quiz 2 A&P- Bones (intramembranous, Wolff's law, bone strength, Bonne health), joints Flashcards
know the vocab:
articulation
arth-
articulation- A joint, also known as an articulation, is a location where two or more bones meet. Most joints contain a single articulation. Each articulation contains the names of two bones (or sockets)
arth- The prefix (arthr- or arthro-) means a joint or any junction between two different parts
axial vs appendicular skeleton
axial bones: skull, neck, vertebrae, ribs, sacrum
appendicular bones: shoulders, arms, legs, feet, hands, and pelvis not including the sacrum
can you identify all the parts of the skeleton (axial & appendicular) yet?
yes!
if not, go and do that and come back
hyoid
the only bone in the body that does not articulate with another bone
ways to classify joints
what they are made of (the type of tissues) and how they move
what kind of tissue(s) are found at the joint?
fibrous joints
cartilaginous joints
synovial joints
fibrous joints
generally synarthrotic
synovial joints
generally diarthrotic
what types of movement are allowed in joints
synarthroses
amphiarthroses
diarthroses
synarthroses
no movement, tight together so no movement
amphiarthroses
partially moveable
diarthroses
fully moveable
finger and hip joints
details on fibrous joints
-fibrous joints join bones
- generally synarthroses(so these joints do not move)
- 3 subtypes: sutures, syndesmoses, gomphoses
sutures
-lines that connect the parts of the skull
-this joint is held together with very short, interconnecting fibers and bone edges interlock
- synostosis- closed suture, from fibrous tissue ossification,
-synarthroses joints
-there are also facial sutures not just cranial
-dense regular connective tissue fibers are continuous with the periosteum (which itself has dense irregular connective tissue)
-craniosynostosis- a birth defect in which the bones in a baby’s skull join together too early
what are syndesmoses (syndesmosis)
-amphiarthrotic joints
-a joint held together by a ligament
-fibrous tissue can vary in length but is longer than in sutures
-a fibrous joint in which two adjacent bones are linked by a strong membrane or ligaments.
-ball and socket joint.
-made of dense regular collagenous tissue
-For ex: between the radius and ulna, there is a syndesmosis that is made of dense regular collagenous tissue
what are gomphoses (a gomphosis)
- found only in teeth
-a fibrous mobile peg-and-socket joint. The roots of the teeth (the pegs) fit into their sockets in the mandible and maxilla and are the only examples of this type of joint.
-they are synarthrotic joints- so they do not move!
-the peg fits into the osseous pocket, and into the socket of the alveolar process
-the teeth are connected by the periodontal ligament
cartilaginous joints
-the bones are joined together by the cartilage tissue
-there are 2 types: synchondroses and symphyses
synchondroses
-one of the two types of cartilaginous joints (can you name the other one?)
-these are synarthrotic, so they do not move
-the name translates to together cartilage
-syn: together
-an example is hyaline cartilage which is articular cartilage that is found on both epiphyses of the long bone- so it is a cartilaginous joint and specifically a synchondroses because it will connect the long bone to other bones using the synchondroses joint
-hyaline cartilage is found in synchondroses
-singular: synchondrosis
-examples of synchondroses: epiphyseal plates of the long bone
-the mobility of these joints is synarthrotic
-another example of synchondroses joints: costochondral joints (between the ribs and rib cage) and first sternocostal joints (between the first rib and sternum)
what is found in symphyses cartilaginous joints?
-fibrocartilage which have collagen fibers and chondrocytes in the lacunae
symphyses
-singular: symphysis
-bones are united by fibrocartilage
-in the public symphysis- the two ox coxae (or hip bones) are joined together with fibrocartilage
-in pregnancy, a hormone releases for the symphysis to move so hips can widen
-another example of symphyses joint (fibrocartilage)- the intervertebral joint which contains a fibrocartilaginous intervertebral disc (sandwiched between hyaline cartilage)
-note: there is still hyaline cartilage at bone surfaces, fibrocartilage is in between
intervertebral disc
-contains two parts: annulus fibrous and nucleus pulposus
-annulus fibrous are a ring of fibers on the outer part of the intervertebral disc (ring)
-nucleus pulposus are gelatinous inner part of intervertebral disc (center)
herniated disc (AKA slipped di, prolapsed disc)
what happens:
annulus ruptures
nucleus protrudes through (pokes through)
parts of the spinal cord at their curvature names
cervical curvature (concave)- the neck, C1 to C7 bones- secondary curvature!
thoracic curvature (convex)- the rib cage, T1 to T12 bones- primary curvature
lumbar curvature (concave)- the mid-back- L1 to L5 bones, secondary curvature
sacral curvature (convex)- lower back, sacrum, and coccyx, primary curvature
the vertebrae column has many curvatures
remember the names of C1 and C2. vertebrae? These form a diarthrotic synovial joint. What does that tell you about their mobility?
C1- Atlas
C2- Axis
diarthrotic synovial joint- full moveable joints
meaning of primary and secondary curvatures
primary curvatures- are present at birth (the thoracic and sacral curvatures)
secondary curvatures- are not present at birth (the cervical and lumbar curvatures)
cervical curvatures develop after birth when the infant starts to hold up their head
lumbar curvatures develop when the baby is standing and walking
newborns only have the primary curvatures
scoliosis, lordosis, kyphosis
scoliosis- a sideways curvature of the spine that most often is diagnosed in adolescents.
lordosis- excessive inward lumbar curvature of the spine usually caused by and common in pregnancy.
kyphosis- an exaggerated, forward rounding of the thoracic curvature, usually caused by osteoporosis
synovial joints
-freely moveable aka, diarthrotic
-different structure than fibrous and cartilaginous joints, although they may have similar components
-fluid-filled to make a friction-free surface
what types of movements are allowed at synovial joints?
Gliding
Flexion, Extension
Hyperextension
Abduction, Adduction
Circumduction
Rotation
Pronation , Supination
Inversion, Eversion
Opposition
Protraction, Retraction
what are the components of the synovial joints
articular cartilage
fibula
tibia
articular capsule:
(joint space containing synovial fluid
synovial membrane-where synoviocytes are made (inner layer)
fibrous outer layer)
femur
periosteum
what else is present in the synovial joint structure
Reinforcing ligaments
capsular ligaments
continuous with fibrous layer of articular capsule
extra- or intracapsular ligaments
one type is deep to the capusle, one is outside. Which is which?- extra: out, intra: deep
ligament
articular capsule
periosteum
Rheumatoid Arthritis
0.5% - 1% of people in developed world
Cause? Probably multifactorial (like most things…)
some genetic risk factors
environmental risk factors may include infection and smoking
-Autoimmune disease- immune system attacks own self, treats what is in the joints are foreign and attacks itself
Articular, extra-articular and systemic effects
Brief info about adaptive immunity (B and T cells)
-B cells
If a B cell encounters an antigen, it will proliferate and start making lots of antibodies against that antigen
-make antibodies-tag + bind to foreign things
Antibodies “tag” foreign cells or particles, marking them to be destroyed/engulfed.
-T cells
Activated T cells respond to foreign antigens that are presented to them by an antigen presenting cell.
Remember from our skin health discussion?- yes macrophages and dendritic cells do this
T cells can secrete cytokines and affect activity of other immune cells.
cytokines are proteins that act as messengers between immune system components
in RA
Synovitis = inflammation of synovial membrane. Caused by infiltration of immune cells and angiogenesis
Synovial membrane becomes hyperplastic, expands
Osteoclast rich region of the synovial membrane destroys bone.
3a) Enzymes destroy cartilage.
Potential results of RA
At Joints
Scar tissue formation
Scar tissue ossification
Loss of joint mobility (ankylosis)
Systemic effects possible
Anemia
Cardiovascular disease
Osteoporosis
Fatigue
Depression
Other types of arthritis?
Osteoarthritis
“wear and tear”
Age-related
Articular cartilage breakdown
Gouty arthritis (Gout)
Uric acid (normal waste product) rises in blood
Crystals form in soft tissues of joints
Elements of signaling
Signal (from outside the cell)
Proteins, steroids, other molecules; could be hormonal (long distance) or paracrine (short distance)
Receptor (cell)
Membrane proteins or intracellular proteins
Signal transduction (inside the cell)
Note that Gap junctions may transmit second messengers and intracellular signaling molecules from cell to cell.
Response
Examples: altered metabolism, proliferation or even perhaps apoptosis
Bone as a reservoir for blood Ca2+
involves bone remodeling
Calcium information:
Human body has how many grams of Ca2+
What is Ca2+ necessary for in the body?
-Human body has 1200-1400 g of Ca2+
-What is Ca2+ necessary for in the body?- Muscle contraction, neuronal functions, signaling
-Just because you eat a lot of calcium does not mean that they are absorbed and entering into your blood stream to eventually get to your bones
-so you eat, then your food goes to your digestive system and there are blood vessels adjacent to your digestive system so the calcium from the food can be absorbed into the blood
Calcium information:
Human body has how many grams of Ca2+
What is Ca2+ necessary for in the body?
-Human body has 1200-1400 g of Ca2+
-What is Ca2+ necessary for in the body?- Muscle contraction, neuronal functions, signaling
-Just because you eat a lot pff calcium does not mean that they are absorbed and entering into your blood stream to eventually get to your bones
-so you eat, then your food goes to your digestive system then it goes out, but there are blood vessels adjacent to your digestive system so the calcium from the food can be absorbed into the blood
-taking vitamin D increases the absorption of the Ca2+ into the blood from the intestine
Where is Ca2+ found?
-99% in bones
-9-11 mg/dl of blood
(9-11 mg/100 ml blood)
We get Ca2+ from our diet but what helps the Ca2+ get into the blood to get into the bones?
Vitamin D is necessary for absorption across intestine to blood stream.
Remember Vitamin D production and activation?
Which tissues and organs are involved?
1- UV + Cholesterol make the Vitamin D precursor
2- The precursor (made by skin cells) goes to the liver to be modified, then goes to the kidney
3- full activation in the kidney
6.15 Maintaining homeostasis: response to low blood calcium ion level by a negative feedback loop.
1- stimulus- the blood Ca2+ decrease below normal range
2- receptor- parathyroid gland (in the thyroid) cells detect a low blood Ca2+ level
3- control center- parathyroid gland cells release PTH (parathyroid hormone) into the blood; PTH is released when the blood Ca2+ is too low
4- effector/response- Osteoclasts resorb bone; they dissolve the bone matrix (osteoid) to release Ca2+ to the blood, kidneys retain Ca2+ (so it is not lost from blood via the urine), intestines absorb Ca2+ to go into the blood
An added wrinkle to PTH
PTH recruits and activates osteoclasts to promote matrix break-down.
But it also can promote bone formation (osteoblasts).
Signaling systems are complex!
what happens in Bone marrow:
hematopoiesis (blood cell formation) & fat storage
hem-
heme-
hemat-
refers to blood
-poiesis: to make
Red marrow is found
in spongy bone and medullary cavities in children; everywhere.
In adults, red marrow is more restricted to the epiphyses
This is a reminder that children are not just mini versions of adults! Their anatomy and physiology is unique!
endochondral ossification
1- chondroblasts become mitotic
2- chondroblasts become amitotic
3- chondroblasts expand by hyperplasia and mature
4- chondroblasts die then their matrix is calcified and the dead and expanded condroblasts are now replaced by Bone
osteoblasts
synthesize bone matrix by secreting it; bone builders
osteoclasts
cells that degrade bone to initiate normal bone remodeling; bone breakers
osteocytes
the cells residing within the bone matrix and comprising 90% to 95% of the all bone cells; mature bone cells; maintain bone
signals for bone growth
and
why do we need to exercise
growth hormone and sex hormones
why must exercise because exercise puts stress on our bones and this stress helps our bones become stronger
Factors that influence bone remodeling.
increased osteoblasts activity:
-compression load or exercise
-tension placed on bone
-adequate dietary intake of calcium and vitamins C, D and K
Increase osteoclast activity:
-continuous press placed on bone
-parathyroid hormone
-decrease in blood calcium ion concentration
decreased osteoblasts activity:
-inadequate exercise
-inadequate dietary intake of calcium or vitamins C, D and K
decrease osteoclast activity:
-estrogen
-calcitonin
-increase in blood calcium ion concentration
Bone repair
-What cells are involved?
-How is this similar to or different from growth and development of bones?
-What is osteogenesis coupled with?
What cells are involved?- osteoblasts and osteoclasts
How is this similar to or different from growth and development of bones?- similar in that both involve blasts and clasts; bone growth is the increase in the diameter of bones by the addition of bone tissue at the surface of bones. Bone remodeling involves the processes of bone deposition by osteoblasts and bone resorption by osteoclasts. Bone repair occurs in four stages and can take several months.
What is osteogenesis coupled with?- angiogenesis
Fractures result from…
result from trauma, or may be a result of weakening/thinning bones (why is it important to keep physically active in old age? What does this mean for bone health?– stress on bones makes for stronger and healthier bones)
Fractures can be classified in many ways:
displaced vs. nondisplaced (refers to bone end position)
complete vs. incomplete (does the break in the bone go through the middle?)
open (compound) or closed (refers to skin penetration)- does the bone go through skin?
What is Vitamin D is important for?
Ca2+ absorption in gut (from diet)
Regulating calcium and phosphate use
Poor mineralization of bones:
osteomalacia
rickets
osteomalacia
Soft, weak bones; Pain upon bearing weight
Rickets
(osteomalacia of children)
Bowed legs and other bone deformities
Bone ends enlarged and abnormally long
Cause of poor mineralization of bones:
malnutrition of Ca2+ and vitamin D
for Poor mineralization of bones what is more active /inactive
-osteoblast activity decrease
-osteoclast activity increase
Osteoporosis (Group of Diseases)
Bone resorption outpaces deposit
Spongy bone of spine and neck of femur most susceptible
Vertebral and hip fractures common
Risk Factors for Osteoporosis
Most often aged, postmenopausal women
30% of women 60 – 70 years of age; 70% by age 80
Occurs less often in men
Sex hormones maintain normal bone health and density
As secretion wanes with age osteoporosis can develop
Some Risk Factors for Osteoporosis
Diet poor in calcium and protein
Insufficient exercise to stress bones
Immobility
Also:
Smoking
Hormone-related conditions
Thyroid problems
Diabetes mellitus
Men taking androgen-suppressing drugs
Arthritis
This is joint disease
arth- refers to joints (think arthropods and their jointed appendages)
-itis means inflammation
what makes up the central nervous system (CNS) and peripheral nervous system (PNS)
CNS- brain and spinal cord
PNS is everything else
ANATOMICAL TERMS TO KNOW FOR CNS
Gyrus (raises of the brain)
cortex (below the gyrus– gray matter)
sulcus (indents of the brain)
fissure (deeper indents of the brain; deep sulcus)
white matter–deep to the white mater
left & right cerebral hemispheres
transverse cerebellum fissure (fissure that separates the cerebellum from the cerebrum)
cerebellum (little brain; controls voluntary motion)
parietal-occipital sulcus (one medial surface of hemisphere)
lateral sulcus
occipital lobe
temporal lobe
central sulcus
frontal lobe
pons
medulla oblongata
some more vocab of the brain
frontal, parietal, occipital, temporal lobes
lateral fissure (deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal lobe)
central sulcus
pre-central gyrus
postcentral gyrus
anterior (where the frontal lobe is)
posterior (where the occipital lobe is)
few more vocab of the brain
parieto-occipital sulcus
lateral sulcus
transverse cerebral fissure
cerebellum
pons
medulla oblongata
spinal cord
The nervous system: different terminology for the CNS & PNS
CNS
Tracts = bundles of neuron processes
Nuclei = clusters of cell bodies
PNS
Nerves = bundles of neuron processes
Ganglia = clusters of cell bodies
White & gray matter in the CNS
White matter = myelinated fiber tracts
Gray matter = cell bodies, dendrites, glia, non-myelinated fibers
-cerebral gray matter- looks gray
-cerebral white matter- looks white
Cerebral cortex
-outermost part of the cerebrum , gray matter (all neurons of the cortex are interneurons)
-There is also deep gray matter in the brain: basal nuclei
structure of cerebrum
-cerebral cortex
-basal nuclei
-limbic system
cerebral cortex
substructures:
-primary motor
-primary somatosensory cortices
-multimodal association areas
basal nuclei
caudate nuclei
putamen
globus pallidus
limbic system
-hippocampus
-amygdala
primary motor cortex function
-plans and executes the movement
-Conscious control of precise voluntary muscle movements
-Axons from here project to the spinal cord
-Somatotropy – the body is spatially represented in the primary motor cortex
primary somatosensory function
-receive and process different types of sensory input
-Concerned with conscious awareness of sensation
-Receives info from sensory receptors in the skin and inside the skeletomuscular system
We’ve talked about skin receptors!
-Neurons can identify the part of the body stimulated.
multimodal association areas function
-integrate sensory and motor information from a variety of different primary cortices
caudate nuclei
putamen
globus pallidus
function
regulate movement
hippocampus function
plays a role in memory and learning
amygdala
plays a role in behavioral expression and emotion
cerebellum function
coordinates voluntary function
motor and sensory areas
primary motor cortex
primary somatosensory cortex
primary motor cortex
-Conscious control of precise voluntary muscle movements
-Axons from here project to spinal cord
-Somatotropy – body is spatially represented in primary motor cortex
1° somatosensory cortex
-Concerned with conscious awareness of sensation
-Receives info from sensory receptors in skin and inside the skeletomuscular system
-We’ve talked about skin receptors!
-Neurons can identify part of body stimulated.
contralateral side of the body
Each cerebral hemisphere controls the contralateral (opposite) side of the body, as far as sensory and motor functions go.
brain cortex
the outermost layer of the brain that is associated with our highest mental capabilities.