Flex Your Knowledge 💪

Histology + Cells and Metabolism

100

What are the general characteristics and functions of epithelial tissues?

Characteristics: cells are closely packed, with little extracellular material between them 

Function: protection, absorption, secretion 

200

Describe the structure and function of nervous tissue

Structure: neurons and neuroglial cells

Function: transmit electrical signals 

300

List the ways proteins can be denatured

1. Heat:

   • High temperatures disrupt protein structure.

2. pH Changes:

   • Extreme pH levels alter protein conformation.

3. Chemicals:

   • Certain chemicals interfere with protein folding.

400

What are the properties of a cell membrane?

The cell membrane is selectively permeable, and composed of a phospholipid bilayer with embedded proteins for functions, stability, and cell recognition.

500

What's the difference between diffusion and active transport

Diffusion is the passive movement of particles from high to low concentration, while active transport requires energy to move particles against their concentration gradient

Digestive System

100

What are the structures of the alimentary canal and what's the overall function?

Structure: mouth, pharynx, esophagus, stomach, small intestine, large intestine 

Function: ingestion, digestion, absorption, elimination 

200

Explain the difference between mechanical and chemical digestion and provide an example of each.

Mechanical Digestion: Physical breakdown of food (chewing)

Chemical Digestion: Breakdown of food by enzymes (amylase breaking down starch) 

300

How are digestive secretions controlled and regulated?

The brain and the endocrine system control digestive processes. The brain controls the responses to hunger and fullness. The endocrine system controls the release of hormones and enzymes required for digestion.

400

Where is CCK primarily produced in the body, and what triggers its release? What's the main function?

Produced in the small intestine; triggered by the presence of fats and proteins. Stimulates the release of bile and pancreatic enzymes to aid in digestion.

500

What are the main enzymes used in chemical digestion? what is the function of each?

1. Amylase:

   • Function: Breaks down carbohydrates into sugars 

2. Pepsin:

   • Function: Digests proteins into smaller peptides.

3. Lipase:

   • Function: Break down lipids into fatty acids and glycerol.

Integumentary System

100

Explain how the integumentary system is involved in temperature regulation.

Sweating and vasodilation/ constriction of blood vessels 

200

What are the different types of skin cancer and how do they develop?

Basal cell carcinoma, squamous cell carcinoma, and melanoma. 

Basal and squamous cell carcinomas develop due to prolonged sun exposure, while melanoma is associated with moles or excessive UV radiation.

300

What's the difference between Apocrine and Eccrine Glands?

Apocrine glands, found in areas with hair follicles, produce a thicker secretion, and are activated during emotional stress, while eccrine glands, distributed across the skin, release a watery sweat for thermoregulation

400

What is the structure and function of melanocytes?

Melanocytes are specialized cells in the skin that produce melanin, the pigment responsible for skin, hair, and eye color, protecting against UV radiation by absorbing and dissipating sunlight

500

Explain the process by which common acne occurs

Occurs when hair follicles become clogged with oil and dead skin cells, leading to the growth of acne-causing bacteria, inflammation, and the formation of pimples, blackheads, or whiteheads

Muscular System

100

What's a motor unit?

1 motor neuron and all the muscle cells (fibers) that it stimulates to contract 

200

How does oxygen debt develop? 

During intense exercise, lactic acid builds up causing muscle fatigue. After exercise, oxygen is needed to clear lactic acid, restore ATP, and repair cells. Oxygen consumption remains high during recovery for metabolic processes.

300

What's the difference between a twitch, recruitment, and a sustained contraction?

Twitch:

• Definition: Brief contraction in response to a single stimulus.
• Duration: Very short-lived
• Force: Single stimulation.

Recruitment:

• Definition: Activation of more motor units for increased force.
• Process: Involves additional motor units working together.
• Force: Gradual increase in force with more recruitment.

Sustained Contraction:

• Definition: Continuous muscle contraction due to frequent stimulation.
• Cause: Results from a frequency preventing complete relaxation.
• Force: Higher force output, continuous stimulation.

400

How does the motor neuron stimulate muscle contraction?

By releasing ACh

500

Describe the events that lead to a skeletal muscle contraction, beginning with the release of acetylcholine.

1. Neuron releases acetylcholine

2. Acetylcholine binds to receptor proteins on the sarcolemma 

3. Na+ ions rush across the sarcolemma initiating an action potential 

4. The action potential travels along the sarcolemma

5. The action potential travels down a T-tubule 
6. The sarcoplasmic reticulum releases Ca2+ ions
7. Ca2+ ions bind to troponin 
8. Troponin pulls tropomyosin off of actin 
9. Myson heads bind to actin and initiate a contraction cycle 
10. The action potential stops 
11. Ca is pumped back into the sarcoplasmic reticulum 
12. Troponin covers tropomyosin back up and contractions of muscle stops 

Nervous System

100

What are the two main divisions of the nervous system, and what is the main function of each?

Divisions: Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Functions: CNS is for integrations and processing/ PNS is for communication between CNS and the rest of the body 

200

What's the difference between white matter and grey matter? Where is each located in the CNS?

White Matter: composed of myelinated axons, found deep in the brain and on the outer part of the spinal cord. Acts as a communication pathway, facilitating the transmission of signals between different parts of the brain and spinal cord 

Grey Matter: contains cell bodies, dendrites, and unmyelinated axons. Located in the cerebral cortex and in clusters within the brain (nuclei) and inner parts of the spinal cord (horns). Responsible for processing and integrating information.

300

What is membrane potential? How is it determined?

Electrical potential across a cell membrane; determined by ion concentration (K+ and Na+)

400

4 major REGIONS of the brain. What are the functions?

1. Cerebral Cortex = higher cognitive functions (thinking, reasoning, language, memory) 

2. Cerebellum = coordination of voluntary movements, maintains posture and balance.

3. Brainstem = composed of the midbrain, pons, medulla oblongata. Regulates basic life functions (breathing, heartbeat, blood pressure). Pathways for exchange of info between cerebral cortex and spinal cord

4. Diencephalon = consists of the thalamus (relay station for sensory info), and hypothalamus (regulation of physiological processes such as body temp, hunger and thirst, and sleep-wake cycle) 

500

Explain the process of an action potential, detailing the events from the resting state to repolarization. Include the role of ion channels and the movement of ions.

1. Resting State:

   • The neuron is at its resting membrane potential, with a negative charge inside and a positive charge outside.
   • Voltage-gated sodium (Na+) channels are closed, maintaining the resting potential.

2. Depolarization:

   • When the neuron is stimulated, sodium channels open, allowing Na+ ions to rush into the cell.
   • The influx of positive ions causes a rapid depolarization, reversing the membrane potential from negative to positive.

3. Threshold and Action Potential:

   • If the depolarization reaches a critical threshold, voltage-gated sodium channels open further, leading to a positive feedback loop.
   • This results in a rapid increase in membrane potential, creating the action potential.

4. Repolarization:

   • Voltage-gated potassium (K+) channels open, allowing K+ ions to move out of the cell.
   • This outward movement of positive ions leads to repolarization, restoring the negative charge inside the cell.

5. Hyperpolarization and Refractory Period:

   • Potassium channels may briefly overshoot, causing hyperpolarization, making the membrane potential more negative than the resting state.
   • The neuron enters a refractory period during which it is less responsive to additional stimuli.