Title: Anatomy and Physiology
1Anatomy and Physiology
- Heart, Lungs, Pancreas, Liver, Kidneys and Skin
B. Paul White, MD HOD ID 2078
2(No Transcript)
3HEART
4HEART
- Hollow, muscular organ
- 300 grams (size of a fist)
- 4 chambers
- found in chest between lungs
- surrounded by membrane called Pericardium
- Pericardial space is fluid-filled to nourish and
protect the heart.
5HEART ANATOMY
- The heart is a complex muscular pump that
maintains blood pressure and flow through the
lungs and the rest of the body. - The heart pumps about 100,000 times and moves
7200 liters (1900 gallons) of blood every day.
6HEART ANATOMY
- The heart has four chambers.
- Two atria act as collecting reservoirs.
- Two ventricles act as pumps.
- The heart has four valves for
- Pumping action of the heart.
- Maintaining unidirectional blood flow.
7Functions of the Heart
- Generates blood pressure
- Routes blood
- Heart separates pulmonary and systemic
circulation - Ensures one-way blood flow
- Heart valves ensure one-way flow
8Functions of the Heart
- Regulates blood supply
- Changes in contraction rate and force match blood
delivery to changing metabolic needs - Most healthy people can increase cardiac output
by 300500 - Heart failure is the inability of the heart to
provide enough blood flow to maintain normal
metabolism
9Cardiac Cycle
- The heart is two pumps that work together, right
(pulmonary) and left (systemic) half - Repetitive, sequential contraction (systole) and
relaxation (diastole) of heart chambers - Blood moves through circulatory system from areas
of higher to lower pressure. - Contraction of heart produces the pressure
10Cardiac Cycle
11HEART
- Deoxygenated blood returns to the heart via the
superior and inferior vena cava, enters the right
atrium, passes into the right ventricle, and from
here it is ejected to the pulmonary artery. - Oxygenated blood returning from the lungs enters
the left atrium via the pulmonary veins, passes
into the left ventricle, and is then ejected to
the aorta.
12Blood Vessels
- Blood vessels are divided into a pulmonary
circuit and systemic circuit. - Artery - vessel that carries blood away from the
heart. Usually oxygenated - Vein - vessel that carries blood towards the
heart. Usually deoxygenated. - Capillary - a small blood vessel that allow
diffusion of gases, nutrients and wastes between
plasma and interstitial fluid.
13Blood Vessels
- Systemic vessels
- Transport blood through the body part from left
ventricle and back to right atrium - Pulmonary vessels
- Transport blood from right ventricle through
lungs and back to left atrium - Blood vessels and heart are regulated to ensure
blood pressure is high enough for blood flow to
meet metabolic needs of tissues
14Blood Flow
15LUNGS
- Lungs comprised of
- Airways
- Alveoli
http//www.aduk.org.uk/gfx/lungs.jpg
16What do the lungs do?
- Primary function is gas exchange
- Let oxygen move in
- Let carbon dioxide move out
17How do the lungs do this?
- First, air has to move to the region where gas
exchange occurs. - For this, you need a normal ribcage and
respiratory muscles that work properly (among
other things).
18Conducting Airways
- Air travels via laminar flow through the
conducting airways comprised of the following
trachea, lobar bronchi, segmental bronchi,
subsegmental bronchi, small bronchi, bronchioles,
and terminal bronchioles.
19How do the lungs do this?
- The airways then branch further to become
transitional/respiratory bronchioles. - The transitional/respiratory zones are made up of
respiratory bronchioles, alveolar ducts, and
alveoli.
20The Airways
- Conducting zone no gas exchange occurs
- Anatomic dead space
- Transitional zone alveoli appear, but are not
great in number - Respiratory zone contain the alveolar sacs
- Over 8 million branches
Weibel ER Morphometry of the Human Lung. Berlin
and New York Springer-Verlag, 1963
21How does gas exchange occur?
- Numerous capillaries are wrapped around alveoli.
- Gas diffuses across this alveolar-capillary
barrier. - This barrier is as thin as 0.3 µm in some places
and has a surface area of 50-100 square meters!
22Gas Exchange
- Diffusion Barrier crossed by O2 moving from air
to blood and CO2 from blood to air is made up
of - 1. an aqueous surface film
- 2. epithelial cells of alveolus
- 3. interstitial layer
- 4. endothelial cells of capillaries
- 5. blood plasma
- 6. membrane of RBCs
23Alveoli
- Approximately 300 million alveoli
- 1/3 mm diameter
- Total surface area about 85 sq. meters (size of a
tennis court)
24Gas Exchange
From Netter Atlas of Human Anatomy, 1989
25Control of Ventilation
- Arterial PO2
- When PO2 is VERY low, ventilation increases
- Arterial PCO2
- The most important regulator of ventilation,
small increases in PCO2, greatly increases
ventilation - Arterial pH
- As hydrogen ions increase, alveolar ventilation
increases, but hydrogen ions cannot diffuse into
CSF as well as CO2
26PANCREAS
27Anatomy of the Pancreas
- 5" long by 1" thick
- Head close to curve in C-shaped duodenum
- Main duct joins common bile duct from liver
- Sphincter of Oddi on major duodenal papilla
- Opens 4" below pyloric sphincter
28Anatomy of the Pancreas
Grays Anatomy of the Human Body
29Anatomy of the Pancreas
Exocrine glands have ducts that carry their
secretions to specific locations.
Digestive gland that secretes digestive enzymes
into the duodenum through the pancreatic duct.
Grays Anatomy of the Human Body Robbins Basic
Pathology http//faculty.clintoncc.suny.edu/facult
y/Michael.Gregory/default.htm
30Histology of the Pancreas
31Histology of the Pancreas
- Acini- dark clusters
- 99 of gland
- produce pancreatic juice
- Islets of Langerhans
- 1 of gland
- pale staining cells
- produce hormones
32Bicarbonate Ion Production
33Functions of the Pancreas
- Anatomy
- Endocrine
- Pancreatic islets produce insulin and glucagon
- Exocrine
- Acini produce digestive enzymes
- Regions Head, body, tail
- Secretions
- Pancreatic juice (exocrine)
- Trypsin
- Chymotrypsin
- Carboxypeptidase
- Pancreatic amylase
- Pancreatic lipases
- Enzymes that reduce DNA and ribonucleic acid
34Bicarbonate Ion Production
35LIVER
36LIVER
- Largest gland in the body (1.4 kg 3 lbs.)
- Produces bile
- Stored in GB
- Emulsifies fats
- Involved in metabolism
- Diaphramatic and visceral surface
- Right and left lobes
- Porta hepatis major vessels and nerves
- Right and left hepatic ducts, common bile, common
37Histology of the Liver
- Hepatocytes arranged in lobules
- Sinusoids in between hepatocytes are blood-filled
spaces - Kupffer cells phagocytize microbes foreign
matter
38Histology of the Liver
39Histology of the Liver
40Functions of the Liver
- Bile production
- Salts emulsify fats, contain pigments as
bilirubin - Storage
- Glycogen, fat, vitamins, copper and iron
- Nutrient interconversion
- Detoxification
- Hepatocytes remove ammonia and convert to urea
- Phagocytosis
- Kupffer cells phagocytize worn-out and dying red
and white blood cells, some bacteria - Synthesis
- Albumins, fibrinogen, globulins, heparin,
clotting factors
41Bile
- About 600 ml of bile is produced daily
- Bile acid
- Phospholipids
- Cholesterol
- Bilirubin
- Waste products
- Electrolytes
- Mucin
42KIDNEYS
43KIDNEYS
- Play a major role in maintaining homeostasis
- Maintain water balance
- Regulate the quantity and concentration of ECF
ions - Regulate the plasma volume
- Regulate pH by controlling elimination of acid
and base in urine - Maintain osmolarity
- Regulate the concentration of plasma constituents
(e.g. electrolytes and water)
44KIDNEYS
- Kidneys have excellent blood supply 0.5 total
body weight but 20 of Cardiac Output. - Kidneys process plasma portion of blood by
removing substances from it, and in a few cases,
by adding substances to it. - Works with cardiovascular system (and others!) in
integrated manner
45Functions of the kidneys
- Regulation of H2O and inorganic ion balance
most important function! - Removal of metabolic waste products from blood
and excretion in urine. - Removal of foreign chemicals in the blood (e.g.
drugs) and excretion in urine. - Gluconeogenesis
- Endocrine functions (e.g. renin, erythropoetin,
1,25-dihydroxyvitamin D) - In kidney disease, build-up of waste serious, but
not a bad as ECF volume and composition
disturbances.
46Functions of the kidneys
- Water balance
- Electrolyte balance
- Plasma volume
- Acid-base balance
- Osmolarity balance
- Excretion
- Hormone secretion
47Acid-Base Balance
- Kidneys VERY important for acid-base balance,
along with respiratory system. - Important because all biochemical processes must
occur within an optimal pH window. - Prevent ACIDOSIS or ALKALOSIS.
- Although the lungs excrete a large amount of CO2,
a potential acid formed by metabolism, the
kidneys are crucial for excreting non-volatile
acids. - To maintain acid-base balance, kidney must not
only reabsorb virtually all filtered HCO3-, but
must also secrete into the urine the daily
production of non-volatile acids.
48KIDNEY
49Internal Anatomy of Kidneys
- Cortex Outer area
- Renal columns
- Medulla Inner area
- Renal pyramids
- Calyces
- Major Converge to form pelvis
- Minor Papillae extend
- Nephron Functional unit of kidney
- Juxtamedullary
- Cortical
50Kidney Failure
- at age 49 years, the expected duration of life of
a patient with end-stage renal disease on
hemodialysis is 7 additional years compared with
approximately 30 additional years for a person of
the same age from the general population.
51Dialysis and Transplant
Hemo-dialysis
Peritoneal dialysis
52SKIN
53SKIN
- Largest organ of the body.
- Surface area 1.5 - 2 m2.
- Average adult weight 9 kg.
- Functions - protection, defence, sensation,
thermoregulation, vit D synthesis, excretion,
storage.
54SKIN
- 2 Principal portions
- Epidermis - epithelium
- Dermis areolar dense irregular connective
tissue - Hypodermis
- beneath the dermis
- the subcutaneous layer next to
- adipose layer or
- muscle or
- bone
55Functions of the Skin
- Protection
- Prevents invasion of environmental toxins and
microorganisms - Immunologic
- Sebum has antibacterial properties which helps
shed topical bacteria - Thermoregulation
- Insulates from heat loss and controls loss of
heat through evaporation
56Functions of the Skin
- Fluid and Electrolyte Balance
- Controls sodium excretion
- Sebum retards fluid loss from skin
- Metabolism
- Produces Vitamin D
- Prevents excessive fluid loss
- Neurosensory
- Nerve endings and receptors process environmental
stimuli for pain, touch, heat and cold - Social and Interactive
- Provides body image and personal identity
-
57Epidermis
- Provides barrier function.
- Multilayered structure, continually regenerating.
- Thickness dependent on exposure to friction.
- Stratified squamous epithelium, organised in five
layers. - Stratum basale Stratum spinosum, Stratum
granulosum, Stratum lucidum, Stratum corneum.
58Epidermis
- First layer of defense
- Composed of dead, keratinized cells and
surrounded by a lipid monolayer - There are no blood vessels. It is fed by
capillaries in the dermis. - If the epidermis is destroyed but the appendages
of the dermis remain, a new epidermis is formed
when the epithelial grow out of the hair
follicles.
59- EPIDERMIS
- 4 cell types
- Keratinocytes - 90
- filled with keratin (protein)
- waterproof barrier
- Melanocytes - 8
- produce melanin (pigment)
- pass melanin to keratinocytes
- Langerhans cells
- phagocytes (from immune system)
- easily damaged by UV light
- Merkel cells
- in deepest layer of hairless skin
- sensory transduction - touch
60Epidermis
SC
SG
SS
B
61Dermis
- Varies in thickness across body.
- 1 mm on face , 4 mm on back.
- Responsible for most major functions of the skin.
- Two distinct layers
- Papillary dermis,
- Reticular dermis.
62Dermis
- Few cells present - fibroblasts, macrophages,
adipocytes - Intracellular matrix thick with many protein
fibers collagen, elastin, reticular - The location for blood vessels, nerves and
sensory receptors, glands, hair follicles
63Dermis
- Collagen and fibrous connective tissue
- Contains capillaries and arterioles
- Has special sensory nerve fibers and lymph system
- Meissner Corpuscle light touch, just beneath
epidermis - Vater Pacini Corpuscles pressure sensors, deep
in subq - Ruffini Corpuscles heat sensors, deep in subq
tissue - Krause Corpuscles cold sensors, deep in
subcutaneous tissue
64Dermis
- Papillary region - outer layer - 20
- areolar connective tissue, elastic fibers
- dermal papillae mound-like projections to
increase the surface area for nutrition from
capillaries - some papillae contain Meissner's corpuscles (for
light touch)
65Dermis
- Reticular region-80
- dense, irregular connective tissue
- collagen, elastic fibers in a network surrounding
the various cells - fibers give strength, elasticity, extensibility
- tears in reticular region - "stretch marks -
long straight red or white streaks
66Layers of the Dermis.
67Subcutaneous Tissue
- Connective tissue
- Fat cells in most areas
- Blood vessels
- Nerves
- Base of hair follicles
- Function
- Insulation
- Storage of nutrients
68Skin Blood Vessels
Superficial dermal plexus.
Cutaneous plexus
Subcutaneous plexus.
69Types of Burns
- Superficial
- Superficial partial thickness
- Deep partial thickness
- Full thickness
70Partial Thickness Burn
- Can be superficial or deep
- Involves epidermis and dermis
- Has blister formation
- Moist appearance
- Tactile and pain sensors intact
- Will usually heal on own but will scar
71Full Thickness Burn
- Involves all layer of skin
- Has waxy and dry appearance
- Elasticity destroyed
- Painless
- Does not heal without intervention
- Autologous skin graft or banked skin