Lecture on Body Systems and Homeostasis

This set of flashcards covers essential concepts from the lecture on body systems, homeostasis, and the nervous system, providing a comprehensive review for exam preparation.

What are epithelial cells primarily responsible for?

Protection, regulation, and sensing stimuli within the body.

Where can you find epithelial cells in the body?

On the external surfaces of the body and lining most internal organs.

What are connective tissues used for?

To fill in gaps, provide support, and connect different body parts.

What type of tissue is fat classified as?

Connective tissue.

What is the main function of muscle tissue?

Responsible for movement of the body.

What does nervous tissue primarily do?

Responsible for communication and coordination of movements.

What is homeostasis?

The maintenance of internal balance within the body.

What happens when blood sugar is high?

The pancreas stimulates the production of insulin.

What is glycogen?

A stored form of glucose in the body.

What hormone is released when blood sugar levels drop?

Glucagon.

How do plants store energy?

By converting glucose into starch.

What is the optimal body temperature for enzyme function?

Around 36.5 to 37 degrees Celsius.

What is the role of sweat glands in body temperature regulation?

To promote evaporation and cool the body.

What system controls voluntary muscle movements?

The somatic nervous system.

What is the main division of the nervous system?

Central nervous system (CNS) and peripheral nervous system (PNS).

What structures are part of the central nervous system?

Brain and spinal cord.

What does the afferent division of the nervous system do?

Transmits sensory information to the CNS.

What is the function of the efferent division?

Transmits motor commands from the CNS to muscles.

What are the two branches of the autonomic nervous system?

Sympathetic and parasympathetic nervous systems.

What is the function of the sympathetic nervous system?

Prepares the body for fight or flight responses.

What does the parasympathetic nervous system do?

Calms the body and conserves energy.

What is the primary role of neurons?

To transmit information throughout the body.

What are glial cells?

Support cells in the nervous system.

What is the resting membrane potential of a neuron?

Approximately -70 millivolts.

What is depolarization in a neuron?

The process of making the inside of the neuron more positively charged.

What causes action potential in a neuron?

The threshold is reached, leading to changes in membrane potential.

What happens during the repolarization phase?

Potassium ions flow out of the neuron, restoring negative internal charge.

What is the synaptic cleft?

The gap between the axon terminal of one neuron and the dendrite of another.

What is the role of neurotransmitters?

To communicate signals between neurons.

What disease is characterized by the accumulation of tau proteins in the brain?

Alzheimer's disease.

What neurotransmitter is deficient in Parkinson's disease?

Dopamine.

What is the primary function of the cerebellum?

To coordinate balance and motor control.

How does the body respond to high temperatures?

Through sweating and vasodilation.

What is an example of a reflex arc?

A quick response to a painful stimulus involving sensory neurons, integration centers, and motor neurons.

What happens when a neuron exceeds its action potential threshold?

It fires an action potential and transmits a signal.

What is meant by 'all or none' reaction in neurons?

Once the threshold is reached, action potentials occur fully or not at all.

How do sodium and potassium ions affect action potential?

Sodium influx leads to depolarization, while potassium efflux causes repolarization.

What is the function of action potentials in neural communication?

To propagate electrical signals along the neuron.

What condition occurs when neurons fail to regenerate?

Nervous system disorders.

Why are nervous system diseases difficult to treat?

Neurons generally do not regenerate.

What is hyperpolarization in a neuron?

When the inside of the neuron becomes more negative than resting membrane potential.

What does the central nervous system integrate?

Sensory information to produce responses.

What is a classic symptom of Alzheimer's disease?

Cognitive decline and memory loss.

What is the primary treatment challenge for Parkinson's disease?

Restoring dopamine levels.

What part of the brain is associated with higher cognitive functions?

Cerebral cortex.

What do astrocytes do in the nervous system?

Support neuronal health and function.

What is the primary composition of blood tissue?

Cells suspended in plasma.

Why does the body maintain a temperature around 37 degrees Celsius?

To optimize enzyme activity and inhibit pathogen growth.

What happens to neurotransmitters once they've acted on a receptor?

They are either broken down or reabsorbed by the presynaptic neuron.

What are mechanoreceptors?

Receptors that respond to mechanical pressure or distortion.

What is the function of the myelin sheath on neurons?

To increase the speed of electrical signal transmission.

What is the role of the pituitary gland in homeostasis?

Regulates various hormonal functions in the body.

What are the effects of stress on the body?

Activates the sympathetic nervous system and releases stress hormones.

What is the relationship between blood glucose levels and insulin?

Insulin lowers blood glucose levels by facilitating cellular uptake.

What is the role of the pancreas in regulating blood sugar?

Secretes insulin and glucagon based on blood sugar levels.

What is the difference between sensory neurons and motor neurons?

Sensory neurons carry signals to the CNS, while motor neurons carry commands from the CNS.

What types of information do dendrites of neurons receive?

Sensory information from the environment.

What is the function of the autonomic nervous system?

Regulates involuntary bodily functions.

What is the significance of the spinal cord in the nervous system?

It serves as a major conduit for information between the brain and peripheral nervous system.

What happens during a reflex action?

A sensory signal bypasses the brain and directly activates muscle response.

What is the role of the thalamus in the CNS?

Acts as a relay station for sensory information.

What initiates the release of neurotransmitters at a synapse?

An action potential reaching the axon terminal.

What is an autoimmune disease affecting the nervous system?

Multiple sclerosis.

What is the relevance of action potential to everyday life?

It is essential for all neural communications and responses.

What are the main functions of the human nervous system?

Processing sensory information, coordinating motor responses, and maintaining homeostasis.

What happens during the refractory period of a neuron?

The neuron is less likely to fire another action potential.

How does the body detect a hot surface?

Thermoreceptors send signals through sensory neurons to the CNS.

What is the unified purpose of the nervous system?

To control and coordinate bodily functions.

What are neurotransmitter receptors?

Proteins that bind neurotransmitters and mediate their effects on target cells.

What do glial cells outnumber in the nervous system?

Neurons.

What is the effect of stress hormones on blood sugar levels?

They increase blood sugar levels for energy.