Anatomy and Physiology B/C

[reninkidney]

There's a lot of embedded questions, but give them a try:

1. What is DEXA (list its full form as well), what disease does it primarily diagnose, and what is the difference between a "t-score" and a "z-score"?

2. What causes skin to shrivel up in water? Why does this happen? What purpose does it serve?

3. Sort SO, FO, and FG muscle fibers into their respective alphanumeric types. Explain why you sorted this way. Which type has the most myoglobin? What is the purpose of myoglobin in these fibers? What replaces myoglobin in other fiber types?

1. It stands for Dual Energy X-ray absorptiometry. It diagnoses osteoporosis. It is a low energy x-ray which can detect bone loss and can measure spine & hip bone density. A T-score is a measure of bone density relative to a healthy 30 year old & a z-score is a measure of bone density relative to the person's age & sex.
2. The stratum corneum absorbs the water and swells and to compensate for the increase in surface area, the skin wrinkles. It allows people to grip wet objects.
3. SO: Type I
FO: Type IIa
FG: Type IIb/x
Type I has the most myoglobin, followed by Type IIa and Type IIb. Myoglobin is a pigment which stores oxygen in it, which is necessary for aerobic respiration. Since Type I fibers primarily use aerobic respiration, they have the most myoglobin, followed by Type IIa and Type IIb. Glycogen replaces myoglobin in Type IIb fibers because these fibers primarily use creatine phosphate metabolism, which requires glycogen stores.

[Locoholic]

1. It stands for Dual Energy X-ray absorptiometry. It diagnoses osteoporosis. It is a low energy x-ray which can detect bone loss and can measure spine & hip bone density. A T-score is a measure of bone density relative to a healthy 30 year old & a z-score is a measure of bone density relative to the person's age & sex.
2. The stratum corneum absorbs the water and swells and to compensate for the increase in surface area, the skin wrinkles. It allows people to grip wet objects.
3. SO: Type I
FO: Type IIa
FG: Type IIb/x
Type I has the most myoglobin, followed by Type IIa and Type IIb. Myoglobin is a pigment which stores oxygen in it, which is necessary for aerobic respiration. Since Type I fibers primarily use aerobic respiration, they have the most myoglobin, followed by Type IIa and Type IIb. Glycogen replaces myoglobin in Type IIb fibers because these fibers primarily use creatine phosphate metabolism, which requires glycogen stores.

All good, except in number 3, I kinda wanted you to also say that myoglobin is used in Type I fibers to store some of the oxygen needed for aerobic respiration, as well as give the fiber its red color. Edit: Your turn!

[reninkidney]

1. Describe the structure of the basement membrane of the skin.

2. What is the plasticity of smooth muscle?

3. Jane comes into the clinic complaining of stiffness and joint pain in her knees and hips. Her hands exhibit swollen nodes at the joints. Examination of her cartilage shows an increase in water content and a decrease in proteoglycans. At some points, the cartilage has worn out and the underlying bone is hard and glossy. What disease does she have and what are some risk factors for this disease?

[Locoholic]

1. Describe the structure of the basement membrane of the skin.

2. What is the plasticity of smooth muscle?

3. Jane comes into the clinic complaining of stiffness and joint pain in her knees and hips. Her hands exhibit swollen nodes at the joints. Examination of her cartilage shows an increase in water content and a decrease in proteoglycans. At some points, the cartilage has worn out and the underlying bone is hard and glossy. What disease does she have and what are some risk factors for this disease?

1. It's a thin layer of fibers connecting the papillary dermis to the epidermis. It's composed of 2 layers: the basal lamina which is extracellular matrix from epithelial cells and the reticular layer which is composed of Type III collagen. It conforms to dermal papillae, which are ridge-shaped.
2. Honestly have no idea, maybe it's that smooth muscle can change function depending on external stimuli?
3. Jane has rheumatoid arthritis. I haven't really touched on risk factors, but I'd guess smoking, old age, genetics, obesity, etc.

[reninkidney]

1. Describe the structure of the basement membrane of the skin.

2. What is the plasticity of smooth muscle?

3. Jane comes into the clinic complaining of stiffness and joint pain in her knees and hips. Her hands exhibit swollen nodes at the joints. Examination of her cartilage shows an increase in water content and a decrease in proteoglycans. At some points, the cartilage has worn out and the underlying bone is hard and glossy. What disease does she have and what are some risk factors for this disease?

1. It's a thin layer of fibers connecting the papillary dermis to the epidermis. It's composed of 2 layers: the basal lamina which is extracellular matrix from epithelial cells and the reticular layer which is composed of Type III collagen. It conforms to dermal papillae, which are ridge-shaped.
2. Honestly have no idea, maybe it's that smooth muscle can change function depending on external stimuli?
3. Jane has rheumatoid arthritis. I haven't really touched on risk factors, but I'd guess smoking, old age, genetics, obesity, etc.

All right, but for number 2: Plasticity refers to the variability of tension generated by smooth muscle (it behaves more like viscous mass than tissue), and that there is no correlation between length & tension for smooth muscle. and for number 3: Jane has osteoarthritis, which is the wearing down of articular cartilage at the joints (Rheumatoid arthritis is the swelling of the joint capsule). Your turn!

[Locoholic]

Again, embedded questions! Fun, right?

1. Bob goes to the doctor, citing a ton of pain in his ankle. The doctors examined this and found that his left tibia was 0.5 mm longer than his right tibia, protruding into his calcaneus (ouch!). The base of Bob's (edit: left) tibia looks crushed, but there's no significant break in the bone. Bob is 11 years old, and this visit is 1.5 years later than a previous visit to the ER.
a) What radiology method did the doctors most likely use to examine Bob?
b) How could Bob's condition have happened? What was the reason Bob went to the ER 1.5 years ago? What mistake did the doctors make 1.5 years ago that could have lead to this condition? Explain in detail and be specific.

2. Compare and contrast Trousseau's Sign and the Chvostek Sign. What condition does a positive test of each sign help diagnose? What structurally occurs in these signs? How else are they similar and different? Are there any subtypes of these signs? If so, describe them.

3. The spinous processes of vertebrae are an example of what bone marking? (Don't say process lol there's another one). A joint is an example of what broader class of bone markings? What is the broad term for the bone marking where tendons and ligaments attach?

[Locoholic]

Ok I don’t want this thread to die, so feel free to pm me if you all want any hints.

[Locoholic]

Aw man

I'll give it one more week for submissions and then I'll give answers.

[reninkidney]

Again, embedded questions! Fun, right?

1. Bob goes to the doctor, citing a ton of pain in his ankle. The doctors examined this and found that his left tibia was 0.5 mm longer than his right tibia, protruding into his calcaneus (ouch!). The base of Bob's (edit: left) tibia looks crushed, but there's no significant break in the bone. Bob is 11 years old, and this visit is 1.5 years later than a previous visit to the ER.
a) What radiology method did the doctors most likely use to examine Bob?
b) How could Bob's condition have happened? What was the reason Bob went to the ER 1.5 years ago? What mistake did the doctors make 1.5 years ago that could have lead to this condition? Explain in detail and be specific.

2. Compare and contrast Trousseau's Sign and the Chvostek Sign. What condition does a positive test of each sign help diagnose? What structurally occurs in these signs? How else are they similar and different? Are there any subtypes of these signs? If so, describe them.

3. The spinous processes of vertebrae are an example of what bone marking? (Don't say process lol there's another one). A joint is an example of what broader class of bone markings? What is the broad term for the bone marking where tendons and ligaments attach?

1a. X-ray
1b. This was a Salter-Harris fracture and maybe... the doctors didn't set the bone correctly??? (idk)
2. Both the tests diagnose hypocalcemia.
Trousseau's sign: While taking blood pressure, the muscles of the hand & forearm will spasm. This is because in the absence of blood flow, the patient's hypocalcemia will cause the muscles to be irritable which will induce a spasm of the muscles of the hand. It is more sensitive than Chvostek's sign (94% success rate).
Chvostek Sign: When the facial nerve is tapped near the ear, the facial muscles will undergo a spasm due to the hyperexcitability of nerves from hypocalcemia. It is less sensitive then Trousseau's sign (29%).
Subtypes:
Chvostek sign – type I
Obtained by striking a point that is 2 cm in front of the lobe of the ear & 1 cm below the zygomatic process. The labial & nasal fold move toward the stimulated side.
Chvostek sign – type II
Hitting a point btwn the middle 3rd & upper 3rd of the line joining the angle of the mouth to the zygomatic process. The muscles of the mouth + nose contract.
3. projection, articulation, protrusion

[Mr.Epithelium]

Aw man

I'll give it one more week for submissions and then I'll give answers.

Anatomy QM is the best and will never die