General Medical
General Medical
 The body has 4 basic parts
 Cells
 Tissues
 Organs
 Organ systems
 Cells and tissue form the basic substance of the human
body
 Organs and their systems derive structure from their
cells and tissue makeup
Cells
 Smallest living functional unit in the body
 Cells are the “concrete” that make up the “building
blocks” of tissue
 4 activities characterize all cells
 Produce energy
 Reproduce
 Interact with their environment
 Regulate themselves internally
Cells
 Cells divide through 2 processes
 Mitosis
 Cytokinesis
 Approximately 1% of body cells die each day
 Cell death is call apoptosis
 Cells continually reproduce in order to keep the body
alive
Tissue
 Body has 4 types of tissue
 Nerve


Transmits messages in the form of electrical impulses
Brain, spinal cord, nerve fibers
 Muscle
 Movement
 Epithelial
 Protection, absorption, secretion
 Skin, salivary glands
 Connective
 Fat tissue, connective tissue proper, bone and cartilage, blood
Cardiovascular System
 Heart, blood vessels, blood
 Purpose is to carry lifesustaining nutrients to all
parts of the body
 Arteries

Large blood vessels that
carry blood from the heart
 Veins
 Blood vessels that bring
blood from the capillaries
back to the heart
 Capillaries
 Smallest of blood vessels,
connect arterioles to
venules
http://en.wikipedia.org/wiki/Venule
Heart
 The heart has 4 chambers
 2 upper chambers= right
and left atria
 2 lower chambers= right
and left ventricles
 Blood coming into the
heart is received by the
atria, pumped to the
ventricles, which pump it
out again to the lungs and
the rest of the body
http://www.southdartmoor.devon.sch.uk/pe/300pxDiagram_of_the_human_heart_cropped.svg.png
Circulation
 Arteries carry blood away
from the heart
 Aorta carries blood from the
left ventricle to all parts of
the body
 Pulmonary artery carries
blood from the right
ventricle to the lungs
 Veins carry blood back to the
heart
 Pulmonary veins bring blood
to the left atrium
 Superior/inferior vena cava
bring blood to the right
atrium
Circulation
 Blood circulates through the
heart in a very organized way
 Blood from all parts of the body
comes into the right atrium
from the superior and inferior
vena cava
 Blood is then pumped into right
ventricle, then through
pulmonary arteries, where it
enters the lungs to receive
oxygen
 Blood then returns to left atrium
via the pulmonary veins
 Blood is then pumped to the left
ventricle, which contracts to
pump blood through the aorta
to all parts of the body
Circulation
http://www.iradonline.org/images/aorta.gif
 The coronary arteries
supply blood to the heart
muscle itself
 Blockage of these arteries
result in a heart attack
 The superior aspect of the
aorta separates into
branches, including the
right and left carotid
arteries
 Right carotid supplies
blood to brain, right eye
 Left carotid supplies blood
to brain, left eye
http://www.iradonline.org/images/aorta.gif
Blood
 Blood is composed of plasma and cells
 Plasma is mostly water and contributes to the liquidity
of blood

Plasma also contains electrolytes, glucose, fats, and proteins
 Cells are the solid component of blood

Cells include white blood cells (leukocytes) red blood cells
(erythrocytes) and platelets
Blood
 Leukocytes form a major part of the body’s defense
against disease
 Erythrocytes are the reason for blood’s red color
 Erythrocytes have hemoglobin, which transport oxygen
from the lungs
 Carbon dioxide produced by tissues is carried by
erythrocytes to lungs, where it is exhaled
 Platelets help stop bleeding
Cardiovascular Diseases
 Atherosclerosis
 Build up of fat in the arteries
 Can block vessels and weaken the vessel wall
 Can form clots (emboli) that can migrate to other parts
of the body and cause damage (strokes, heart attacks,
retinal artery occlusions)
 High cholesterol, smoking, high blood pressure are
major causes of atherosclerosis
Cardiovascular Disease
 Hypertension (High Blood Pressure)
 Considered high when greater than 140/90


Top number is systolic reading (maximum pressure in
arteries)
Bottom number is diastolic reading (minimum pressure in
arteries)
 Blood pressure that remains chronically high can
damage organs, especially heart, brain, kidneys
 Symptoms of high blood pressure may include
headaches, dizziness, nose bleeds
Cardiovascular Disease
 Retinal blood vessels can be damaged by hypertension
 Vessels narrow and may become twisted (tortuous)
 Vessel walls develop fibrous tissue, which gives a copper
or silver wire appearance
 Retinal veins may be compressed by the arteries crossing
over them, causing them to appear squeezed or cut (AV
nicking)
 Retinal hemorrhages may occur
 Areas of the retina may have blood supply cut off,
resulting in cotton wool spots
Cardiovascular Disease
 Carotid artery disease
 Carotid arteries are the main source of blood to the
brain
 They also provide primary blood supply to the eyes
 When carotids are blocked, the blood supply and the
oxygen to the brain is reduced

Can result in stroke
 Plaque from the arteries may break off, resulting in
blockage to the vessels in the retina


Retinal artery occlusions cause a sudden, painless loss of VA
Temporary retinal artery blockage causes a few minutes of VA
loss (amaurosis fugax)
Cardiovascular Disease
 Mitral Valve Prolapse
 When left ventricle contracts, the mitral valve normally
closes, preventing blood from returning to atrium
 With MVP, part of the valve prolapses back into the atrium,
allowing some blood to return to atrium

This produces a heart murmur
 Patients with MVP are more prone to endocarditis (infection
of the heart lining, valves)

This is why MVP patients undergoing surgical procedures may need
to be placed on preop antibiotics
 MVP patients can have abnormal platelets
 Platelets may clump together, causing blockage to blood vessels
 MVP patients can have abnormal heart rhythms
(arrhythmias)
Respiratory System
 Responsible for providing oxygen to cells and expelling
carbon dioxide from the body
 Oxygen is taken in to the body, transferred to the
blood, which then transfers it to tissues
 Normal adult respirations are 12 breaths per minute
Respiratory System
 Upper respiratory tract
 Nasal cavity, sinuses, pharynx
 Sinuses




Maxillary = below eyes
Frontal= above eyes
Ethmoid= behind frontal sinuses
Sphenoid= behind nose, just below pituitary gland
 Lower respiratory tract


Trachea
Bronchi, bronchioles
Respiratory System, Sinuses
http://www.umm.edu/respiratory/images/respiratory_anatomy.jpg
http://4.bp.blogspot.com/_zjxkKle7aHw/SUppJTxCHgI/AAAAAAAABtE/eHdRWr4H-s/s400/sinus_s.%2520paranasales(1).jpg
Respiratory Disease
 Chronic Obstructive Pulmonary Disease (COPD)
 Narrowed breathing passages reduce ability to move air in
and out of the lungs
 2 disease processes in COPD are chronic bronchitis and
emphysema
 Chronic bronchitis
 Excessive airway mucous production, chronic cough, wheezing,
shortness of breath
 Emphysema
 Results from distention of alveoli and surrounding airways
 Compromises the lung’s ability to absorb oxygen, causes shortness of
breath, wheezing, and cough with little mucous production
Respiratory Disease
 Asthma
 Airways become inflamed and swollen, breathing
becomes difficult
 Predisposes to chronic inflammation of the lungs
 Unlike other forms of COPD, the airway obstruction
caused by an asthma attack is reversible

Symptoms of asthma attacks include shortness of breath,
wheezing, tightness in chest, increased respiratory rate
Endocrine system
 The body has 2 types of glands
 Exocrine


Secrete products through tube-shaped ducts
Salivary, sweat glands are exocrine
 Endocrine
 Secrete products directly into the blood
 Each endocrine gland secretes unique hormones
 Hormones produce powerful effects in the body and their
regulation is controlled by negative feedback
 5 glands make up the endocrine system
 Pituitary, thyroid, parathyroid, pancreas, adrenal glands
Endocrine System
 Pituitary gland
 Master gland
 Directs the action of
many other glands in
the body
 Located close to the
optic chiasm
 Enlargement of the
pituitary gland will
compress the optic
chiasm, resulting in VF
loss
http://www.mayoclinic.com/images/image_popup/r7_pituitary_optic.jpg
Endocrine System
 Thyroid controls body’s
metabolism
 Helps regulate body
temperature, oxygen
use, heart rate
 Hypothyroid= low
thyroid hormone level
 Hyperthyroid=high
thyroid hormone level
 Graves’ disease
 Exophthalmos, DES
http://www.ght.org.uk/userfiles/image/webgeneral/Thyroid.jpg
Endocrine System
 Pancreas
 Both exocrine (secretes
digestive enzymes) and
endocrine (secretes
insulin and glucagon)
 Insulin causes cells to
draw glucose out of the
blood, reducing blood
sugar
 Glucagon stimulates cells
to release glucose, causing
blood sugar to increase
http://www.cancerinformation1.com/images/pancreas-2.jpg
Endocrine Disease
 Pituitary Adenoma
 Most common pituitary
gland disorder


Can cause damage to
surrounding structures as
they enlarge
Can cause problems from
changes in normal hormone
secretion from the pituitary
 When the adenoma
enlarges it can compress
the optic chiasm

Results in bitemporal VF
defect or junctional
scotoma
http://www.med.yale.edu/caim/cnerves/cn2/cn2_graphics/cn2_9a.gif
Endocrine Disease
 Hyperthyroidism
 Overactive thyroid gland, secretes high levels of thyroid
hormone
 Causes anxiety, heat intolerance, increased heart rate
and may cause arrhythmias
 Can cause inflammation of the extraocular muscles,
resulting in exopthlamos
 Lid retraction from exophthalmos can lead to corneal
dryness, irritation, hyperemia
 Eye muscle inflammation can compress optic nerve,
resulting in VA loss
Endocrine Disease
 Diabetes
 Pancreas does not secrete sufficient insulin, resulting in elevated
blood glucose levels
 Diabetes severely affects multiple organ systems

Can lead to kidney and blood vessel damage, neuropathy, retinopathy;
predisposes to high blood pressure, high cholesterol, and atherosclerosis
 Type 1 diabetes



10% of diabetes cases
Typically young people
Requires insulin
 Type 2 diabetes



90% of diabetes cases
Occurs later in life
Sometimes requires insulin
Endocrine Disease
 Diabetic retinopathy
 Result of microvascular retinal changes
 Small blood vessels (such as those in the eye) are
particularly susceptible to poor blood sugar control
 Nonproliferative diabetic retinopathy

Retinal blood vessel damage leads to microaneurysms,
dot/blot hemorrhages, exudates
 Proliferative diabetic retinopathy
 The hypoxic retina grows new, abnormal blood vessels
(neovascularization)
 These vessels are weak and can easily break, resulting in
vitreous and retinal hemorrhages, fibrovascular proliferation
Nervous System
 Nervous system
 Central nervous system

Brain and spinal cord
 Peripheral nervous system

Nerves that travel to and from brain (cranial nerves) and
spinal cord (spinal nerves)
Nervous System
 Brain
 Largest and most
complex part of the
nervous system
 3 layers of tissue cover
the brain



Dura matter (outermost
lining, adheres to inner
skull)
Arachnoid (middle layer,
below dura)
Pia (innermost layer,
adheres directly to brain)
http://www.thewellingtonneurosurgeryunit.com/images/coverings2_.jpg
Nervous System
 Between the arachnoid and the pia is a water-like
substance called the cerebral spinal fluid (CSF)
 CSF surrounds the entire brain and spinal cord
 CSF is replaced 3-4 times in a 24 hour period
 After circulating, the CSF is absorbed by the blood
stream
 CSF produces intracranial pressure (ICP)
 Blockage to the normal circulation of CSF results in
increased intracranial pressure

Leads to papilledema
Nervous System
 Brain has 3 major divisions
 Cerebrum, Cerebellum,
Brainstem
 Cerebral cortex



Controls speech, critical
thinking, personality
Cerebrum is divided into
right and left hemispheres
Each hemisphere is further
divided into 4 lobes

Frontal, parietal, occipital,
temporal
http://quantumlearningblog.files.wordpress.com/2009/02/brain1.jpg
Nervous System
 Cerebellum
 Coordinates muscle
groups
 Responsible for smooth
motion, balance
 Coordinates larger
muscles and small
muscles for fine
movements of arms,
legs, hands
http://www.neuroskills.com/images/cerebellum.jpg
Nervous System
 Brainstem
 Includes medulla oblongata,
pons, midbrain, diencephlon
 Regulates the central nervous
system
 Connects to spinal cord
 Controls many involuntary
actions, including respiratory
and cardiac functions
 All cranial nerves except for
CN I and CN II originate
from the brainstem
http://www.pattymemorial.org/fromJaredPattyhome/Autism/Brainstem.jpg
Nervous System
 Spinal cord
 Begins at medulla
 Extends 16-17” down the
back
 Protected by vertebrae
 Signals travelling to and
from the brain go
through the spinal cord
 Peripheral nerves
connect to spinal cord
through 31 pairs of
spinal nerves
http://training.seer.cancer.gov/images/brain/spinal_cord.jpg
Nervous System
 2 types of peripheral nerves
 Motor nerves


End in muscle
Produce motion or other types of action
 Sensory nerves

Enable us to feel pain, touch, temperature, pressure
Nervous System
 There are 12 cranial nerves, which have both motor
and sensory functions
 CN II through CN VII are connected with normal eye






function
CN II optic nerve
CN III oculomotor nerve
CN IV trochlear nerve
CN V trigeminal nerve
CN VI abducens nerve
CN VII facial nerve
Terminology
 Aneurysm= A balloon-like bulge in an artery wall





caused by weakening of the artery
Microaneurysm= An enlargement of the venous end of
a retinal capillary
Hypoxia= Condition in which the body as a whole or a
region of the body is deprived of oxygen
Ischemia= Restriction of blood flow
-itis = Suffix used to indicate inflammation (arthritis,
vitritis, etc)
Atrophy= Withering of an organ or tissues
Terminology
 Cyanosis= Bluish discoloration of skin, mucous





membranes due to lack of oxygen
Edema= Excessive accumulation of fluid in body
tissues causing swelling
Embolus= Free moving blood clot
Fibrosis= Thickening or scarring of connective tissue
Idiopathic= Of unknown cause
Neuralgia= Pain along the route of a nerve
http://www.medicalproductsonline.org/glofcomete.html
 The retinal blood vessels of diabetics sometimes
develop bulges known as:
 Emboli
 Microaneurysm
 Atheromas
 Exudates
Ledford, Daniels & Campbell, 2000
 The difference between background and proliferative
diabetic retinopathy is that PDR exhibits
 No appreciable worsening
 Only cotton wool spots
 Only soft exudates
 Neovascularization and venous bleeding
Ledford, Daniels & Campbell, 2000
 The most common effect of atherosclerosis on the eye
is
 Artery obstruction
 Hemorrhage
 Tractional retinal detachment
 Formation of microaneurysms
Ledford, Daniels & Campbell, 2000
 The main cause of unilateral or bilateral exophthalmus
in adults is
 Pseudotumor
 Neuroblastoma
 Graves’ disease
 Orbital cellulitis
Ledford, Daniels & Campbell, 2000
 The ocular changes seen in Graves’ disease are mainly
due to
 Lack of blood supply
 Involvement of the extraocular muscles
 Macular edema
 Associated uveitis
Ledford, Daniels & Campbell, 2000
 Pituitary tumors affect the
 Retina
 Optic nerve
 Optic chiasm
 Visual cortex
Ledford, Daniels & Campbell, 2000
 The visual field defect generally seen in pituitary
tumor is
 Binasal hemianopsia
 Loss of both right fields
 Bitemporal hemianopsia
 Loss of both left fields
Ledford, Daniels & Campbell, 2000