Anatomy & Physiology ppt.

1. Anatomy & Physiology
An Introduction

2. Anatomy - The study of the structure of
the human body
Physiology - The study of body function
An Overview of Anatomy

3. Chemical level – atoms form molecules
Cellular level – cells and their subunits
Tissue level – a group of cells performing a common function
Organ level – a discrete structure made up of more than one
tissue
Organ system – organs working together for a common
purpose
Organism – the result of all simpler levels working together
Structural Organization

4. Structural Organization

5. Forms external body
covering
Protects deeper tissues
from injury
Synthesizes vitamin D
Site of cutaneous
receptors (pain, pressure,
etc.) and sweat and oil
glands
The Integumentary
System

6. The Integumentary System
• Integument is skin
• Skin and its appendages make up the
integumentary system
• A fatty layer (hypodermis) lies deep to it
• Two distinct regions
– Epidermis
– Dermis

7. Functions of skin
• Protection
– Cushions and insulates and is waterproof
– Protects from chemicals, heat, cold, bacteria
– Screens UV
• Synthesizes vitamin D with UV
• Regulates body heat
• Prevents unnecessary water loss
• Sensory reception (nerve endings)

8. Epidermis
• Keratinized stratified squamous epithelium
• Four types of cells
– Keratinocytes – deepest, produce keratin (tough fibrous protein)
– Melanocytes - make dark skin pigment melanin
– Merkel cells – associated with sensory nerve endings
– Langerhans cells – macrophage-like dendritic cells
• Layers (from deep to superficial)
– Stratum basale or germinativum – single row of cells attached to dermis;
youngest cells
– Stratum spinosum – spinyness is artifactual; tonofilaments (bundles of
protein) resist tension
– Stratum granulosum – layers of flattened keratinocytes producing keratin
(hair and nails made of it also)
– Stratum lucidum (only on palms and soles)
– Stratum corneum – horny layer (cells dead, many layers thick)

9. Dermis
• Strong, flexible connective tissue: your “hide”
• Cells: fibroblasts, macrophages, mast cells, WBCs
• Fiber types: collagen, elastic, reticular
• Rich supply of nerves and vessels
• Critical role in temperature regulation (the vessels)
• Two layers (see next slides)
– Papillary – areolar connective tissue; includes dermal
papillae
– Reticular – “reticulum” (network) of collagen and reticular
fibers

10. *Dermis layers
*
*
*Dermal papillae

11. Hypodermis
• “Hypodermis” (Gk) = below the skin
• “Subcutaneous” (Latin) = below the skin
• Also called “superficial fascia”
“fascia” (Latin) =band; in anatomy: sheet of connective tissue
• Fatty tissue which stores fat and anchors skin
(areolar tissue and adipose cells)
• Different patterns of accumulation
(male/female)

12. Skin color
• Three skin pigments
– Melanin: the most important
– Carotene: from carrots and yellow vegies
– Hemoglobin: the pink of light skin
• Melanin in granules passes from melanocytes
(same number in all races) to keratinocytes in
stratum basale
– Digested by lysosomes
– Variations in color
– Protection from UV light vs vitamin D?

13. Skin appendages
• Derived from epidermis but extend into dermis
• Include
– Hair and hair follicles
– Sebaceous (oil) glands
– Sweat (sudoiferous) glands
– Nails

15. Nails
• Of hard keratin
• Corresponds to hooves and claws
• Grows from nail matrix

16. • Functions of hair
– Warmth – less in man than other mammals
– Sense light touch of the skin
– Protection - scalp
• Parts
– Root imbedded in skin
– Shaft projecting above skin surface
• Make up of hair – hard keratin
• Three concentric layers
– Medulla (core)
– Cortex (surrounds medulla)
– Cuticle (single layers, overlapping)

17. • Types of hair
– Vellus: fine, short hairs
– Intermediate hairs
– Terminal: longer, courser hair
• Hair growth: averages 2 mm/week
– Active: growing
– Resting phase then shed
• Hair loss
– Thinning – age related
– Male pattern baldness
• Hair color
– Amount of melanin for black or brown; distinct form of
melanin for red
– White: decreased melanin and air bubbles in the medulla
– Genetically determined though influenced by hormones
and environment

18. Sebaceous (oil) glands
• Entire body except palms and soles
• Produce sebum by holocrine secretion
• Oils and lubricates

19. Disorders of the integumentary system
• Burns
– Threat to life
• Catastrophic loss of body fluids
• Dehydration and fatal circulatory shock
• Infection
– Types
• First degree – epidermis: redness (e.g. sunburn)
• Second degree – epidermis and upper dermis: blister
• Third degree - full thickness
• Infections
• Skin cancer

20. SKELETON SYSTEM

21. – Protects and
supports body
organs
– Provides a
framework for
muscles
– Blood cells
formed within
bones
– Stores minerals
The Skeletal
System

22. Bone- hardest tiddue in body consist of 80% organic
and inorganic material and 20 % of water. Bone cells
are called osteocytes.
Func. of bones :- 1. provide framework to the body.
2. gives attachment to muscles and tendons
3. permit movement of the body as a whole and parts
of the body by forming joints.
4. are site of blood cells development
5. provide reservoir for calcium.

23. Joints- site at which any 2 or more bone come
together.Joint can be broadly classified as of 3
types :-
1. Fibrous or fixed joints-immovable, fibrous
tissue between bones. e.g.between bones of
the skull.
2. Cartilaginous or slightly movable joints-
have a pad of cartilaginous between ends of
bones making up the joints allowing very
slight movement caused by compression of
the pad. e.g joint between bones of vertebral
column.

24. 3. Synovial or freely movable joints- These joints
allows maximum movement and are classified
according to the range of movement possible.
a) ball and socket joint
b) Hinge joint
c)Gliding joint
d) pivot joint
e) Saddle joint

25. MUSCULAR SYSTEM

26. Allows
manipulation of
environment
Locomotion
Facial expression
Maintains posture
Produces heat
The Muscular System

27. The Muscular
System
• The ability to move is an
essential activity of the human
body
• ½ our body weight comes from
muscles
• Consists of over 600 individual
muscles.
• 3 purposes:
– Body movement
– Body shape
– Body heat (maintain temp.)

28. The Muscular
System
• Body movements are
determined by three
types of muscles
– Smooth (involuntary) –
cannot be controlled by
will.
– Cardiac – control the
contractions of the
heart.
– Skeletal (Voluntary) –
can be controlled by
will.

29. Function of Skeletal muscles
• Attach to bones to provide voluntary
movement
– Tendons: strong, tough connective cords
– Fascia: tough, sheet-like membrane
• Produce heat and energy for the body
• Help maintain posture
• Protect internal organs
• Called striated (striped) because they have
striations of alternating light and dark band

30. Functions cont’d.
• Fleshy body parts are made of skeletal
muscles
• Provide movements to the limbs, but
contract quickly, fatigue easily and lack the
ability to maintain contraction for long
periods
– Blinking eyes, talking, breathing, eating,
dancing and writing all produced by these
muscles

32. Function of Smooth Muscle
• Called smooth muscle because they are
unmarked by striations, small spindle shaped
• Unattached to bones, act slowly, do not tire
easily and can remain contracted for a long
time
• Not under conscious control so they are also
called involuntary muscles
• Found in walls of internal organs (intestines,
bladder, stomach, uterus, blood vessels)

33. Function of cardiac muscle
• Found only in the heart
• Involuntary muscle
• Requires a continuous supply of oxygen to
function
• Cardiac muscle cells begin to die after 30
seconds of oxygen cut-off
• Striated and branched

35. Characteristics of Muscles
• All muscles have 4 common characteristics
– Excitability – ability to respond to a stimulus
(ie: nerve impulse)
– Contractibility – muscle fibers that are
stimulated by nerves contract (become shorter)
and causes movement
– Extensibility – ability to be stretched
– Elasticity – allows the muscle to return to its
original shape after it has been stretched

36. • FIBROMYALGIA
• Chronic, widespread
pain in specific muscle
site; numbness and
tingling in arms or legs;
headaches
• Cause unknown
• Treat symptoms – pain
relief; stress reduction
and muscle relaxers
• MUSCULAR
DYSTROPHY
• Group of inherited
diseases that cause
chronic, progressive
muscle atrophy
resulting in total
disability and early
death
• No cure
• Treatment used to slow
progression of disease

37. • MYASTENIA GRAVIS
• Chronic condition where
nerve impulses are not
transmitted correctly
leading to progressive
muscular weakness and
paralysis; affects respiratory
muscles and can be fatal
• Cause unknown
• Treatment is supportive
• MUSCLE
SPASMS/CRAMPS
• Sudden, painful involuntary
muscle contractions
• Caused from overexertion,
low electrolytes or poor
circulation
• Treat by applying gentle
pressure and stretching of the
affected muscle

38. • STRAIN
• Overstretching of a
muscle or tendon
frequently in legs, back
or arms
• Caused by sudden
muscle exertion
• Treated by resting,
muscle relaxants, or
pain medications,
elevation of extremity
and applying hot/cold
compresses

39. NERVOUS SYSTEM

40. Fast-acting control
system
Responds to
internal and external
changes
The Nervous System

41. Peripheral Nervous System
• 3 kinds of neurons connect CNS
to the body
– sensory
– motor
– interneurons
• Motor - CNS to muscles and
organs
• Sensory - sensory receptors to
CNS
• Interneurons: Connections
Within CNS
Spinal
Cord
Brain
Nerves

42. Peripheral Nervous System
Skeletal
(Somatic)
Sympathetic Parasympathetic
Autonomic
Peripheral Nervous System

43. Somatic System
• Nerves to/from spinal cord
– control muscle
movements
– somatosensory inputs
• Both Voluntary and reflex
movements
• Skeletal Reflexes
– simplest is spinal reflex
arc
Muscle
Motor
Neuron
Interneuron
Skin receptors
Sensory
Neuron
Brain

44. Autonomic System
• Two divisions:
– sympathetic
– Parasympatheitic
• Control involuntary functions
– heartbeat
– blood pressure
– respiration
– perspiration
– digestion
• Can be influenced by thought and emotion

45. Sympathetic
• “ Fight or flight” response
• Release adrenaline and
noradrenaline
• Increases heart rate and blood
pressure
• Increases blood flow to skeletal
muscles
• Inhibits digestive functions
CENTRAL NERVOUS SYSTEM
Brain
Spinal
cord
SYMPATHETIC
Dilates pupil
Stimulates salivation
Relaxes bronchi
Accelerates heartbeat
Inhibits activity
Stimulates glucose
Secretion of adrenaline,
nonadrenaline
Relaxes bladder
Stimulates ejaculation
in male
Sympathetic
ganglia
Salivary
glands
Lungs
Heart
Stomach
Pancreas
Liver
Adrenal
gland
Kidney

46. Parasympathetic
• “ Rest and digest ”
system
• Calms body to
conserve and
maintain energy
• Lowers heartbeat,
breathing rate,
blood pressure
CENTRAL NERVOUS SYSTEM
Brain
PARASYMPATHETIC
Spinal
cord
Stimulates salivation
Constricts bronchi
Slows heartbeat
Stimulates activity
Contracts bladder
Stimulates erection
of sex organs
Stimulates gallbladder
Gallbladder
Contracts pupil

47. Central Nervous System
• Brain and Spinal Cord
Spinal
Cord
Brain

48. Problems from lack of
movement• Contractures
– Tightening and shortening of a muscle resulting in a
permanent flexing of a joint
• Muscle atrophy
– Muscles become weak and joints become stiff
• Circulatory impairment
– Blood clots and pressure ulcers can develop
• Mineral loss
– Especially calcium from the bones making bones brittle
and easily to be fractured
• Other problems
– Poor appetite; constipation; urinary infections; respiratory
problems; and pneumonia

49. • Left & Right sides are separate
• Corpus Callosum : major
pathway between hemispheres
• Some functions are ‘lateralized’
– language on left
– math, music on right
• Lateralization is never 100%
Brain has 2 Hemispheres
Left
Hemisphere
Corpus Callosum
Right
Hemisphere

50. Each hemisphere is
divided into 4 lobes
Frontal
Parietal
Occipital
Temporal

51. Localization of function
Frontal
Parietal
Occipital
Temporal

52. The Nervous System: Summary
• Major structures of the nervous
system
– CNS: Brain & Spinal Cord
– PNS: Somatic, Autonomic (Sympathetic &
Parasympathetic)
– Two hemispheres & 4 lobes
• Organization
– Afferent (sensory) neurons-towards CNS
– Efferent (motor) neurons-away from CNS
– Sympathetic-speeds up
– Parasympathetic-slows down
Central Nervous System
Peripheral Nervous System

53. The Nervous System:
Summary

54. ENDOCRINE SYSTEM

55. Glands secrete
hormones that regulate
Growth
Reproduction
Nutrient use
The Endocrine
System

56. Endocrine Overview
• Hormones- chemical
messengers travel through
body
• Target cell or organ- organ
or cells that a hormone
affects

57. Anterior Pituitary Gland
• Growth Hormone (GH)- affects growth of
skeletal muscles and bones
• Prolactin (PRL)- stimulates milk production
after pregnancy
• Gonadotropic- regulates hormone activity
of sex organs
• Also effects adrenal cortex and thyroid
hormone release

58. Posterior Pituitary
• Oxytocin- helps during
pregnancy
• Antidiuretic hormone
(ADH)- inhibits urine
production
– Alcohol inhibits ADH
causing increased output
of urine

59. Thyroid Gland
• Thyroid hormone
– Controls the rate at
which glucose is
“burned”
• Calcitonin
– Decreases calcium
levels in blood deposits
on bone

60. Parathyroid Gland
• Parathyroid hormone
(PTH)- regulates
Ca2+ in blood
– If Ca2+ level drops
bones is broken down

61. Adrenal Gland
• Adrenal Cortex
– Releases hormones that
regulate mineral content in
blood
• Adrenal Medulla
– Produces epinephrine and
norepinephrine
– Helps with stressful situations

62. Pancreas
• Insulin- increases glucose
uptake into cells and
stores in liver
• Glucagon- stimulates
breakdown of glucose
stores in the liver

63. Pineal Gland
• Melatonin
– Establishes body’s day/ night cycle

64. Thymus
• Thymosin
– “Programs” T cells

65. Gonads
• Androgens (male)- sperm formation,
development of male char
• Estrogens (female)- development of female
char

66. The Circulatory System
The Heart, Blood Vessels, Blood Types

67. The Closed Circulatory System
•Humans have a closed circulatory system, typical of
all vertebrates, in which blood is confined to vessels
and is distinct from the interstitial fluid.
–The heart pumps blood into large vessels
that branch into smaller ones leading into the organs.
–Materials are exchanged by diffusion between the blood
and the interstitial fluid bathing the cells.

68. The Cardiovascular System
•Three Major Elements –
Heart, Blood Vessels, & Blood
–1. The Heart- cardiac muscle
tissue
–highly interconnected cells
–four chambers
•Right atrium
•Right ventricle
•Left atrium
•Left ventricle

70. Pathway of the
blood
•Superior Vena Cava
•Right Atrium
•Tricuspid Valve
•Right Ventricle
•Pulmonary Semilunar Valve
•Lungs
•Pulmonary Vein
•Bicuspid Valve
•Left Ventricle
•Aortic Semilunar Valve
•Aorta
•To the bodies organs & cells

71. The Cardiovascular System
2. Blood Vessels -A network of tubes
–Arteriesarterioles move away from the heart
•Elastic Fibers
•Circular Smooth Muscle
–Capillaries – where gas exchange takes place.
•One cell thick
•Serves the Respiratory System
–VeinsVenules moves towards the heart
•Skeletal Muscles contract to force blood back from legs
•One way values
•When they break - varicose veins form

72. The Cardiovascular System
3. The Blood
A. Plasma
Liquid portion of the blood.
Contains clotting factors,
hormones, antibodies, dissolved
gases, nutrients and waste

73. The Cardiovascular System
•The Blood
B. Erythrocytes - Red Blood
Cells
–Carry hemoglobin and
oxygen. Do not have a
nucleus and live only about
120 days.
–Can not repair themselves.

74. The Cardiovascular System
•The Blood
C. Leukocytes – White Blood
cells
–Fight infection and are formed in
the bone marrow
–Five types – neutrophils,
lymphocytes, eosinophils,
basophils, and monocytes.

75. The Cardiovascular System
The Blood
•D. Thrombocytes – Platelets.
–These are cell fragment that are
formed in the bone marrow from
magakaryocytes.
–Clot Blood by sticking together
– via protein fibers called fibrin.

76. Disorders of the Circulatory System
• Anemia - lack of iron in the blood, low RBC count
• Leukemia - white blood cells proliferate wildly, causing anemia
• Hemophilia - bleeder’s disease, due to lack of fibrinogen in
thrombocytes
• Heart Murmur - abnormal heart beat, caused by valve problems
• Heart attack - blood vessels around the heart become blocked with
plaque, also called myocardial infarction

77. Functions of the Heart
• Generating blood pressure
• Routing blood
– Heart separates pulmonary and systemic circulations
• Ensuring one-way blood flow
– Heart valves ensure one-way flow
• Regulating blood supply
– Changes in contraction rate and force match blood
delivery to changing metabolic needs

78. Size, Shape, Location
of the Heart
•Size of a closed fist
•Shape
–Apex: Blunt rounded
point of cone
–Base: Flat part at
opposite of end of cone
•Located in thoracic
cavity in mediastinum

79. Heart Wall
• Three layers of tissue
– Epicardium: This serous membrane of smooth
outer surface of heart
– Myocardium: Middle layer composed of
cardiac muscle cell and responsibility for heart
contracting
– Endocardium: Smooth inner surface of heart
chambers

80. External Anatomy
•Four chambers
–2 atria
–2 ventricles
•Auricles
•Major veins
–Superior vena cava
–Pulmonary veins
•Major arteries
–Aorta
–Pulmonary trunk

81. Heart Valves
•Atrioventricular
–Tricuspid
–Bicuspid or mitral
•Semilunar
–Aortic
–Pulmonary
•Prevent blood from
flowing back

82. Blood Flow Through Heart

83. The Cardiovascular System
Blood vessels transport
blood
Carries oxygen and carbon
dioxide
Also carries nutrients and
wastes
Heart pumps blood through
blood vessels

84. The Cardiovascular System
Blood vessels transport
blood
Carries oxygen and carbon
dioxide
Also carries nutrients and
wastes
Heart pumps blood through
blood vessels

85. Conducting System of Heart

86. Cardiac Arrhythmias
• Tachycardia: Heart rate in excess of 100bpm
• Bradycardia: Heart rate less than 60 bpm
• Sinus arrhythmia: Heart rate varies 5% during
respiratory cycle and up to 30% during deep
respiration
• Premature atrial contractions: Occasional shortened
intervals between one contraction and succeeding,
frequently occurs in healthy people

87. Cardiac Cycle
• Heart is two pumps that work together, right and
left half
• Repetitive 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

88. Heart Sounds
• First heart sound or “lubb”
– Atrioventricular valves and surrounding fluid vibrations as valves
close at beginning of ventricular systole
• Second heart sound or “dupp”
– Results from closure of aortic and pulmonary semilunar valves at
beginning of ventricular diastole, lasts longer
• Third heart sound (occasional)
– Caused by turbulent blood flow into ventricles and detected near
end of first one-third of diastole

89. Location of Heart Valves

90. Mean Arterial Pressure (MAP)
• Average blood pressure in aorta
• MAP=CO x PR
– CO is amount of blood pumped by heart per
minute
• CO=SV x HR
– SV: Stroke volume of blood pumped during each heart beat
– HR: Heart rate or number of times heart beats per minute
• Cardiac reserve: Difference between CO at rest and
maximum CO
– PR is total resistance against which blood must be
pumped

91. Picks up fluid leaked from
blood vessels
Disposes of debris in the
lymphatic system
Houses white blood cells
(lymphocytes)
Mounts attack against
foreign substances in the
body
The Lymphatic System

92. RESPIRATORY SYSTEM

93. Keeps blood supplied with oxygen
Removes carbon dioxide
Gas exchange occurs through walls of air sacs in
the lungs
The Respiratory
System

94. Organization and Functions of
the Respiratory System
• Consists of an upper respiratory tract (nose to larynx)
and a lower respiratory tract ( trachea onwards) .
• Conducting portion transports air.
- includes the nose, nasal cavity, pharynx, larynx,
trachea, and progressively smaller airways, from the
primary bronchi to the terminal bronchioles
• Respiratory portion carries out gas exchange.
- composed of small airways called respiratory
bronchioles and alveolar ducts as well as air sacs
called alveoli

96. Respiratory System Functions
1. supplies the body with oxygen and
disposes of carbon dioxide
2. filters inspired air
3. produces sound
4. contains receptors for smell
5. rids the body of some excess water and
heat
6. helps regulate blood pH

97. Breathing
• Breathing (pulmonary ventilation).
consists of two cyclic phases:
• inhalation, also called inspiration - draws
gases into the lungs.
• exhalation, also called expiration - forces
gases out of the lungs.

98. Upper Respiratory Tract
• Composed of the nose and nasal
cavity, paranasal sinuses, pharynx
(throat), larynx.
• All part of the conducting portion of the
respiratory system.

99. Respiratory mucosa
• A layer of pseudostratified ciliated
columnar epithelial cells that
secrete mucus
• Found in nose, sinuses, pharynx, larynx
and trachea
• Mucus can trap contaminants
– Cilia move mucus up towards mouth

100. Nose
• Internal nares - opening to exterior
• External nares opening to pharynx
• Nasal conchae - folds in the mucous
membrane that increase air turbulence
and ensures that most air contacts the
mucous membranes

101. Nose
rich supply of capillaries warm the inspired air
• olfactory mucosa – mucous membranes that
contain smell receptors
• respiratory mucosa – pseudostratified ciliated
columnar epithelium containing goblet cells that
secrete mucus which traps inhaled particles,
• lysozyme kills bacteria and lymphocytes and
• IgA antibodies that protect against bacteria

102. Nose
provides and airway for respiration
• moistens and warms entering air
• filters and cleans inspired air
• resonating chamber for speech
detects odors in the air stream
rhinoplasty: surgery to change shape of
external nose

103. Paranasal Sinuses
• Four bones of the skull contain paired air
spaces called the paranasal sinuses -
frontal, ethmoidal, sphenoidal,
maxillary
• Decrease skull bone weight
• Warm, moisten and filter incoming air
• Add resonance to voice.
• Communicate with the nasal cavity by ducts.
• Lined by pseudostratified ciliated
columnar epithelium.

104. Pharynx
• Common space used by both the
respiratory and digestive systems.
• Commonly called the throat.
• Originates posterior to the nasal and
oral cavities and extends inferiorly near
the level of the bifurcation of the larynx
and esophagus.
• Common pathway for both air and food.

105. Nasopharynx
• Superior-most region of the pharynx. Covered with
pseudostratified ciliated columnar epithelium.
• Located directly posterior to the nasal cavity and superior
to the soft palate, which separates the oral cavity.
• Normally, only air passes through.
• Material from the oral cavity and oropharynx is typically
blocked from entering the nasopharynx by the uvula of
soft palate, which elevates when we swallow.
• In the lateral walls of the nasopharynx, paired
auditory/eustachian tubes connect the nasopharynx
to the middle ear.
• Posterior nasopharynx wall also houses a single
pharyngeal tonsil (commonly called the adenoids).

106. Laryngopharynx
• Inferior, narrowed region of the pharynx.
• Extends inferiorly from the hyoid bone to the
larynx and esophagus.
• Terminates at the superior border of the
esophagus and the epiglottis of the larynx.
• Lined with a nonkeratinized stratified
squamous epithelium.
• Permits passage of both food and air.

107. Lower Respiratory Tract
• Conducting airways (trachea, bronchi,
up to terminal bronchioles).
• Respiratory portion of the respiratory
system (respiratory bronchioles,
alveolar ducts, and alveoli).

108. Larynx
• Voice box is a short, somewhat cylindrical
airway ends in the trachea.
• Prevents swallowed materials from entering
the lower respiratory tract.
• Conducts air into the lower respiratory tract.
• Produces sounds.
• Supported by a framework of nine pieces of
cartilage (three individual pieces and three
cartilage pairs) that are held in place by
ligaments and muscles.

109. Larynx
• Muscular walls aid in voice production and
the swallowing reflex
• Glottis – the superior opening of the larynx
• Epiglottis – prevents food and drink from
entering airway when swallowing
• pseudostratified ciliated columnar
epithelium

110. Conducting zone of lower
respiratory tract

111. Trachea
• A flexible tube also called windpipe.
• Extends through the mediastinum and lies anterior to
the esophagus and inferior to the larynx.
• Anterior and lateral walls of the trachea supported by
15 to 20 C-shaped tracheal cartilages.
• Cartilage rings reinforce and provide rigidity to the
tracheal wall to ensure that the trachea remains open
at all times
• Posterior part of tube lined by trachealis muscle
• Lined by ciliated pseudostratified columnar
epithelium.

112. Respiratory Zone of Lower Respiratory
Tract

113. Conduction vs. Respiratory
zones
• Most of the tubing in the lungs makes up
conduction zone
– Consists of nasal cavity to terminal bronchioles
• The respiratory zone is where gas is exchanged
– Consists of alveoli, alveolar sacs, alveolar ducts
and respiratory bronchioles

114. Respiratory Bronchioles,
Alveolar Ducts, and Alveoli
• Lungs contain small saccular outpocketings called
alveoli.
• They have a thin wall specialized to promote
diffusion of gases between the alveolus and the
blood in the pulmonary capillaries.
• Gas exchange can take place in the respiratory
bronchioles and alveolar ducts as well as in
the alveoli, each lung contains approximately 300
to 400 million alveoli.
• The spongy nature of the lung is due to the packing
of millions of alveoli together.

115. Gross Anatomy of the Lungs
• Each lung has a conical shape. Its wide, concave
base rests upon the muscular diaphragm.
• Its superior region called the apex projects superiorly
to a point that is slightly superior and posterior to the
clavicle.
• Both lungs are bordered by the thoracic wall
anteriorly, laterally, and posteriorly, and supported by
the rib cage.
• Toward the midline, the lungs are separated from
each other by the mediastinum.
• The relatively broad, rounded surface in contact with
the thoracic wall is called the costal surface of the
lung.

116. Lungs
Left lung
• divided into 2 lobes by oblique fissure
• smaller than the right lung
• cardiac notch accommodates the heart
Right
• divided into 3 lobes by oblique and horizontal
fissure
• located more superiorly in the body due to liver on
right side

117. Pleura and Pleural Cavities
• The outer surface of each lung and the
adjacent internal thoracic wall are lined by a
serous membrane called pleura.
• The outer surface of each lung is tightly
covered by the visceral pleura.
• while the internal thoracic walls, the lateral
surfaces of the mediastinum, and the superior
surface of the diaphragm are lined by the
parietal pleura.
• The parietal and visceral pleural layers are
continuous at the hilus of each lung.

118. Blood supply of Lungs
• pulmonary circulation -
• bronchial circulation – bronchial arteries supply
oxygenated blood to lungs, bronchial veins carry
away deoxygenated blood from lung tissue 
superior vena cava
• Response of two systems to hypoxia –
pulmonary vessels undergo vasoconstriction
bronchial vessels like all other systemic vessels
undergo vasodilation

119. Respiratory events
• Pulmonary ventilation = exchange of
gases between lungs and atmosphere
• External respiration = exchange of gases
between alveoli and pulmonary capillaries
• Internal respiration = exchange of gases
between systemic capillaries and tissue cells

120. Two phases of pulmonary
ventilation
• Inspiration, or inhalation - a very active process
that requires input of energy.The diaphragm,
contracts, moving downward and flattening, when
stimulated by phrenic nerves.
• Expiration, or exhalation - a passive process that
takes advantage of the recoil properties of elastic
fiber. ･ The diaphragm relaxes.The elasticity of
the lungs and the thoracic cage allows them to
return to their normal size and shape.

121. DIGESTIVE SYSTEM

122. Breaks down food into absorbable units
Indigestible foodstuffs eliminated as feces
The Digestive System

123. Introduction
There are four stages to
food processing:
1.Ingestion: taking in food
2.Digestion: breaking down
food into nutrients
3.Absorption: taking in
nutrients by cells
4.Egestion: removing any
leftover wastes

124. The Human Digestive System
• Begins when food
enters the mouth.
• It is physically broken
down by the teeth.
• It is begun to be
chemically broken
down by amylase, an
enzyme in saliva that
breaks down
carbohydrates.

125. The Human Digestive System
• The tongue moves the
food around until it
forms a ball called a
bolus.
• The bolus is passed to
the pharynx (throat) and
the epiglottis makes
sure the bolus passes
into the esophagus and
not down the windpipe!

126. The Human Digestive System
• The bolus passes down
the esophagus by
peristalsis.
• Peristalsis is a wave of
muscular contractions
that push the bolus
down towards the
stomach.

127. The Human Digestive System
• To enter the stomach,
the bolus must pass
through the lower
esophageal sphincter, a
tight muscle that keeps
stomach acid out of the
esophagus.

128. The Human Digestive System
• The stomach has folds
called rugae and is a big
muscular pouch which
churns the bolus
(Physical Digestion)
and mixes it with gastric
juice, a mixture of
stomach acid, mucus
and enzymes.

129. The Human Digestive System
The acid kills off any
invading bacteria or
viruses.
The enzymes help break
down proteins and lipids.
Chemical Digestion.
The mucus protects the
lining of the stomach from
being eaten away by the
acid.

130. The Human Digestive System
The stomach does do
some absorption too.
Some medicines (i.e.
aspirin), water and alcohol
are all absorbed through
the stomach.
The digested bolus is now
called chyme and it leaves
the stomach by passing
through the pyloric
sphincter.

131. The Human Digestive System
• Chyme is now in the
small intestine.
• The majority of
absorption occurs here.
• The liver and pancreas
help the small intestine
to maximize absorption.
• The small intestine is
broken down into three
parts:

132. The Human Digestive System
1. Duodenum
• Bile, produced in the
liver but stored in the
gall bladder, enters
through the bile duct.
It breaks down fats.
• The pancreas secretes
pancreatic juice to
reduce the acidity of
the chyme.

133. The Human Digestive System
2. Jejunum
• The jejunum is where
the majority of
absorption takes place.
• It has tiny fingerlike
projections called villi
lining it, which
increase the surface
area for absorbing
nutrients.

134. The Human Digestive System
• Each villi itself has tiny fingerlike projections called
microvilli, which further increase the surface area
for absorption.

135. The Human Digestive System
3. Ileum
• The last portion of the
small intestine is the
ileum, which has fewer
villi and basically
compacts the leftovers
to pass through the
caecum into the large
intestine.

136. The Human Digestive System
• The large intestine (or
colon) is used to absorb
water from the waste
material leftover and to
produce vitamin K and
some B vitamins using
the helpful bacteria that
live here.

137. The Human Digestive System
• All leftover waste is
compacted and stored at
the end of the large
intestine called the
rectum.
• When full, the anal
sphincter loosens and
the waste, called feces,
passes out of the body
through the anus.

138. Digestion and Homeostasis
• The endocrine, nervous,
digestive and
circulatory systems all
work together to control
digestion.
• Before we eat, smelling
food releases saliva in
our mouths and gastrin
in our stomachs which
prepares the body for a
snack.
The Hormone Gastrin

139. Digestion and Homeostasis
A large meal activates
receptors that churn the
stomach and empty it
faster.
If the meal was high in
fat, digestion is slowed,
allowing time for the fat to
be broken down.
Hence why we feel fuller
after eating a high fat
meal.

140. THE IMMUNE SYSTEM
Immune system has three main function:-
1.To fight against invading pathogens to defend the
body.
2.Immune surveillance (inspection).
3.Get rid of worn- out body cells.

141. Bacteria and microbes cause several diseases in man.
Normally our body is able to defend against most
diseases causing microbes. Usually bacteria are
engulfed and rapidly destroyed by the WBC.
The resistance of a body to a disease is called
immunity.
The foreign microbes or toxins produced by them
may act as antigens, which in turn cause formation
of antibodies.
Part of antibodies sometimes remain in the blood
plasa and this seems to protect the individual from
future attacks.

142. Immune system consists of white blood cells,
lymphatics and some other organs involved in body
like liver and spleen.

143. Overall function is to produce offspring
Testes produce sperm and male sex hormones
Ovaries produce eggs and female sex hormones
Mammary glands produce milk
Reproductive System

144. Eliminates
nitrogenous wastes
Regulates water,
electrolyte, and acid-
base balance
The Urinary
System

145. Thank you for your
attention