Anatomy, Blood, Skin, Tissues and Bone. Flashcards
1
Q
What is the function of desmosomes?
A
Provide a strong bond between adjacent epithelial cells.
2
Q
What is the function of cilia?
A
Provide a mechanism for movement of material over the surface of epithelia.
3
Q
What is the function of hemidesmosomes?
A
Attach epithelial cells to the basement membrane.
4
Q
Describe stratified epithelia.
A
They have more than one layer of cells.
5
Q
What is the average circulating volume of blood in a typical adult male?
A
5 litres
1L lungs, 3L systemic venous circulation, 1L heart and arterial circulation
6
Q
List the main functions of blood.
A
- carriage of physiologically active compounds
- clothing
- defense
- carriage of gases
- thermoregulation
- maintenance of ECF pH
7
Q
Describe the composition of plasma.
A
Plasma proteins and interstitial fluid.
8
Q
What are the main types of plasma proteins?
A
Albumin (60%), Globulin (38%), Fibrinogen and clotting factors (2%)
9
Q
What is the function of albumin?
A
Generates colloid pressure, transport steroids, fats and vitamins, buffers H+ ions.
10
Q
What is oncotic pressure generated by?
A
Plasma proteins
11
Q
What is the average measurement of oncotic pressure?
A
approx 25mmHg
12
Q
Define oncotic/colloid somatic pressure.
A
A form of osmotic pressure exerted by proteins, notably albumin, in a blood vessel’s plasma that usually tends to pull water into the circulatory system.
13
Q
What is the opposing force of oncotic pressure?
A
Hydrostatic pressure
14
Q
The net movement of fluid between capillary and interstitial space is subject to two forces. What are they?
A
- Capillary Hydrostatic pressure (favours movement out)
2. Plasma protein concentration (favours movement into capillaries)
15
Q
What is the normal circulating level of WBCs?
A
1x10^10/litre
16
Q
What is the lifespan of a RBC?
A
120 days
17
Q
Describe the structure of a RBC.
A
Flexible, bi-concave, non-nucleated, packed with Hb
18
Q
How long is the delay between erythropoietin rise to increase in RBCs?
A
2-3 days
19
Q
Basal levels of erythrpoeitin are always circling. When is it released?
A
When O2 delivery to kidney fails due to cardiac dysfunction, haemorrhage, anaemia and lung disease
20
Q
What is the function of erythropoietin?
A
Stimulates pluripotent stem cells to produce erythroblasts (immature RBC)
21
Q
What are the five main types of WBC?
A
Monocytes, Neutophils, Eosinophils, Lymphocytes
22
Q
What are the most abundant WBC?
A
Neutrophils (68%)
23
Q
What are the least abundant WBCs?
A
Basophils
24
Q
What WBCs rise following an allergic response and parasitic infections?
A
Eosinophils
25
Discuss monocytes.
After 72 hours in circulation, migrate to CT where they become macrophages and live for 3 months.
26
Compare monocyte and macrophage.
```
Monocyte = macrophage precursor, in circulation for 72 hours.
Macrophage = In connective tissue for 3 months, phagocytosis
```
27
What controls WBC formation?
Leukopoiesis (more complex than erythropoiesis)
28
What controls leukopoiesis?
Cytokines (released from endothelial cells, fibroblasts and/or mature WBCs):
1. Colony stimulating factors
2. Interleukins
29
What type of WBC increases in response to bacterial infections?
Neutrophils
30
What type of WBC increases in response to viral infections?
Lymphocytes
31
What are the functions of platelets?
Adhere to damaged vessel walls and exposed connective tissue to form scaffolds and clots.
32
What is the structure of platelets?
Membrane bound cell fragments from cytoplasm of megakaryocytic from bone marrow.
33
What is the life-span of platelets?
10 days
34
What is the formation of platelets governed by?
Thrombopoietin stimulating bone marrow
35
Define haematocrit.
The percentage of RBCs as % of whole blood.
36
When does haematocrit increase?
- Heart and lung disease
| - At altitude
37
What are the normal levels of haematocrit?
```
Male = 40-54%
Female = 37-47%
```
38
Define viscosity.
How thick/sticky blood is.
39
What is the viscosity of plasma and whole blood in relation to water?
Plasma = 1.8 x thicker than water
| Whole blood = 3.4 x thicker than water
40
In what circumstance will the viscosity of blood and plasma increase?
1. Increase in haematocrit
2. Decrease in temperature
3. Decrease in flow rate
41
What is the largest organ in the human body?
The integumentary system.
42
What are the four tissues that make up skin?
1. Epithelium
2. Connective tissue
3. Muscle
4. Nerve
43
Describe the layers of skin.
1. Epidermis
2. Dermis (papillary and reticular layers)
3. Hypodermis
44
Describe the epidermis.
1. Epithelium
2. Forms boundaries between internal and external compartments.
3. Prevents water loss by evaporation.
45
Describe the dermis.
1. Connective tissue
2. Give structural strength
3. Reduces risk of external injury, maintains epidermis by blood flow, permits body cooling, immune surveillance etc...
46
Describe the hypodermis.
1. Adipose (fatty) connective tissue layer beneath the skin.
47
What is the function of superficial or subcutaneous tissue in skin?
Anchors skin to underlying structures.
48
Define keratinisation.
Organic process whereby keratin is deposited in cells, these become horny as in dead skin, nails and hair.
49
What type of epithelium is found in skin?
Stratified squamous keratinising epithelium.
50
What is psoriasis?
Autoimmune disorder affecting keratinisation
51
At what layer of the skin does stem cell division take place?
Stratum basale.
52
At what layer of the skin are dead cells sloughed off?
Stratum corneum
53
What are the five layers of the skin from top to bottom?
1. Stratum corneum
2. Stratum lucid
3. Stratum granulosum
4. Stratum spinous
5. Stratum basale
CLGSB (Caitlin Likes Grapes and Strawberries)
54
What are the four cell types found in the skin?
Keratinocytes, Melanocytes, Langerhans cells, Merkel cells.
55
Describe the organisation of connective tissue in the dermis.
1. Papillary layer
| 2. Reticular layer
56
Describe the papillary layer of the dermis.
- Loose CT
- Irregular interface with epithelium
- Cellular e.g macrophages
- Blood vessels
- Nerve endings - sense organ
57
Describe the reticular layer of the dermis.
- dense irregular CT
- collagen bundles in 3 planes
- elastic fibres (loss of elasticity in old age)
58
identify the accessory structures of the skin.
Hair, nails, sweat glands
59
Describe the structure and function of hair.
Hair follicle = hair + sheath(s), arrestor pilling muscles, sebaceous gland
Function = thermoregulation
60
Describe the structure and function of nails.
Hard keratin with same four layers as epidermis (nail plate is analogous to stratum corneum)
61
What are the eponycheum and hyponycheum?
Parts of nail (eponycheum is closest to cuticle)
62
Describe the sweat glands.Apocrine
- Sebaceous (hair follicles - sebum)
- Apocrine (axilla, protein rich)
- Eccrine
63
What are eccrine glands?
- simple tubular glands
- coiled and straight duct located in the dermis.
- spiral channel in epidermis
64
What are the main functions of eccrine glands?
Water secretion and thermoregulation
65
Describe the blood supply of the skin.
In dermis.
Can be horizontally arranged superficial and deep plexus, perpendicular to the surface or anastomoses to form continuous vascular network.
66
List the sensory receptors of the skin.
1. Meissener's corpuscles
2. Paccinian corpuscles
3. Nocicieptors
4. Thermoreceptors
67
What do moistener's corpuscles detect?
Touch
68
What do paccinian corpuscles detect?
Pressure and touch
69
Describe the roles of skin as a barrier between muscle and outside of body.
1. Waterproofing (epidermis, keratin, intracellular spaces filled with lipid component)
2. Wear and tear
3. Protection against UV light penetration
4. Immune protection
5. Chemical resistance
6. Repair (blood clot - granulation tissue - scab - scar)
70
Why is epithelium thin?
For diffusion
71
What are the different types of surface epithelium?
1. Simple (squamous, cuboidal or columnar)
2. Stratified (squamous, cuboidal or columnar)
3. Transitional
4. Pseudostratified columnar
72
Where would you find pseudo stratified columnar epithelia?
The trachea
73
Where would you find stratified transitional epithelia?
Bladder
74
Where would you find stratified squamous epithelia?
Skin
75
Where would you find stratified cuboidal epithelia?
Secretary gland
76
Where would you find stratified columnar epithelia?
Secretory gland
77
Where would you find simple cuboidal epithelia?
In gut and ovaries.
78
What simple epithelia is most active?
Simple columnar
79
Describe simple squamous epithelia.
One layer of cells, flattened
80
Where would you find simple squamous epithelia?
Blood vessels
81
Describe simple cuboidal epithelia.
One layer with same height and width
82
Describe simple columnar epithelia.
One layer, taller, thinner = better
83
Describe stratified squamous epithelia.
Multiple layers of varying shapes and sizes.
84
Describe stratified cuboidal epithelia.
Multiple ayers of cuboidal shaped cells
85
Describe stratifies columnar epithelia.
Multiple layers of columnar shaped cells.
86
Describe epithelial components of the liver.
- Parenchymal cells - hepatocytes (arranged in rows between synosoids)
- support epithelia lining blood vessels and bile ducts.
87
Describe epithelial components of the kidneys.
- Parenchymal cells - epithelial cells organised into nephrons
- support epithelia line blood vessels and renal pelvis (CT) which receives toxic urine)
88
What are the consequences of abnormal function of glands?
- over proliferation (e.g of growth hormone)
- under-proliferation ( e.g of growth hormone)
- loss of cilia (chlamydia)
- under secretion
89
Define gland.
Specialised epithelium (e.g in liver) which can be single or multicellular with selection of secretory cells.
90
What are the basic functions of glandular epithelium?
1. Exocrine (secreted into tubes, e.g mucous or serous gland)
2. Endocrine (secreted into blood, e.g proteinaceous secretion of steroid hormones)
91
Give examples of exocrine glands.
Pancreas, mucous glands of trachea and ilium, salivary gland.
92
Give an example of an endocrine gland.
Adrenal cortex
93
Define connective tissue and it's basic functions.
- Connects
- ECM + fluid
- Liquid to solid matrix
94
What are the three components of the ECM?
1. Fibres
2. Ground substance
3. Tissue fluid (liquid)
95
What kind of secretions are produced by the exocrine gland?
Mucous or serous secretions
96
What kind of secretions are released by endocrine glands?
Proteinaceous
97
Describe fibre in the ECM.
1. Most abundant = collagen (type 1 = tendons, type 3 = reticulum, type 4 = basal lamina)
2. Elastin (e.g in aorta, stretch 1.5 times, with microfibrils and amorphous components)
98
Describe ground substance of ECM.
- Jelly-like proteoglycan which absorbs water to have this form.
- Contains hyaluronic acid and glycoproteins
99
Describe tissue fluid.
Can be loose, dense, regular or irregular.
100
What are the consequences of abnormal function of connective tissue?
- collagen = tear
- bone = osteoporosis
- blood/bone marrow = sickle cell anaemia and leukaemia
- loose/dense = loss/abnormal fibres (epidermolysis bullosa - constant interruption of blood supply)
101
Describe are the four main functions of bone.
1. Weight bearing/support
2. Muscle attachments
3. Mineral store (hydroxyapatate)
4. Blood formation
102
How is bone arranged to reflect direction of mechanical force?
Orientation of trabeculae and collagen fibres along the direction of force.
103
What is the function of mechanical load on bones?
Regulates bone mass e.g higher BMD in athletes (especially resistance and high-impact sports)
104
Describe the two main methods of bone development.
1. Endochondrial
| 2. intramembranous
105
Describe endochondrial ossification.
From hyaline cartilage model - blood vessels invade - primary ossification centre - secondary ossification centre - medullary cavity formed
106
Give an example of a secondary endochondrial ossification site.
Epiphyseal plate
107
Describe intramembranous ossification.
NO CARTILAGE PHASE.
- mesenchymal cells - osteoprogenitor cells - osteoblasts start depositing bone
- residual mesenchymal cells develop blood vessels and bone marrow
108
Where does intramembranous ossification occur>
Flat bones of skull in infants and adult cortical bone.
109
Where are the supporting tissue of haemopoiesis located in bone?
Bone marrow with RBCs produced in heads of long bones.
110
Describe trabecular/spongy/cancellous bone.
- less dense
- network of lamellate trabeculae, filled with bone marrow
- orientation of trabeculae reflect directions of mechanical force.
111
Describe cortical/compact bone.
- dense
- organised in osteons/harversian systems
- horizontally perforating Volkman's canals
- osteocytes of concentric rings of bone matrix (lamellae) around H canal joined by cannaliculi.
112
Describe the composition of bone.
Type 1 collagen and minerals
113
What is the function of type 1 collagen in bone?
Gives flexibility and decreases risk of fracture and has high strength under tension.
114
What are the minerals found in bone?
Non-collaginous proteins mineralised by hydroxyapatate for stiffness and support structures.
115
Discuss the process of bone renewal.
- Constant process even in adults
| - Healthy bone = balance between bone removal and formation with a new skeleton every 10 years in adult.
116
What are the two cells involved in bone remodelling?
1. Osteoclasts break down old bone
| 2. Osteoblasts build new bone (initiate calcification)
117
Where are osteoclasts derived from?
Monocytes/macrophages (haemapoietic lineage)
118
What are Howship's lacunae?
Resorption pits of osteoclasts.
119
What are osteoblasts derived from?
From osteoprogenitor cells in periosteum and endossteum (mesenchymal lineage).
120
What do osteoblasts eventually become?
Osteocytes when surrounded by matrix.
121
Where are osteocytes found?
Found in lacunae of mature bone.
122
What is the function of osteocytes?
Function not well understood (may maintain matrix and sense forces)
123
What is the anatomical position?
Standing upright, head facing forward, upper limbs by sides nd palms facing anteriorly, fingers together, lower limbs straight, heels together, toes anteriorly.
In males = erected penis.
124
List the spatial directions.
Superior/inferior, anterior/posterior, medial/lateral, distal/proximal
125
List the main anatomical planes.
Median (mid-sagittal), sagittal, frontal (coronal), transverse
126
What is a joint?
An articulation between two or more rigid components (bone or cartilage)
127
Why do we need joints?
Growth and movements
128
What are the three types of joints?
1. Fibrous
2. Cartilaginous
3. Synovial
129
Describe fibrous joints.
Dense fibrous connective tissue with high tensile strength and little movement in adults
130
Give examples of fibrous joints.
Skull sutures and tooth in socket.
131
What are the two types of cartilaginous joints?
1. Synchondroses (primary)
| 2. Symphyses (secondary)
132
Describe synchondroses.
Allow for bone growth (endochondrial ossification)
133
Give an example of a synchondrosis joint.
Long bones
134
Describe symphyses.
- Do not ossify with age, found in midline with limited movement.
- contains hyaline AND fibrocartilage.
135
Give two examples of symphese joints.
1. Pubic symphysis
| 2. Intervertebral bodies and discs.
136
Describe the structure of a synovial joint.
Contains ligaments, articular discs, bursar, synovial fluid, synovial capsule
137
Give examples of synovial hinge joints.
Elbow, Knee, Ankle
138
Give an example of a pivot joint.
Atlanto-axial joint
139
Give an example of a saddle joint.
Thumb and scaphoid
140
Give examples of ellisoid joints.
Origin of fingers and atlanto-occipital joint
141
Give an example of a ball and socket joint.
Glenohumeral joint and acetabulofemoral (hip) joint
142
Give examples of plane joints.
Articular facets of vertebrae and clavicle to scapula.
143
What accounts for joint stability?
Shape of articulating surfaces, fibrous capsule and ligaments and muscles (e.g rotator cuff)
144
What is Hilton's Law?
The nerve supplying a muscle that crosses a certain joint, also innervated the joint.
145
List some joint pathologies.
Trauma, arthritis (osteoporosis or rheumatoid), craniosynostosis
146
What are the three main types of muscle?
1. Skeletal
2. Cardiac
3. Muscle
147
What are the different arrangements of muscle fibres?
Unipentate, bupentate and multipentate.
148
Describe tendons.
Dense connective tissue, don't shorten and can alter force direction.
149
What is the nerve supply of muscle compartments?
Muscles of the same compartment are usually supplied by the same nerve e.g radial nerve supplies all extensors in the upper limb.
150
How many spinal nerves exist?
31
151
Where are the spinal nerves located?
In the intervertebral foramen.
152
What fibres are found in the roots?
Sensory OR motor
153
What fibres are found in the rami?
Sensory AND motor
154
In what pathway do the motor fibres not synapse?
Somatic pathway
155
What are the sympathetic ganglia?
Where MOST sympathetic motor fibres synapse (except fibres to the abdominopelvic viscera)
156
Where are the ganglia of the parasympathetic system located?
Close to the effector organ
157
What is a motor unit?
One motor neuron and various muscle fibres.
158
What are dermatomes used for?
Used clinically to test for lesions at specific levels of the spinal cord.
