Human Anatomy: Kidney and Cartilage Structure

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Questions and Answers

What structure is the basic functional unit of the kidney responsible for urine production?

Glomerulus

Nephron (correct)

Renal corpuscle

Collecting duct

Which part of the nephron is responsible for reabsorbing water and sodium?

Proximal convoluted tubule (correct)

Loop of Henle

Collecting duct

Distal convoluted tubule

Which layer of the Bowman's capsule is made up of podocytes?

Inner visceral layer (correct)

Capsular space

Glomerular layer

Outer parietal layer

What is the purpose of the collecting duct in the kidney?

To concentrate and carry urine to the ureter Signup and view all the answers

Which of the following regions of the kidney is primarily responsible for containing renal corpuscles?

Outer cortex Signup and view all the answers

Which type of cartilage contains abundant elastic fibers?

Elastic cartilage Signup and view all the answers

What type of collagen can be found in fibro-cartilage?

Type I collagen Signup and view all the answers

Which of the following sites is typical for hyaline cartilage?

Ends of long bones Signup and view all the answers

What is a characteristic feature of compact bone?

Regularly arranged bone lamellae Signup and view all the answers

Which cells are primarily responsible for bone formation?

Osteoblasts Signup and view all the answers

Which type of cartilage is NOT covered by a perichondrium?

Fibro-cartilage Signup and view all the answers

What is the primary function of bone marrow?

To produce blood cells Signup and view all the answers

What type of cartilage is primarily found in the trachea?

Hyaline cartilage Signup and view all the answers

What is the primary function of chondroblasts in cartilage?

Synthesize cartilage matrix Signup and view all the answers

Which component primarily makes up the extracellular matrix (ECM) of cartilage?

Type II collagen fibrils Signup and view all the answers

What role does the perichondrium play in cartilage?

Offers nutrition and repair support Signup and view all the answers

What is a distinguishing feature of articular cartilage compared to other types of cartilage?

It derives nutrition from synovial fluid. Signup and view all the answers

How are chondrocytes characterized in terms of their cellular structure?

They are rounded cells located inside lacunae. Signup and view all the answers

Which of the following statements about cartilage healing is correct?

Cartilage has poor healing and repairing capacities. Signup and view all the answers

What percentage of tissue fluid is found in the ground substance of cartilage?

75% Signup and view all the answers

Where are chondroblasts primarily located?

In the inner layer of the perichondrium Signup and view all the answers

What is a distinguishing feature of spongy bone compared to compact bone?

Multiple bone marrow cavities Signup and view all the answers

Which of the following accurately describes the structure of dendrites?

Short and numerous with branching Signup and view all the answers

What primarily makes up the cytoplasm of the neuron cell body?

Nissl’s bodies and Golgi complex Signup and view all the answers

What is the role of the axon in a neuron?

To conduct nerve impulses away from the cell body Signup and view all the answers

Which structure lacks Nissl granules?

Axon Signup and view all the answers

What is the primary characteristic of the tunica intima in a blood vessel?

Endothelial layer Signup and view all the answers

What happens to Nissl's granules in a neuron during injury?

They disappear due to chromatolysis Signup and view all the answers

Which of the following components is abundant in the axon terminals?

Mitochondria Signup and view all the answers

Which layer of an artery is characterized by a thick wall and the presence of an external elastic lamina?

Tunica media Signup and view all the answers

What is the primary function of the alveoli in the respiratory system?

Gas exchange Signup and view all the answers

Which type of cells make up the majority of the alveolar epithelium?

Type I pneumocytes Signup and view all the answers

In veins, which structural characteristic differs from arteries?

Collapsed, wide lumen Signup and view all the answers

What type of connective tissue is found in the tunica adventitia of an artery?

Loose areolar connective tissue Signup and view all the answers

What is the role of Type II pneumocytes in the alveoli?

To secrete surfactant Signup and view all the answers

Which structure is a major component of the conducting portion of the respiratory system?

Trachea Signup and view all the answers

Which of the following is NOT a feature of capillaries?

A thick wall for support Signup and view all the answers

What is the main function of the cuboidal cells in the lungs?

Synthesize and secrete pulmonary surfactant Signup and view all the answers

Which type of epithelium is found in the epidermis of the skin?

Keratinized stratified squamous epithelium Signup and view all the answers

What distinguishes thick skin from thin skin?

Thick skin is found primarily on the palms and soles Signup and view all the answers

What are the two major layers of the skin?

Epidermis and Dermis Signup and view all the answers

Which of the following cell types in the epidermis has an immunological function?

Langerhans cells Signup and view all the answers

Which of the following correctly describes the liver's function?

Production of bile and synthesis of plasma proteins Signup and view all the answers

What is the structural unit of the liver called?

Hepatic lobule Signup and view all the answers

What type of endothelium lines the blood sinusoids in the liver?

Fenestrated endothelium Signup and view all the answers

Study Notes

Cartilage

Definition: A specialized supportive connective tissue with a firm, non-vascular matrix.
Histological Structure: Composed of cells and extracellular matrix.
Extracellular Matrix Components: Fibers (type II collagen fibrils) and ground substance (75% tissue fluid) for nutrient diffusion.
Cells: Chondroblasts and chondrocytes.
General Histological Characteristics: Cells are widely separated by abundant extracellular matrix, avascular, poor healing and repairing capacities.
The cartilage is covered from outside by perichondrium for nutrition and repair.
The perichondrium is absent in articular cartilage of joints and its nutrition depends from synovial fluid.
The perichondrium is essential for repair and regeneration, especially in young age.
Types of Cartilage cells: Chondroblasts and Chondrocytes
- Chondroblasts: Located on inner layer of perichondrium, actively dividing cells, flat, oval, and actively synthesize cartilage matrix, secreting collagen type II. Eventually, chondroblasts change into chondrocytes when trapped inside lacunae.
- Chondrocytes: Old, mature cells, located deeper in the cartilage matrix, rounded cells in lacunae, maintain cartilage matrix.

Types of Cartilage

Hyaline Cartilage (Most common):
- Covered by perichondrium
- Homogenous and basophilic matrix containing type II collagen fibrils.
- Found in ends of long bones, ends of ribs, trachea, and bronchi.
Elastic Cartilage:
- Covered by perichondrium.
- Heterogenous and basophilic matrix containing type II collagen fibrils + abundant elastic fibers.
- Flexible
- Found in ear pinna, external ear, and Eustachian tube.
Fibrocartilage:
- No perichondrium.
- Scanty matrix containing parallel bundles of collagen fibers (type I).
- Chondrocytes within lacunae in between.
- Found in intervertebral discs.

Bone

Definition: A specialized supportive connective tissue with a hard (solid) matrix.
Covered externally by periosteum and lined internally by endosteum.
Formed of Bone cells and solid ECM (calcified calcium & phosphate) with less tissue fluid (25%) and collagen type I.
Highly vascular.
Functions: Protects and supports vital organs (brain and spinal cord), storage site for calcium and phosphate, and contains bone marrow which acts as a hematopoietic organ.
Major Types of Bone Cells: Osteogenic cells, Osteoblasts, Osteocytes, and Osteoclasts.
- Osteogenic Cells: Stem cells within inner layer of periosteum and endosteum.
- Osteoblasts: Present side by side on bone surfaces (periosteum and endosteum), synthesize bone matrix
- Osteocytes: Located within the bone matrix in lacunae, maintain bone tissue.
- Osteoclasts: Present on bone surface (endosteum), in cavities (Howship's lacunae), resorb bone.

Types of Bone Tissue

Compact Bone: Bone lamellae are regularly arranged, formed of concentric bone lamellae around haversian canals, haversian systems (osteons), contain osteocytes in lacunae in-between lamellae, and has one bone marrow cavity. Found in shafts of long bones.
Spongy Bone (Cancellous Bone): Branching and anastomosing bone trabeculae with multiple bone marrow cavities, bone lamellae are irregularly arranged, contains osteocytes in-between, and lack haversian systems. Found in ends of long bones, vertebrae, ribs, and skull.

Neuron

Structure: Cell body (perikaryon), dendrites, and axon.
- Cell Body (perikaryon): Trophic center, receives impulses from other neurons (dendrites), conducts nerve impulse via axon to other neurons.
- Dendrites: Branching extensions on cell bodies, numerous, short, receive impulses from other neurons, become thinner when branching, impulse towards cell body and contains Nissl granules, mitochondria, neurofilaments and microtubules.
- Axon: Single long extension, not branching except at terminal axon terminals, has a constant diameter, impulse away from cell body and contains mitochondria, neurofilaments and microtubules, but no Nissl granules.
Key Components: Nissl bodies/granules, Golgi complex, mitochondria, neurofilaments, microtubules and cytoplasmic organelles.

Histology of Cell Body

Nucleus: Single, spherical, large, central, pale vesicular, euchromatin, prominent nucleolus.
Cytoplasm: Nissl bodies/granules (large basophilic granules scattered in perikaryon and dendrites but not in axon; involved in neurotransmitter transport), free ribosomes & RER; nerve cell Nissl's granules disappear (chromatolysis) after injury.
Golgi complex: Network around nucleus in cell body, well-developed in EM.
Mitochondria: Scattered in cytoplasm, abundant in axon terminals.
Neurofilaments & Microtubules: In cell body, axon and dendrites, supportive and maintain shape, neuro-tubules share in neurotransmitter transport.

Blood Vessel Wall

Structure: Endothelium, Intima (inner layer), Media (middle layer), Adventitia (outer layer)
Layers: Endothelium (innermost layer), Subendothelium (layer of connective tissue beneath endothelium), Intima (internal elastic lamina, and smooth muscle layer), Media (smooth muscle cells, connective tissue, and elastic fibers), Adventitia (outermost layer, composed of connective tissue and contains large blood vessels that supply the vessel wall (vasa vasorum)).

Connections Between Arteries & Veins

Capillaries: Endothelial cell rests on basal lamina, surrounded by pericytes, forms a tube.
Sinosoids: Specialized capillaries.
Arteriovenous anastomosis: Direct connections between arterioles and venules.

Respiratory System

Divided into conducting portion and respiratory portion.
Conducting portion: Nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles.
Respiratory portion: Bronchioles, alveolar ducts, alveolar sacs (alveoli)
- Alveoli: Basic structural and functional unit for gas exchange, thin walls enable CO2 and O2 exchange between inspired air and blood, lined by alveolar epithelium.
Type I pneumocytes: Majority of alveolar epithelium, simple squamous epithelium, abundant in alveolar space, and involved in gas exchange.
Type II pneumocytes: Secretory cells, synthesize and secrete pulmonary surfactant, cuboidal-shaped, prevent alveolar collapse, allow for gas exchange between inspired air and blood.

Skin

Largest organ in the body (about 16% of total body weight).
Two layers: Epidermis (outer layer, epithelium) and dermis (deeper layer, connective tissue).
Epidermis cell types: Keratinocytes (85%), Melanocytes, Langerhans cells, Merkel cells.
Keratinocytes: Stratified squamous epithelium, keratin formation; linked by desmosomes; superficial layers continuously shed off; deep layers dividing, accumulating keratin filaments.
Thick and Thin skin: Differences in epidermal thickness, presence of sweat glands, and hair follicles.

Liver

Largest internal organ.
Mixed exocrine and endocrine gland.
- Endocrine: Synthesis of plasma proteins and coagulation factors.
- Exocrine: Production of bile to aid fat digestion.
- Hepatocytes: Liver cells arranged in anastomosing cords, with spaces (sinusoids) between cords, and bile canaliculi.
LM & EM of Hepatocytes: Hepatocytes have large nuclei, prominent nucleolus, abundant cytoplasm, extensive SER, RER, Golgi, mitochondria, and glycogen.
Histological Structure: An anastomosing cords of cells, blood sinusoids (dilated spaces) lined by fenestrated endothelium and permanent macrophages

Kidney

2 bean-shaped organs with a thin connective tissue capsule and surrounded by adipose tissue.
Formed of outer cortex and inner medulla.
- Outer Cortex: Reddish due to rich blood supply, granular (renal corpuscles), underneath the capsule.
- Inner Medulla: Gray in color, consists of 6-12 medullary pyramids, each with an apex directed to the minor calyx, opening into major calyx, then to the renal pelvis.
- Urinary passages lined by transitional epithelium.

Uriniferous Tubules

Nephron and collecting ducts form uriniferous tubules.
- Nephrons: Structural and functional units, form urine.
  - Renal corpuscle: Double-walled capsule, outer layer (parietal, lined by simple squamous epithelium), inner layer (visceral, modified simple squamous cells called podocytes), and glomerulus.
Collecting ducts: Concentrate and carry urine to ureters.

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Description

This quiz covers essential topics in human anatomy, focusing on the structure and function of the kidney and different types of cartilage. Test your knowledge on nephron components, cartilage types, and bone formation. Perfect for students studying anatomy and physiology.