how the various parts function
individually and in relation to each other
) the sagittal
plane divides the body into right and left halves
on its vertical axis. This plane passes through
the sagittal suture of the cranium; any plane
parallel to it is called a sagittal plane. Frontal
planes are drawn perpendicular to the sagittal
lines and divide the body into anterior (front)
and posterior (rear) sections.
To aid in understanding the location of
anatomical structures, a standard body position
called the anatomical position is used as the
point of reference. This anatomical position is
assumed when the body stands erect with the
arms hanging at the sides and the palms of the
hands turned forward (Fig. 6-2).
Anterior or Ventral: Toward the front, or
along the belly side of the body
Posterior or Dorsal: Toward the back, or
along the vertebral side of the body
Medial: Near or toward the mid-sagittal
plane of the body
Lateral: Away from the mid-sagittal plane
of the body
Internal: Inside
External: Outside
Proximal: Nearest to the point of origin or
towards the trunk
Distal: Away from the point of origin or
away from the trunk
Superior: Toward the top of the body or
above
Caudal: Toward the lower end of the body
Inferior: Toward the bottom of the body or
below
Supine: Lying position of the body, face up
Prone: Lying position of the body, face
down
Lateral recumbent: Lying position of the
body, on either side
Peripheral: The outward part or surface of a
structure
In man, some of the characteristic
functions necessary for survival include
digestion, metabolism, and homeostasis.
Digestion involves the physical and chemical
breakdown of food into its simplest forms.
Metabolism is the process of absorption,
storage, and use of these foods for body
growth, maintenance, and repair. Homeostasis
is the body’s self-regulated control of its
internal environment. It allows the organism to
maintain a state of constancy or equilibrium, in
spite of vast changes in the external
environment.
The human body is broken down into
various levels of organization, the chemical,
organelle, cellular, tissue, organ, organ
system, and the organism levels.
System level: Systems are the most
complex of the organizational units of the
body. The system level of organization
involves varying numbers of kinds of organs
arranged so that, together, they can perform
complex functions for the body. There are 11
major systems that make up the human body:
integumentary, skeletal, muscular, nervous,
endocrine, circulatory, lymphatic,
respiratory, digestive, urinary, and
reproductive.
The nucleus is a small, dense, usually
spherical body that controls the chemical
reactions occurring in the cell. The substance
contained in the nucleus is called
nucleoplasm. The nucleus is also important in
the cell’s reproduction, due to the storage of
genetic information. Every human cell contains
46 chromosomes, and each chromosome has
thousands of genes that determine the cell’s
function.
Cells are composed largely of a gel-like
substance, called cytoplasm, upon which
depend all the vital functions of nutrition,
secretion, growth, circulation, reproduction,
excitability, and movement. The cytoplasm is a
gelatinous substance surrounding the nucleus
and is contained by the plasma membrane. The
cytoplasm is made of various organelles and
molecules suspended in a watery fluid called
cytosol, or intracellular fluid (Fig. 6-3).
The simplest living organism consists of a
single cell. The amoeba is a unicellular
animal. The single cell of a one-celled organism
must be able to carry on all processes necessary
for life. This cell is called a simple or
undifferentiated cell, one that has not
acquired distinguishing characteristics.
Tissues are groups of specialized cells
similar in structure and function. They are
classified into four main groups: epithelial,
connective, muscular, and nervous.
Muscular tissue provides for all body
movement. Contracting muscles cause body
parts to move. The three types of muscle tissue
are skeletal, smooth, and cardiac.
Adipose tissue is “fatty tissue.” The adipose
cell at first appears star-shaped.
Areolar tissue consists of a meshwork of
thin fibers that interlace in all directions, giving
the tissue both elasticity and tensile strength.
Skeletal (voluntary) muscle fiber is striated,
or striped, and is under the control of the
individual’s will
This type of tissue, known as “bone tissue”
is dense fibrous connective tissue that forms
tendons, ligaments, cartilage, and bones.
Nerve tissue is the most complex tissue in
the body. It is the substance of the brain, spinal
cord, and nerves. Nerve tissue requires more
oxygen and nutrients than any other body
tissue. The basic cell of the nerve tissue is the
neuron
The skin, or integument, consists of two
layers, the epidermis and the dermis, and
supporting structures and appendages
The appendages of the skin are the nails,
hairs, sebaceous glands, sweat glands, and
ceruminous glands.
SMOOTH MUSCLES.—Smooth involuntary
muscles are found in the dermis. They are
responsible for controlling the skin surface
area. When dilated, these muscles allow for
maximum skin surface exposure to aid heat
loss. When constricted, the skin surface
exposure is decreased, thus impeding heat
radiation. Repeated muscle contractions
(shivering) are also a rapid means of
generating body heat.
Osteology is the study of the structure of
bone. Bone is made up of inorganic mineral
salts (calcium and phosphorus being the most
prevalent) and an organic substance called
ossein. Inorganic mineral salts give bone its
strength and hardness.
There are two types of
marrow, yellow and red. Yellow marrow is
ordinary bone marrow in which fat cells
predominate. It is found in the medullary
canals and cancellous tissue of long bones. Red
marrow is one of the manufacturing centers of
red blood cells and is found in the articular
ends of long bones and in cancellous tissue.
The skull consist of 28 bones
The appendicular skeleton consists of the
bones of the upper and lower extremities.
Innominate. The innominate bone,
commonly known as the hip, is a large,
irregularly shaped bone composed of three
parts: the ilium, ischium, and pubis (Fig. 6-21).
In children these three parts are separate
bones, but in adults they are firmly united to
form a cuplike structure, called the
acetabulum, into which the head of the femur
fits.
The ilium forms the outer prominence of
the hip bone (the crest of the ilium, referred to
as the iliac crest, provides an anatomical
landmark above the ilium); the ischium forms
the hard lower part; and the pubis forms the
front part of the pelvis.
Symphysi Pubis. The area where the two
pubic bones meet is called the symphysis pubis
and is often used in anatomical measurements.
The largest foramen, or opening, is located in
the hip bone, between the ischium and the
pubis, and is called the obturator foramen
Joint movements are generally divided into
four types: gliding, angular, rotation, and
circumduction
