Introduction
• Anatomy and physiology affect your life
everyday
– Anatomy is the oldest medical science
• 1600 B.C.
– Physiology is the study of function
• Biochemistry
• Biology
• Chemistry
• Genetics
Introduction
• Study strategies crucial for success
– Attend all lectures, labs, and study sessions
– Read your lecture and laboratory assignments before
going to class or lab
– Devote a block of time each day to your A&P course
– Set up a study schedule and stick to it
– Do not procrastinate!
– Approach the information in different ways
– Develop the skill of memorization, and practice it
regularly
– As soon as you experience difficulty with the course,
seek assistance
Structure and Function
• Anatomy
– Describes the structures of the body
• What they are made of
• Where they are located
• Associated structures
• Physiology
– Is the study of
• Functions of anatomical structures
• Individual and cooperative functions
Anatomy and Physiology
Integrated
• Anatomy
– Gross anatomy, or macroscopic anatomy,
examines large, visible structures
• Surface anatomy: exterior features
• Regional anatomy: body areas
• Systemic anatomy: groups of organs working
together
• Developmental anatomy: from conception to death
• Clinical anatomy: medical specialties
Anatomy and Physiology
Integrated
• Anatomy
– Microscopic anatomy examines cells and
molecules
• Cytology: study of cells and their structures
• cyt- = cell
• Histology: study of tissues and their structures
Anatomy and Physiology
Integrated
• Physiology
– Cell physiology: processes within and
between cells
– Special physiology: functions of specific
organs
– Systemic physiology: functions of an organ
system
– Pathological physiology: effects of diseases
Levels of Organization
• The Chemical (or Molecular) Level
– Atoms are the smallest chemical units
– Molecules are a group of atoms working together
• The Cellular Level
– Cells are a group of atoms, molecules, and organelles
working together
• The Tissue Level
– Tissues are a group of similar cells working together
• The Organ Level
– An organ is a group of different tissues working
together
Levels of Organization
• The Organ System Level
– Organ systems are a group of organs working
together
– Humans have 11 organ systems
• The Organism Level
– A human is an organism
Levels of Organization
Organ Systems
Levels of Organization
FIGURE 1–1 Levels of Organization.
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Levels of Organization
Homeostasis
• Homeostasis: all body systems working
together to maintain a stable internal
environment
– Systems respond to external and internal
changes to function within a normal range
(body temperature, fluid balance)
Homeostasis
• Mechanisms of Regulation
– Autoregulation (intrinsic)
• Automatic response in a cell, tissue, or organ to some
environmental change
– Extrinsic regulation
• Responses controlled by nervous and endocrine systems
Homeostasis
• Receptor
– Receives the stimulus
• Control center
– Processes the signal and sends instructions
• Effector
– Carries out instructions
Homeostasis
FIGURE 1–3 The Control of Room Temperature.
Negative and Positive Feedback
• The Role of Negative Feedback
– The response of the effector negates the
stimulus
– Body is brought back into homeostasis
• Normal range is achieved
Negative and Positive Feedback
FIGURE 1–4 Negative Feedback in the Control of Body Temperature.
Negative and Positive Feedback
• The Role of Positive Feedback
– The response of the effector increases
change of the stimulus
– Body is moved away from homeostasis
• Normal range is lost
– Used to speed up processes
Negative and Positive Feedback
FIGURE 1–5 Positive Feedback: Blood Clotting.
Systems Integration
• Systems integration
– Systems work together to maintain
homeostasis
• Homeostasis is a state of equilibrium
– Opposing forces are in balance
• Physiological systems work to restore
balance
– Failure results in disease or death
Systems Integration
Anatomical Terminology
• Superficial Anatomy
– Anatomical position: hands at sides, palms
forward
– Supine: lying down, face up
– Prone: lying down, face down
Anatomical Terminology
• Superficial Anatomy
– Anatomical Landmarks
• References to palpable structures
– Anatomical Regions
• Body regions
• Abdominopelvic quadrants
• Abdominopelvic regions
– Anatomical Directions
• Reference terms based on subject
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Anterior
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Anterior
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Posterior
Anatomical Terminology
FIGURE 1–6 Anatomical Landmarks. Posterior
Anatomical Terminology
Anatomical Terminology
Anatomical Terminology
FIGURE 1–7 Abdominopelvic Quadrants.
Anatomical Terminology
FIGURE 1–7 Abdominopelvic Regions.
Anatomical Terminology
FIGURE 1–7 Abdominopelvic Relationships.
Anatomical Terminology
FIGURE 1–8 Directional References. A Lateral View.
Anatomical Terminology
FIGURE 1–8 Directional References. An Anterior View.
Anatomical Terminology
Anatomical Terminology
• Sectional Anatomy
– Planes and sections
• Plane: a three-dimensional axis
• Section: a slice parallel to a plane
• Used to visualize internal organization and
structure
• Important in radiological techniques
– MRI
– PET
– CT
Anatomical Terminology
FIGURE 1–9 Sectional Planes.
Anatomical Terminology
Body Cavities
• Body cavities have two essential functions
– Protect organs from accidental shocks
– Permit changes in size and shape of internal organs
• Ventral body cavity (coelom)
– Divided by the diaphragm:
• Thoracic cavity
• Abdominopelvic cavity
Body Cavities
FIGURE 1–10 Relationships Among the Subdivisions of the Ventral
Body Cavity.
Body Cavities
• Serous membranes
– Line body cavities and cover organs
– Consist of parietal layer and visceral layer
• Parietal layer — lines cavity
• Visceral layer — covers organ
Body Cavities
• The Thoracic Cavity
– Separated into regions
• Right and left pleural cavities
– contain right and left lungs
• Mediastinum
– upper portion filled with blood vessels, trachea,
esophagus, and thymus
– lower portion contains pericardial cavity
» the heart is located within the pericardial
cavity
Body Cavities
FIGURE 1–11 The Ventral Body Cavity and Its Subdivisions.
Body Cavities
FIGURE 1–11 The Ventral Body Cavity and Its Subdivisions.
Body Cavities
FIGURE 1–11 The Ventral Body Cavity and Its Subdivisions.
Body Cavities
• The Abdominopelvic Cavity
– Peritoneal cavity — chamber within
abdominopelvic cavity
• Parietal peritoneum lines the internal body wall
• Visceral peritoneum covers the organs
Body Cavities
• The Abdominopelvic Cavity
– Abdominal cavity — superior portion
• Diaphragm to top of pelvic bones
• Contains digestive organs
• Retroperitoneal space
– Area posterior to peritoneum and anterior to muscular
body wall
– Contains pancreas, kidneys, ureters, and parts of the
digestive tract
Body Cavities
• The Abdominopelvic Cavity
– Pelvic cavity — inferior portion
• Within pelvic bones
• Contains reproductive organs, rectum, and bladder
Internal Framework of the Body
• Connective tissues
– Provide strength and stability
– Maintain positions of internal organs
– Provide routes for blood vessels, lymphatic vessels,
and nerves
Supportive Connective Tissues
Figure 4–15 Bone.
Supportive Connective Tissues
• Bone or osseous tissue
– Strong (calcified: calcium salt deposits)
– Resists shattering (flexible collagen fibers)
• Bone cells or osteocytes
– Arranged around central canals within matrix
– Small channels through matrix (canaliculi) access
blood supply
• Periosteum
– Covers bone surfaces
– Fibrous layer
– Cellular layer
Supportive Connective Tissues
Supportive Connective Tissues
• Types of Cartilage
– Hyaline cartilage
• Stiff, flexible support
• Reduces friction between bones
• Found in synovial joints, rib tips, sternum, and trachea
– Elastic cartilage
• Supportive but bends easily
• Found in external ear and epiglottis
– Fibrous cartilage (fibrocartilage)
•
•
•
•
Limits movement
Prevents bone-to-bone contact
Pads knee joints
Found between pubic bones and intervertebral discs
Supportive Connective Tissues
Figure 4–14 The Types of Cartilage.
Supportive Connective Tissues
Figure 4–14 The Types of Cartilage.
Supportive Connective Tissues
Figure 4–14 The Types of Cartilage.
An Introduction to the Skeletal
System
• Skeletal system includes
– Bones of the skeleton
– Cartilages, ligaments, and connective tissues
Functions of the Skeletal
System
• Support
• Storage of minerals (calcium)
• Storage of lipids (yellow marrow)
• Blood cell production (red marrow)
• Protection
• Leverage (force of motion)
Classification of Bones
• Bones are classified by
– Shape
– Internal tissue organization
– Bone markings (surface features; marks)
Classification of Bones
Figure 6–1 A Classification of Bones by Shape.
Classification of Bones
• Bone Shapes
– Long bones
• Are long and thin
• Are found in arms, legs, hands, feet, fingers, and toes
– Flat bones
• Are thin with parallel surfaces
• Are found in the skull, sternum, ribs, and scapulae
– Sutural bones
• Are small, irregular bones
• Are found between the flat bones of the skull
Classification of Bones
• Bone Shapes
– Irregular bones
• Have complex shapes
• Examples: spinal vertebrae, pelvic bones
– Short bones
• Are small and thick
• Examples: ankle and wrist bones
– Sesamoid bones
• Are small and flat
• Develop inside tendons near joints of knees, hands, and feet
Classification of Bones
• Bone Markings
– Depressions or grooves
• Along bone surface
– Projections
• Where tendons and ligaments attach
• At articulations with other bones
– Tunnels
• Where blood and nerves enter bone
Classification of Bones
Classification of Bones
Classification of Bones
• Structure of a Long Bone
– Diaphysis
• The shaft
• A heavy wall of compact bone, or dense bone
• A central space called medullary (marrow) cavity
– Epiphysis
•
•
•
•
Wide part at each end
Articulation with other bones
Mostly spongy (cancellous) bone
Covered with compact bone (cortex)
– Metaphysis
• Where diaphysis and epiphysis meet
Classification of Bones
Figure 6–2 Bone Structure.
Classification of Bones
• Structure of a Flat Bone
– The parietal bone of the skull
– Resembles a sandwich of spongy bone
– Between two layers of compact bone
– Within the cranium, the layer of spongy bone between
the compact bone is called the diploë
Classification of Bones
Figure 6–2 Bone Structure.
Bone (Osseous) Tissue
• Dense, supportive connective tissue
• Contains specialized cells
• Produces solid matrix of calcium salt
deposits
• Around collagen fibers
Bone (Osseous) Tissue
• Characteristics of Bone Tissue
– Dense matrix, containing
• Deposits of calcium salts
• Osteocytes (bone cells) within lacunae
organized around blood vessels
– Canaliculi
• Form pathways for blood vessels
• Exchange nutrients and wastes
– Periosteum
• Covers outer surfaces of bones
• Consists of outer fibrous and inner cellular layers
Bone (Osseous) Tissue
• Matrix Minerals
– Two thirds of bone matrix is calcium phosphate,
Ca3(PO4)2
• Reacts with calcium hydroxide, Ca(OH)2
• To form crystals of hydroxyapatite, Ca10(PO4)6(OH)2
• Which incorporates other calcium salts and ions
• Matrix Proteins
– One third of bone matrix is protein fibers (collagen)
Bone (Osseous) Tissue
• The Cells of Bone
– Make up only 2% of bone mass
– Bone contains four types of cells
• Osteocytes
• Osteoblasts
• Osteoprogenitor cells
• Osteoclasts
Bone (Osseous) Tissue
• Osteocytes
– Mature bone cells that maintain the bone matrix
– Live in lacunae
– Are between layers (lamellae) of matrix
– Connect by cytoplasmic extensions through
canaliculi in lamellae
– Do not divide
– Functions
• To maintain protein and mineral content of matrix
• To help repair damaged bone
Bone (Osseous) Tissue
• Osteoblasts
– Immature bone cells that secrete matrix
compounds (osteogenesis)
– Osteoid—matrix produced by osteoblasts,
but not yet calcified to form bone
– Osteoblasts surrounded by bone become
osteocytes
Bone (Osseous) Tissue
• Osteoprogenitor cells
• Mesenchymal stem cells that divide to produce
osteoblasts
• Are located in endosteum, the inner, cellular layer
of periosteum
• Assist in fracture repair
Bone (Osseous) Tissue
• Osteoclasts
– Secrete acids and protein-digesting enzymes
– Giant, multinucleate cells
– Dissolve bone matrix and release stored
minerals (osteolysis)
– Are derived from stem cells that produce
macrophages
Bone (Osseous) Tissue
Figure 6–3 Types of Bone Cells.
Bone (Osseous) Tissue
• Homeostasis
– Bone building (by osteoblasts) and bone
recycling (by osteoclasts) must balance
• More breakdown than building, bones become
weak
• Exercise, particularly weight-bearing exercise,
causes osteoblasts to build bone
Compact and Spongy Bone
• The Structure of Compact Bone
– Osteon is the basic unit
• Osteocytes are arranged in concentric lamellae
• Around a central canal containing blood vessels
• Perforating Canals:
– perpendicular to the central canal
– carry blood vessels into bone and marrow
– Circumferential Lamellae
• Lamellae wrapped around the long bone
• Bind osteons together
Compact and Spongy Bone
Figure 6–4a The Histology of Compact Bone.
Compact and Spongy Bone
Figure 6–4b The Histology of Compact Bone.
Compact and Spongy Bone
Figure 6–5 The Structure of Compact Bone.
Compact and Spongy Bone
Figure 6–5 The Structure of Compact Bone.
Compact and Spongy Bone
• The Structure of Spongy Bone
–
–
–
–
Does not have osteons
The matrix forms an open network of trabeculae
Trabeculae have no blood vessels
The space between trabeculae is filled with red bone
marrow:
• Which has blood vessels
• Forms red blood cells
• And supplies nutrients to osteocytes
– Yellow marrow
• In some bones, spongy bone holds yellow bone marrow
• Is yellow because it stores fat
Compact and Spongy Bone
Figure 6–6 The Structure of Spongy Bone.
Compact and Spongy Bone
• Weight-Bearing Bones
– The femur transfers weight from hip joint to
knee joint
• Causing tension on the lateral side of the shaft
• And compression on the medial side
Compact and Spongy Bone
Figure 6–7 The Distribution of Forces on a Long Bone.
Compact and Spongy Bone
• Compact bone is covered with a membrane
– Periosteum on the outside
• Covers all bones except parts enclosed in joint
capsules
• Is made up of an outer, fibrous layer and an inner,
cellular layer
• Perforating fibers: collagen fibers of the
periosteum:
– connect with collagen fibers in bone
– and with fibers of joint capsules; attach
tendons, and ligaments
Compact and Spongy Bone
• Functions of Periosteum
– Isolates bone from surrounding tissues
– Provides a route for circulatory and nervous
supply
– Participates in bone growth and repair
Compact and Spongy Bone
Figure 6–8a The Periosteum.
Compact and Spongy Bone
• Compact bone is covered with a membrane:
– Endosteum on the inside
• An incomplete cellular layer:
– lines the medullary (marrow) cavity
– covers trabeculae of spongy bone
– lines central canals
– contains osteoblasts, osteoprogenitor cells, and
osteoclasts
– is active in bone growth and repair
Compact and Spongy Bone
Figure 6–8b The Endosteum.
Bone Formation and Growth
• Bone Development
– Human bones grow until about age 25
– Osteogenesis
• Bone formation
– Ossification
• The process of replacing other tissues with bone
Bone Formation and Growth
• Bone Development
– Calcification
• The process of depositing calcium salts
• Occurs during bone ossification and in other tissues
– Ossification
• The two main forms of ossification are
– intramembranous ossification
– endochondral ossification
Bone Formation and Growth
• Endochondral Ossification
– Ossifies bones that originate as hyaline
cartilage
– Most bones originate as hyaline cartilage
– There are six main steps in endochondral
ossification
Bone Formation and Growth
Figure 6–10 Endochondral Ossification.
Bone Formation and Growth
Figure 6–10 Endochondral Ossification.
Bone Formation and Growth
Figure 6–10 Endochondral Ossification.
Bone Formation and Growth
• Appositional growth
– Compact bone thickens and strengthens long
bone with layers of circumferential lamellae
Endochondral Ossification
Bone Formation and Growth
• Epiphyseal Lines
– When long bone stops growing, after puberty
• Epiphyseal cartilage disappears
• Is visible on X-rays as an epiphyseal line
• Mature Bones
– As long bone matures
• Osteoclasts enlarge medullary (marrow) cavity
• Osteons form around blood vessels in compact
bone
Bone Formation and Growth
Figure 6–11 Bone Growth at an Epiphyseal Cartilage.
Bone Formation and Growth
Figure 6–11 Bone Growth at an Epiphyseal Cartilage.
Bone Formation and Growth
• Intramembranous Ossification
– Also called dermal ossification
• Because it occurs in the dermis
• Produces dermal bones such as mandible (lower
jaw) and clavicle (collarbone)
– There are three main steps in
intramembranous ossification
Bone Formation and Growth
Figure 6–12 Intramembranous Ossification.
Bone Formation and Growth
Figure 6–12 Intramembranous Ossification.
Bone Formation and Growth
• Blood Supply of Mature Bones
– Three major sets of blood vessels develop
• Nutrient artery and vein:
– a single pair of large blood vessels
– enter the diaphysis through the nutrient foramen
– femur has more than one pair
• Metaphyseal vessels:
– supply the epiphyseal cartilage
– where bone growth occurs
• Periosteal vessels provide:
– blood to superficial osteons
– secondary ossification centers
Bone Formation and Growth
Figure 6–13 The Blood Supply to a Mature Bone.
Bone Formation and Growth
• Lymph and Nerves
– The periosteum also contains
• Networks of lymphatic vessels
• Sensory nerves
Bone Formation and Growth
Figure 6–9 Heterotopic Bone Formation.
Bone Remodeling
• Process of Remodeling
– The adult skeleton
• Maintains itself
• Replaces mineral reserves
• Recycles and renews bone matrix
• Involves osteocytes, osteoblasts, and osteoclasts
– Bone continually remodels, recycles, and replaces
– Turnover rate varies
• If deposition is greater than removal, bones get stronger
• If removal is faster than replacement, bones get weaker
Exercise, Hormones, and
Nutrition
• Effects of Exercise on Bone
– Mineral recycling allows bones to adapt to stress
– Heavily stressed bones become thicker and stronger
• Bone Degeneration
– Bone degenerates quickly
– Up to one third of bone mass can be lost in a few
weeks of inactivity
Exercise, Hormones, and
Nutrition
• Normal bone growth and maintenance requires
nutritional and hormonal factors
– A dietary source of calcium and phosphate salts
• Plus small amounts of magnesium, fluoride, iron, and
manganese
– The hormone calcitriol
• Is made in the kidneys
• Helps absorb calcium and phosphorus from digestive tract
• Synthesis requires vitamin D3 (cholecalciferol)
Exercise, Hormones, and
Nutrition
• Normal bone growth and maintenance depend
on nutritional and hormonal factors
– Vitamin C is required for collagen synthesis, and
stimulation of osteoblast differentiation
– Vitamin A stimulates osteoblast activity
– Vitamins K and B12 help synthesize bone proteins
– Growth hormone and thyroxine stimulate bone growth
– Estrogens and androgens stimulate osteoblasts
– Calcitonin and parathyroid hormone regulate calcium
and phosphate levels
Exercise, Hormones, and
Nutrition
Exercise, Hormones, and
Nutrition
FIGURE 6–14 Examples of Abnormal Bone Development.
Calcium Homeostasis
• The Skeleton as a Calcium Reserve
– Bones store calcium and other minerals
– Calcium is the most abundant mineral in the
body
• Calcium ions are vital to:
– membranes
– neurons
– muscle cells, especially heart cells
Calcium Homeostasis
• Calcium Regulation
– Calcium ions in body fluids
• Must be closely regulated
– Homeostasis is maintained
• By calcitonin and parathyroid hormone
• Which control storage, absorption, and excretion
Calcium Homeostasis
• Calcitonin and parathyroid hormone control and
affect
– Bones
• Where calcium is stored
– Digestive tract
• Where calcium is absorbed
– Kidneys
• Where calcium is excreted
Calcium Homeostasis
• Parathyroid Hormone (PTH)
– Produced by parathyroid glands in neck
– Increases calcium ion levels by
• Stimulating osteoclasts
• Increasing intestinal absorption of calcium
• Decreasing calcium excretion at kidneys
• Calcitonin
– Secreted by C cells (parafollicular cells) in thyroid
– Decreases calcium ion levels by
• Inhibiting osteoclast activity
• Increasing calcium excretion at kidneys
Calcium Homeostasis
Figure 6–15 A Chemical Analysis of Bone.
Calcium Homeostasis
Figure 6–16a Factors That Alter the Concentration of Calcium Ions in
Body Fluids.
Calcium Homeostasis
Figure 6–16b Factors That Alter the Concentration of Calcium Ions in
Body Fluids.
Fractures
• Cracks or breaks in bones
• Caused by physical stress
Fractures
• Fractures are repaired in four steps
– Bleeding
• Produces a clot (fracture hematoma)
• Establishes a fibrous network
• Bone cells in the area die
– Cells of the endosteum and periosteum
• Divide and migrate into fracture zone
• Calluses stabilize the break:
– external callus of cartilage and bone surrounds break
– internal callus develops in medullary cavity
Fractures
• Fractures are repaired in four steps
– Osteoblasts
• Replace central cartilage of external callus
• With spongy bone
– Osteoblasts and osteocytes remodel the
fracture for up to a year
• Reducing bone calluses
Steps in the Repair of a Fracture
Fractures
Figure 6–17 Steps in the Repair of a Fracture.
Fractures
Figure 6–17 Steps in the Repair of a Fracture.
Fractures
• The Major Types of Fractures
– Pott fracture
– Comminuted fractures
– Transverse fractures
– Spiral fractures
– Displaced fractures
– Colles fracture
– Greenstick fracture
– Epiphyseal fractures
– Compression fractures
Fractures
Figure 6–18 Major Types of Fractures.
Fractures
Figure 6–18 Major Types of Fractures.
Fractures
Figure 6–18 Major Types of Fractures.
Osteopenia
• Bones become thinner and weaker with
age
– Osteopenia begins between ages 30 and 40
– Women lose 8% of bone mass per decade,
men 3%
Osteopenia
• The epiphyses, vertebrae, and jaws are most
affected:
– Resulting in fragile limbs
– Reduction in height
– Tooth loss
• Osteoporosis
– Severe bone loss
– Affects normal function
– Over age 45, occurs in
• 29% of women
• 18% of men
Osteopenia
Figure 6–19 The Effects of Osteoporosis on Spongy Bone.
Aging
• Hormones and Bone Loss
– Estrogens and androgens help maintain bone mass
– Bone loss in women accelerates after menopause
• Cancer and Bone Loss
– Cancerous tissues release osteoclast-activating
factor
• That stimulates osteoclasts
• And produces severe osteoporosis
Classification of Joints
• Two methods of classification
– Functional classification is based on range
of motion of the joint
– Structural classification relies on the
anatomical organization of the joint
An Introduction to Articulations
• Articulations
– Body movement occurs at joints
(articulations) where two bones connect
• Joint Structure
– Determines direction and distance of
movement (range of motion)
– Joint strength decreases as mobility increases
Classification of Joints
• Functional Classifications
– Synarthrosis (immovable joint)
• No movement
• Fibrous or cartilaginous connections
• May fuse over time
– Amphiarthrosis (slightly movable joint)
• Little movement
• Fibrous or cartilaginous connections
– Diarthrosis (freely movable joint)
• More movement
• Also called synovial joints
• Subdivided by type of motion
Classification of Joints
Classification of Joints
Classification of Joints
• Structural Classifications
– Bony
– Fibrous
– Cartilaginous
– Synovial
Classification of Joints
Classification of Joints
• Functional Classifications
– Synarthroses (immovable joints)
• Are very strong
• Edges of bones may touch or interlock
• Four types of synarthrotic joints:
– suture
– gomphosis
– synchondrosis
– synostosis
Classification of Joints
• Synarthrotic Joints
– Suture
• Bones interlocked
• Are bound by dense fibrous connective tissue
• Are found only in skull
– Gomphosis
• Fibrous connection (periodontal ligament)
• Binds teeth to sockets
Classification of Joints
• Synarthrotic Joints
– Synchondrosis
• Is a rigid cartilaginous bridge between two bones:
– epiphyseal cartilage of long bones
– between vertebrosternal ribs and sternum
– Synostosis
• Fused bones, immovable:
– metopic suture of skull
– epiphyseal lines of long bones
Classification of Joints
• Functional Classifications
– Amphiarthroses
• More movable than synarthrosis
• Stronger than freely movable joint
• Two types of amphiarthroses
– syndesmosis:
» bones connected by ligaments
– symphysis:
» bones separated by fibrous cartilage
Classification of Joints
• Functional Classifications
– Synovial joints (diarthroses)
• Also called movable joints
• At ends of long bones
• Within articular capsules
• Lined with synovial membrane
Synovial Joints
• Components of Synovial Joints
– Articular cartilages
• Pad articulating surfaces within articular
capsules:
– prevent bones from touching
• Smooth surfaces lubricated by synovial fluid:
– reduce friction
Synovial Joints
• Components of Synovial Joints
– Synovial fluid
• Contains slippery proteoglycans secreted by
fibroblasts
• Functions of synovial fluid:
– lubrication
– nutrient distribution
– shock absorption
Synovial Joints
• Components of Synovial Joints
– Accessory structures
• Cartilages:
– cushion the joint:
» Fibrous cartilage pad called a meniscus
(articular disc)
• Fat pads:
– superficial to the joint capsule
– protect articular cartilages
• Ligaments:
– support, strengthen joints
– sprain: ligaments with torn collagen fibers
Synovial Joints
• Components of Synovial Joints
– Accessory structures
• Tendons:
– attach to muscles around joint
– help support joint
• Bursae:
– pockets of synovial fluid
– cushion areas where tendons or ligaments rub
Synovial Joints
• Factors That Stabilize Synovial Joints
– Prevent injury by limiting range of motion
• Collagen fibers (joint capsule, ligaments)
• Articulating surfaces and menisci
• Other bones, muscles, or fat pads
• Tendons of articulating bones
Synovial Joints
[INSERT FIG. 9.1a]
Figure 9–1a The Structure of a Synovial Joint.
Synovial Joints
Figure 9–1b The Structure of a Synovial Joint.
Synovial Joints
• Injuries
– Dislocation (luxation)
• Articulating surfaces forced out of position
• Damages articular cartilage, ligaments, joint capsule
– Subluxation
• A partial dislocation
Movements
• Types of Dynamic Motion
– Linear motion (gliding)
– Angular motion
– Rotation
• Planes (Axes) of Dynamic Motion
– Monaxial (1 axis)
– Biaxial (2 axes)
– Triaxial (3 axes)
Movements
Figure 9–2 A Simple Model of Articular Motion.
Movements
Figure 9–2 A Simple Model of Articular Motion.
Movements
• Types of Movements at Synovial Joints
– Terms describe
• Plane or direction of motion
• Relationship between structures
Movements
• Types of Movements at Synovial Joints
– Linear motion
• Also called gliding
• Two surfaces slide past each other:
– between carpal or tarsal bones
Movements
• Angular Motion
– Flexion
• Angular motion
• Anterior–posterior plane
• Reduces angle between elements
– Extension
• Angular motion
• Anterior–posterior plane
• Increases angle between elements
Movements
• Angular Motion
– Hyperextension
• Angular motion
• Extension past anatomical position
Angular Movements
Movements
Figure 9–3a Angular Movements.
Movements
• Angular Motion
– Abduction
• Angular motion
• Frontal plane
• Moves away from longitudinal axis
– Adduction
• Angular motion
• Frontal plane
• Moves toward longitudinal axis
Movements
Figure 9–3 Angular Movements.
Movements
Figure 9–3 Angular Movements.
Movements
• Angular Motion
– Circumduction
• Circular motion without rotation
• Angular motion
Movements
Figure 9–3 Angular Movements.
Movements
• Types of Movement at Synovial Joints
– Rotation
• Direction of rotation from anatomical position
• Relative to longitudinal axis of body
• Left or right rotation
• Medial rotation (inward rotation):
– rotates toward axis
• Lateral rotation (outward rotation):
– rotates away from axis
Movements
Figure 9–4a Rotational Movements.
Movements
• Types of Movements at Synovial Joints
– Rotation
• Pronation:
– rotates forearm, radius over ulna
• Supination:
– forearm in anatomical position
Movements
Figure 9–4b Rotational Movements.
Movements
• Types of Movements at Synovial Joints
– Special movements
• Inversion:
– twists sole of foot medially
• Eversion:
– twists sole of foot laterally
• Dorsiflexion:
– flexion at ankle (lifting toes)
• Plantar flexion:
– extension at ankle (pointing toes)
Movements
• Special Movements at Synovial Joints
– Opposition
• Thumb movement toward fingers or palm
(grasping)
– Protraction
• Moves anteriorly
• In the horizontal plane (pushing forward)
– Retraction
• Opposite of protraction
• Moving anteriorly (pulling back)
Movements
• Special Movements at Synovial Joints
– Elevation
• Moves in superior direction (up)
– Depression
• Moves in inferior direction (down)
– Lateral flexion
• Bends vertebral column from side to side
Movements
Figure 9–5 Special Movements.
Movements
Figure 9–5 Special Movements.
Movements
• Classification of Synovial Joints by Shape
– Gliding
– Hinge
– Pivot
– Ellipsoid
– Saddle
– Ball-and-socket
A Functional Classification of Synovial Joints
Movements
• Gliding Joints
– Flattened or slightly curved faces
– Limited motion (nonaxial)
• Hinge Joints
– Angular motion in a single plane (monaxial)
• Pivot Joints
– Rotation only (monaxial)
Movements
Figure 9–6 Movements at Synovial Joints.
Movements
• Ellipsoid Joints
– Oval articular face within a depression
– Motion in two planes (biaxial)
• Saddle Joints
– Two concave, straddled (biaxial)
• Ball-and-Socket Joints
– Round articular face in a depression (triaxial)
Movements
Figure 9–6 Movements at Synovial Joints.
Movements
• A joint cannot be both mobile and strong
• The greater the mobility, the weaker the
joint
• Mobile joints are supported by muscles
and ligaments, not bone-to-bone
connections
Intervertebral Articulations
• Intervertebral Articulations
– C2 to L5 spinal vertebrae articulate
• At inferior and superior articular processes (gliding
joints)
• Between adjacent vertebral bodies (symphyseal
joints)
Intervertebral Articulations
• Intervertebral Articulations
– C2 to L5 spinal vertebrae articulate
• Intervertebral discs:
– pads of fibrous cartilage
– separate vertebral bodies
– anulus fibrosus:
» tough outer layer
» attaches disc to vertebrae
– nucleus pulposus:
» elastic, gelatinous core
» absorbs shocks
Intervertebral Articulations
Figure 9–7 Intervertebral Articulations.
Intervertebral Articulations
• Vertebral Joints
– Also called symphyseal joints
– As vertebral column moves
• Nucleus pulposus shifts
• Disc shape conforms to motion
• Intervertebral Ligaments
– Bind vertebrae together
– Stabilize the vertebral column
Intervertebral Articulations
• Six Intervertebral Ligaments
– Anterior longitudinal ligament
• Connects anterior bodies
– Posterior longitudinal ligament
• Connects posterior bodies
– Ligamentum flavum
• Connects laminae
Intervertebral Articulations
• Six Intervertebral Ligaments
– Interspinous ligament
• Connects spinous processes
– Supraspinous ligament
• Connects tips of spinous processes (C7 to sacrum)
– Ligamentum nuchae
• Continues supraspinous ligament (C7 to skull)
Intervertebral Articulations
• Damage to Intervertebral Discs
– Slipped disc
• Bulge in anulus fibrosus
• Invades vertebral canal
– Herniated disc
• Nucleus pulposus breaks through anulus fibrosus
• Presses on spinal cord or nerves
Intervertebral Articulations
Figure 9–8a Damage to the Intervertebral Discs.
Intervertebral Articulations
Figure 9–8b Damage to the Intervertebral Discs.
Intervertebral Articulations
• Movements of the Vertebral Column
– Flexion
• Bends anteriorly
– Extension
• Bends posteriorly
– Lateral flexion
• Bends laterally
– Rotation
• Turning
Articulations of the Axial
Skeleton
Articulations of the Axial
Skeleton
Articulations of the Axial
Skeleton
The Shoulder Joint
• Also called the glenohumeral joint
– Allows more motion than any other joint
– Is the least stable
– Supported by skeletal muscles, tendons, ligaments
• Ball-and-socket diarthrosis
• Between head of humerus and glenoid cavity of
scapula
The Shoulder Joint
• Socket of the Shoulder Joint
– Glenoid labrum
• Deepens socket of glenoid cavity
• Fibrous cartilage lining
• Extends past the bone
• Processes of the Shoulder Joint
– Acromion (clavicle) and coracoid process (scapula)
• Project laterally, superior to the humerus
• Help stabilize the joint
The Shoulder Joint
• Shoulder Ligaments
– Glenohumeral
– Coracohumeral
– Coraco-acromial
– Coracoclavicular
– Acromioclavicular
• Shoulder Separation
– Dislocation of the shoulder joint
The Shoulder Joint
• Shoulder Muscles (also called rotator cuff)
–
–
–
–
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
• Shoulder Bursae
– Subacromial
– Subcoracoid
– Subdeltoid
– Subscapular
The Shoulder Joint
Figure 9–9a The Shoulder Joint.
The Shoulder Joint
Figure 9–9b The Shoulder Joint.
The Elbow Joint
• A stable hinge joint
• With articulations involving humerus,
radius, and ulna
The Elbow Joint
• Articulations of the Elbow
– Humero-ulnar joint
• Largest articulation
• Trochlea of humerus and trochlear notch of ulna
• Limited movement
– Humeroradial joint:
• Smaller articulation
• Capitulum of humerus and head of radius
The Elbow Joint
Figure 9–10a The Elbow Joint.
The Elbow Joint
• Supporting Structures of the Elbow
– Biceps brachii muscle
• Attached to radial tuberosity
• Controls elbow motion
– Elbow Ligaments
• Radial collateral
• Annular
• Ulnar collateral
The Elbow Joint
Figure 9–10b The Elbow Joint.
The Hip Joint
• Also called coxal joint
• Strong ball-and-socket diarthrosis
• Wide range of motion
The Hip Joint
• Structures of the Hip Joint
– Head of femur fits into it
– Socket of acetabulum
– Which is extended by fibrocartilaginous acetabular
labrum
• Ligaments of the Hip Joint
– Iliofemoral
– Pubofemoral
– Ischiofemoral
– Transverse acetabular
– Ligamentum teres
The Hip Joint
Figure 9–11a The Hip Joint.
The Hip Joint
Figure 9–11b The Hip Joint.
The Hip Joint
Figure 9–11c The Hip Joint.
The Knee Joint
• A complicated hinge joint
• Transfers weight from femur to tibia
• Articulations of the knee joint
– Two femur–tibia articulations
• At medial and lateral condyles
• One between patella and patellar surface of femur
The Knee Joint
• Menisci of the Knee
– Medial and lateral menisci
• Fibrous cartilage pads
• At femur–tibia articulations
• Cushion and stabilize joint
• Give lateral support
– Locking knees
• Standing with legs straight:
– “locks” knees by jamming lateral meniscus between tibia
and femur
The Knee Joint
• Seven Ligaments of the Knee Joint
– Patellar ligament (anterior)
– Two popliteal ligaments (posterior)
– Anterior and posterior cruciate ligaments (inside joint
capsule)
– Tibial collateral ligament (medial)
– Fibular collateral ligament (lateral)
The Knee Joint
Figure 9–12a The Knee Joint.
The Knee Joint
Figure 9–12b The Knee Joint.
The Knee Joint
Figure 9–12c The Knee Joint.
The Knee Joint
Figure 9–12d The Knee Joint.
The Knee Joint
The Knee Joint
Aging
• Rheumatism
– A pain and stiffness of skeletal and muscular
systems
• Arthritis
– All forms of rheumatism that damage articular
cartilages of synovial joints
• Osteoarthritis
– Caused by wear and tear of joint surfaces, or
genetic factors affecting collagen formation
– Generally in people over age 60
Aging
• Rheumatoid Arthritis
– An inflammatory condition
– Caused by infection, allergy, or autoimmune
disease
– Involves the immune system
• Gouty Arthritis
– Occurs when crystals (uric acid or calcium
salts)
• Form within synovial fluid
• Due to metabolic disorders
Aging
• Joint Immobilization
– Reduces flow of synovial fluid
– Can cause arthritis symptoms
– Treated by continuous passive motion
(therapy)
• Bones and Aging
– Bone mass decreases
– Bones weaken
– Increases risk of hip fracture, hip dislocation,
or pelvic fracture
Integration with Other Systems
• Bone Recycling
– Living bones maintain equilibrium between
• Bone building (osteoblasts)
• And breakdown (osteoclasts)
• Factors Affecting Bone Strength
– Age
– Physical stress
– Hormone levels
– Calcium and phosphorus uptake and excretion
– Genetic and environmental factors
Integration with Other Systems
• Bones Support Body Systems
– The skeletal system
• Supports and protects other systems
• Stores fat, calcium, and phosphorus
• Manufactures cells for immune system
– Disorders in other body systems can cause
• Bone tumors
• Osteoporosis
• Arthritis
• Rickets (vitamin D deficiency)
Integration with Other Systems
Figure 9–13 Functional Relationships between the Skeletal System and
Other Systems.
Integration with Other Systems
Figure 9–13 Functional Relationships between the Skeletal System and
Other Systems.