Cells & Tissues GPT Flashcards
What is the nucleus responsible for in a cell?
It stores genetic instructions and is the control center of the cell.
What is DNA replication?
The process of copying DNA before cell division so that each new cell receives a full set.
What is a nucleosome?
A complex of DNA wrapped around histone proteins.
What enzyme unzips the DNA strands in replication?
Helicase.
What enzyme adds nucleotides during DNA replication?
DNA polymerase.
What is transcription?
The process of copying a gene’s DNA sequence into mRNA.
What is translation?
The process of synthesizing a protein from mRNA using tRNA and ribosomes.
What are the phases of the cell cycle?
Interphase (G1, S, G2), Mitosis, and Cytokinesis.
What occurs during the S phase?
DNA replication.
What are the stages of mitosis?
Prophase, Prometaphase, Metaphase, Anaphase, Telophase.
What is cytokinesis?
The division of cytoplasm into two distinct cells after mitosis.
What are the two main types of human cells?
Germ cells and somatic cells.
What is a germ cell?
A sex cell (sperm or oocyte) used for reproduction.
What is a somatic cell?
Any body cell other than a germ cell, involved in growth, repair, and maintenance.
What is the function of red blood cells?
To carry oxygen to tissues and return carbon dioxide to the lungs.
What do white blood cells do?
They identify and destroy pathogens or foreign particles.
What do osteoblasts do?
They synthesize bone matrix and initiate calcification.
What are fibroblasts?
Connective tissue cells that provide structural framework by secreting collagen.
Where are skeletal muscle cells found?
Attached to the skeleton, they enable voluntary movement.
Where are smooth muscle cells found?
In walls of internal organs, blood vessels, and the eye; they function involuntarily.
What are cardiac muscle cells responsible for?
Pumping blood by contracting in a coordinated manner.
What is the function of neurons?
To perceive stimuli and transmit information through electrical and chemical signals.
What are the three cell shapes used to classify epithelial tissues?
Squamous, cuboidal, and columnar
What is the main difference between simple and stratified epithelium?
Simple epithelium has one cell layer; stratified epithelium has multiple layers.
Where is pseudostratified columnar epithelium typically found?
In the respiratory tract, where some of the cells have cilia.
What is the function of goblet cells?
To secrete mucus; they are found in mucous membranes between columnar epithelial cells.
What is transitional epithelium and where is it found?
A stratified epithelium that can change shape; found in the bladder and urinary system.
What are the three basic components of connective tissue?
Cells, ground substance, and protein fibers.
Which connective tissue stores energy and provides insulation?
Adipose tissue.
What type of cartilage is most common in the body?
Hyaline cartilage.
What is the function of fibroblasts?
To secrete protein fibers and matrix into the extracellular space.
What type of connective tissue forms ligaments and tendons?
Dense regular connective tissue.
Which type of muscle tissue is under voluntary control?
Skeletal muscle.
Which muscle type is responsible for pumping blood through the heart?
Cardiac muscle.
What are intercalated discs?
Specialized junctions that connect cardiac muscle cells and allow synchronized contraction.
Where is smooth muscle typically found?
In the walls of organs and passageways, such as the digestive tract and blood vessels.
What are the two main types of cells in nervous tissue?
Neurons and neuroglia.
What is the function of myelin?
To insulate axons and speed up the transmission of nerve impulses.
What are astrocytes and what do they do?
Star-shaped glial cells that maintain the blood-brain barrier and regulate the intercellular environment.
Which cell produces myelin in the peripheral nervous system?
Schwann cells.
What is the primary function of simple squamous epithelium?
Facilitates diffusion and filtration; found in alveoli and capillaries.
Where is stratified squamous epithelium found?
In areas subject to abrasion like the skin, mouth, and esophagus.
What is the ground substance in connective tissue composed of?
Water, glycosaminoglycans, proteoglycans, and glycoproteins.
Which connective tissue type provides flexible support in the ear and epiglottis?
Elastic cartilage.
Why are skeletal muscle fibers multinucleated?
Because they form from the fusion of multiple myoblasts.
What causes the striated appearance in skeletal and cardiac muscle?
The alignment of actin and myosin filaments.
What is the function of microglia?
They act as immune defense cells in the central nervous system.
What is the function of oligodendrocytes?
They produce myelin for axons in the central nervous system.
What is the anatomical position?
Standing upright, feet shoulder-width apart, arms at the sides, and palms facing forward.
What does ‘axial’ refer to in the body?
The central part of the body, including the head, neck, and trunk.
What does ‘appendicular’ refer to?
The limbs and their attachments to the axis of the body.
What is the medical term for wrist?
Carpal.
What do the terms ‘prone’ and ‘supine’ describe?
Body lying face down (prone) or face up (supine).
What does anterior (ventral) mean?
Toward the front of the body.
What does posterior (dorsal) mean?
Toward the back of the body.
What does superior (cranial) mean?
Above or higher than another part.
What does inferior (caudal) mean?
Below or lower than another part.
What does lateral mean?
Away from the midline of the body.
What does medial mean?
Toward the midline of the body.
What does proximal mean?
Closer to the point of attachment to the trunk.
What does distal mean?
Farther from the point of attachment to the trunk.
What does superficial mean?
Closer to the surface of the body.
What does deep mean?
Farther from the surface of the body.
What is the sagittal plane?
Divides the body into right and left sides.
What is the frontal (coronal) plane?
Divides the body into front (anterior) and back (posterior) parts.
What is the transverse plane?
Divides the body into upper (superior) and lower (inferior) parts.
What are the two main body cavities?
Dorsal (posterior) and ventral (anterior) cavities.
What does the dorsal cavity contain?
The cranial cavity and spinal (vertebral) cavity.
What does the ventral cavity contain?
The thoracic cavity and abdominopelvic cavity.
What separates the thoracic and abdominopelvic cavities?
The diaphragm.
What are the three serous membranes?
Pleura (lungs), pericardium (heart), and peritoneum (abdominopelvic organs).
What is the function of serous fluid?
To reduce friction between organs and body walls.
How are abdominal regions divided?
Into nine regions or four quadrants.
What cavity houses the brain?
The cranial cavity.
What cavity encloses the spinal cord?
The spinal (vertebral) cavity.
What organs are located in the thoracic cavity?
The lungs and heart.
What organs are found in the abdominal cavity?
Digestive organs like the stomach, liver, and intestines.
What organs are found in the pelvic cavity?
Reproductive organs, bladder, and rectum.
What region is located directly above the umbilical region?
The epigastric region.
What abdominal quadrant contains the liver and gallbladder?
Right upper quadrant (RUQ).
Which serous membrane surrounds the heart?
Pericardium.
Which serous membrane surrounds the abdominal organs?
Peritoneum.
Which serous membrane surrounds the lungs?
Pleura.
What is homeostasis?
The maintenance of relatively stable internal conditions despite external changes.
What is the typical set point for human body temperature?
Approximately 98.6°F (37°C).
What are controlled conditions in homeostasis?
Variables like temperature, salinity, ion concentration, oxygen levels, and pH.
What are normal limits in a set point range?
The upper and lower boundaries around the set point.
Why is maintaining homeostasis challenging?
Because internal and external environments are constantly changing.
What is a stimulus in a feedback system?
Any disruption or change in a controlled condition.
What is a receptor?
A sensor that detects changes and sends information to the control center.
What is the control center in a feedback system?
Processes input from receptors and signals effectors to respond.
What are examples of control centers?
The hypothalamus and pituitary gland.
What is an effector?
A structure that carries out the response to restore homeostasis.
What are some examples of effectors?
Muscles, glands, and organs.
What is a response in a feedback system?
A change that returns the body to the set point.
What is feedback in a homeostatic loop?
The information sent back to the control center to refine response.
What is a negative feedback system?
A system that reverses a deviation from the set point.
Give an example of negative feedback.
Thermoregulation or blood glucose regulation.
How does the body respond to high blood sugar?
Pancreatic beta cells release insulin to lower blood glucose.
What happens when blood sugar drops too low?
Pancreatic alpha cells release glucagon to raise it.
What is the role of sweat glands in thermoregulation?
They release sweat to cool the body.
How does vasodilation help in cooling?
Increases blood flow to the skin, releasing heat.
What happens during cold exposure?
Vasoconstriction, shivering, and hormonal changes to generate heat.
Which hormone increases metabolism in cold conditions?
Thyroid hormone.
What is the role of epinephrine in thermoregulation?
It increases glycogen breakdown and heat production.
What is a positive feedback system?
A system that intensifies a change rather than reversing it.
When is positive feedback normal?
During processes with a clear endpoint like childbirth or clotting.
How does positive feedback work during childbirth?
Stretching of cervix triggers oxytocin, leading to stronger contractions.
What stops the positive feedback loop in childbirth?
Birth of the baby stops cervical stretching and oxytocin release.
How does blood clotting involve positive feedback?
Each clotting step triggers more clotting until the wound is sealed.
Why is positive feedback dangerous if uncontrolled?
It can lead to homeostatic imbalance and worsen injury or illness.
What is homeostatic imbalance?
Disruption in homeostasis that can lead to disease or death.
What causes homeostatic imbalance?
Failure or inefficiency in feedback systems.
What are signs of severe homeostatic failure?
Organ failure, immune suppression, metabolic collapse.
What happens when negative feedback is overwhelmed?
Positive feedback may dominate, worsening instability.
Why is feedback system efficiency critical for health?
It ensures internal balance and prevents pathological conditions.
What is mRNA?
mRNA stands for messenger RNA.
It’s a copy of a gene from your DNA that acts like an instruction manual to build a specific protein.
• It’s made in the nucleus through a process called transcription.
• Then, it travels to the ribosome (the cell’s protein factory), where the instructions are read.
Think of mRNA like a blueprint or recipe for making a protein.
What is tRNA?
tRNA stands for transfer RNA.
Its job is to bring the right amino acids to the ribosome so they can be put together in the correct order to make a protein.
• Each tRNA molecule carries one specific amino acid.
• tRNA has an anticodon that matches a codon (3-letter sequence) on the mRNA.
Imagine tRNA as a delivery truck that brings the right building blocks (amino acids) to the construction site (the ribosome), based on the blueprint (mRNA).
The organelles of the endomembrane system include
the endoplasmic reticulum, Golgi apparatus, and vesicles.
tissue
It is a group of cells with similar function and structure.
The most abundant cell in connective tissue proper is the
fibroblast
a less active form of fibroblast, is the second most common cell type in connective tissue proper.
fibrocyte
What is another term for reproductive cell division?
Meiosis
What are connective tissue cells dispersed in?
Matrix
What are two types of connective tissue?
Loose and dense
Which type of tissue assists with the transport of fluid, nutrients, waste, and chemical messengers?
Connective tissue
What are the cells that are abundant in the central nervous system and have many functions, including the formation of the blood-brain barrier?
Astrocytes
myocyte:
muscle cells
Microglia are the
immune cells of the central nervous system (CNS).
They act like bodyguards for your brain and spinal cord—constantly scanning for damage, infection, or debris. When they detect a problem, they respond by removing dead cells, pathogens, or waste through a process called phagocytosis.
Think of them as tiny cleanup and defense units that help keep the brain healthy.
Dendrites are the
branch-like extensions of a neuron that receive signals from other neurons.
They act like antennae, picking up electrical messages (called impulses) and carrying them toward the cell body of the neuron. The more dendrites a neuron has, the more information it can receive from other neurons.
Where is stratified squamous epithelium found, and what is its function?
Lining the esophagus and mouth; provide protection against abrasions
Where is stratified cuboidal epithelium found, and what is its function?
In sweat glands, salivary glands, and mammary glands; protect tissues)
Where is simple cuboidal epithelium found, and what is its function?
In ducts and secretory portions of small glands and in the kidney tubules; secrete and absorb
