Transcript File

Chapter 6
Overview of Body Systems and
Their Functions
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Anatomy and Physiology
• Anatomy is the branch of science that deals
with the structure of body parts, their forms,
and their organization
• Physiology concerns the functions of body
parts – how they work and what they
accomplish
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Integumentary System
• The skin, and the various accessory structures
that are associated with it, is the largest organ
in the body by surface area
• Integumentary structures include the hair,
nails, sensory receptors, and glands
• Together they make up the integumentary
system
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
The Skin
• Certain skin cells called keratinocytes assist
the immune system by producing hormonelike substances that stimulate development of
certain white blood cells (T lymphocytes)
• Specialized cells in the epidermis called
melanocytes produce melanin, a dark pigment
that provides skin color and that also absorbs
the ultraviolet radiation in sunlight
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Skin Layers
• The outer skin layer, called the epidermis, is
composed of stratified squamous epithelium
• The inner layer, or dermis, is thicker than the
epidermis
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Skin Layers
• It includes connective tissue consisting of:
–
–
–
–
–
–
Blood
Collagenous and elastic fibers
Nervous tissue
Smooth muscle
Sebaceous glands
Sweat glands
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Skin Layers
• Beneath the dermis is loose connective tissue
that binds the skin to the underlying organs,
forming the subcutaneous layer
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Skin Layers
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Musculoskeletal System
• This system actually consists of two different systems
that work closely together to support the frame and
allow movement of the body
• It includes connective tissue, muscles, bones, and
joints
• The muscular system consists of skeletal, smooth, and
myocardial muscles
• The skeletal system consists of bones and joints
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Divisions of the Adult Skeleton
• Axial skeleton
–
–
–
–
–
Skull (8 cranial bones, 14 facial bones)
Middle ear (6 bones)
Hyoid bone (1)
Vertebral column (26 bones)
Thoracic cage (25 bones)
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Divisions of the Adult Skeleton
• Appendicular skeleton
–
–
–
–
Pectoral girdle (4 bones)
Upper limbs (60 bones)
Pelvic girdle (2 bones)
Lower limbs (60 bones)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Joints and Structures
• The joints allow the body to be mobile and
flexible
• The capsule or bursa surrounding the joints is
lined with a connective (synovial) membrane
that has fluid inside
• Diseases of the joints are called arthritis
• Osteoporosis is a condition in which bone
mass is reduced
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Nervous System
• The nervous system is composed of the brain,
spinal cord, and nerves
• It is divided into two sections:
– Central nervous system (CNS)
– Peripheral nervous system (PNS)
• The CNS is located in the dorsal cavity, the
brain is enclosed in the cranium, and the spinal
cord is inside the spinal cavity
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
The Brain
• The brain is subdivided into the cerebrum,
diencephalon, brainstem, and cerebellum
• The cerebrum consists of 2 cerebral
hemispheres, connected by the corpus
callosum
• The diencephalon contains the thalamus and
hypothalamus
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Peripheral Nervous System
• The peripheral nervous system (PNS) consists
of cranial and spinal nerves
• They branch from the brain and spinal cord to
all body parts
• The PNS is subdivided into the somatic and
autonomic nervous systems
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Autonomic Nervous System
• The autonomic nervous system (ANS)
functions without any conscious effort, and it
regulates the visceral activities that maintain
homeostasis
• It is subdivided into the sympathetic and
parasympathetic nervous systems
• The sympathetic nervous system responds to
stress and emergency situations
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Neurons and Structures
• The neuron is the basic cell of the nervous
system, carrying nerve impulses from one part
of the body to another
• At the junction of the neurons, the continuation
of messages is performed by neurotransmitters,
such as acetylcholine (ACh), which stimulates
the nerve endings
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Neurons and Structures
• There are some other neurotransmitters, called
neurohormones, including:
–
–
–
–
Cholinesterase
Catecholamines
Serotonin
Endorphins
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Parts of the Neuron
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Special Senses (Eyes and Ears)
• The special senses are those whose sensory
receptors lie within large, complex sensory
organs in the head
• These senses and their respective organs
include:
–
–
–
–
Smell (olfactory organs)
Taste (taste buds)
Ears (hearing and equilibrium)
Eyes (sight)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Eyes
• The eyes contain visual receptors and provide
vision with the assistance of accessory organs
• These accessory organs include eyelids and
lacrimal apparatus
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Eyes
• The eye is a hollow, spherical structure about
2.5 centimeters in diameter
• The anterior of the outer layer bulges forward
as the transparent cornea (the “window” of the
eye)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Parts of the Eye
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Ears
• The ears are the organs of hearing and also
function in the sense of equilibrium
• The outer portion is called the auricle
• The 2nd portion is an S-shaped tube called the
external acoustic meatus
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Ears
• These bones transmit sound vibrations from
the eardrum to the oval window
• The auricle of the ear helps to:
– Collect sound waves
– Directs the sound waves into the eardrum (tympanic
membrane)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
The Middle Ear
• The middle ear is an air-filled space that
contains 3 small bones called auditory ossicles
(called malleus, incus, and stapes)
• These bones transmit sound vibrations from
the eardrum to the oval window
• The auditory tube (eustachian tube) connects
the middle ear to the throat (pharynx)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Parts of the Middle Ear
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
The Inner Ear
• The inner ear is a complex system of
connected fluid-filled chambers and a tube
called a labyrinth
• The parts of the labyrinth include:
– Three semicircular canals, which provide a sense of
equilibrium
– One cochlea, which functions in hearing
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Endocrine System
• The endocrine system consists of specialized
cell clusters, glands, hormones, and target
tissues
• It regulates metabolic activities, and along
with the nervous system, it maintains internal
homeostasis
• Endocrine glands secrete hormones, or
chemical messengers, directly into the
bloodstream
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Organs and Hormones
• The major organs of the endocrine system are
the:
–
–
–
–
Hypothalamus
Thyroid gland
Adrenal glands
Testes
– Pituitary gland
– Parathyroid glands
– Pancreas
– Ovaries
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Organs and Hormones
• Insulin is secreted when blood glucose levels
rise
• Glucagon is released when blood glucose
levels fall below normal
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hormonal Regulation
• The hypothalamus is the main integrative
center for the endocrine and autonomic
nervous systems
• It helps control some endocrine glands by
neural and hormonal pathways
• The hypothalamus also exerts hormonal
control at the anterior pituitary gland by
releasing and inhibiting hormones and factors,
which arrive by a portal system
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hormones
• Hormones are natural chemical substances
secreted into the bloodstream from the
endocrine glands that regulate and control the
activity of an organ or tissues in another part
of the body
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Endocrine Glands and
Their Hormones
•
•
•
•
Hypothalamus – GnRH, GHRH, TRH
Anterior Pituitary – GH, ACTH, TSH, LH, FSH, PRL
Posterior Pituitary – OT, ADH
Thyroid – T4, T3, Calcitonin
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Endocrine Glands and
Their Hormones
•
•
•
•
Parathyroid – PTH
Thymus – Thymosin
Pancreas – Insulin, Glucagon
Adrenal Cortex – Cortisol, Aldosterone, Androgens
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Endocrine Glands and
Their Hormones
• Adrenal Medulla – Epinephrine, Norepinephrine
• Testes – Testosterone
• Ovaries – Estrogen, Progesterone
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Pituitary Gland
• The pituitary gland is under the control of the
hypothalamus in the brain
• It is small, situated at the base of the brain
• It is also called the “master gland”
• It secretes hormones directly into the
bloodstream to control and regulate the other
endocrine glands
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Anterior Pituitary Gland
• The anterior lobe of the pituitary gland is
particularly important in sustaining life
• It secretes:
–
–
–
–
–
–
Growth hormone (somatotropin, GH)
Adrenocorticotropic hormone (ACTH)
Thyroid-stimulating hormone (TSH)
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Prolactin (PRL)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Posterior Pituitary Gland
• The posterior lobe of the pituitary gland, or the
neurohypophysis, is the release point of
antidiuretic hormone (ADH, or vasopressin)
and oxytocin
• It releases ADH when stimulated by the
hypothalamus
• The hormone acts on the distal and collecting
tubules of the kidneys
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Thyroid Gland
• The thyroid gland is located in the anterior
neck and is the largest of the endocrine glands
• It secretes 3 hormones essential for proper
regulation of metabolism:
– Thyroxine (T4)
– Triiodothyronine (T3)
– Calcitonin
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Parathyroid Glands
• Four tiny parathyroid glands lie along the
posterior surface of the thyroid gland
• They secrete parathyroid hormone (PTH or
parathormone)
• The stimulus for the release of PTH is a low
plasma level of calcium, targeting the bones,
digestive tract (intestines), and kidneys
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Adrenal Glands
• The adrenal glands are located at the top of
each kidney
• They consists of an outer cortex and an inner
medulla
• The cortex synthesizes glucocorticoids
(cortisol), mineralocorticoids (primarily
aldosterone) and androgens
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Pancreas
• The pancreas is one of the accessory organs of
the digestive system, located below the
stomach
• It produces digestive enzymes that are
deposited in the small intestine
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Pancreas
• The most important disease involving the
endocrine pancreas is diabetes mellitus, a
disorder of carbohydrate metabolism that
involves either:
– Insulin deficiency
– Insulin resistance
– Both insulin deficiency and resistance
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Gonadal Hormones
• Three main classes of steroid hormones are
produced by gonadal tissues:
– Estrogenic
– Progestational
– Androgenic
• The ovary is the primary site for synthesis and
secretion of estrogen and progestin hormones
in women
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Gonadal Hormones
• In men and postmenopausal women, the
principal source of estrogen is adipose tissue
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Ovarian Hormones
• The ovaries are known as gonads
• They produce ova and form endocrine
secretions that initiate and maintain the
secondary sex characteristics in women
• The gonadotropins from the pituitary gland are
responsible for the development and
maintenance of sexual gland functions
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Progesterone
• During a female’s reproductive years,
progesterone is secreted primarily by the
ovarian cells in the corpus luteum at the time
of ovulation
• The greatest amount of progesterone is
secreted during the week after ovulation has
taken place
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Progesterone
• It is responsible for the changes in the uterine
endometrium during the 2nd half of the
menstrual cycle
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Testicular Hormone
• The hypothalamus, anterior pituitary gland,
and testes secrete hormones that control male
reproductive functions
• These hormones initiate and maintain sperm
cell production and oversee the development
and maintenance of male secondary sex
characteristics
• Androgens include testosterone and
androsterone
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Cardiovascular System
• The cardiovascular system consists of the heart
and blood vessels
• The heart is a hollow muscular organ located
within the mediastinum, resting on the
diaphragm
• The heart is divided into two atria and two
ventricles
• The right atrium receives blood from the venae
cavae
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Cardiovascular System
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Blood Vessels
• The blood vessels include arteries, capillaries,
and veins
• The heart’s pumping forces blood through the
arteries, which connect to the smaller diameter
vessels
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Blood Vessels
• The tiniest tubes, the capillaries, are the sites
that exchange:
–
–
–
–
Nutrients
Electrolytes
Gases
Wastes
• Capillaries converge into venules, which in
turn converge into veins that return blood to
the heart
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Blood
• Blood consists of red blood cells, white blood
cells, and platelets suspended in a liquid
known as plasma
• It transports substances between body cells
and the external environment, helping to
maintain a stable internal environment
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Blood
• Red blood cells contain hemoglobin, which
combines with oxygen
• White blood cells are either:
– Granulocytes (neutrophils, eosinophils, and basophils)
– Agranulocytes (which include monocytes and
lymphocytes)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
White Blood Cell Actions
• Neutrophils and monocytes phagocytize foreign
particles
• Eosinophils kill parasites and help to control
inflammation and allergic reactions
• Basophils release heparin, which inhibits blood
clotting, and histamine, which increases blood
flow to injured tissues
• Lymphocytes produce antibodies that attack
specific foreign substances
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
White Blood Cells
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Lymphatic System
• The lymphatic system, like the cardiovascular
system, includes a network of vessels that
transport fluids
• It is made up of a vast collection of cells and
biochemicals that travel through lymphatic
vessels, as well as the organs and glands that
produce them
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Lymphatic System
• Special capillaries called lacteals are located in
the lining of the small intestine where they:
– Absorb digested fats
– Transport the digested fats to the venous circulation
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Lymphatic System and Immunity
• The lymphatic system consists of:
–
–
–
–
–
–
Lymph
Lymph nodes and vessels
Tonsils
Spleen
Thymus gland
Peyer’s patches (tissue found in the ileum of the small
intestine)
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Lymphatic System and Immunity
• Immunity against disease also protects against
toxins and cancer
• When the body’s immune response is not
normal, the result may be:
–
–
–
–
Infections
Cancers
Autoimmune disorders
Allergies
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Respiratory System
• The most important function of the respiratory
system is inspiration of oxygen and expiration
of carbon dioxide
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Respiratory System
• The respiratory system consists of
–
–
–
–
–
–
–
–
Nasal passages
Mouth
Pharynx
Larynx
Trachea
Lungs
Skeletal muscles of the chest wall
Diaphragm
(continues)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Respiratory System
• Lung bronchioles end in alveolar ducts and
sac-like clusters called alveolar sacs (alveoli)
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Urinary System
• Cells produce a variety of wastes that are toxic
if they accumulate
• The urinary system removes certain salts and
nitrogenous wastes, and helps maintain the
normal concentrations of water and
electrolytes in body fluids
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Urinary System
• The urinary system consists of:
–
–
–
–
Two kidneys
Ureters
Urinary bladder
Urethra
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Nephrons
• A kidney contains about 1 million nephrons
• Each nephron consists of a renal corpuscle
and a renal tubule
• The nephron begins as a double-walled globule
known as Bowman’s glomerular capsule
• A renal corpuscle is composed of a cluster of
blood capillaries called a glomerulus
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Structures of the Nephron
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Digestive System
• The digestive tract is a hollow tube extending
from the mouth to the anus
• Mechanical digestion is the breakdown of
large food particles into smaller pieces by
physical means
• Chemical digestion is the chemical alteration
of food
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Digestive System
• The digestive system basically consists of:
–
–
–
–
–
Mouth
Esophagus
Stomach
Liver
Large and small intestines
Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.