Download BIOL 4260 Human Evolu$onary Anatomy Lecture 6: Trunk and

BIOL 4260 Human Evolu3onary Anatomy Lecture 6: Trunk and Respiratory Anatomy Lecture 2: Fossil Record
Appositional Bone Growth
- increases diameter of bone
Q: As you grow, how much wider do your bones get? Bone Remodeling
Bone is dynamic living tissue
•  500 mg of calcium may enter or leave the adult skeleton each day. •  Cancellous bone of the skeleton is replaced every 3 – 4 years •  Compact bone is replaced every 10 years •  Other real life examples: •  Realignment of teeth by orthodon3st •  Shrinking of bone following disuse •  Hardening of bone with exercise Bone Remodeling
•  Bone deposit and removal
•  Occurs at periosteal and endosteal surfaces •  Bone remodeling
•  Bone deposi.on – accomplished by osteoblasts (blast=Greek germinate) •  Bone reabsorp.on – accomplished by osteoclasts (clast=Greek to break). •  Summary: Bone remodeling is coordinated by a fine mix of osteoblast, osteocyte ac.vity •  Control: •  Indirectly via Calcium regula.on •  Directly arising from stresses Vertebral Column
Dual pillar system
for weight
bearing:
anterior/ventral
pillar (bodies) &
posterior/dorsal
pillar (arch)
Monotonic
increase in size of
body
The Axial Skeleton
80 named bones
Consists of:
skull-­‐22 bones associated bones Hyoid+6 auditory bones vertebral column bony thorax Support for head, neck,
trunk
Protection
The Vertebral Column
•  Formed from 26 bones in the adult
•  Supports and transmits weight of head, neck and
trunk to the appendicular skeleton of lower limbs
•  Surrounds and protects the spinal cord
•  Serves as attachment sites for the ribs and muscles
of the neck and back
¨ 
Held in place by ligaments
¤  Anterior and posterior longitudinal ligaments
¤  Ligamentum flavum
¤  Others
The Vertebral Column regions and Normal
curvatures
Vertebral column is divided into five major regions Four dis.nct curvatures give vertebral column an S-­‐shape Normal Curvatures
•  Four distinct curvatures give vertebral column
an S-shape
•  Primary: Thoracic and sacral curvatures •  Are convex posteriorly •  Secondary: Cervical and lumbar curvature •  Are concave posteriorly •  Curvatures increase the resilience of the spine
•  Note: In fetus, only the primary curves
present. Column therefore C shaped
Abnormal curvatures
•  Abnormal spinal curvatures
•  Scoliosis – an abnormal lateral curvature •  Kyphosis – an exaggerated thoracic curvature •  Lordosis – an accentuated lumbar curvature – “swayback” •  Stenosis of the lumbar spine
•  A narrowing of the vertebral canal General features of vertebrae
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A. Centrum-aka body: weight bearing
•  Separated by IV discs B. Pedicle paired: Encloses posteriolateral
C. Lamina paired
D. Spinous process
E. Transverse process paired
F. Neural arch b+c. Some people say
“A” contributes to arch. Not entirely accurate
G. Intervertebral disc
H. Articular facets
Ligaments and Intervertebral Discs
Herniated Disc
•  May be caused by
trauma to the
spine
•  Aging is also a
contributing factor
•  Nucleus pulposes loses cushioning proper3es •  Anulus fibrosis weakens Herniated Disc
Rib Formation
Derived from costal processes
of thoracic vertebrae
Rib Anatomy
•  Head (with articular facets)
Neck
•  Tubercle (with articular facet)
Posterior angle
•  Body/shaft
Costal groove
Sternum
Manubrium, body, xiphoid process
Articulates with clavicle and typically 7
ribs (via costal cartilage)
Only bony contact between shoulder
girdle and axial skeleton
Respiratory System
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8 Functions of the Respiratory System
• Air inhalation
• Provides site for exchange of oxygen and CO2
• Provides protection against invading pathogens
• By moving air, produces sound
• Olfaction
• Assists in the regulation of blood volume, blood
pressure, and body fluid pH
Division of respiratory system
Functional
Conduction pathway (non collapsible) tubes
Exchange surfaces (lungs)
Anatomical division
Upper respiratory system
Lower respiratory
Anatomic Division of respiratory system
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Nose
Nasal cavity
Sinuses
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
Alveoli
Upper respiratory system
Lower respiratory system
Figure 24.1 Structures of the Respiratory System
Frontal sinus
Nasal cavity
Nasal conchae
Nose
Sphenoidal sinus
UPPER
RESPIRATORY
SYSTEM
LOWER
RESPIRATORY
SYSTEM
Clavicle
Internal nares
Tongue
Nasopharynx
Hyoid bone
Larynx
Esophagus
Trachea
Bronchus
Bronchioles
RIGHT
LUNG
Ribs
LEFT
LUNG
Diaphragm
Air pathway
•  Air enters the
external nares
•  Passes by the nasal
vestibule
• Area surrounded
by the two pairs
of alar cartilage
Air pathway
Air enters the nasal vestibule and flows in and
around the nasal conchae
Q: Func3on? Sinuses of nasal cavity
•  Spaces in frontal,
maxillary, ethmoid and
sphenoid bones
•  Continuous with nasal
cavity
•  Thin respiratory
epithelium with cilia
•  Fewer goblet cells
The Lower Respiratory System
The Larynx
•  A cylinder whose
cartilaginous walls
are stabilized by
ligaments or skeletal
muscles or both
•  Level of vertebrae C4
or C5 to C7
Anatomy of the Larynx
Anatomy
of the
Larynx
The Vocal Cords
Fig. 24-­‐5 30 The Lower Respiratory System
•  Air passing between the vocal cords creates sound
•  Pitch - diameter, length, and tension in the vocal
cords
• Children have slender, short vocal folds • At puberty, male vocal cords of males thicker • Amplification of sound - sinus cavities
• Sound articulation - lips, tongue, and cheeks
Breathing vs. Swallowing
Figure 24.8 Movements of the Larynx during Swallowing
Tongue forces
compacted bolus
into oropharynx.
Hard palate
Soft palate
Tongue
Bolus
Epiglottis
Larynx
Trachea
Laryngeal movement
folds epiglottis;
pharyngeal muscles
push bolus into
esophagus.
Soft palate
Bolus
Epiglottis
Bolus moves along
esophagus; larynx
returns to normal
position.
Epiglottis
Bolus
Trachea
The Trachea
•  About 2.5 cm in diameter •  Contains tracheal car3lage • Each car3lage ring is actually C-­‐shaped, not a complete ring • annular ligaments connect adjacent rings • Respiratory epithelia Hyoid
bone
Larynx
Annular
ligaments
Trachea
Tracheal
cartilages
Location of carina
(internal ridge)
Root of
right lung
Root of
left lung
Superior
lobar bronchus
Lung
tissue
Primary
bronchi
Superior
lobar bronchus
Secondary
bronchi
Middle lobar
bronchus
Inferior
lobar bronchi
RIGHT LUNG
LEFT LUNG
Anterior view showing the plane of section for part (b)
ANTERIOR AND POSTERIOR VIEWS OF TRACHEA IN SITU
anterior
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6 Esophagus
Trachealis
muscle
Lumen of
trachea
Thyroid
gland
Respiratory
epithelium
Tracheal
cartilage
The trachea
Histological cross-sectional view of the trachea
showing its relationship to surrounding structures
LM × 3
The Primary Bronchi
•  The left and right primary bronchi branch
off the trachea at the area of the carina
The Primary Bronchi
• The right primary
bronchus is steeper
and larger in
diameter than the
left
**Children can aspirate foreign
objects more commonly onto
the right lung**
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0 Structure of the Pulmonary Bronchi
•  Outside the lungs – extrapulmonary; inside the
lungs they are called intrapulmonary bronchi
•  Each primary bronchus divides to form:
• Secondary bronchi and tertiary bronchi
• Bronchopulmonary segment
Bronchial Tree and Lung Divisions
Detailed Branching of the Primary Bronchi
•  Right lung
•  10 tertiary bronchi and therefore 10
bronchopulmonary segments
•  Left lung
•  8 or 9 segments
•  Trachea and primary bronchi - rings of cartilage
•  Secondary and tertiary - cartilage plates
•  Bronchioles - no cartilage
The Bronchioles
•  Ø = 0.3–0.5 mm
•  Self-supporting
•  Smooth muscle for bronchodilation
(sympathetic stimulation) and bronchoconstriction
(parasympathetic stimulation)
•  Bronchioles: clusters of alveolar sacs
Figure 24.13a Bronchi and Bronchioles
Trachea
Respiratory
epithelium
Bronchiole
Bronchial artery (red),
vein (blue), and
nerve (yellow)
Left
primary
bronchus
Visceral
pleura
Branch of
pulmonary
artery
Smooth muscle
around terminal
bronchiole
Terminal
bronchiole
Secondary
bronchus
Tertiary
bronchi
Respiratory
bronchiole
Elastic fibers
Smaller
bronchi
Bronchioles
Branch of
pulmonary
vein
Capillary
beds
Terminal bronchiole
Respiratory bronchiole
Arteriole
Lymphatic
vessel
Alveolar
duct
Alveoli
Alveoli in a
pulmonary
lobule
Bronchopulmonary
segment
Alveolar sac
Interlobular
septum
Visceral pleura
Pleural cavity
Parietal pleura
The structure of one portion of a single pulmonary lobule
Alveolar Ducts and Alveoli
•  150 million alveoli per lung
•  Extensive network of capillaries surround
each alveolus
• Gas exchange
•  Elastic tissue surrounds each alveolus
The Pleural Cavities and Pleural Membranes
Each lung is lined by a serous membrane
•  Visceral pleura
•  Parietal pleura
•  Pleural cavity
Respiratory Muscles and Pulmonary Ventilation
The muscles involved in pulmonary ventilation
(breathing) are:
•  Diaphragm
•  Contracts (lowers) to cause inhalation
•  Relaxes (raises) to cause exhalation
•  External intercostals
•  Elevate the ribs to aid in inhalation
•  Internal intercostals
•  Depress the ribs to aid in exhalation
Ribs and
sternum
elevate
Diaphragm
contracts
As the ribs are elevated or the diaphragm is
depressed, the volume of the thoracic cavity
increases and air moves into the lungs. The outward
movement of the ribs as they are elevated resembles
the outward swing of a raised bucket handle.
Accessory Muscles
of Inspiration
External intercostal muscles
Sternocleidomastoid
muscle
Scalene muscles
Accessory Muscles
of Exhalation
Internal intercostal
muscles
Pectoralis
minor muscle
Transversus thoracis
muscle
Serratus
anterior muscle
External oblique
muscle
Diaphragm
Rectus abdominus
Internal oblique
muscle
The primary and accessory
muscles of respiration
Pneumothorax
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