BPK 105 Study Guide - Midterm Guide: Resting Potential, Cardiac Muscle, Membrane Potential
27 Apr 2018
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Module 3 - Review Questions - Part 1
1. Describe the functions of the muscular system, include whether it is skeletal,
smooth or cardiac muscle involved. [7 marks]
1. Movement of the body.
Contraction of skeletal muscles is responsible for the overall
movements of the body, such as walking, running, and manipulating objects with the hands.
2. Maintenance of posture.
Skeletal muscles constantly maintain tone, which keeps us sitting
or standing erect.
3. Respiration.
Muscles of the thorax (between neck + abdomen) carry out the movements
necessary for respiration.
The skeletal muscles responsible for respiration.
4. Production of body heat.
When skeletal muscles contract, heat is given off as a by-product.
This released heat is critical to the maintenance of body temperature.
5. Communication.
Skeletal muscles are involved in all aspects of communication, including
speaking, writing, typing, gesturing, and facial expressions.
6. Constriction of organs and vessels.
The contraction of smooth muscle within the walls of
internal organs and vessels causes those structures to constrict. This constriction can help
propel and mix food and water in the digestive tract, propel secretions from organs, and regulate
blood flow through vessels.
7. Contraction of the heart.
The contraction of cardiac muscle causes the heart to beat,
propelling blood to all parts of the body.
2. Describe resting membrane potential. Include the distribution of ions and
charge across the membrane, the state of ion channels (open or closed), and
concentration and electrical gradients that exist. [4 marks]
Resting membrane potential. Na+ channels (pink) and some, but not all, K+ channels (purple)
are closed. K+ diffuses down its concentration gradient through the open K+ channels, making
the inside of the cell membrane negatively charged compared to the outside.
Resting membrane potential (results in electrical potential energy) occurs because there is an
uneven distribution of ions across the cell membrane. Na+ channels and some, but not all, K+
diffuses down its concentration gradient through the open K+ channels, making the inside of the
cell membrane negatively charged compared to the outside.
- outward concentration gradient for K+
- inward electrical gradient for K+.
- resting membrane potential results from the equilibrium of K+ movement across the cell
membrane
Document Summary
Module 3 - review questions - part 1: describe the functions of the muscular system, include whether it is skeletal, smooth or cardiac muscle involved. Contraction of skeletal muscles is responsible for the overall movements of the body, such as walking, running, and manipulating objects with the hands: maintenance of posture. Skeletal muscles constantly maintain tone, which keeps us sitting or standing erect: respiration. Muscles of the thorax (between neck + abdomen) carry out the movements necessary for respiration. The skeletal muscles responsible for respiration: production of body heat. When skeletal muscles contract, heat is given off as a by-product. This released heat is critical to the maintenance of body temperature: communication. This constriction can help propel and mix food and water in the digestive tract, propel secretions from organs, and regulate blood flow through vessels: contraction of the heart.
