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By Serge Kreutz (2010)
6 level of body organization
1 - chemical
2 - cellular
3 - tissue
4 - organ
5 - organ system
6 - organism
11 organ systems
01 - integumentary system (hair, skin, nails)
02 - skeletal system
03 - muscular system
04 - cardiovascular system
05 -
nervous system
07 -
reproductive system
08 -
endocrine system
09 -
respiratory system
10 -
urinary system
11 -
lymphatic and immune system
integument
- a natural covering, such as skin, hair, rind, or shell
Structural:
integumentary, skeletal, muscular
Distributive:
cardiovascular, lymphatic
Metabolic:
digestive, urinary, respiratory
Control:
nervous, endocrine
Procreative:
reproductive
Methods
of examination
palpation -
examination by feeling body surfaces by hand (of the examiner)
auscultation
- listening to body sounds (with a stethoscope)
percussion
- tapping on a body surface to listen to specific echoes
The six
most important life processes of the human body
1.
metabolism
2.
responsiveness (to internal, external environment)
3. movement
(of the body, organs, cells, or organelles)
4. growth
5.
differentiation (cells develop from unspecialized to specialized)
6.
reproduction (either of new tissue to replace old one, or the production of new
individuals)
homeostasis
- relative balance of the internal environment of the body (a dynamic
physiological constancy)
Body fluids
ICF =
intracellular fluid
ECF =
extracellular fluid (interstitial fluid)
ECF in
blood = blood plasma
ECF in
lymphatic vessels = lymph
ECF around
brain and spinal cord = cerebrospinal fluid
ECF in
joints = synovial fluid
ECF in the
eyes = aqueous humor and vitreous body
Interstitial
fluid surrounds all body cells and therefore is referred to as “internal
environment” of the body.
The nervous
system and the endocrine system control homeostasis, either in concert or
independently.
Glands
release hormones into the blood.
Three basic
components of a feedback system: receptor (receives nerve impulse or
chemical signal), control center (output as nerve impulse, hormone, or
other chemical signal), effector (produces a response; nearly every
organ or tissue in the body can behave as effector)
Negative
feedback cycle reverses original stimulus - returns the body to a previous
homeostatic condition, interrupts the effect of a stimulus; moves a bodily
function in the opposite direction as a change that has been detected by a
receptor
Positive
feedback cycle enhances original stimulus - moves a bodily function into the
same direction as a change that has been reported by a receptor; for example,
at the first signs of labor, more labor symptoms are effected
A positive
feedback loop has to be stopped by an outside event (e.g. baby born); while
negative feedback systems are constantly at work, positive feedback systems
play a role in extraordinary events.
Imbalances
A disorder
is a general lack of optimal function.
A disease
is a rather specific disorder.
A sign is
an indicator of a disorder or disease that can be observed by another person.
E.G., vital signs: blood pressure, body temperature
A symptom
is an indicator that is felt by the individual who is sick, such as nausea,
feeling weak, etc.
Anatomical
position - standing and facing the observer, palms of the hands facing observer
Prone
position - lying face down
Supine
position - lying face up
Regional
names: head, neck, trunk, upper limbs, lower limbs
Anatomical
descriptive adjectives for body parts:
Cephalic
(area, features, disorders) - related to the head
Cranial -
related to the scull
Facial -
related to the face
Frontal -
related to the forehead
Orbital -
related to the eye
Otic -
related to the ear
Nasal -
related to the nose
Buccal -
related to the cheeks
Oral -
related to the mouth
Mental -
related to the chin
Occipital -
related to the base of the skull (viewed from behind)
Thoracic -
related to the chest
Sternal -
related to the breastbone
Mammary -
related to the breasts
Acromial -
related to the shoulders
Scapular -
related to the shoulder blades
Vertebral -
related to the spinal column
Dorsal -
related to the back
Abdominal -
related to the abdomen
Umbilical -
related to the navel
Coxal -
related to the hips
Lumbar -
related to the lower back
Pelvic -
related to the pelvis
Inguinal -
related to the groins
Pubic -
related to the genital region
Sacral -
related to the area between the hips
Gluteal -
related to the buttocks
Axillary -
related to the armpits
Brachial -
related to the arms
Antecubital
- related to the front of the elbow (anterior part if viewed in the anatomical
position)
Olecranal -
related to the back of the elbow
Antebrachial
- related to the forearm
Carpal -
related to the wrists
Manual -
related to the hands
Digital (or
phalangeal) - related to the fingers
Palmar -
related to the palms of the hqands
Dorsum -
related to the back of the hands
Femoral -
related to the thighs (vorderer Oberschenkel)
Patellar -
related to the anterior knee
Popliteal -
related to the area behind the knee
Crural -
related to the lower leg
Sural -
related to the back of the lower leg (calves, Waden)
Pedal -
related to the feet
Tarsal -
related to the ankles of the feet
Digital (or
phalangeal) - related to the toes
Plantar -
related to the sole
Calcaneal -
related to the heels
Dorsum -
related to the top of the feet
superior
(cephalic, cranial) - towards the upper part
inferior
(caudal) - towards the lower part
anterior
(ventral) - towards the front
posterior
(dorsal) - towards the back
medial -
nearer to the midline
lateral -
further from the midline
intermediate
- between two structures
ipsilateral
- on the same side of the body
contralateral
- on the opposite side of the body
proximal -
nearer to the origin of a structure, especially a limb
distal -
further from the origin of a structure, especially a limb
superficial
- towards the surface of the body
deep -
further from the surface of the body
Planes
through the human body:
midsagittal
- dividing into left and right along the midline of the body
parasagittal
- dividing into left and right, but not along the midline of the body (rather
left or right of the midline)
transverse
- dividing into upper and lower
frontal -
dividing into front and back
oblique -
dividing by a slanting plane
Two body
cavities:
Dorsal
body cavity - the
cranial cavity and the vertebral (spinal) canal together form the dorsal
cavity; the meninges (three layers of protective tissue) line the dorsal body
cavity
Ventral
body cavity - the
superior, thoracic and the inferior, abdominopelvic cavity together form the
ventral body cavity; the diaphragm (a dome-shaped MUSCLE) separates the
thoracic and abdominopelvic cavities; all the organs of the ventral cavity
together are named “viscera”
Thoracic
body cavity (the
upper part of the ventral body cavity) - the space of the thoracic cavity that
is not occupied by the lungs is named the mediastinum; the mediastinum contains
the following organs: the heart (in the pericardial cavity), esophagus,
trachea, thymus, blood vessels, etc
Abdominopelvic
body cavity (the
lower part of the ventral body cavity) - divided into two parts (though no real
barrier separates the two portions), the abdominal cavity (with the stomach,
spleen, liver, gallbladder, small intestine, and most of the large intestine)
and the pelvic cavity (with then urinary bladder, parts of the large intestine,
and the internal organs of the reproductive system)
Thin,
double-layer, fluid-filled serous membranes compartmentalizes the thoracic and
abdominopelvic body cavities. Attention: the spaces between the layers are also
called cavities. For example, the pericardial cavity is the cavity BETWEEN the
parietal and visceral layers of the pericardium; it is not the space where the
heart as a whole is located.
The serous
membrane of the pleural cavities is the pleura; the parietal layer of the
pleura attaches to the wall of the thoracic body cavity, and the visceral layer
lines the lungs.
The serous
membrane of the heart is the pericardium; the parietal layer of the pericardium
attaches to the wall of the thoracic body cavity, and the visceral layer lines
the heart.
perineum -
region below the pelvic diaphragm
peritoneum
- a serous membrane
The serous
membrane of the abdominopelvic cavity is the peritoneum. With its parietal
layer, it covers the anterior and lateral abdominopelvic cavity, but in the
posterior abdominopelvic cavity, some organs lie between the parietal layer of
the peritoneum and the posterior wall of the abdominopelvic cavities. This is
the case for the kidneys, adrenal glands, duodenum of the small intestine,
ascending and descending colons of the large intestine, parts of the aorta and
vena cava. The other viscera of the abdominopelvic cavity are lined by the
visceral layer of the peritoneum, while the parietal layer of the peritoneum
attaches to the wall of the abdominapelvic cavity.
The region
is divided either into 9 or 4 parts
If divided
into 9 regions, this is done like this: vertical lines are imagined from the
midpoint of the clavicles (just medial to the nipples) through the abdomen.
These vertical lines result in a wider midsection and a left and a right
narrower section.
Horizontal
lines are imagined just below the rib cage (subcostal line) and just inferior
to the top of the hip bones (transtubercular line).
Parts above
the subcostal line, from left to right (when viewed by the observer):
Right
hypochondriac region, epigastric region, left hypochondriac region
Parts below
the subcostal line (above the transtubercular line), from left to right (when
viewed by the observer):
Right
lumbar region, umbilical region, left lumbar region
Parts below
the transtubercular line, from left to right (when viewed by the observer):
Right
inguinal (iliac) region, hypogastric (pubic) region, left inguinal (iliac)
region
Radiography
(x-ray) - (clear images of bones which appear in light color; poor images of
soft internal organs)
Magnetic
resonance imaging (MRI) - uses a high-energy magnetic field, shows fine detail
for soft tissues, but not for bones; can detect brain abnormalities and tumors,
as well as artery-clogging fatty plaques
Computed
tomography (CT) [formerly named computerized axial tomography, CAT] - a kind of
x-ray, taken from various angles
Sonography
(ultrasound) - safe, noninvasive; primarily used to show fetuses
Positron
emission tomography (PET) - injection of a substance that emits positively
charged particles (positrons); when they collide with negatively charged
particles, they produce gamma rays (similar to x-rays); a PET scan basically
shows where in the brain (or other body structure) a lot of activity is taking
place
4 types of
tissue:
1.
epithelial (from endoderm, mesoderm, ectoderm)
2.
connective (from mesoderm)
3. muscle
(from mesoderm)
4. nervous
(from ectoderm)
biopsy -
the removal of a sample of living tissue for microscopic examination (usually
for cancer)
Tight
junctions (common for the linings of internal organs through which materials
are channeled, e.g. stomach, intestine, urinary bladder; transmembrane proteins
knot cells to each other and avoid that substances enter intracellular space)
Adherens
junctions (the formation of adhesion belts between cells; plaques of proteins
underneath cell membranes that are “screwed” together by transmembrane
glycoproteins called cadherins; the primary function of adherens
junctions is providing physical strength, so that adjacent cells cannot be
separated)
Desmosomes
(desmosomes are similar to adherens junctions in both function and structure;
common for epidermis and cardiac muscle; however, they are more like spot
wielding between cells, not forming long adhesion belts)
Hemidesmosomes
(like desmosomes, but they are not found between equal cells; rather, they
anchor cells to a basement membrane)
Gap
junctions (these are junctions that provide tiny pipes, named connexons,
between the cytoplasm of adjacent cells through which ions and small molecules
can be exchanged between cells; the connexons are formed from the protein connexin)
Apical
surface of epithelial tissue faces the outer surface of the body, or lines a
body cavity or the lumen of organs or an internal duct that receives
secretions. The opposite surface is the basal surface.
Epithelial
tissue lacks blood supply but is enervated. Nutrients diffuse into epithelial
cells from connective tissue below the epithelial tissue.
Epithelial
tissue has a high rate of cell division. Damaged or old epithelial cells are
sloughed off.
Two kinds
of epithelial tissue:
1. Covering
(lining) epithelium
2.
Glandular epithelium (the secreting portion of glands)
Covering
epithelium can come as layers of single or multiple cells. Layers of single
cells are referred to as simple epithelium. Layers of multiple cells are called
stratified epithelium. There is also pseudostratified epithelium. It looks like
stratified because the nuclei are not at a uniform level, and not all cells
have apical surfaces.
Glands are
either single cells or groups of cells.
Glands are
either endocrine or exocrine, or both.
The
secretions of endocrine glands are hormones. Hormones enter the interstitial
fluid, and from there the blood. No ducts needed.
Goblet
cells are unicellular glands that secrete mucus directly onto the apical
surface of epithelium, not into ducts
Multicellular
exocrine glands secrete their products into ducts that empty through covering
epithelium either to the outside of the body, or into the lumen of a hallow
organ.
Products of
exocrine glands: mucus, sweat, oil, earwax, saliva, and digestive enzymes.
Multicellular
exocrine glands can either be tubular (tube-shaped) or acinar (berry-shaped).
Exocrine
glands can also be categorized as merocrine (released by exocytosis), apocrine
glands (part of the cell that holds the secretion divides from the rest of the
cell), or holocrine glands (secretory products accumulate in the cytosol and
the cell raptures to release the secretion; example sebaceous glands of the
skin).
Functions
of connective tissue: it binds together, supports, and strengthens other
tissue; it protects and insulates organs; it compartmentalizes body structures;
it stores energy (adipose tissue is a type of connective tissue); blood is also
a type of connective tissue; the immune response is also primarily a function
of connective tissue.
Connective
tissue consists of cells and matrix in between the cells. The matrix is usually
formed by the cells. Most connective tissues have rich blood supply and also
nerve supply. The matrix of connective tissues is different from place to
place, depending on the specific function of connective tissue.
Areolar
connective tissue lines joint cavities.
Immature
cells of connective tissue are named “-blasts” (fibroblasts for loose and dense
connective tissue, chondroblasts for cartilage, osteoblasts for bones).
Blast cells
can divide and they secrete the matrix. When the cells mature (then named
“-cytes”) they no longer easily divide and no longer secrete matrix, but have a
role in the maintenance of the matrix.
Some
connective tissue cells:
Fibroblasts
- among the most
common connective tissue cells; they secrete the fibers and ground substances
of the matrix
Macrophages
- they develop from
monocytes (a type of white blood cells); there are fixed macrophages and
wandering macrophages
Plasma
cells - they
develop from white blood cells called B lymphocytes and secrete antibodies;
they are found in many places of the body but are most common in connective
tissue (especially the GI and the respiratory tract)
Mast
cells - most common
near blood vessels; they produce histamine, which deletes blood vessels;
histamine plays an important role in inflammations
Adipocytes
- fat cells that
store triclycerides; common below the skin and around internal organs
White blood cells - not normally in connective
tissue, but neutrophils (infections) and eosinophils (parasites, allergies)
accumulate during problems
Matrix
consists of fluid, semifluid, gelatinous, or calcified ground substance, and
protein fibers
Ground
substance consists of water and an assortment of large molecules, many of which
are combinations of polysaccharides and proteins.
Polysaccharides
in matrix - glycosaminoglycans (GAGs)
Proteins in
matrix - proteoglycans
In
combinations, the proteogycans form the cores and the GAGs project like the
bristles of a brush; this shape assures that the matrix traps water and becomes
jellylike.
Hyaluronic
acid - a viscious, slippery substance that binds cells together, lubricates
joints, and helps maintain the shape of the eyeball; white blood cells, sperm
cells, and some bacteria produce the enzyme hyaluronidase, which dissolves
hyaluronic acid and makes it watery and less resitant
Fibronectins
- adhesion proteins that bind ground substance and collagen fibers
Three kinds
of fibers in connective tissue: collagen fibers, elastic fibers, reticular
fibers
Collagen fibers are made of the protein collagen,
which is the most abundant protein in the human body, accounting for some 25 %
of all proteins. Collagen fibers often lie in parallel bundles’ they provide
strength to the tissue.
Elastic
fibers form
networks; they are made from the protein elastin, which is surrounded by the
glycoprotein fibrillin. Elastic fibers can be stretched up to 150 % and will
return to their original form when the stretching subsides. Elastic fibers are
important in skin and in blood vessels.
Reticular
fibers are also
made of collagen, but they are not bundled but rather form networks of thin
fibers; reticular fibers are plentiful in the stroma (the supporting framework
of sift organs; they also are an essential feature of the basement membrane
Marfan
syndrome - an inherited disorder caused by a defective fibrillin gene
Main
classification:
Embryonic
and mature connective tissue
Embryonic
connective tissue is subdivided only into two subtypes: mesenchyme and mucous
connective tissue. All other connective tissue eventually arises from
mesenchyme. Mucous connective tissue is found mainly in the umbilical cord.
There are
six types of mature connective tissue:
1. loose
connective tissue (areolar, adipose, reticular)
2. dense
connective tissue (regular, irregular, elastic)
3.
cartilage (hyaline, fibro-, elastic)
4. bone
(details chapter 6)
5. blood
(details chapter 19)
6. lymph
(details chapter 22)
Areolar connective tissue - semifluid; under
the skin, around blood vessels, nerves, and internal organs
Adipose connective tissue - fat cells;
reduces heat loss, stores energy; under the skin, padding around joints and
behind the eyeball, yellow bone marrow; brown adipose tissue in newborns
generates heat (in mitochondria) to maintain body temperature
Reticular
connective tissue -
stroma (supporting framework) of liver, spleen, and lymph nodes; binds smooth
muscle cells; filters blood in spleen (for worn out cells) and lymph in lymph
nodes (for microbes)
Dense
connective tissue contains more fiber, but fewer cells than loose connective
tissue
Dense
regular connective
tissue - consists mainly of collagen fibers in bundles; forms ligaments,
tendons, and aponeuroses (sheetlike tendons between muscle and muscle or muscle
and bone)
Dense
irregular connective
tissue - also consists mainly of collagen fibers, but they are not arranged in
bundles as is dense regular connective tissue; found in areas in which the pull
is not primarily in a specific direction (as it is for tendons and ligaments);
forms fascia (tissue beneath skin and around muscles);
Elastic connective tissue - this connective
tissue allows the stretching of organs; it is found in the lungs and the walls
of elastic arteries;
Cartilage
is a dense network of collagen fibers in chondroitin sulfate which is stronger
than loose or dense connective tissue. Cartilage grows slowly, and tissue
repair is also slowly. This is the case because cartilage is avascular.
During
childhood and adolescence, cartilage grows interstitially; this means
that the chondrocytes divide and produce cartilage, expanding the cartilage
from within.
In appositional
growth, cartilage growth is effected by fibroblasts in the perichondrium
some of which differentiate into chondroblasts, then chondrocytes; they add
cartilage to the outer surface of the cartilage.
Hyaline cartilage - the most abundant
cartilage; bluish-white; fine collagen fibers and plenty of chondrocytes; forms
the skeleton of embryos and fetuses; in adults: ends of long bones, nose, parts
of larynx, trachea, bronchial tubes.
Fibrocartilage
- forms
intervertebral discs, menisci (cartilage of the knee pads); consists of
collagen bundles with chondrocytes
Elastic cartilage - the auricle (external
ear), Eustachian (auditory) tubes; consists of chondrocytes in networks of
elastic fibers
Bones are a
type of connective tissue that will be discussed in a separate file.
Epithelial
membranes are a combination of an epithelial layer and a connective tissue
layer.
Synovial
membranes (that line joints) consist of connective tissue only.
The skin is
a stratified squamous epithelial membrane which will be discussed in a separate
file.
Mucous
membranes line surfaces that open to the outside, such as the entire GI tract,
the respiratory and reproductive tracts, and much of the urinary tract.
Goblet
cells in the epithelial layer of mucous membranes secrete mucus which provides
a barrier against microbes, and smoothes the passage of food, lubricates, and
prevents the membrane from drying out. The epithelial layer of the GI mucous
membrane also secretes enzymes and allows the absorption of nutrients.
The
connective tissue layer of mucous membranes consists of areolar connective
tissue and is called lamina propria. The lamina propria binds the epithelial
layer of a mucous membrane to the underlying structure and delivers oxygen and
absorbs carbon dioxide (epithelial tissue is avascular… it does not have its
own blood supply; connective tissue has ample blood supply).
Serous
membranes line body cavities that do not open to the outside and cover internal
organs within the cavity. Serous membranes have two layers, the (outer)
parietal layer that lines the cavity, and the (inner) visceral layer that
covers the organ. Serous membranes consist of areolar connective tissue and
simple squamous epithelium (mesothelium), which secretes serous fluid. The
serous fluid lubricates and allows the organs to slide against each other or
along the internal cavities.
Pleura -
the serous membrane lining the thoracic cavity and covering the lungs
Pericardium
- the serous membrane of the heart
Peritoneum
- the serous membrane lining the abdominal cavity and and covering abdominal
organs
Synovial
membranes line the cavities of freely movable joints; they are composed of
areolar connective tissue with adipocytes and elastic fibers. Articular
synovial membranes secrete synovial fluid to nourish and lubricate the
cartilage of joints. Synovial membranes also line tendon sheaths in the hands
and feet.
Skeletal
muscle tissue consists of long cells called muscle fibers. Each has many nuclei
located at the periphery of the cell. Skeletal muscle is striated. The muscle
fibers in a single muscle lie parallel to each other.
Cardiac
muscle cells are also striated. They are branched and normally have only one
nucleus. Cardiac muscle cells are attached to each other end-to-end by
intercalated discs (traverse thickening of plasma membranes). The intercalated
discs connect the muscle cells both through desmosomes and gap junction. The
desmosomes provide strength, and the gap junctions allow the conduction of
muscle action potentials from cell to cell.
Smooth
muscle tissue is not striated, and there is only one nucleus per cell. Smooth
muscle tissue forms the walls of hallow internal organs such as blood vessels,
airways to the lungs, stomach, intestines, gallbladder, urinary bladder.
More on
muscle tissue in a separate file.
Nervous
tissue will be discussed in a separate file.
Stroma -
supporting connective tissue
Parenchyma
- cells of the functioning part of a tissue or organ
Epithelial
tissue has a continuous capacity for renewal. Epithelial stem cells reside in
protected areas of the skin and the GI tract.
Stem cells
in red bone marrow continually provide new red and white blood cells and
platelets. Bone also can replenish lost cells.
Muscle
tissue has a poor capability for renewal. There are a few muscle stem cells in
skeletal muscle, called satellite cells, but their rate of renewal is slow.
Heart muscle also has only a very limited capacity for renewal, though it lacks
satellite cells; stem cells for heart muscle are delivered by the blood from
red bone marrow. Smooth muscle also only has a limited capacity for renewal;
it’s not as good as the capacity of connective tissue, but better than that of
skeletal muscle tissue.
Nervous
tissue practically does not regenerate.
If
parenchymal cells achieve tissue repair, the repair site will be functional; if
the repair is handled by stroma, then connective tissue will grow instead of
whatever the original tissue was, and a scar will show. The process of scaring
= fibrosis.
Granulation
tissue - replaced tissue, including replaced blood vessels
Nutrition
important for wound healing, especially protein; vitamin C is also needed.
In the
young, tissue heals faster. In fetuses, surgery leaves no scars.
A negative
effect of glucose with aging: within and outside cells, glucose causes
irreversible links between protein, which then loose elasticity of aging
tissue. Loss of elasticity is also caused by an increase of collagen and the
affinity for calcium of elastin.
Autoimmune
diseases such as rheumatoid arthritis (attacks synovial membranes of joints)
are the most common tissue disorders.
Sjoegren’s
Syndrome - autoimmune disorder causing inflammation and destruction of exocrine
glands, especially lacrimal (tear) glands and salivary glands; can manifest
itself as pancreatitis, pleuritis, and migraine. Affects females nine times
more than males.
Systemic
lupus erythematosus - an autoimmune tissue disease; chronic connective tissue
inflammation most common in non-white women of childbearing age. Can be mild or
even fatal. Females nine times more often affected. Exact causes unknown, but
may be estrogen-triggered. No treatment. Often with a rush on the cheeks across
the nose (butterfly rush).
Atrophy - a
decrease in the size of cells, with a subsequent decrease in the size of a
tissue
Hypertrophy
- an increase in tissue size because cells grow in size without becoming more
numerous
Tissue
rejection - an immune response against foreign proteins
Tissue
transplantation - best if a body’s own tissue can be used
Xenotransplantations
- the use of tissue from other animals; porcine and bovine heart valves are
used
Characteristics of the living human organism
Control of homeostasis
Anatomical terminology
Cervical - related to the
neck
Trunk
Upper
limb
Lower
limb
Anatomical directional terms
Abdominopelvic regions
Medical imaging
Types of tissue and their origin
Cell junctions
Epithelial tissue
Covering (lining) epithelium
Glandular epithelium
Connective tissue
General features
Connective tissue cells
Connective tissue matrix
Ground substance
Fibers
Classification of connective tissue
Loose connective tissue
Dense connective tissue
Cartilage
Membranes
Epithelial membranes
Synovial membranes
Muscle tissue
Nervous tissue
Tissue repair
Aging and tissue
Disorders
Medical terminology
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Copyright Serge Kreutz