Physiology Second Stage Lecture 1

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Questions and Answers

What is the primary role of homeostasis in the human body?

To enhance the effects of external stimuli

To entirely eliminate external changes

To maintain relatively constant internal conditions (correct)

To increase variability in body functions

Which of the following components is NOT part of a homeostatic system?

The Control Center

The Stabilizer (correct)

The Sensor

The Effector

What is an example of a negative feedback mechanism?

Nerve impulse transmission

Blood clotting

Childbirth contractions

Regulation of blood glucose levels (correct)

Which tissue type is characterized by the presence of neurons and supporting cells?

Nervous tissue Signup and view all the answers

In the regulation of body temperature through negative feedback, what role does sweating play?

It cools the skin through evaporation Signup and view all the answers

Which of the following describes an organ?

A structure formed by two or more tissue types Signup and view all the answers

Which primary tissue is responsible for movement?

Muscle tissue Signup and view all the answers

What is the function of the control center in a homeostatic system?

To send messages to adjust the stress detected Signup and view all the answers

What is the primary role of the nucleus in a cell?

It acts as the genetic control center of the cell. Signup and view all the answers

Which component of the nucleus is responsible for the production of ribosomes?

Nucleolus Signup and view all the answers

What is the function of the nuclear envelope?

To control the flow of materials in and out of the nucleus. Signup and view all the answers

What is the composition of the nucleoplasm?

A jelly-like matrix made mostly of water. Signup and view all the answers

Which characteristic of chromatin is true?

It consists of thread-like material that makes up chromosomes. Signup and view all the answers

What is the primary function of lysosomes?

Digest foreign molecules and damaged organelles Signup and view all the answers

What distinguishes rough endoplasmic reticulum from smooth endoplasmic reticulum?

Rough ER has ribosomes attached to its surface. Signup and view all the answers

Which of the following substances is primarily synthesized by ribosomes attached to the rough endoplasmic reticulum?

Enzymatic proteins Signup and view all the answers

What role does the smooth endoplasmic reticulum play in cellular function?

Synthesis and storage of non-protein substances Signup and view all the answers

What is a key structural feature of mitochondria?

Folded inner membrane known as cristae Signup and view all the answers

Which type of ribosomes is responsible for synthesizing hemoglobin?

Free ribosomes in the cytoplasm Signup and view all the answers

What components are found in ribosomes?

Proteins and ribosomal RNA Signup and view all the answers

Which of the following is NOT a function of the smooth endoplasmic reticulum?

Degradation of worn-out organelles Signup and view all the answers

What is the primary function of integral proteins in the cell membrane?

Penetrate the phospholipid bilayer Signup and view all the answers

Which of the following is NOT a function of glycoproteins in the glycocalyx?

Provide structural support Signup and view all the answers

What role does the Golgi complex play in cellular function?

Package molecules for secretion Signup and view all the answers

What is a key characteristic of peripheral proteins?

They are loosely attached to the membrane surfaces Signup and view all the answers

Which function is NOT associated with the cell membrane?

Storage of nutrients Signup and view all the answers

What component of the cytoplasm describes the fluid portion?

Cytosol Signup and view all the answers

Which organelle is primarily involved in protein synthesis?

Endoplasmic reticulum Signup and view all the answers

What is a function of the glycocalyx related to immune reactions?

Involvement in immune reactions Signup and view all the answers

What is the primary function of peroxisomes?

Breakdown fatty acids and detoxify harmful substances Signup and view all the answers

What structure is responsible for the organization of spindle fibers during cell division?

Centrosome Signup and view all the answers

Which of the following functions is NOT associated with vacuoles?

Move particles along the cell surface Signup and view all the answers

What role do microfilaments and microtubules play in the cell?

Provide support to the cytoplasm and aid in transportation Signup and view all the answers

Which of the following best describes cilia and flagella?

Cytoplasmic projections for movement Signup and view all the answers

The cytoskeleton is essential for which of the following functions?

Maintaining cell shape and movement Signup and view all the answers

Which organelle is responsible for the formation of secretory vesicles?

Golgi apparatus Signup and view all the answers

What is the main structural component of the cytoskeleton?

Proteins Signup and view all the answers

Study Notes

Physiology Overview

Physiology studies organ functions and the physical and chemical processes involved in life.
Homeostasis is the maintenance of a stable internal environment despite external changes, exemplified by body temperature and blood glucose regulation.

Homeostatic Mechanisms

Negative Feedback: Most common mechanism; reduces or stops the original stimulus to restore balance.
Positive Feedback: Enhances the original stimulus, pushing the variable further away from its set point.

Components of Homeostatic Systems

Sensor: Detects changes in internal or external environment.
Control Center: Processes information from the sensor and sends out responses.
Effector: Executes responses that restore homeostasis.

Body Temperature Regulation

In hyperthermia, heat receptors in the skin detect the increase in temperature.
The hypothalamus acts as the control center, triggering perspiration and increased blood flow to the skin to cool the body.

Levels of Organization in the Body

Cell: Basic structural and functional unit of life.
Tissue: Group of similar cells; four primary types:
- Muscle: Skeletal, smooth, cardiac.
- Nervous: Neurons and support cells.
- Epithelial: Squamous, columnar, cuboidal.
- Connective: Various forms including cartilage and bone.
Organ: Composed of two or more tissue types working together to perform specific functions.

Membrane Proteins

Integral Proteins: Penetrate the phospholipid bilayer fully or partially.
Peripheral Proteins: Attached to the inner or outer surfaces of the membrane.

Functions of Membrane Proteins

Act as transport proteins, enzymes, receptors, and cell adhesion molecules (CAMs).
Glycocalyx is a carbohydrate coat that serves various functions including repelling bacteria and acting as hormone receptors.

Functions of Cell Membrane

Protective barrier, selective permeability, absorption, excretion, gas exchange, and maintaining cell shape and size.

Cytoplasm and Organelles

Cytoplasm: Jelly-like substance where organelles are suspended; site for chemical reactions.
Organelles: Specialized structures within cells, categorized as membrane-bound or non-membrane-bound.

Organelles' Structure & Function

Endoplasmic Reticulum (ER): Network of membranes;
- Rough ER synthesizes proteins with ribosomes.
- Smooth ER synthesizes non-protein substances and stores calcium.
Ribosomes: Protein/RNA structures; essential for protein synthesis.
Golgi Complex: Processes and packages molecules; produces secretory vesicles.
Mitochondria: Energy producers; convert food molecules into ATP.
Lysosomes: Digest foreign molecules and damaged organelles.

Ribosomes

Composed of two subunits; critical for synthesizing enzymatic, hormonal, and lysosomal proteins.
Free ribosomes synthesize proteins for cellular use.

Mitochondria Details

Double-membranous organelle responsible for energy production via ATP synthesis.
Inner membrane features invaginations (cristae) to increase surface area.

Other Cytoplasmic Organelles

Peroxisomes: Detoxify harmful substances; involved in fatty acid metabolism.
Centrosome & Centrioles: Organize spindle fibers for chromosome movement during mitosis.
Vacuoles: Store and release various substances.
Cilia & Flagella: Aid in movement across cell surfaces.

Cytoskeleton

Composed of microtubules, intermediate filaments, and microfilaments; provides cell shape, support, and facilitates movement.

Nucleus Structure and Function

Nuclear Envelope: Double membrane with pores regulating material exchange between nucleus and cytoplasm.
Nucleoplasm: Jelly-like matrix supporting nuclear contents.
Nucleoli: Sites for ribosome production within the nucleus.
Chromatin: Thread-like material forming chromosomes, carrying genetic information.

This summary encapsulates key concepts from physiology, highlighting important functions, structures, and processes fundamental to understanding living organisms.

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Description

Explore the foundational concepts of medical physiology in this quiz covering the general and cellular basis of body functions. Understand key terms such as homeostasis, and how internal environments maintain stability despite external changes. This quiz is suitable for students in advanced physiology courses.