Alexander ch08 lecture

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Advanced EMT
A Clinical-Reasoning Approach, 2nd Edition
Chapter 8
Human Body Systems

• Integrates complex knowledge of the anatomy and
physiology of the airway, respiratory, and
circulatory systems to the practice of EMS.
Advanced EMT
Education Standard

1. Define key terms introduced in this chapter.
2. Explain the concepts of metabolism and homeostasis.
3. Describe each of the levels of organization of the human
body.
4. Describe the anatomy and physiology of a typical body
cell.
5. Explain the physiology and distribution of fluids and
electrolytes in the body.
6. Describe the regulation of acid–base balance and blood
gases.
Objectives (1 of 3)

7. Identify the anatomy and explain the basic physiology of
the following body systems:
– Gastrointestinal
– Genitourinary
– Integumentary
– Male and female reproductive
– Musculoskeletal
Objectives (2 of 3)

8. Identify the anatomy and explain the functions, including
mechanisms for maintaining homeostasis, of the
following systems:
– Cardiovascular, with particular attention to cardiac
electrophysiology, cardiac output, hemodynamics, and perfusion
– Endocrine, with particular emphasis on the regulation of glucose
– Nervous, with particular focus on the autonomic nervous system
and its sympathetic and parasympathetic receptors and
neurotransmitters
– Respiratory, with particular attention to the mechanics of
ventilation, and external and internal respiration
Objectives (3 of 3)

• To recognize what is abnormal you must have
understanding of what is normal.
• Structures of body designed precisely to carry out
their functions.
– Anatomy
– Physiology
Introduction (1 of 3)

• Body consists of several layers of organization.
– Chemical
– Cell
– Tissue
– Organ
– System
– Organism

• Cell—basic building block of life
– Cytoplasm
– organelles
• Groups of cells form tissues, which form organs
and body systems.
– Homeostasis

• What organs do you suspect may have been
injured by each of the gunshot wounds?
• How can the patient’s injuries explain the weak,
rapid pulse and difficulty breathing?
• What mechanisms is the patient’s body using to
try to compensate for the effects of the injuries?
• How could the patient’s injuries lead to death?
Think About It

• Cells
– composed of chemicals.
– surrounded by chemical environment.
• Chemistry
– study of composition of substances and interactions
between various elements and compounds.
– Chemistry allows cells to engage in metabolism and
maintain homeostasis.
General Concepts in Anatomy and Physiology:
Chemical Basis of Life (1 of 21)

• Chemical element
– A substance that cannot be broken down further
• Atom
– Simplest unit of an element
– Subatomic particles
 Electrons—negatively charged
 Protons—positively charged
 Neutrons—electrically neutral
• Electrical charge of subatomic particles allows
atoms to bind with atoms of opposite charge.

• Some atoms capable of either gaining or losing
electrons.
• Define each of the following terms
– Ion
– Cation
– Anion
– Electrolyte

Figure 8-1
Typical structure of atoms.

Figure 8-2
Electrolytes are compounds made of a positively charged ion (cation) and a negatively
charged ion (anion). When an electrolyte is placed in a solution, it will dissociate into
charged ions. (Illustration from Bledsoe, Bryan E.; Martini, Frederic H.; Bartholomew, Edwin F.; Ober,
William C.; Garrison, Claire W.; Anatomy & Physiology for Emergency Care, 2nd Edition, © 2008.
Reprinted with permission of Pearson Education, Inc., Upper Saddle River, NJ)

Table 8-2
Principal Chemical Elements in the Body
Element Symbol
Percent of
Body Weight Significance
Oxygen O 65 A component of water and other compounds; oxygen gas is essential
for respiration
Carbon C 18.6 Found in all organic molecules
Hydrogen H 9.7 A component of water and most other compounds in the body
Nitrogen N 3.2 Found in proteins, nucleic acids, and other organic compounds
Calcium Ca 1.8 Found in bones and teeth; important for membrane function, nerve
impulses, muscle contraction, and blood clotting
Phosphorus P 1.0 Found in bones and teeth, nucleic acids, and high-energy compounds
Potassium K 0.4 Important for proper membrane function, nerve impulses, and muscle
contraction
Sodium Na 0.2 Important for membrane function, nerve impulses, and muscle
contraction
Chlorine Cl 0.2 Important for membrane function and water absorption
Magnesium Mg 0.06 Required for activation of several enzymes
Sulfur S 0.04 Found in many proteins
Iron Fe 0.007 Essential for oxygen transport and energy capture
Iodine I 0.0002 A component of hormones of the thyroid gland

General Concepts in Anatomy and
Physiology (4 of 21)
• Four chemical elements that comprise most of the
body’s atoms
– Hydrogen (H)
– Oxygen (O)
– Carbon (C)
– Nitrogen (N)

• Water
– Body
 Composed largely of water (H20)
– Intracellular fluid (ICF)
 Water within cells
– Extracellular fluid (ECF)
 Outside of the cells
– Intravascular
– Interstitial

• Solutes
– Formed particles in body fluids
 electrolytes, carbohydrates, proteins, lipids, drugs
– Osmosis
 movement of water across semipermeable membrane along
gradient from lower to higher solute concentration
– Water and solutes move to make the concentration
equal throughout the solution

• Solutes (continued)
– Osmotic pressure is caused by the difference in
concentrations of solutes
 ability to “pull” water across the cell membrane.
 Measured in milliosmols (mOsm).
– Oncotic pressure is a portion of total osmotic pressure
 Returns fluid to the bloodstream.

– Isotonic
– Hypertonic
– Hypotonic
• Osmolarity of body fluids between 280 and 310
mOsm/L

Figure 8-4
In the presence of a hypotonic environment, water moves into cells. In the presence of a
hypertonic environment, water moves out of cells.

• Sodium/potassium pump—protein on cell
membranes that keeps ions at proper levels inside
and outside cell.
– Principal intracellular cation is potassium (K+)
– Principal extracellular cation is Na+

• Sodium/potassium pump requires energy
– To move across the concentration gradient
– If not enough energy is produced, Na+ is not removed
from cell; water will enter cell in quantities such that
cell will burst and die.

Figure 8-5
The sodium/potassium pump on the cell membrane uses energy to move sodium and
potassium ions across the membrane. (Illustration from Bledsoe, Bryan E.; Martini, Frederic
H.; Bartholomew, Edwin F.; Ober, William C.; Garrison, Claire W.; Anatomy & Physiology for
Emergency Care, 2nd Edition, © 2008. Reprinted with permission of Pearson Education,
Inc., Upper Saddle River, NJ)

• Energy
– Work of the body requires energy.
– Energy production in cells is the chemical process of
breaking down glucose.
– Cells require constant supply of glucose and oxygen.
 Glucose from the digestive tract
 Oxygen from the respiratory tract

• Metabolism
– Anabolism
– Catabolism
 Adenosine triphosphate (ATP)

• Adenosine Triphosphate
– First phase—Glycolysis
 Glucose broken down into pyruvic acid
 Anaerobic metabolism
– Second phase— Aerobic metabolism
 is the complex process that results in larger amount of ATP
releasing heat.
– If oxygen levels are not quickly restored, cell death and
death of individual will occur.

Figure 8-6
Metabolism is the sum of all chemical and physical changes in the body.
(Illustration from Bledsoe, Bryan E.; Martini, Frederic H.; Bartholomew, Edwin F.; Ober,
William C.; Garrison, Claire W.; Anatomy & Physiology for Emergency Care, 2nd Edition,
© 2008. Reprinted with permission of Pearson Education, Inc., Upper Saddle River, NJ)

• pH—potential of hydrogen
– Acid is a substance that can donate a H+.
– Alkali is a substance that can accept a H+.
– Acid-base balance measured using pH scale.
– pH scale is inverse logarithm; ranges from 0 to 14,
with 7 being neutral.

• Acid–base balance
– Acidic
 Concentration of hydrogen ions high
– Alkalotic
 Concentration of hydrogen ions low
– Buffer system is when excess hydrogen ions are
converted into substances that prevent acid
accumulation, maintaining acid-base balance.

• Membrane potential
– Chemical phenomenon reflected by the difference in
concentration of electrically charged ions on the inside
and the outside of the cell.
– Electrical charge of ions determined by the ability to
gain or lose electrons.
– Electrical current is movement of ions that have too few
or too many electrons.
– Ions move from areas of greater abundance to areas
of less abundance.

• Membrane potential (continued)
– Sodium/potassium pump maintains negative charge
within cell and restores difference in charges in
repolarization.
• Polarized
• Depolarized

Figure 8-8
The cell is the basic unit of the body, consisting of organelles suspended in cytoplasm,
and is separated from its environment by a cell membrane.

Table 8-3
Cellular Components
Component Function
Cell membrane Serves as the boundary of the cell. Selectively allows substances to
move in and out of the cell.
Cytoplasm (cytosol) The fluid substance in which the organelles are suspended; allows
substances to move within the cell by diffusion.
Cytoskeleton (composed of
microtubules and microfilaments)
Provides support.
Centrioles Allow movement of chromosomes during cell division.
Ribosomes (free ribosomes within
cytoplasm and ribosomes bound to
the rough endoplasmic reticulum)
Synthesize protein.
Endoplasmic reticulum Smooth endoplasmic reticulum synthesizes lipids and carbohydrates.
Rough endoplasmic reticulum is lined with ribosomes; packages
proteins.
Golgi apparatus Stores and packages substances that will be secreted from the cell.
Lysosomes Contain powerful enzymes to rid the cell of damaged organelles and
pathogens.
Mitochondria Produce ATP.
Nucleus Contains RNA and DNA.

• Cell membrane
– semipermeable, allowing water and small molecules to
move through it.
– consists of double layer of molecules called
phospholipids.
• Channels
– allow substances to move through cell at certain times.
• Movement of other substances regulated by
electrical charge of molecules that comprise it.

• Cytoplasm
– is fluid medium within cell.
• Nucleus
– contains DNA that comprises chromosomes that create
body’s genetic code.

• DNA transcribed to ribonucleic acid (RNA).
• Transcribed by ribosomes into proteins.
• Golgi apparatus
– modifies protein prior to secretion.
• Mitochondria
– produce energy in form of ATP through oxidative
phosphorylation.

• Vacuoles
– Store and transport proteins within cell.
• Centrioles
– Provide support and form microtubules and spindle
apparatus of cell.
• Lysosomes
– Destroy waste and toxins within cell and possess
powerful enzymes.

General Concepts in Anatomy and
Physiology: Tissues
• Tissues are a group of specialized cells
surrounded by a matrix.
– What are the four general types of tissues in the
human body?

Think About It
• What role does each play in the body?
• Epithelial tissue
– Thin linings of body surfaces
• Connective tissue
– Fibers such as collagen and elastin
• Muscle tissue
– Cells with proteins that can change in length
• Nervous tissue
– Specialized nerve cells

Figure 8-10
The anatomical position, with anatomical planes shown.

Anatomical Terminology and
Topographic Anatomy (1 of 3)
• Anatomic position
– Body is standing upright, looking forward, with feet
together and arms at sides with palms facing forward
• Planes
– Sagittal
– Frontal
– Transverse

• Lines of reference
– Midaxillary
– Midclavicular
– Abdomen divided into nine regions

Figure 8-13
The body cavities.

• Body divided into cavities in which internal organs
are contained
– Dorsal cavity
 Cranial and spinal
– Ventral cavity
 Thoracic and abdominopelvic

• Organs composed of tissues that work together to
perform specific function.
• Most organs consist of a variety of tissues.
• Organs and tissues interact to carry out complex
set of functions.
Chemical Basis of Life

Think About It
• Systems are collections of organs and tissues that
interact to carry out a complex set of functions.
• What system provides structure to the body?
• What system perfuses the body?

Support, Movement, and Protection:
Skeletal System (1 of 6)
• Bones, cartilage, tendons, ligaments.
• Provides body with
– Structure, support, protection.
– Reservoir of calcium and bone marrow, where new
blood cells created.
 Skeletal muscles allow movement.
• 206 bones classified as long, short, or flat.

• What is cartilage?
• What are tendons?
• What are ligaments?

Figure 8-15
Structure of a typical long bone.

• Short bones are comprised of wrist and ankle;
they are roughly cube shaped.
• Flat bones include sternum, ribs, scapula, and
pelvis.
• Long bones are in extremities
– Diaphysis
– Epiphys
– Metaphysis
– Epiphyseal plate

Figure 8-16
The skeleton consists of 206 bones divided between its axial and appendicular divisions.
The axial skeleton consists of the skull, spine, and thorax. The appendicular skeleton
consists of the bones of the extremities, including the bones that allow them to attach to the
axial skeleton.

• Axial skeleton is a straight line at the core of the
body.
– Skull, spine, ribs, sternum
• Appendicular skeleton consists of bones in the
upper and lower extremities.
– Bones of shoulder and pelvis

Muscular System (1 of 2)
• Muscle tissue built from cells with unique proteins
(actin/myosin) arranged in filaments that contract
and relax, allowing movement.
• Contraction occurs in response to nervous
stimulation
– requires complex chemical interaction within the
muscle cell.

Muscular System (2 of 2)
• Types of muscles
– Skeletal muscle (striated)
 Attaches to bones and allows movement; controlled voluntarily
– Smooth muscle
 Involuntary control; in organs
– Cardiac muscle
 Involuntary control; unique function is allowing heart to pump
blood throughout body

Think About It
• What is the purpose of smooth muscle in hollow
organs?
• How does cardiac muscle differ from skeletal and
smooth muscle?

Figure 8-23
The skin consists of an outer protective layer called the epidermis, and an inner layer that
contains the glands, nerves, and blood vessels, called the dermis.

Integumentary System
• Skin (integument) largest organ in body
– Maintains body warmth and protects from external
pathogens
– Oil and sweat glands maintain fluid balance
• Skin layers
– Epidermis
– Dermis
– Subcutaneous layer

Think About It
• What are the consequences of substantial
damage to the skin, such as from extensive burns,
disease, or abrasions?

Respiration and Circulation:
Respiratory System (1 of 11)
• Function is to obtain oxygen for cell metabolism
and eliminate carbon dioxide.
• Respiration
– The exchange of oxygen and carbon dioxide
• Ventilation
– Mechanical process of moving air in and out of lungs

Figure 8-24
Respiration is the exchange of gases between the body and the environment.

Figure 8-26
Ventilation is the mechanical process that allows air to enter and exit the lungs. It consists
of two phases. (A) Inspiration is an active muscular process of enlarging the thoracic cavity
to decrease the intrathoracic pressure. (B) Expiration is a passive process by which the
muscles of ventilation relax, allowing the thoracic cavity to return to the smaller size of its
resting state.

• Gases
– Partial pressure (Pa)
 Amount of pressure an individual gas contributes to total
pressure
– Air
 79% nitrogen; 21% oxygen; 1% trace gases

• Gases (continued)
– Gases diffuse along gradient from higher to lower
pressure
– Carbon dioxide carried in three ways
 form of bicarbonate
 bound to hemoglobin
 dissolved in plasma

• Gases (continued)
– Oxygen is used at the cell, blood returns to the heart
(deoxygenated)
 Amount of oxygen in blood that returns to heart is low
 PaO2 is about 40mmHg
– Oxygen diffuses from the alveoli to the capillaries
(oxygenated)
 Amount of oxygen in the blood increases
 PaO2 increase to 100mmHg

• Boyle’s law
– The pressure of a fixed gas varies inversely with its
volume.
– Inhalation—thoracic cavity increase in size
 Air diffused in
– Exhalation—thoracic cavity decreases in size
 Air diffused out

Figure 8-27
The upper and lower airways serve as a conduit for gases to reach the alveolar level for
gas exchange.

• Upper airway warms and humidifies air and filters
out particulate debris.
– Nose
– Mouth
– Oropharynx
– Nasopharynx

• Lower airway allows air to reach alveolar beds so
gas exchange can occur.
– Larynx (vocal cords)
– Trachea (windpipe)
– Left and right mainstem bronchi
– Bronchioles
– Alveolar ducts
– Alveoli

• Lungs
– Respiratory membrane
 Gas exchange occurs between respiratory and cardiovascular
system
– Divided into sections called lobes
– Covered with thin membrane visceral pleura
– Pleural fluid provides lubrication

• Lungs (continued)
– Hilum
 is the point of entry on each lung for bronchus, bronchial
artery and vein, pulmonary artery and vein, lymphatic vessels.
– Pulmonary vessels
 carry blood between heart and alveoli for gas exchange.
– Bronchial vessels
 carry oxygenated blood from aorta to lung and return to vena
cava.

• What are the two phases of ventilation?
– Respiratory cycle occurs once every 3 to 5 seconds
 12 to 20 breaths per minute.
– Primary stimulus to breathe
 Hypercarbic drive
– Secondary stimulus
 Hypoxic drive

• Tidal volume (TV)
– Volume of air inhaled in a typical breath (500ml)
• Minute respiratory volume (MRV)
– The volume exchanged over a minute (TV  rate)
• Vital capacity
– Volume of air exchanged in a single maximal
inspiration and expiration (4L)
• Residual volume
– Amount of air that remains in the lungs after exhalation

Figure 8-29
The cardiovascular system consists of the heart, blood vessels, and blood. The heart is a
two-sided pump that pumps blood to the lungs for oxygenation and then pumps the
returning oxygenated blood to the body. Blood travels through three types of vessels:
arteries, capillaries, and veins. Blood is a liquid medium that transports blood cells,
proteins, nutrients, drugs, wastes, and other substances throughout the body.

Cardiovascular System (1 of 18)
• Heart, blood, blood vessels
• Closed system
– Oxygenated blood pumped from left side of heart
through arteries to the capillary beds where exchange
of substances takes place
– Deoxygenated blood pumps through venous system to
right side of heart, which pumps blood to lungs to
eliminate carbon dioxide and gain oxygen

• Blood is tissue
– Plasma and formed elements
• Average five liters of blood in adult
• Plasma
– serves as transport for proteins, nutrients, elements,
gases, chemical messengers, wastes.
• Red blood cells
– carry iron-containing protein (hemoglobin) to which
oxygen is bound for transport throughout the body.

• Mature RBCs
– no nucleus (so hemoglobin can fill the space)
– life span 120 days
• Hematocrit (Hct)
– Percentage by volume of formed elements in blood,
majority consists of RBCs

• Blood type (A, B, AB, or O)
– A cells have A antigens
– B cells have B antigens
– AB cell have both A and B antigens
– O cells have neither
• Rh factor
– Blood type is positive or negative

Figure 8-33
Hemostasis consists of three phases. First, vasoconstriction decreases the diameter of the
blood vessel to decrease blood flow through it. Second, platelets are activated by chemical
factors released from the exposed collagen of the damaged vessels. Platelets clump
together at the site to form a platelet plug. Third, the clotting cascade results in formation of
a stable blood clot.

• White blood cells (WBCs)
– provide protection from invading antigens; support
development of inflammation resulting from injury or
infection.
• Platelets
– small cell fragments that arise from the break up of
larger cells.
– activated by chemical events in response to injury to
blood vessels (hemostasis).

Figure 8-35
Internal anatomy of the heart.

• Heart is a muscular pump that circulates blood
throughout vessels of cardiovascular system.
– Roughly size of fist
– Located in mediastinum in center of chest between
lungs
– Surrounded by pericardium
– Four chambers function as two side-by-side pumps

• Right atrium
– Deoxygenated blood for vena cavas
• Right ventricle
– Deoxygenated blood from right atrium through mitral
valve
• Left atrium
– Oxygenated blood from the pulmonary vein
• Left ventricle
– Oxygenated blood from the left atrium through the
tricuspid valve

Figure 8-36
The cardiac conduction system.

• Cardiac conduction system
– Heart stimulated to contract by autonomic nervous
system
 Begins with sinoatrial (SA) node.
 Each impulse travels through atria.
 From atrioventricular (AV) node impulse spreads down bundle
of His.
 Purkinje fibers.
 Special properties of myocardium allow it to contract in
uniform, rhythmic fashion to pump blood throughout circulatory
system.

• Cardiac cycle
– Heart follows regular cycle of events with each beat.
– Series of electrical events produces mechanical
contraction of the heart muscle.
– Electrical activity involves exchange of sodium,
potassium, and other ions.
– Calcium required for contraction of myocardial cells.

• Cardiac action potential has two phases
– Systole is contraction phase.
– Diastole is relaxation phase.
• Movement of ions and associated differences in
electrical charge across cell membranes.
• Heart functions as two hearts in one.

• Cardiac electrophysiology
– Automaticity
 heart self-depolarizes to initiate its own electrical activity.
– Excitability
 allows myocardial cells to respond to electrical impulse and
contract.
– Conductivity
 allows electrical impulse to move quickly from one cell to
another.

• Cardiac output (CO) is the amount of blood
ejected from the heart.
– CO determined by two factors.
 Stroke volume (SV) and heart rate (HR).
– SV is the amount of blood (milliliters) ejected from the
ventricle with each contraction.
 Average CO 4.9 liters per minute.

• Stroke volume adjusted by several factors to
maintain homeostasis
– Preload, contractility of heart, and afterload.
 What is afterload?
 What is preload?

Figure 8-38
Both arteries and veins consist of three tissue layers. Capillaries consist of only one layer
of endothelial cells.

• Vascular refers to blood vessels.
– Arteries
– Capillaries
– Veins

• Goal of cardiovascular system is perfusion; for
perfusion to occur, blood pressure (BP) must be
adequate.

• Arterial blood pressure is the force that blood
exerts against walls of arteries as it moves
through them; measured in mmHg.
– Systolic blood pressure (SBP) is the highest during
ventricular systole.
– Diastolic blood pressure (DBP) is lower pressure
exerted against walls of arteries.

• American Heart Association
– Normal adult blood pressure 120 mmHg systolic/80
mmHg diastolic
• Mean arterial pressure (MAP)
– Pulse pressure

• Factors that influence blood pressure
– Function of heart
– Volume of blood
– Capacity of vascular system
• Volume of blood and function of heart determine
cardiac output.

Figure 8-41
Neurons may take on different shapes, but they have the same basic features in
common: dendrites that receive input, a cell body, and an axon that carries information
to adjacent cells.

Control, Communication, and Integration:
The Nervous System (1 of 9)
• Nervous system allows integration of sensory
input and coordination of responses to it.
• Together with endocrine system, nervous system
allows for control and communication.

• Neurons
– are a basic unit of structure and function of the nervous
system.
– Soma, dendrites, axon
• Neurotransmitters
– allow communication between neurons, and neurons
and target tissues.

Figure 8-42
Functional divisions of the nervous system.

• Central nervous system (CNS)
– Neurons within brain and spinal cord
• Peripheral nervous system
– Neurons outside brain and spinal cord
• Voluntary functions (somatic)
– Responsible for movement
• Involuntary functions (autonomic)
– Sympathetic and parasympathetic
• Functional classifications of neurons
– Sensory, motor, interneurons

Figure 8-44
The cerebrum is the seat of higher brain functions.

• Brain central integrating organ of nervous system.
• Brain within cranium, cushioned by CSF,
surrounded by meninges.
– Pia mater
– Arachnoid layer
– Dura mater

• Cerebrum
– Part of forebrain, center of consciousness and higher
thought
• Thalamus
– Coordination center for signals traveling between
cerebrum and spinal cord
• Hypothalamus
– Coordinates hormones of the endocrine system

• Brainstem
• Core bodily functions of heart rate, respiratory rate,
body temperature controlled
• Twelve pairs of cranial nerves
• each serves a different function
• Reticular activating system (RAS)
• Network of neurons in brainstem, thalamus, cerebrum;
responsible for consciousness, sleep-wake cycles,
attention.

Figure 8-47
The spinal cord consists of tracts of tissue that ascend toward the brain and tracts of tissue
that descend toward the spinal nerves.

• Spinal cord
– a long bundle of nerve bodies that goes from the
brainstem to level of L2 vertebra.
• Neural tissue
– arranged into bundles called tracts.
• When spinal cord injury completely severs the
spinal cord, all communication ceases.

• Peripheral nervous system begins where spinal
nerves and cranial nerves enter and exit
meningeal coverings of spinal cord and brain.
• Sensory nerves (afferent)
– travel toward the spinal cord.
• Motor nerves (efferent)
– travel away from the spinal cord.

• Voluntary system
– Any nerve involved in action that brain must
consciously think about to initiate
• Autonomic nervous system
– Sympathetic
 Fight-or-flight system
– Parasympathetic
 Rest-and-digest system

Figure 8-49
The endocrine system is a collection of ductless glands that secrete hormones, which are
carried in the bloodstream to target cells that have specific receptors for the hormone. The
hormone acts as a chemical messenger that regulates the function of the cell.

Endocrine System (1 of 2)
• Endocrine system
– Ductless glands that secrete chemicals (hormones)
into bloodstream
– Pituitary
 Master gland secretes tropic hormones
– Hypothalmus
 Controls and influences the pituitary gland

Endocrine System (2 of 2)
• Endocrine system (continued)
– Pancreas
 Dual-function organ (upper abdomen) with both endocrine and
exocrine roles
– Adrenal
 Small pyramid-shaped structures on top of each kidney

Think About It
• How is blood glucose regulated by pancreatic
hormones?

Figure 8-50
The gastrointestinal system consists of the alimentary canal and accessory organs of
digestion. The alimentary canal consists of the mouth, pharynx, esophagus, stomach, small
intestine, large intestine (colon), rectum, and anus. The accessory organs include the
salivary glands, liver, gallbladder, and pancreas.

Nutrition and Excretion:
Gastrointestinal System (1 of 4)
• Gastrointestinal (GI) system receives and digests
food, absorbing nutrients into the body, and
excretes waste.
• Gastrointestinal tract
– Mouth, pharynx, esophagus, stomach, small intestine,
large intestine, rectum, and anus

• Esophagus
– Muscular tube that runs from oropharynx to connect
with the stomach
• Stomach
– Muscular container found in left upper quadrant of
abdomen

• Small intestine
– Divided into duodenum, jejunum, and ileum
• Large intestine
– Absorbs water and forms and stores stool
• Accessory organs
– Salivary glands, liver, gall bladder, and pancreas

• The peritoneum
– a thin epithelial lining, surrounds most of the abdominal
organs.
– consists of a visceral layer that is fixed to the organ
surfaces and folds over itself to create a parietal layer.

Figure 8-51
The urinary system consists of the kidneys (renal system) and urinary tract (ureters,
bladder, and urethra).

Nutrition and Excretion: Urinary System
(1 of 2)
• Kidneys
– maintain fluid and electrolyte balance, maintain blood
pressure, filter waste products from blood.
• Urine drains into ureters
– which carry urine to bladder for storage; emptied via
urethra.
• Nephrons
– filter blood, manage electrolytes, excrete waste as
urine.

Figure 8-52
Internal anatomy of the kidney.

Nutrition and Excretion: Urinary System
(2 of 2)
• Ureters
– Insert into bladder, a hollow and muscular organ found
in lower pelvis.
– Upon urination, bladder contracts and urine passes
through urethra.
• Kidneys affect pH through secretion of
bicarbonate.

Figure 8-54
The male reproductive organs.

Figure 8-55
The female reproductive organs.

Reproduction: Reproductive System (1
of 2)
• Consists of organs that store human DNA in male
and female sex cells
– Sperm and egg
 Each carry a set of 23 chromosomes; combined upon
fertilization become a full set of 46.
• Male reproductive organs
– Testes, prostate gland, penis, and epididymis

Reproduction: Reproductive System (2
of 2)
• Female reproductive system
– Ovaries, fallopian tubes, uterus, vagina, and vulva
• Each month of childbearing years a mature egg
(ovum) is ejected from ovary into fallopian tubes.
• If fertilization does not occur, tissue sloughs off,
resulting in menstrual flow.

Chapter Summary
• Human body consists of complex structures and
functions.
• Systems work together, allowing body to maintain
homeostasis.
• You must distinguish abnormal structure and
function from normal; first step in recognizing
patient is sick or injured.
• Understanding roles of respiratory, nervous,
cardiovascular, endocrine systems is critical.

Alexander ch08 lecture

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Alexander ch08 lecture