Chapter 4 -Tissues
What is the connective tissue that is support and structure in the umbiliform cord of the fetus?
Mucous Connective Tissue
How does UV exposure alter melanin production?
Increases melanin production
What is the spongy bone called in the skull?
Dipole
Compare the axial and appendicular skeleton:
The axial skeleton is the central axis of the skeleton and contains skull, rubs, spinal cord, sternum, sacrum, and coccyx.
The appendicular skeleton is used for movement and conatins: upper and lower limbs, scapula, clavicle, and hands and feet.
A microbiologist is checking the tissue sample of a human tissue that is localized and doesn't spread, what would the microbiologist call the tissue sample?
Benign
Compare merocrine, apocrine, and holocrine secretion methods:
Holocrine glands: viscous mixture of cell product and cell fragments (after disintegration)
Merocrine glands: secretions packed in vesicles and released via exocytosis
Apocrine glands: cells pinch off part of apical surface containing cytoplasmic content.
What is the tissue type in the reticular layer of the dermis?
Dense Irregular Connetive Tissue
How do PTH, calcitonin, and calcitriol interact regulate blood calcium levels?
PTH raises low blood calcium by releasing calcium from bones and increasing kidney reabsorption.
Calcitriol, the active form of vitamin D, then increases calcium absorption from the intestines.
Calcitonin is released when blood calcium is high, inhibiting bone breakdown to lower calcium levels.
What are the three cranial fossa and which regions of the brain do they house?
Middle Cranial Fossa: Situated in the middle of the skull, this fossa is home to the temporal lobes. It is also where the pituitary gland is located in the pituitary fossa.
Posterior Cranial Fossa: The deepest and most inferior of the three fossae, it contains the cerebellum and the brainstem (midbrain, pons, and medulla).
2nd: Epidermis and Dermis is gone, and appears with blisters
3rd: Epidermis, Dermis, and Hypodermis are gone, and sensory nerve are destroyed
Why is voluntary control important for the skeletal muscle but not for the other two types?
Because skeletal muscle is where muscle is attached for limbs and used for movement, meanwhile cardiac and smooth is used for organs/heart.
How does vasoconstriction, vasodilation, and sweating interact to regulate body temp.?
Controlling blood flow to the skin's surface.
Explain what are the different types of bone cells and what they do in the bone tissue:
Osteocyte: mature bone cells, regulates bone tissue.
Osteoblast: creates osteoid, builds bone up.
Osteoprogenitor cells: stem cells
Osteoclast: bone reportion (breaks bone down)
Why are the primary and secondary spinal curvatures essential for upright posture?
Acts as a spring for shock absorption, distributes weight evenly, improves balance, and allows for flexibility and a wide range of motion
Why might epidermolysis bullosa causes skin fragility and blistered even under mild friction?
It is a genetic mutations disrupt the proteins that anchor the skin's layers together. Without these strong anchors, which include proteins like keratin and collagen, the layers of the epidermis and dermis separate at the slightest trauma, leading to blisters and open sore
What makes cutaneous membrane unique compared to other body membranes?
It is the body's only dry membrane, exposed to the external environment, and is primarily composed of a thick, keratinized epidermis on top of dense connective tissue ( Skin)
What occurs in the stratum granulosum during keratinization, and why does this process lead to cell death?
In the stratum granulosum, keratinocytes fill with keratin and other proteins, release lipid-based substances, and then begin to die. This process leads to cell death because the cells can no longer receive nutrients and oxygen as they move away from the dermis, and the increasing lipid barrier cuts off supply to the upper layers
What distinguishes endochondral ossification from intramembrous ossification in origin and process?
Endochondral ossification forms bone by replacing a hyaline cartilage template, while intramembranous ossification forms bone directly from mesenchymal connective tissue. The primary distinction is that endochondral ossification involves the replacement of a pre-existing cartilage model, as seen in long bones, whereas intramembranous ossification involves osteoblasts differentiating directly from mesenchymal cells, as seen in the flat bones of the skull.
What happens when the nucleus pulposus herniates through the annulus fibrous?
Herniated disc
What does Osteomalacia revel about the importance of organic and inorganic matrix components in bone strength?
The condition arises from poor mineralization, leading to a deficiency in calcium and phosphate
Why is metaplasia sometimes reversible, while dysplasia or neoplasia may not be?
Metaplasia is often reversible because it is a direct adaptive response to a temporary stressor and does not involve permanent genetic damage. In contrast, dysplasia and neoplasia are less likely to reverse because they involve increasingly severe genetic mutations that drive uncontrolled, abnormal cell growth.
How does Stratum Basale maintain the epidermis and what unique roles do keratinocytes, melanocytes, and Merkel cells play here?
Through continuous cell renewal, driven by stem cells that produce new keratinocytes.
Keratinocytes, which form the bulk of the epidermis and produce protective keratin.
Melanocytes, which produce melanin for UV protection and skin color.
Merkel cells, which are responsible for the sensation of light touch.
What are the key steps in bone repair?
Step 1: After a fracture, blood vessels in the bone and surrounding tissues are torn, leading to bleeding at the fracture site. This blood clots to form a hematoma, which is a crucial first step in the healing process.
Step 2: Fibrocartilaginous callus forms. This soft callus is a mix of collagen fibers and fibrocartilage that bridges the fracture gap, providing a temporary and flexible bridge.
3. Hard callus formation
Step 3: Hard callus forms. Osteoblasts invade the area and begin depositing new bone tissue, a process that involves both the transformation of cartilage into bone (endochondral ossification) and direct bone formation (intramembranous ossification)
Step 4: Bone is remodeled. In the final stage, the immature woven bone is gradually broken down and replaced with stronger, more organized lamellar bone through the action of osteoclasts and osteoblasts.
What structural features make the female pelvis better for childbirth?
Ilium flares more laterally; wider pelvis.
Wide subpubic angle; pelvic inlet is spacious, wide and oval
A patient is admistered into the hospital. After the nurses examined the patient's overall health, they diagnosed them with Osteogenesis Imperfecta. What would they tell the patient about their diagnosis and what treatment would they offer to the patient?
OI is a connective tissue disorder where rare skeletal dysplasia is observed.
• Bone fragility, frequent fractures, growth deficiency, blue sclera,
• Gene mutations (often inherited) that lead to type I collagen to be structurally or
quantitatively deficient.
• “Insufficient osteoid production.”
• Intramembranous and endochondral ossification affected.
• Treatment depends on severity, from avoiding contact sports to surgical
intervention.
• Medical management may help with bone density and minimizing fractures but
does not help with underlying issues.