anatomy quiz 1 Flashcards
What are cells?
Basic structural and functional units of living organisms
Cells contain all the parts necessary to survive in a changing environment.
How many cells are approximately in the human body?
50-60 trillion
There are about 200 different types of cells in the body.
What do the size and shape of cells reflect?
Function
Examples include red blood cells (RBC), nerve cells, and muscle cells.
What organelle is known as the metabolic machinery of the cell?
Mitochondria
Mitochondria are responsible for ATP production.
What is the function of ribosomes?
Protein synthesis for cell membranes
Ribosomes can be found on rough endoplasmic reticulum (ER).
What is epithelial tissue?
A sheet of cells that covers a body surface and lines a body cavity
It forms a boundary between different environments.
What are the two types of epithelial tissue?
- Covering and lining epithelium
- Glandular epithelium
Covering and lining epithelium includes the outer layer of skin and lining of cavities, while glandular epithelium forms glands.
List the functions of epithelial tissue.
- Protection
- Absorption
- Filtration
- Excretion
- Secretion
- Sensory reception
Epithelia can have multiple roles within an organ, such as in the kidney.
What is a key characteristic of epithelial tissue related to cellular composition?
Cellularity
Epithelial tissue is very closely packed with a tiny amount of extracellular material.
What does polarity in epithelial tissue refer to?
Differences between apical (free or exposed surface) and basal surfaces
Microvilli and cilia are structures found on the apical surface.
What is the basement membrane in epithelial tissue?
A structure that lies between epithelium and underlying connective tissue
It acts as a selective filter and scaffold for epithelial cell migration.
What are the two parts of the basement membrane?
- Basal lamina
- Reticular lamina
The basal lamina is superficial, while the reticular lamina is deeper and composed of collagen and protein.
True or False: Epithelial tissue is avascular but innervated.
True
This means it lacks blood vessels but has nerve endings.
What is a significant characteristic of epithelial tissue related to regeneration?
High capacity to regenerate
Rapid cell division is important as epithelial tissues are regularly damaged.
How is epithelial tissue named?
By examining the number of layers and the shape of the apical surface
Different classifications exist based on these criteria.
What is keratin?
A tough protein layer found in epithelial tissues
Keratinized cells are typically dead.
What type of epithelial tissue is found in sweat gland ducts?
Stratified cuboidal epithelium
Usually consists of only two layers of cells.
Where is stratified columnar epithelium commonly found?
In the largest ducts of salivary glands
The basal layer consists of cuboidal cells, and the apical layer consists of columnar cells.
What does transitional epithelium resemble?
Stratified squamous or stratified cuboidal depending on degree of stretch
It is specialized for areas that undergo stretching.
What is histology?
Study of tissues
Histology examines the structure and function of tissues.
What are the four main types of tissue?
- Epithelial tissue – covering/lining
- Connective tissue - support
- Muscle tissue - movement
- Nervous tissue - control
What is the primary function of connective tissue?
Connect different structures and perform various additional roles
List the functions of connective tissue.
- Binding and support
- Protection
- Insulation
- Transportation
- Protection from microorganisms
What is ground substance in connective tissue?
Unstructured material that fills space between cells and fibers
What are the three types of fibers in connective tissue?
- Collagen fibers
- Elastic fibers
- Reticular fibers
What is the composition of collagen fibers?
Constructed of a fibrous protein called collagen
True or False: Collagen fibers are the strongest fibers in connective tissue.
True
What is the role of elastic fibers?
Provide a rubbery or resilient property to the matrix
What are reticular fibers?
Fine collagenous fibers that form delicate 3D networks
What are the common characteristics of connective tissue?
- Common origin from mesenchyme
- Varying degrees of vascularity
- Composed largely of extracellular matrix
What is mesenchyme?
Embryonic tissue that gives rise to all other types of connective tissue
What is loose connective tissue?
Packing material of the body that fills spaces between organs
What distinguishes areolar connective tissue?
Reservoir of fluid containing all three fiber types
Fill in the blank: Adipose connective tissue is essentially _______ but with an increased number of adipocytes.
areolar CT
What is the function of reticular connective tissue?
Supports other fibers in lymphoid organs like spleen and bone marrow
What is dense connective tissue primarily composed of?
Mainly fibers, specifically collagen fibers
What characterizes dense regular connective tissue?
Parallel strands of collagen fibers with slight give
Where is dense irregular connective tissue found?
In skin (dermis), stomach, and joint capsules
What is a unique feature of elastic connective tissue?
Ability to stretch and snap back into place
What are the two main types of membranes?
- Epithelial tissue + Connective tissue
- Serous membranes
What is the cutaneous membrane?
The skin, composed of keratinized stratified squamous tissue over dense irregular connective tissue
What is the function of mucous membranes?
Lines body cavities open to the exterior
What distinguishes serous membranes?
Moist membranes found in closed ventral body cavities
What is the difference between visceral and parietal epithelial tissue?
Visceral lines internal organs, parietal lines the cavity walls
What is cartilage?
Qualities somewhere between dense connective tissue and bone
Cartilage is avascular and not innervated, making it slow to heal.
What is the water content of cartilage?
80% water
Nutrients and proteins are also present.
What is the role of fluid movement in cartilage?
Important to maintenance of cartilage integrity
Acts like a sponge.
What cells are found in cartilage?
Chondrocytes in lacunae
Lacunae are small spaces within the cartilage matrix.
What are the two layers of the perichondrium?
- Sheath of dense irregular connective tissue
- Inner cellular layer (chondroblasts)
Chondroblasts appear flattened.
What type of cartilage is the most abundant in the body?
Hyaline cartilage
It is also the weakest type of cartilage.
What type of fibers primarily compose hyaline cartilage?
Type I collagen fibers
It has a glassy shiny appearance.
Where can hyaline cartilage be found?
- Ends of long bones (articular cartilage)
- Tip of nose
- Connects ribs to sternum
- Forms most of larynx
- Cartilages of trachea and bronchi
- Epiphyseal plates
It creates a low friction surface and helps absorb shock.
What is osteoarthritis often described as?
Wear and tear
It is a non-inflammatory condition with a multi-factorial etiology.
What distinguishes elastic cartilage from hyaline cartilage?
More elastic fibers (elastin)
Stains black and is very tolerant to bending.
Where is elastic cartilage found?
- External ear
- Epiglottis
- Cuneiform cartilages of larynx
- Auditory tube
Contains type I collagen.
What is fibrocartilage primarily composed of?
- Type I and II collagen
- Little elastin
It is durable, tough, and compressible.
What is a key characteristic of fibrocartilage?
No perichondrium
It is often found where hyaline cartilage meets a true ligament or tendon.
What is the function of fibrocartilage?
Shock absorption
Examples include menisci in the knee and intervertebral disks.
What percentage of bone is made up of water?
25-30%
The remainder is composed of organic and inorganic materials.
What are the main components of the organic part of the bone matrix?
- Collagen
- Osteoblasts
- Osteocytes
- Osteoclasts
- Osteoid
Accounts for 30-40% of the matrix.
What provides compressive strength to bones?
Inorganic material
Includes calcium phosphate, hydroxyapatites, and calcium carbonate.
What is the primary function of bone?
- Support
- Protection
- Movement
- Mineral storage
- Blood cell formation
Bones act as levers and store minerals like calcium.
What are the types of bone?
- Compact (dense) bone
- Cancellous (trabecular, spongy) bone
Trabeculae are little beams in cancellous bone.
What is the biological architecture of bone characterized by?
Trabeculae arranged with stress lines
This arrangement helps in load distribution.
What are the classifications of bones?
- Long bones
- Short bones
- Flat bones
- Irregular bones
- Sesamoid bones
Examples include femur (long), carpals (short), skull (flat), mandible (irregular), and patella (sesamoid).
What is the diaphysis of a long bone?
The shaft of the bone, composed of compact bone that is very dense and resistant to bending and torsion.
What is the medullary cavity lined with?
Simple squamous epithelium, known as the endosteum.
What are the components of the epiphysis in a long bone?
Proximal and distal ends, composed of spongy bone internally, covered by hyaline cartilage at the articular surfaces.
What fills the space in spongy bone?
Red marrow, which is the site of RBC production.
What is the epiphyseal line?
A remnant of the epiphyseal plate, which is the growth plate during childhood.
What is the periosteum?
The external layer of bone, consisting of dense irregular connective tissue and an inner cellular layer with osteoblasts and osteoclasts.
What supplies the periosteum with blood, nerves, and lymph?
Nutrient foramina.
What are Sharpey’s fibers?
Fibers that secure the periosteum to the underlying bone.
What is the Haversian system?
A structural unit of compact bone consisting of concentric rings called lamellae surrounding a central Haversian canal.
What connects Haversian canals?
Horizontal canals known as Volkmann’s canals.
What are lacunae in bone tissue?
Gaps between lamellae that house osteocytes, connected by canaliculi.
What is osteogenesis?
The process of bone formation.
At what stage does the human embryo’s skeleton mainly consist of fibrous membrane and hyaline cartilage?
At approximately 4-6 weeks.
What are the two ways bone develops?
- Intramembranous ossification
- Endochondral ossification
What is intramembranous ossification?
Bone formation from a fibrous membrane, primarily resulting in flat bones.
What is osteoid?
Unmineralized ‘pre-bone’ secreted by osteoblasts.
What are spicules in bone formation?
Little spikes of bone that later form trabeculae.
What occurs during endochondral ossification?
Hyaline cartilage is broken down to form long bones.
What happens to the perichondrium during endochondral ossification?
It is infused with blood vessels and transforms into periosteum.
What forms the medullary cavity?
Osteoclasts brought in via the periosteal bud.
What stimulates osteoblasts during bone growth?
Growth hormone, estrogen, and testosterone.
Fill in the blank: The growth plates allow _______ growth of the bone until the early 20s.
longitudinal
True or False: The ossification process is the same for both primary and secondary ossification centers.
True
