A&P Exam 3
What is the resting membrane potential of skeletal muscle cells?
- 90 mV
What are the functions of the skin?
1. Resistance to trauma and infection 2. Other barrier functions, like water, UV radiation and harmful chemicals 3. Vitamin D synthesis 4. Sensation 5. Thermoregulation 6. Nonverbal communication
What is a triad?
A T tubule and two terminal cisterns associated with it
What is voltage (electrical potential)?
A difference in electrical charge from one point to another
What is twitch?
A quick cycle of contraction and relaxation when stimulus is at the threshold or higher
Collagen lends ______ to skin. A. elasticity B. Structure C. Color D. UV Protection
A. Elasticity
What rule should we use in watching for moles or any skin growth?
A: Asymmetry B: Borders C: Color D: Diameter
All muscle contraction depends on ______.
ATP
What neurotransmitter will slow the heart, but stimulates the GI tract to do digestion?
Acetylcholine
What breaks down Ach, allowing for relaxation?
Acetylcholinesterase (AChE)
Thin filament?
Actin, light band, I band
Striations result from the precise organization of ____ and _____ in cardiac and skeletal muscle cells.
Action and myosin
What are the two main pathways of ATP synthesis?
Aerobic respiration and anaerobic fermentation
Cardiac muscle use _______ exclusively.
Aerobic respiration; rich in myoglobin and glycogen
What is white skin due to the genetic lack of melanin?
Albinism
Third-degree burns involve _______ and may require ______.
All of the dermis and often some deeper tissues; skin grafts
What is thinning of the hair or baldness?
Alopecia
What is the growth stage of the hair cycle, which 90% of scalp follicles are at a given time?
Anagen
What are the three stages of the hair cycle?
Anlagen, catagen and telogen
Axillary skin has what type of sweat glands?
Apocrine glands
Endomysium?
Around muscle cell
What are the excitation of smooth muscle?
Autonomic activity, hormones, carbon dioxide, oxygen, pH, temperature, stretch and autorhythmicity
Cardiac muscle receives innervation from where?
Autonomic nervous system (sympathetic and parasympathetic)
Where are the apocrine sweat glands found?
Axillary region, beard in men, groin and anal region
•Sebaceous glands ________. a)are a type of sweat gland b)are associated with hair follicles c)may function in response to touch d)release a watery solution of salt and metabolic waste
B.) Associated with hair follicles
Why do muscle cells shorten?
Because their individual sarcomeres shorten
The dermis is well supplied with ____________.
Blood vessels, sweat glands, sebaceous glands and nerve endings
What is the disagreeable body odor produced by bacterial action on sweat from apocrine glands?
Bromhidrosis.
Eumelanin?
Brownish-black
What is echar?
Burned, dead tissue
The papillary and reticular layers are composed mainly of A. Melanocytes B. Keratinocytes C. Connective tissue D. Adipose tissue
C. Connective tissue
Which of the following is not a function of the Hypodermis? a. Protects underlying organs b. Helps maintain body temperature c. Source of blood vessels in the epidermis d. a site to long-term energy storage
C. Source of blood vessels in the epidermis
Which of the following is not part of the skin? a)Epidermis b)Papillary layer c)Hypodermis Stratum basale
C. hypodermis
Contraction is always triggered by ______ energized by ______ and achieved by _______.
Calcium, ATP sliding filaments
Which muscle has especially large mitochondria?
Cardiac
Cardiac muscle cells are called _______.
Cardiomyocytes
What is the degeneration of the hair cycle?
Catagen
The dermis is composed mainly of _________.
Collagen
_________ makes up hair and nails.
Compact hard keratin
Unnaturally high frequencies produce ______.
Complete (fused) tetanus
Voluntary means subject to _______.
Conscious control
What is blueness due to oxygen deficiency?
Cyanosis
Hair and nails are composed mostly of ________.
Dead, keratinized cells
What cell will act as a macrophage in order to do the phagocytosis?
Dendritic
In smooth muscle, Z discs are absent and replaced by ______.
Dense bodies
The reticular layer is what kind of tissue? What is its function?
Dense irregular connective tissue and it is associated with stretch marks
Fingerprints left on things we touch are associated with our ________.
Dermal papillae
______ are upward, finger-like extensions of the dermis.
Dermal papillae
Hypodermis is a common site of _________.
Drug injections
Need for muscle contraction, or calcium, comes from _____by ways of channels in sarcolemma.
ECF
There are excess sodium Na+ in the _____.
ECF
Which cutaneous glands are concerned with cooling the body?
Eccrine
What are the most numerous skin glands in the adult skin?
Eccrine (merocrine) glands
_____ are downward waves of epidermis.
Epidermal ridges
What are the 2 layers of the skin?
Epidermis and dermis
What are the connective tissue wrappings of skeletal muscle?
Epimysium, perimysium and endomysium
What neurotransmitter will stimulate the heart?
Epinephrine
What is redness to the skin due to increased blood flow to skin?
Erythema
What are two forms of the pigment melanin?
Eumelanin and pheomelanin
What are the universal characteristics of muscle?
Excitability, conductivity, contractility, extensibility and elasticity
What are the four major phases of contraction and relaxation?
Excitation, excitation-contraction coupling, contraction and relaxation
Cardiac muscle is highly resistant to _____.
Fatigue
Damaged cardiac muscle cells repair by
Fibrosis >Unfortunately, after a heart attack, functional muscle is not regenerated
Small motor units?
Fine degree of control, eyes and hand muscles
Deaths from burns result primarily from ________.
Fluid loss, infection and toxic effects of eschar
What are flat, melanized patches?
Freckles
What are tan to black aggregations of melanocytes?
Freckles and moles
Smooth muscle fibers have a _______ shape and only have _____ nucleus located _________.
Fusiform, 1, near the middle of the cell
What is the synaptic cleft?
Gap between axon terminal and sarcolemma
Electrical _____ allow each cardiomyocyte to directly stimulate its neighbors
Gap junctions
What is the carbohydrate thats stored to provide energy for exercise?
Glycogen
What is rigor mortis?
Hardening of the muscles or stiffening of the body beginning 3-4 hours after death. Muscles stay contracted and cannot relax because muscle relaxation requires ATP is ATP is no longer produced after death
What are patches of discolored skin (birthmarks) caused by benign tumors of dermal capillaries?
Hemangiomas
What is bruising or clotted blood under the skin?
Hematoma
Excessive hairiness is called _____.
Hirsutism
There are excess potassium ions in the ______.
ICF
What is the difference of melanin in dark and light skinned individuals?
In dark-skinned individuals, melanocytes produce greater quantities of melanin and melanin breaks down more slowly
Cardiomyocytes are joined at its ends to other cells by _______.
Intercalated discs
How does carotene affect the skin?
It is acquired from egg yolks and yellow/orange vegetables and adds a yellow pigment to the skin
How does hemoglobin affect the skin?
It is the pigment in red blood cells and it adds reddish to pinkish hue of the skin
Increased bilirubin levels cause a skin discoloration called __________.
Jaundice
What is the yellowing of the skin due to bilirubin in blood?
Jaundice
Calluses or corns are the result of accelerated multiplication by ____.
Keratinocytes
Which hair is fine, downy unpigmented hair that appears on the fetus in the last 3 months of development?
Lanugo
What is the most significant factor in skin color?
Melanin
Eccrine glands are also known as _________.
Merocrine glands
Mammary glands produce ______ and only develop during _______.
Milk; pregnancy and lactation
Apocrine glands produce sweat that is _________.
Milky and contains fatty acids
Smooth muscle is capable of ______ and _______.
Mitosis and hyperplasia
What are elevated, melanized patches often with hair?
Moles
Large motor units?
More strength than control
What are the four important functions of muscle?
Movement, maintain body posture and body position, stabilize joints and generate
What is isometric contraction?
Muscle develops tension but does not shorten
Skeletal muscles are also called ______ or _______.
Muscle fibers or myofibers
What are the long protein chords occupying most of the sarcoplasm?
Myofibrils
Myofibrils has __________.
Myofilaments
What is the red pigment, that provides some oxygen needed for muscle activity?
Myoglobin
What are the contractile proteins?
Myosin and actin
Thick filament?
Myosin, dark band, A band
When a muscle or nerve fiber is stimulated, what happens?
Na+ goes inside, causing depolarization: inside of plasma membrane becomes more positive
In an unstimulated cell, there are more _________ on the inside of the membrane than on the outside.
Negatively charged particles
Skeletal muscle never contracts unless stimulated by a ___.
Nerve
Synaptic vesicles contain______.
Neurotransmitters such as acetylcholine
Cardiac and smooth muscle have one ________.
Nucleus
What is sebum?
Oily secretion of the sebaceous glands
Each muscle fiber is supplied by _____ motor neuron.
One
What is a motor unit?
One nerve fiber and all the muscle fibers innervated by it
ATP supply depends on availability _____ and ____.
Oxygen and organic energy sources (glucose and fatty acids).
Cardiac muscles have a built-in ______ that rhythmically sets off a wave of electrical excitation
Pacemaker
What is paleness due to decreased blood flow to the skin?
Pallor
Which skin color is most likely a result of anemia?
Pallor
Where is thick skin found?
Palms of the hands and soles of the feet
What are the two layers of the dermis?
Papillary and reticular layers
An individual using a sharp knife notices a small amount of blood where he just cut himself. Which of the following layers did he have to cut in order to bleed?
Papillary dermis
Second-degree burns involve _____ and may appear to be ______.
Part of the dermis; blistered
What is a synapse?
Point where a nerve fiber meets its target cell
Apocrine glands are inactive until __________.
Puberty
Pheomelanin
Reddish-yellow (sulfur containing)
Contraction is activated by the _________.
Release of calcium from sarcoplasmic reticulum to sarcoplasm and the binding of calcium to Troponin
Loss of positive potassium ions turns the membrane negative again, causing _____.
Repolarization
What is the plasma membrane of a muscle fiber?
Sarcolemma
What is the functional contractile unit of a muscle fiber?
Sarcomere
What is the cytoplasm of muscle fiber?
Sarcoplasm
Which structure stores and releases calcium through channels to activate contraction?
Sarcoplasmic reticulum
What is less/more developed in cardiac muscle?
Sarcoplasmic reticulum less developed, but T tubules are larger and admit ions from the extracellular fluid
The oil of your scalp is secreted by ________ associated with the hair follicles.
Sebaceous glands
What is the longest of all muscle tissue?
Skeletal
What is the body's largest and heaviest organ?
Skin
What constitutes the integumentary system?
Skin and accessory organs Hair Nails Cutaneous glands
Cardiac muscle exhibits very ____ twitches, to give the heart time to expel blood.
Slow
What is the sarcoplasmic reticulum (SR)?
Smooth ER that forms a network around each myofibril
Resting membrane potential maintained by _______.
Sodium-potassium pump
What axons lead to the skeletal muscle?
Somatic motor fibers
What are the five cells of the epidermis?
Stem cells, keratinocytes, melanocytes, dendritic and tactile cells
What kind of tissue is found in the epidermis?
Stratified squamous epithelium
What is the deepest epidermal layer?
Stratum basale
The papillary layer of the dermis is most closely associated with which layer of the epidermis?
Stratum basale; at the bottom
As you are walking down the beach, you see a dead, dry, shriveled-up fish. Which layer of the epidermis keeps you from drying out?
Stratum corneum
What layer of the epidermis consists up to 30 layers of dead cells?
Stratum corneum
What are the layers of the epidermis from top to bottom?
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale
What layer is seen only in thick skin?
Stratum lucidum
Langerhans cells are commonly found in the ______.
Stratum spinosum
Apocrine glands respond to ____________.
Stress and sexual stimulation
Alternating light and dark transverse bands are called ______.
Striations
Smooth muscle lacks ____.
Striations
Hypodermis is a ____________ tissue.
Subcutaneous
What is the axon terminal?
Swollen end of a nerve fiber `
What permits the conduction of electrical impulses?
T-tubules
What cell is associated with the sense of touch?
Tactile
What is the resting stage of the hair cycle?
Telogen
High frequencies produce ________.
Temporal summation or incomplete tetanus
What is isotonic eccentric?
Tension remains and muscle lengthens
What is isotonic concentric contraction?
Tension remains contact but the muscle shortens
Which hair is found on the scalp, eyelashes and eyebrows?
Terminal
What surrounds the T tubules?
Terminal cisterns
First-degree burns only involve _______.
The epidermis
What is debridement?
The removal of eschar
What is found and not found on thick skin?
Thick skin has sweat glands but no hair follicles or sebaceous (oil) glands
What kind of skin covers the rest of the body?
Thin skin
The papillary layer is what kind of tissue? What is its function?
Thin zone of Areolar tissue that allows for the mobility of leukocytes and other defense cells. It is rich in small blood vessels
Perimysium?
Tissue around the muscle fascicle (fibers)
Epimysium?
Tissue surrounding entire muscle
Actin contains ___________ and ________.
Troponin and tropomyosin
T or F: Dark and light skinned individuals have the same number of melanocytes.
True
What exposure stimulates melanin secretion and darkens the skin?
UV light exposure
Which hair replaces lanugo by the time of birth? It is also found in 2/3 of hair of women and 1/10 of the hair in men?
Vellus
Muscle fibers and neurons are electrically electrically excitable. Their membranes exhibit _________ in response to stimulation.
Voltage changes
Eccrine glands produce _____________.
Watery perspiration that helps cool the body
What is the neuromuscular junction (NMJ)?
When target cell is a muscle fiber
Sarcomere is segment from _____>
Z disc to Z disc
Cardiac muscles are auto rhythmic meaning ______.
able to contract rhythmically and independently
What are the two kinds of sweat glands?
apocrine and eccrine (merocrine) glands
•Eccrine sweat glands ________ a)Are present on hair b)Are present in the skin throughout the body and produce watery sweat c)Produce sebum d)Act as a moisturizer
b)Are present in the skin throughout the body and produce watery sweat
The dermis houses _______ and _______.
hair follicles and nail roots
The skin discoloration most likely to suggest physical abuse is ______.
hematoma
Cardiac muscles are _____.
involuntary
Smooth muscle is ______.
involuntary, nonstriated
What are the three types of hair?
lanugo, vellus and terminal
What is threshold?
minimum voltage necessary to generate an action potential in the muscle fiber and produce a contraction
Where are dendritic cells found?
stratum spinosum and stratum granulosum
What are the regulatory proteins?
troponin and tropomyosin
What is the latent period?
very brief delay between stimulus and contraction
Skeletal muscle can be classified as __________.
voluntary, striated muscle that is attached to one or more bones.