1
Q
Bones
A
- Cellular structures in which extracellular fluid is surrounded by a rigid calcified frame
2
Q
Medullary cavity of bone
A
Principle location of blood formation
3
Q
Axial Skeleton
A
-On long axis of body
- Skull, vertebrae, and bones attached to vertebrae, ribs and ventral connections of ribs and sternum
4
Q
Appendicular Skeleton
A
- Bones of front (thoracic) and hind. (pelvic) limbs and respective pectoral girdle and pelvic girdle
5
Q
Lone bone
A
- Compact, solid
- Spongy: cancellous
6
Q
Trabeculae
A
- Mineralized tissue
- Spongy bone
- Regions between are filled with bone marrow
7
Q
Epiphysis
A
- Either extremity of long bone
- Epiphyseal plate composed of hyaline cartilage and represents point of growth in a longitudinal direction; gets replaced by bone in mature bone
8
Q
Diaphysis
A
- Cylindrical shaft between two epiphyses
- Contains marrow cavity, where blood cell production occurs
9
Q
Metaphysis
A
- Flared part at the end of the diaphyses
10
Q
Periosteum
A
- Covers outer surfaces of bone
- Contains osteoblasts/osteoprogenitor cells
11
Q
Bone composition
A
- 25% water
- 45% mineral (37% calcium, 18.5% phosphorus)
- 30% organic matter (about 90% collagen)
12
Q
Osteoblasts
A
-Deposition of Ca2+ into bone
-Differentiated bone forming cell responsible for producing bone matrix
-Secretes collagen, makes up osteoid
13
Q
Osteoclasts
A
-Resorption of Ca2+ from bone
- Large, motile, multi-nucleated bone resorbing cells
- Precursors come from bone marrow and spleen
- Apart of the mononuclear phagocytic system
14
Q
Ca2+ Deposition and Resorption
A
-Tightly controlled by hormones
-Osteoblasts and osteoclasts
- Guarantees a rapidly exchangeable pool
15
Q
What is in the central canal of a bone
A
- Lymphatic vessel
- Vein and artery
- Nerve
16
Q
Osteoprogenitor cells
A
- Innermost layer of periostem, enosteal lining cells of marrow cavity, lining cells of haversian and Volkmann canals
- Stimulation leads to more active osteoblasts
17
Q
Osteocyte
A
- Mature bone cell/transformed osteoblast
- Maintain bone matrix, synthesize and resorb matrix to an extent
- Use gap junctions to communicate and respond to hormones
18
Q
Bone remodeling cycle
A
- Resorption and formation of bone by osteoclasts and osteoblasts is coupled
1. Osteoclast resorption (initially thick bone is chewed down)
2. Osteoblast activity, matrix formation (osteoid) (bone is built back up from lowest thickness)
3. Mineralization
4. Resting phase
19
Q
Uncoupled osteoblastogenesis and osteoclastogenesis
A
Leads to apoptotic osteoclast
20
Q
Bone formation
A
- Identified according to environment
- Heteroplastic, endochondral, intramembranous
21
Q
Heteroplastic
A
In tissue other than skeleton (penis)
22
Q
Endochondral
A
- Develops from cartilage and is mostly preformed in the fetus
- Occurs after birth from cartilage plates of long bone
23
Q
Intramembranous
A
- Formed without intervention of cartilage
- Flat bones of skull and face
24
Q
Long bone growth
A
- Depends on epiphyseal plate
- 4 zones
- Cartilage does not have blood supply and extracellular fluid provides nutrients
25
Apposition
-Bone growth that increases the width
- Shaft of bone
26
Bone remodeling
- Coordinated formation of new bone at outer surfaces
- Resorption of bone at inner surfaces
27
Types of Bone Remodeling Cycles
1. Coupled and balanced bone remodeling (no net change)
2. Coupled and unbalanced bone remodeling (some net change)
3. Uncoupled bone remodeling (large net change)
28
Vitamin D background
- Steroid hormone
- Biologically inert and must be converted to 25-hydroxyvitamin D3 in liver then 1a,25-dihydroxyvitamin D3 in kidney
- Works via nuclear Vitamin D receptor
29
What does Vitamin D regulate
- Calcium/Phosphate absorption in the gut, calcium mobilization in the bone, calcium reabsorption in kidney
- Affects T cell immunity
- VDR found in many diverse cells
30
Estrogen deficiency effect on bone
Causes bone loss
31
Calcium deficiency effect on bone
Slows bone formation
32
Chronic stress effect on bone
Decreases bone formation
33
Distribution of water in body
- Water is 60% of body weight. Of that:
- 67% is intracellular
- 27% is interstitial
- 6% is circulating plasma
34
Homeostasis
Maintenance of relatively constant physical and chemical conditions within an organism
35
Why is diffusion not sufficient in complex organisms
Distance
36
Open circulatory system
- Hemolymph flows directly into interstitial fluid
37
Closed circulatory system
- Blood flows through capillaries (leisurely flow in diffusion zone)
38
Fish Circulatory System
- Two chambered heart
- Single circuit of blood flow
- Two capillary beds
39
Frog Circulatory System
- Three chambered heart
- 2 circulatory loops
- some mixing of oxygenated and deoxygenated blood in ventricle
40
Mammalian Circulatory System
- Four chambered heart (right atrium, right ventricle, left atrium, left ventricle)
- Two circulatory loops ( Pulmonary circulation, systemic circulation)
41
Purpose of Valves in Veins
To keep blood from pooling
42
Number of Arteries
160
43
Number of Arterioles
5x10^7
44
Number of capillaries
10^10
45
Number of Venules
10^8
46
Number of Veins
200
47
Number of vena cava
2
48
Number of aorta
1
49
Systolic pressure
High pressure
50
Diastolic pressure
Low pressure
51
Arteries
High pressure delivery vessels
52
Arterioles
Resistance vessels regulate flow to capillary beds
53
Capillaries
Exchange vessels, large number with small diffusion distance
54
Veins
Low pressure return vessels
55
Steps of Cardiac Cycle Contraction
1. RA and RV are relaxed, blood filling heart
2. RA contracts, RV still relaxed and has final filling
3. RV contracts, high pressure flow of blood to lungs
1. LA and LV are relaxed, blood filling heart
2. LA contracts, LV is still relaxed and has final filling
3. LV contracts, high pressure flow of blood to body
56
Ventricular systole
Ventricle contracts and generates pressure
57
Ventricular diastole
Ventricle relaxes and creates a vacuum
58
Ventricular filling. (Mid-to-late Diastole)
- Heart relaxed and filling with blood (aortic and pulmonary valve closed)
- Atrial contraction (aortic and pulmonary valve closed)
59
Systole
- Isovolumetric ventricular contraction (all valves closed and ventricles build pressure by contracting)
- Ventricular ejection (once enough pressure has been built, Right AV valve and Left AV valve open)
60
Isovolumetric ventricular relaxation (Early Diastole)
All valves closed and ventricle relaxes and generates low pressure
61
Vena cava
- Superior vena cava (top, returns blood from head, upper limbs)
- Inferior vena cava (bottom, returns blood from trunk, legs)
62
Pulmonary semilunar valve
Valve that leads from right ventricle to pulmonary arteries
63
Right atrioventricular valve
Valve that leads from right atrium (from vena cava) to right ventricle
64
Left atrioventricular valve
Valve that leads from left atrium (from pulmonary veins) to left ventricle
65
Aortic semilunar valve
Valve that leads from left ventricle to aorta
66
Volume comparison of left and right ventricle
They have the same volume. Left ventricular wall is more muscular
67
When does a valve open
When pressure is greater behind the valve
68
When does a valve close
When pressure is greater in front of the valve. It does not open in the opposite direction- valves are one-way
69
Tricuspid valve
Right av valve
70
Prevention of eversion of AV valves
Papillary muscle and chordae tendineae
71
Bicuspid valve
-Left av valve
- closing causes lub sound
72
Semilunar valve
-Aortic or pulmonary valve
- Closing causes dub sound
AN SCI 373
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