Transcript SPHS 170 Introduction Definitions ANATOMY- Greek: to cut up the structure. PHYSIOLOGY- Greek: physis= nature, logis= logic.

SPHS 170
Introduction
Definitions
ANATOMY- Greek: to cut up the structure.
PHYSIOLOGY- Greek: physis= nature,
logis= logic. A branch of biology that
deal with the processes and activities of
living beings and relates form to
function.
Anatomical Nomenclature
Between the time of Vesalius and the end of the
nineteenth century, anatomical names
proliferated so that approximately 5,000
structures had 50,000 names.
In 1895 an international meeting was held in
Basel, Switzerland for the purpose of
adopting a universal anatomical nomenclature.
It was known as the BNA
Basel Nomina Anatomica
Follows these principles:
1. All terms are in Latin but, countries can
translate for teaching purposes.
2. Each structure has one term.
3. Terms should be descriptive.
Anatomical Position and Planes
1. The anatomical position
The anatomical position is used for direction and
orientation. The basic position is upright with the
palms forward and the thumbs extended
peripherally.
2. Planes
a. Sagittal - any vertical plane.
b. Frontal or coronal - section dividing front and
back.
c. Transverse or Horizontal - a section alon
any horizontal plane.
Directions and Positions
a. Ventral - away from the backbone-toward the
front of the body.
b. Dorsal - toward the backbone or away from the
front of the body.
c. Anterior - toward the front, away from the back.
d. Posterior - toward the back, away from the front.
e. Medial - toward the axis or midline.
f. Lateral - away from the axis or midline.
g. Proximal - toward the body or toward the root.
h. Distal - away from the body.
Directions and Positions
i. Cranial or rostral - toward the head.
j. Caudal - toward the tail.
k. External - toward the outer surface.
l. Internal - toward the inner surface.
m.Superficial - toward the surface.
n. Superior- upper, distinct from
superficial.
o. Inferior lower as distinct from deep.
ELEMENTARY TISSUES
(PLATE 511)
There are five basic tissue types:
epithelial
connective
muscular
nervous
vascular
Tissue Derivation
At the stage when the embryo is a blastoderm, some
of the cells become detached and migrate into the
cavity of the vesicle.
The inner layer is known as the endoderm (gr ento,
inside + derma, skin).
The outer layer is the ectoderm.
Tissue Derivation
Cells then fill the space between the endo and
ectodermal layers.
The embryo has become trilaminar and the
intermediate layer is the mesoderm.
These three layers are known as the germ
layers of the embryo
1. EPITHELIAL TISSUE TYPES
Epithelial cells are characteristically
arranged in mosaics, forming sheets of
tissue that cover the surfaces of the body,
line tubes, or passages leading to the
interior of the body and almost without
exception line the cavities of the body.
There are three types of epithelium.
Epithelium Proper
Forms the epidermis (outer layer of the skin) and
the internal membranes which are continuous
with the skin (mucous membranes lining the
digestive, respiratory, urinary, and generative
tracts.)
The shape of the cells is varied. OVERHEAD
Endothelial tissue
is confined almost exclusively to the inner lining of
the blood and lymph vessels, and unlike internal
epithelial tissue has no continuity with the
epidermis.
Endothelial tissue is composed of extremely flat,
single layers of cells which creates a very
smooth surface.It creates the lining of the
blood vessels.
Mesothelial tissue
a specialized form of epithelial tissue, which
lines:
the primary body cavities;
the two pleural cavities,
the peritoneal cavity,
and the pericardial cavity.
2. CONNECTIVE TISSUE
Connective tissue has relatively few cells and a
proportionately large amount of intercellular
substance. These noncelluar components are
called matrix.
Connective tissue is classified on the basis of
the characteristics of the nonliving
intercellular substances which compose the
matrix and not on the living cell
characteristics.
A. Loose Connective Tissue
binds parts together but allows plenty of movement
1. Areolar tissue - a very loose tissue in which the
cells lie in an irregular network of fibers.
Commonly found just beneath the skin forming
the bed for the skin and mucous membrane.
2. Adipose tissue - very similar to areolar but
with many fat cells.
B. Dense Connective Tissue
characterized by an abundance of of closely
packed fibers.
Collagenous fibers predominate in many dense
connective tissues. > gelatin.
Other dense connective tissues are characterized
by the predominance of Elastic fibers.
DCF are classified on the basis of intercellular
substances. White and unyielding or yellow and
elastic.
Tendons
Tendons are tough nonelastic cords composed
of closely packed parallel fibers.
Tendons attach muscles to bone, cartilage or
sometimes to one another.
White, flattened, tendonous coverings of
muscles are called aponeuroses. (PLATE 61)
Ligaments
Ligaments are also characterized by closely
packed parallel fibers.
HOWEVER, they have many elastic fibers.
They join bone to bone, cartilage to bone and
cartilage to cartilage.
Fascia
Fascia is characterized by irregularly arranged
fibers.
Commonly associated with muscles are are
responsible for the arrangement of muscles into
functional mechanical mediators of movement.
Subcutaneous fascia (tela subcutanea) is found
over the entire body just under the skin.
Keeps us from falling apart
Reticular Tissue
Reticular tissue is a very delicate matrix of cells
which have processes extending in all directions
to join neighboring cells.
It is a primitive tissue that often provides
supporting framework for essential organs like
the liver.
SKELETAL SYSTEM: Cartilege
Cartilage - is composed of cells, ground
substance and intercellular spaces.
Chondroblasts - the cells of cartilage
Lacunae - irregularly shaped spaces in the ground
substance in which chondroblasts are found.
In early stage of development, cartilage forms the
entire skeleton. Cartilage is capable of growth.
Growth is via proliferation of chrondroblasts.
Skeletal Sysytem: Cartilege
All cartilage is covered by a though fibrous
covering called the perichondrium. Union
between muscles and tendons is made
possible by the perichondrium.
There are three cartilage sub-types classified by
the nature and relative concentrations of
fibrous substances:
Hyaline Cartilage
Hyaline Cartilage. Appears bluish-white, &
transparent when fresh.
It covers the articular surfaces of the joints and
forms the framework for the lower respiratory
tract.
Hyaline Cartilage has no blood supply. With age
it becomes yellow and brittle and may ossify.
Elastic Cartilage
Elastic Cartilage Appears somewhat yellow
and opaque because of the many elastic
fibers in its matrix.
It is flexible, almost rubbery. Found in the
external ear, external auditory meatus,
epiglottis and some bits in the larynx.
Calcification of this type of cartilage rarely
occurs.
Fibrocartilage
Fibrocartilage. Characterized by a dense
network of collagenous fibers and
cartilage cells. Forms the intervertebral
discs of the vertebral column.
Skeletal System: Bone
Bone (osteum) is the other specialized dense
connective tissue.
It is characterized by a rigid matrix (intercelluar
substance).
Bone is composed of osteoblasts and
osteocytes, collagenous fibers and ground
substance.
Rigidity of bone is due to the large amounts of
inorganic salts that are deposited in its matrix.
Skeletal System: Bone
The salts make up about two-thirds of the
weight of the bone. Salts are composed of:
85% calcium phosphate
10% calcium carbonate
calcium flouride
magnesium floride
Skeletal System: Bone
Bone withstands compression as well as concrete
and is very tensile.
There are 206 bones in the adult human skeleton.
The skeleton is divided into the axial and
appendicular skeletons.
Skeletal System: Bone
Periosteum covers all bone marrow except at the
articular surfaces.
Periosteum performs two functions:
a. provides attachment for muscle tendons.
B. contains osteoblasts which assist in the
initial formation of new bone and later in
life generate new bone for repair
Two types of bone can be identified
a. compact bone forms the hard outer covering
b. spongy bone forms the inner core
Skeletal Terms
Elevations
condyle
crest
head
process
spine
tuberosity
Depressions
fissure
foramen
fossa
fovea
groove
meatus
neck
sinus
sulcus
Classifications of Joints
Three major categories:
1. Synarthrodial-the bones are in almost direct
contact and joined together by thin connective
tissue so as to prevent movement (cranium).
2. Amphiarthrodial-cartilaginous, yielding (two types)
a.synchondros is rather rigid joint that ossifies with
age, such as the skull at birth.
B.symphysis edges of bone are connected by
fibrocartilage, articular facets are covered by
hyaline cartilage with fibrocartilage between.
Ex. vertebra, two pubic bones
Classifications of Joints
Diarthrodial joints (movable)-bones are joined by a
band of fibrous tissue called the articular
capsule, within which is the joint capsule.
A small amount of fluid is produced within the
cavity to lubricate the joint.
There are six types of diarthrodial joints and the
are classified on the basis of their movements
3. MUSCLE TISSUE
There are 329 muscles in the body all but 2 are
paired; diaphragm, procerus.
Muscle accounts for about 40% of total body weight.
It is composed of 2 proteins; myosin and actin.
Muscles usually have two attachments:
Origin refers to the attachment that is fixed or less engaged
in movement.
Insertion is associated with the structure being acted upon in extremities the more distal attachment
Muscle Tissue: Three Types
A. Striated muscle is also known as skeletal
muscle. It consists of long fibers crossed at
regular intervals by transverse bands.
B. Smooth muscle is more primitive than striated.
Innervated by the autonomic nervous system,
thus independent of direct voluntary control.
Found in blood vessels, digestive system,
bronchial tubes.
C. Myocardium is found only in the heart and
properties of both smooth and striated muscle
4. NERVE TISSUE
Nerve tissue is composed of extremely long,
irritable cells that are able to modify their
biochemical composition.
The basic parts of a nerve are
1. Cell body
2. Dendrites-these processes carry information to the cell
body from other cells. Dendrites tend to be short with
multiple branches
3. Axons-conduct information away from the cell body to
other cells. Axons range in length from much less than a
millimeter to a meter
5. Nerve Tissue
Nerves are bundles of nerve cells, their axons and
dendritess.
Sensory nerves are almost exclusively afferent conduct toward from the cell body.
Motor nerves are almost exclusively efferentconduct information away from the cell body.
Mixed nerves have afferent and efferent
components.
The Synapse
Neural synapses permit information to travel in
just one direction.
Neural tissue is capable of manufacturing the
chemical agents (neurotransmitters)that
inhibit or facilitate neural transmission.
There are about 50 neurotransmitters
The Synapse
The initial neural impulse is an electrochemical wave that is
propagated much like a trail of burning gunpowder.
(overhead)
Note the discontinuity in the trail between the neurons. This
represents the synaptic cleft between the two neurons.
As the impulse reaches it’s termination, the small mound at
the end (terminal bouton) releases another bolus of
neurotransmitter which causes a change in the chemical
composition of the nearby neural ending.
However, the neural ending are never in direct contact with
one another.
Motor Unit
The motor unit is a functional unit for producing
movement.
It consists of a nerve cell and all the muscle fibers
innervated by that nerve cell.
Some muscles have a high innervation ratio-there
are many muscle fibers innervated by a few
nerves. These muscles produce crude, large
movements.
Muscles with a low innervation ratio, a few muscle
fibers have lots of neural innervation. These
muscles are capable of small refined rapid
movements.
5. Vascular Tissue
Comprises @ 10% of total body weight.
Blood is composed of corpuscles and platelets in
plasma.
Erythrocytes have no nuclei and so are not true
cells. Nuclei are present early in development
and then disappear.
Lymph is the nutrient plasma of the tissues and
the cells in lymph are called lymphocytes.