Musculoskeletal & Nervous Systems

Question 1

Exoskeletons vs Endoskeletons

Answer 1

External or internal hard structure skeleton that
supports and provides anchorage for muscles
- Exoskeletons : must be shed to allow for growth
- Endoskeletons : are made of bone and cartilage

Question 2

Endoskeleton

Answer 2

Can be separated into axial (along midline) and appendicular portions (limbs and girdles)

Question 3

Vertebrate skeleton functions (5)
- Support. Protect. Anchor. Lipid. Blood cell.

Answer 3

1. Support of body weight
2. Protection of internal organs (think cranium and rib cage)
3. Anchor sites for muscles (leading to movement)
4. Lipid and mineral regulation and storage
5. Blood cell formation in marrow (hematopoiesis)

Question 4

Skull - Cranium

Answer 4

Cranium
- Encloses and protects the brain
- Attachment sites for head and neck muscles

Question 5

Skull - Face

Answer 5

Face
- Contains cavities for sight, taste,
and smell organs
- Attachment sites for facial muscles
- Passage for air and food to the body

Question 6

Vertebral Column (5 Regions)

Answer 6

Can be separated into five regions:
- Cervical (neck)
- Thoracic (chest)
- Lumbar (lower back)
- Sacral (hips), fuse into sacrum
- Coccygeal (“tailbone”), fuse into coccyx

Question 7

Thoracic Cage
- TV. R. S. CC.
- Protec. Support. Attach.

Answer 7

Includes:
- Thoracic vertebrae
- Ribs
- Sternum
- Costal cartilages

Functions :
- Protects vital organs
- Supports shoulder girdles and upper limbs
- Attachment points for muscles of neck, back, chest,
shoulders, and diaphragm

Question 8

Girdles

Answer 8

• Attach limbs (arms & legs) to axial skeleton
• Pectoral girdle is composed of clavicle and scapula

Question 9

Limbs

Answer 9

Bones in the limbs (arms & legs) follow a pattern:
- 1 bone > 2 bones > many small bones > digits

Question 10

Joints

Answer 10

Joints are where two or more bones come together
- Can provide mobility, connection, and/or protection

Joints come in one of three varieties:
- Immovable (fibrous joints)
- Slightly movable (cartilaginous joints)
- Freely movable (synovial joints)

Question 11

Types of Muscle Tissue

Answer 11

Humans have three types of muscle tissue, classified according to their structure, function, and control mechanisms
- Cardiac muscle
- Smooth muscle
- Skeletal muscle

Question 12

Skeletal Muscle Organization
- Myo, MC. GMF. GF.

Answer 12

Hierarchy of muscle
- Myofibril = organelle composed of thick and thin
filaments
- Muscle cell = muscle fiber
- Group of muscle fibers = fascicle
- Group of fascicles = muscle

Question 13

Myofibrils

Answer 13

Many myofibrils go into a muscle cell
- Myofibrils are composed of sarcomeres (the
repeating unit of myofibrils)

Question 14

Sarcomeres
- Thick & thin
- Z lines

Answer 14

Thick (myosin) and thin (actin) filaments arranged in a repeating, overlapping fashion

Z lines mark the ends of sarcomeres
- Z lines give skeletal muscle its striated appearance
- Using ATP, myosin temporarily binds to actin and pulls the Z-lines closer to each other causing muscle contraction

Question 15

The Nervous System

Answer 15

The nervous system senses the environment, interprets that information, and transmits signals for a response

Central nervous system (CNS)
- Brain and nerve cord (spinal cord in vertebrates)

Peripheral nervous system (PNS)
- Nervous cells outside the CNS that relay
info to/from the CNS

Question 16

Cell Body

Answer 16

Each neuron has a cell body (or soma) that contains a nucleus, smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria, and other cellular components

Question 17

Nervous tissue

Neuro & gilal cell

Answer 17

2 cell types:
- Neurons
- Process and transmit information
- Electrically excitable
- Glial cells (a.k.a. neuroglia)
- Provide support, protection, and nutrition to neurons

Question 18

Dendrites

Answer 18

Dendrites are tree-like structures that extend away from the cell body to receive messages from other neurons at
specialized junctions called synapses

Question 19

Synapses
- Cell communication
- Signals –> C & E current

Answer 19

Synapses : junction between neurons and other cells
- This is where communication between these cells occurs.

Signals can be transmitted via chemicals or electric current
- Chemical signals are slower but responses can be modulated
- Electric signals move very quickly and helps to coordinate activation of multiple cells

Question 20

Axon

Answer 20

Axons transmits information between neurons and away from muscles and glands
- Each neuron has an axon that directly connects it with another neuron

Question 21

Schwann cells

Answer 21

Schwann cells (SCs) are a type of glial cell that surrounds neurons, keeping them alive and sometimes covering them with a myelin sheath

Question 22

Central Nervous System

Answer 22

Consists of brain and spinal cord
- It is covered with three layers of
protective coverings called meninges

Question 23

Meninges

Answer 23

Three membrane layers that cover and protect your brain and spinal cord
- Consists of dura mater, arachnoid mater, and pia mater

Question 24

The Brain - Cerebral Cortex & Corpus Callosum

Answer 24

Cerebral Cortex : outermost part of the brain, it is a thick piece of nervous system tissue
- The cerebral cortex, limbic system, and basal ganglia make up the two cerebral hemispheres

Corpus Callosum : A thick fiber bundle connects the two hemispheres

Question 25

Spinal Cord
- A thick bundle of NT
- Conatined within M & VC
- Communicate S.
- Control MR

Answer 25

A thick bundle of nerve tissue that carries information about the body to the brain and from the brain to the body
- Contained within the meninges and the bones of the vertebral column
- Is able to communicate signals to and from the body through its connections with spinal nerves
- Controls motor refelexes

Question 26

Brain/Spinal Cord - Gray Matter and White Matter

Answer 26

Grey matter : place where the processing of sensation, perception, voluntary movement, learning, speech and cognition takes place
- Made up of axons

White matter : provides communication between different grey matter areas and between grey matter and the rest of body
- Made up of neuron and glia cell bodies

Question 27

The Peripheral Nervous System (PNS)

Answer 27

The connection between the central nervous system and the rest of the
body.
- Can be broken down into :
- The autonomic nervous system
- The sensory-somatic nervous system

Question 28

Autonomic nervous system (ANS)

Answer 28

ANS (a.k.a. involuntary nervous system) consists of neurons that innervate smooth and cardiac muscles and glands
- ANS makes adjustments to support internal body activities
- Can be separated into sympathetic and parasympathetic divisions

Question 29

Sympathetic nervous system

Answer 29

Responsible for the immediate responses an animal makes when it encounters
a dangerous situation
- Two response types :
- Sympathetic
- Parasympathetic

Question 30

Sympathetic vs Parasympathetic

Answer 30

Sympathetic
- “Fight or flight” response
- Primes body for action (e.g. emergency situations) and reduces nonessential activities

Parasympathetic
- “Rest & digest” response
- Minimizes body energy use

Both sympathetic and parasympathetic systems innervate the same organs

Question 31

Effects from these systems (parasympathetic & sympathetic) can be antagonistic, such as:

Answer 31

• Increasing (sympathetic) or decreasing (parasympathetic) heart rate
• Inhibiting (sympathetic) or maintaining (parasympathetic) digestion and
  elimination