Physiology 1 Final Flashcards
1
Q
What are the three types of muscle tissue
A
Skeletal, smooth, and cardiac
2
Q
Functions of muscle
A
Movement, Stabilization, Thermogenesis
3
Q
General Characteristics of muscle
A
Irritability, Contractility, Extensibility, and Elasticity. Composed of elongated cells
4
Q
Voluntary or Striated muscle is aka
A
Skeletal M.
5
Q
Where is skeletal m. located
A
Somatic/skeletal m., upper esophagus, diaphragm
6
Q
Origin of the skeletal m. cells
A
Long, multinucleated, and come from the fusion of numerous myoblasts
7
Q
Dense connective tissue surrounding m.
A
Epimysium
8
Q
Bundles of m. cells
A
Fascicles
9
Q
What dense connective tissue covers fasicles
A
Perimysium
10
Q
What make up fascicles
A
M. cells/”fibers”
11
Q
What covers the m. cells/”fibers”
A
Endomysium (made of basal lamina)
12
Q
What occurs at the myotendinous junction
A
Endo, peri, and epimysium become continuous with m. tendon which attaches the m. to bone
13
Q
What is a sarcolemma
A
Cell membrane of a m. fiber
14
Q
Location of Transverse (T) Tubules
A
Continuous with sarcolemma, and extend to interior of fiber surrounding myofibrils
15
Q
What is the Sarcoplasmic Reticulum
A
Specialized ER that forms a tubular network around the myofibrils
16
Q
What are Cisternae
A
Large Chamers of SR around myofibril on either side of T tubule. STORES CA++ ions
17
Q
What is a Triad
A
Unit of T Tubule and flanking cisternae encircling a myofibril
18
Q
What is a Myofibril
A
Micro(Myo)filaments arranged into sarcomeres
19
Q
What makes up thin filaments
A
Contractile protein Actin
20
Q
Regulatory proteins found with thin filaments
A
Troponin and Tropomyosin
21
Q
What structural protein attaches the thin filament to the Z disc
A
Nebulin
22
Q
What primarily makes up thick filaments
A
The protein Myosin
23
Q
What structural protein attaches thick filaments to Z disc and M line
A
Titin
24
Q
What structural protein makes up the M line
A
Myomesin
25
What is Dystrophin, and what does it do
Structural protein that connects thin filaments to the sarcolemma to transmit m. tension to m. tendon
26
What is the sarcomere
Functional unit of a m. contraction
27
What makes up the A band
Dark band, primarily thick filaments
28
Where is the M line located
Center of the A band
29
Where is the H zone
Lighter zone on either side of M line. ONLY HAS THICK FILAMENTS
30
What is the zone of overlap
Overlapping zone of thin and thick filaments
31
What makes up the I band
Light band, ENTIRELY THIN FILAMENTS
32
What is the Z disc/line
Boundary between 2 sarcomeres
33
What makes up the Z disc/line
Structural protein Alpha-Actinin which holds thick and thin filaments in place
34
When the sarcolemma is stimulated by signals from the nervous system, what happens
Generates an AP (electrical impulse) which travels down the sarcolemma
35
How does the AP get to the myofibrils
Through the T tubules
36
What does an AP trigger
The release of Ca++ ions from the cisternae
37
What do the Ca++ ions cause
Exposure of binding sites on the Actin molecules of thin filaments
38
What does Ca++ bind to
Troponin. Causes Tropomyosin to move away and uncover binding sites
39
Myosin binding to Actin and causes what to happen
Thin filaments to slide past thick filaments toward M line. ie: Contraction of m. fiber
40
Before contraction of sarcomere begins, adenosine triphosphate (ATP) binds to the myosin head and immediately hydrolyzes into what
ADP, phosphate group (Pi), and stored energy
41
What causes the release of the Pi
Mysoin heads binding to an actin molecule on thin filament
42
What does the release of Pi initiate
The "Power Stroke". Pulls thin filament toward center of sarcomere
43
What happens at the end of the power stroke
ADP molecule is released from the myosin head
44
What causes the myosin head to detach from the Actin molecule post contraction
Another ATP molecule
45
How often do the steps of a m. traction occur
Until there is either no more Ca++, ATP, or sarcomere is maximally shortened
46
What causes Rigor Mortis
Permanent cross-bridging between actin and myosin because there is no ATP available to break the bond
47
What are the energy sources for skeletal m. contraction
Creatine phosphate stored in m. (anaerobic), Glycolysis of glycogen stored within the muscle and in the liver (anaerobic), and Oxidativemetabolism of lipids, carbohydrates, and proteins(aerobic)
48
Phase 1 of Energy Utilization
Creatine Phosphate and glycogen (Anaerobic)
49
Phase 2 of Energy Utilization
Breakdown of FAs, Carbs, and proteins (Aerobic)
50
Phase 3 of Energy Utilization
Return to glycolysis of remaining glycogen (Anaerobic)
51
Muscle Spindles
In m. belly, monitors changes in m. length
52
Structure of M. Spindles
Intrafusal fibers enclosed in a connective tissue capsule. Contains Nuclear bag and chain fibers
53
Ratio of Nuclear Bag to Nuclear Chain fibers
2:1 ratio of Chain to Bag fibers
54
Sensory N. fibers have what 2 types of endings
Primary and Secondary
55
What are Primary sensory n. endings
Type Ia and wrapped around center of both bag and chain fibers
56
What are Secondary sensory n. endings
Type II and wrapped around ONLY CHAIN fibers
57
What do Gamma-Dynamic motor nerves innervate
Primarily Bag intrafusal fibers
58
What do Gamma-Static motor nerves innervate
Primarily Chain intrafusal fibers
59
Slow prolonged stretch "Static" response
Primary and Secondary sensory endings fire continuously and in proportion to degree of stretch. Gamma-static motor fire proportionate to inc or dec in stretch
60
Sudden stretch "Dynamic" response
Primary fire only while length is changing. Gamma-dynamic fire maintaining spindle fiber length proportions, and thereby maintaining receptor sensitivity
61
What is the Tendon organ (GTO)
Stretch receptor located at the myotendinous junction
62
How do GTOs work
Small bundle of tendon collagen fibers surrounded by a connective tissue sheath, one end connected to muscle fibers, the other end merging into the tendon
63
What kind of fiber wraps around the collagen fibers of the GTO
A single type Ib sensory fiber
64
When/Why does the GTO fire
In response to tension on the organ. Can be either contraction or stretch
65
T/F: The Tendon organ/GTO has both dynamic and static response levels
True
66
What kind of reflex is the muscle stretch reflex
Mono-synaptic, 2 neuron pathway
67
First half of Reflex Cycle (M. Stretch)
Stretch leads to primary sensory activated "dynamic response". AP to spinal cord direct synapse with alpha motor neurons associated with homonymous m.
68
Second Half of Reflex Cycle (M. Stretch)
Alpha motor neurons of homonymous m. cause m. to contract decreasing the stretch on the m. returning the m. spindles to original length and returns firing rate of primary sensory fibers to baseline "static" levels
69
During the reflex cycle, what motor commands are sent from the spinal cord
Contract synergistic m. AND relax antagonistic m.
70
What does the stretch reflex also allow
During voluntary m. contraction, prevents antagonistic m. from contracting. Stabilize posture, and make m. action smooth
71
What kind of reflex it the Golgi Tendon reflex
Di-synaptic, 3 neuron pathway
72
First half of Reflex Cycle (Golgi Tendon)
M. contracts, shorten extrafusal fibers and inc tension on GTOs, activating type Ib sensory afferent fibers;action potentials to spinal cord, synapse directly with inhibitory interneurons; they synapse with alpha motor neurons of the homonymous muscle
73
Second half of Reflex Cycle (Golgi Tendon)
Alpha motor neurons of homonymous m. inhibited from firing. leads to relaxing of homonymous m.
74
What does the GTO reflex also allow
Relax synergistic m. and contract antagonistic m.
75
Functions of GTO
Prevent too much tension in m. protecting it from damage. also equalizes contraction strength of m. fibers w/in a m.
76
What is the flexor-withdrawal reflex
Stimulation of a body part causes contraction of flexor m. Withdrawing body part away from stimulus
77
What spreads the flexor-withdrawal reflex to other associated m.
Diverging Neural Circuits
78
What inhibits contraction of associated antagonist m.
Reciprocal inhibition
79
Diverging Neural Circuits produce an after discharge which does what
Prolongs the contraction of the flexor m. after the stimulus has stopped
80
What is the Crossed-extensor reflex
Ext. of contralateral limb .2-.5 sec after start of flexor-withdrawal reflex. Initial stimulus is moderate or strong
81
What do the cells in Cardiac m. tissue look like
Short and branched with a single nucleus. Striated with actin and myosin arranged into sarcomeres.
82
What is larger and more plentiful in cardiac m. than it is in skeletal m.
Mitochondria
83
What are larger (in diameter) and more numerous in cardiac m. than they are in skeletal m.
Transverse Tubules
84
What is less well developed in cardiac m. than it is in skeletal m.
Sarcoplasmic Reticulum
85
What are the sources of Ca++ during cell contraction
Extracellular Fluid (via T tubules and diffuse across cell membrane to interior) and Released from Cisternae of the SR
86
What do cardiac cells originate from
A Single myoblast
87
How are cells interconnected to each other
Intercalated discs
88
What do Intercalated discs consist of
Numerous adherent and gap junctions
89
What do Desmosomes do
Keep the cells from pulling apart as they contract
90
What do Gap junctions act as
Electrical Synapses passing the contraction signal directly from one cell to all the others within the interconnected network
91
How are the cells in the L/R atria and L/R ventricles connected
Atria are interconnected into single network and Ventricles are interconnected into a single network
92
What is Functional Syncytium
All the cells within each network contract simultaneously as if they were a single cell
93
What is the structure of smooth m.
Short and fusiform (spindle) with a single centrally located nucleus
94
What is different about smooth m. cells compared to skeletal and cardiac cells
Cells are not striated and actin and myosin are arranged differently
95
Membrane Dense Bodies
Some bonded to membrane dense bodies of adjacent cells
96
What are attached to dense bodies in smooth m.
Actin/thin filaments
97
What is different about actin and Ca++ binding in smooth m.
Actin lacks troponin, Ca++ binds to regulatory protein Calmodulin of myosin filaments
98
What are intermediate filaments in smooth m.
Structural proteins forming a framework for the actin and myosin filaments
99
What is different about Sidepolar cross-bridges in smooth m.
Myosin heads on one side bend in one direction, while heads on opp. side hinge/bend in the opp. direction
100
What kind of contraction occurs due to Sidepolar cross-bridges
Spiral, Corkscrew-like contraction
101
What is different about the SR in smooth m.
Sparse and no T Tubules
102
Where does the Ca++ come from in smooth m.
Little in SR, Most from extracellular fluid, and enters via calcium channels in sarcolemma
103
Other names for Visceral smooth m.
Unitary, Syncytial, Single-unit
104
How are cells arranged in Visceral smooth m.
Single sheet interconnected via gap junctions which all contract simultaneously. Can transmit APs
105
Where is Visceral smooth m. typically found
Hollow organs. (stomach, intestines, uterus, bile duct, bladder, blood vessels)
106
Most organs have 2 layers of m. running in what 2 directions
Longitudinally and transversely
107
The stomach has a 3rd layer that runs in what direction
Obliquely
108
How is multi-unit smooth m. composed
Individual smooth m. cells unconnected to nearby cells
109
Characteristics of multi-unit smooth m. cells
Thin collagen & glycoprotein membrane for insulation, own innervation, and found in iris constrictors/dialtors, arrector pili, pulmonary air passages, and walls of largest arteries
110
Smooth m. cell contraction process
Ca++ enters and binds to calmdulin, this binds to MLCK which phosphorylates one of light chains within a mysoin head allowing it to bind to actin.
111
T/F: Myosin-actin cross-bridge cycle in smooth m. cell contractoin is slower that in skeletal m.
True
112
MLCK is de-phosphorylated by what
Action of Myosin phosphatase
113
Why is the cycle slower in smooth m.
Ca++ channels open slower, and stay open longer. slow removal of Ca++ by Ca++ pumps
114
Because the cycle is slower in smooth m. what does it allow for
Prolonged m. tone w/o excessive energy expenditure
115
What regulates smooth m. contraction
Nervous, Hormonal, M. cell stretch, and Nearby chemical environment of m. cell
116
The skin is aka
The integument, an organ within the integumentary system
117
What makes up the integumentary system
Skin and accessory organs (nails, hair, glands, sensory receptors)
118
Functions of the integumentary system
Protection, Regulates body temp, Houses sensory receptors, Vit D synthesis, and Excrete waste materials via perspiration
119
How does the integumentary system regulate body temps
Retains via subcutaneous layer, and eliminates via radiation (dilate blood vessels), convection and conduction, and evaporation of perspiration`
120
What is the most superficial layer of the skin
Epidermis
121
What makes up the Epidermis
Keratinized stratified squamous epithelium
122
What 4 types of cells make up the Keratinized stratified squamous epithelium
Keratinocytes, Melanocytes, Dendritic cells, and Merkel cells
123
What are keratinocytes
Predominate cell type of Keratinized stratified squamous epithelium. Manufacture keratin
124
What is Keratin
Structural protein which toughens and waterproofs the surface of the epidermis
125
What do melanocytes do
Manufacture melanin, a brown-pigment
126
What are Dendritic cells (Langerhans, histocytes) do
Immune cells
127
What are Merkel cells (aka discs)
Type I tactile mechanoreceptors
128
Histologically, how many layers make up the Epidermis
Thin skin (4) vs. Thick skin (5)
129
What is the deepest layer of the Epidermis, and is highly mitotic
Stratum Basale
130
What layer of the Epidermis is mitotic only in its deeper layers and begins the synthesis of keratin
Stratum spinosum
131
What is the Stratum Germinativum and Function
The Stratum basale + Stratum Spinosum. Primary site of cholecalciferol manufacture
132
What layer of the Epidermis is composed of flattened cells, filled up with keratin
Stratum Granulosum
133
What layer of the Epidermis is present only in thick skin (palms and soles)
Stratum Lucidum
134
What layer of the Epidermis is 20-30 layers of flattened keratinized dead cells
Stratum Corneum
135
Characteristics of the Dermis
Connective tissue housing m. fibers, blood vessels, hair follicles, exocrine glands, and nerve fibers
136
What are the 2 layers of the Dermis
Papillary layer and Reticular layer
137
Where is the Papillary layer located and what is it made of
Loose connective tissue directly underlying the epidermis.
138
What causes dermal ridges
(Finger and toe prints) Pulling of elastic fibers in the papillary layer
139
Where is the Reticular layer located, and what is it made of
Dense irregular connective tissue underlying the papillary layer
140
What is significant about the reticular layer
Quite distensible and resilient. When over-stretched it tears producing striae distensae "stretch marks"
141
What is the Subcutaneous layer aka
Hypodermis or superficial fascia
142
Although not officially part of the skin, what is the Subcutaneous layer made up of
Adipose, loose connective tissue, and blood vessels
143
Function of Adipose tissue in Subcutaneous layer
Heat insulator and energy resevoir. Conserves internal body hear or impedes entrance of external heat. Also binds skin to underlying structures
144
How much thicker *generally* is body fat in women than in men
8% thicker
145
Thickness of the subcutaneous layer can be indicative of what
Nutritional Status
146
Cause of Pink skin color
Blood flow in dermis and subcutaneous layers
147
Cause of Yellow skin color
Carotene and having a thicker stratum corneum with increased amounts of structural protein keratin. East Asia
148
What is Carotene
Yellowish pigment acquired through diet
149
Cause of Brown Skin color
Due to melanin, a brown-black pigment produced by melanocytes in stratum basale
150
What are human skin color differences primarily due to
Amount of melanin produced and its distribution. Everybody has approx. same number of melanocytes
151
What are freckles
Small, isolated patches of highly concentrated melanin secretion
152
Geographical distribution of skin colors
Darkest in areas with greatest amount of sunlight. Lightest in areas with least amount of sunlight
153
How does dark skin help
They protect against cell damage due to excessive UV radiation
154
How does melanin help with UV light
It absorbs UV radiation and prevents excessive amounts from reaching the mitotic cells of stratum germinativum and dermis
155
What else can help prevent excessive UVR from reaching the lower mitotic cell layers
Thicker stratum corneum
156
How does tanning work
Melanocytes respond to increased amounts of UVR by producing more melanin
157
Light skin tones and Vit. D
Allow for the synthesis of Vit. D
158
What will happen to darker skin tones in areas of lower UVR exposure
Decreased production of Vit. D
159
What is Vit. D needed for
Proper bone growth and maintenance. Rickets in kids and Osteomalacia in adults
160
T/F: Lighter skin is more susceptible to damage by extreme cold than dark skin
FALSE Dark skin is more susceptible
161
These structures reside in the dermis and subcutaneous layer, but originate from epidermal tissue
Hair and the hair follicle
162
What is a follicle
Tube-like structure which protrudes down into the dermis, houses an individual hair
163
3 Parts of the hair
Bulb, Root, and Shaft
164
What is the bulb
Zone of actively dividing cells at the base of the hair
165
What is the root
Column of flattened, dead keratinized cells within the follicle
166
What is the shaft
Column of flattened, dead keratinized cells external to the skin's surface
167
What makes up the root and shaft of hair
Medulla, cortex, and outer cuticle
168
Goosebumps are caused by these smooth m.
Arrector pili m.
169
What does the arrector pili m. attach to
Hair follicle surface and the dermis
170
High concentration of melanin in hair
Dark hair
171
Moderate concentration of melanin in hair
Light brown
172
Little concentration of melanin in hair
Blonde hair
173
No melanin concentration of melanin in hair
White hair
174
Mix of pigmented and unpigmented hairs
Gray hair
175
Red coloration of hair
Pigment contains iron
176
How is texture of hair determined
Shape and size of hair follicle
177
What is the function of hair
Protection and identification
178
Most human hair is...
Short, fine, and faintly pigmented. Dense is scalp, face, axilla and pubic areas
179
In adults, men are more likely than women to have noticeable hair on...
Back, abdomen, chest, limbs, and face
180
Those of European descent are the hairiest aka
Hirsute
181
Thos of East Asian and Amerinidians are the least hairy aka
Glabrous
182
What makes up the Nail plate
Modified hardened stratum corneum, divisible into nail root, nail body, and free edge
183
What makes up the Nail bed
Underlying nail plate. Continuous with stratum basale and stratum spinosum of surrounding epidermis
184
What makes up the Lunula
Part of nail plate, light half-moon region at the proximal end of the nail plate, coloration due to extreme thickness of underlying nail bed
185
Function of nails
Protection and facilitation of digital dexterity
186
Glands of the integumentary of what kind of glands in function and structure
Exocrine
187
Sebaceous Gland
Branched and acinar/alveolar in shape. connected to hair follicle. Holocrine secretion (sebum), which lubricates and waterproofs hair and stratum corneum
188
Overproduction of sebum may lead to what
Clogged sebaceous ducts, leading to acne
189
Apocrine gland
Tubular in shape and connected to hair follicle. Sudoriferous (sweat) glands concentrated in axillary and pubic regions
190
What does the Apocrine gland produce
An odoriferous merocrine secretion in response to emotonial stress.
191
Eccrine gland
Sudoriferous (sweat) gland found all over body esp. in forehead, back, palms, and soles. Tubular and exit directly onto the surface of the skin
192
What does the Eccrine gland produce
A thin merocrine secretion
193
The thin merocrine secretion functions
Evaporative cooling of the body and elimination of some chemical wastes (lactic and uric acid)
194
Corpuscle of touch aka
Meissner's corpuscle, tactile corpuscle. located in dermal papillae, discriminate touch
195
Hair root plexus
Sensory nerve endings wrapped around the base of the hair follicle, discriminate touch
196
Merkel cell/disc
Type 1 mechanoreceptor located in the stratum basale. discriminate touch
197
Ruffini's endings/corpuscles
Type II mechanoreceptor located deep in the dermis. NON-discriminate touch (crude touch)
198
Pacinian Corpuscles
Pressure: lamellated, responds to sustained pressure. deep in dermis and subcutaneous layer
199
Thermal receptors
Free nerve endings responding to hot or cold. located in epidermis
200
Nociceptors
Pain receptors. free nerve endings, responding to tissue trauma or extreme tissue deformation. located in epidermis
201
Healing of wounds involving just the epidermis
Greater mitotic activity in the stratum basale and stratum spinosum
202
Deep wounds causing rupture of blood vessels within the dermis and subcutaneous layer
Will result in bleeding. blood platelets and fibrinogen protein form a clot which stops bleeding. scab forms
203
What may be seen as a sign of damaged cells and foreign microorganisms are destroyed by immune cells
Inflammation
204
What binds wound edges together within the dermis
Fibroblasts form collagen fibers
205
When does the scab slough off
When healing is nearly complete
206
First degree burn
Superficial partial-thickness. only epidermis. warm and reddened. possible peeling
207
Second degree burn
Deep partial-thickness. epidermis and dermis. skin blisters and healing process will involve epithelial cells from the accessory organs within the damaged area
208
Third degree burn
Destroys epidermis, dermis, and accessory organs. epithelial healing can occur only at margins of injury
209
Fourth degree burn
Destruction of epidermis, dermis, and subcutaneous layer. epithelial healing only at margins
210
Benign neoplasm
Non life threatening
211
Mole aka nevus
Benign abnormal growth of melanocytes
212
Wart aka verruca
abnormal growth of skin tissue caused by viral infection
213
Malignant
Life threatening
214
Cutaneous carcinoma
Long-term exposure to UVR. Malignant. can be divisible into basal cell carcinoma and squamous cell carcinoma
215
Cutaneous melanoma
Due to short but intense exposure to UVR. HIGHLY Malignant.
216
ABCD rule
Asymmetry, Border, Color, Diameter, Evolution
217
What can the integumentary system indicate clinically
Dietary deficiencies, Heavy metal exposure, Allergic rxns, and specific diseases
218
Results of aging on the Integumentary system
Loss of elasticity in the dermis
Decrease in amount of adipose tissue in subcutaneous layer
Decreased activity of hair follicles and exocrine glands (especially, eccrine and sebaceous glands)
Changesin pigmentation (of skin andhair)
Increase in number of moles
