Musculoskeletal & Nervous Systems Flashcards
Exoskeletons vs Endoskeletons
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
Endoskeleton
Can be separated into axial (along midline) and appendicular portions (limbs and girdles)
Vertebrate skeleton functions (5)
- Support. Protect. Anchor. Lipid. Blood cell.
- Support of body weight
- Protection of internal organs (think cranium and rib cage)
- Anchor sites for muscles (leading to movement)
- Lipid and mineral regulation and storage
- Blood cell formation in marrow (hematopoiesis)
Skull - Cranium
Cranium
- Encloses and protects the brain
- Attachment sites for head and neck muscles
Skull - Face
Face
- Contains cavities for sight, taste,
and smell organs
- Attachment sites for facial muscles
- Passage for air and food to the body
Vertebral Column (5 Regions)
Can be separated into five regions:
- Cervical (neck)
- Thoracic (chest)
- Lumbar (lower back)
- Sacral (hips), fuse into sacrum
- Coccygeal (“tailbone”), fuse into coccyx
Thoracic Cage
- TV. R. S. CC.
- Protec. Support. Attach.
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
Girdles
- Attach limbs (arms & legs) to axial skeleton
- Pectoral girdle is composed of clavicle and scapula
Limbs
Bones in the limbs (arms & legs) follow a pattern:
- 1 bone > 2 bones > many small bones > digits
Joints
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)
Types of Muscle Tissue
Humans have three types of muscle tissue, classified according to their structure, function, and control mechanisms
- Cardiac muscle
- Smooth muscle
- Skeletal muscle
Skeletal Muscle Organization
- Myo, MC. GMF. GF.
Hierarchy of muscle
- Myofibril = organelle composed of thick and thin
filaments
- Muscle cell = muscle fiber
- Group of muscle fibers = fascicle
- Group of fascicles = muscle
Myofibrils
Many myofibrils go into a muscle cell
- Myofibrils are composed of sarcomeres (the
repeating unit of myofibrils)
Sarcomeres
- Thick & thin
- Z lines
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
The Nervous System
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
Cell Body
Each neuron has a cell body (or soma) that contains a nucleus, smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria, and other cellular components
Nervous tissue
Neuro & gilal cell
2 cell types:
- Neurons
- Process and transmit information
- Electrically excitable
- Glial cells (a.k.a. neuroglia)
- Provide support, protection, and nutrition to neurons
Dendrites
Dendrites are tree-like structures that extend away from the cell body to receive messages from other neurons at
specialized junctions called synapses
Synapses
- Cell communication
- Signals –> C & E current
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
Axon
Axons transmits information between neurons and away from muscles and glands
- Each neuron has an axon that directly connects it with another neuron
Schwann cells
Schwann cells (SCs) are a type of glial cell that surrounds neurons, keeping them alive and sometimes covering them with a myelin sheath
Central Nervous System
Consists of brain and spinal cord
- It is covered with three layers of
protective coverings called meninges
Meninges
Three membrane layers that cover and protect your brain and spinal cord
- Consists of dura mater, arachnoid mater, and pia mater
The Brain - Cerebral Cortex & Corpus Callosum
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
Spinal Cord
- A thick bundle of NT
- Conatined within M & VC
- Communicate S.
- Control MR
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
Brain/Spinal Cord - Gray Matter and White Matter
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
The Peripheral Nervous System (PNS)
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
Autonomic nervous system (ANS)
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
Sympathetic nervous system
Responsible for the immediate responses an animal makes when it encounters
a dangerous situation
- Two response types :
- Sympathetic
- Parasympathetic
Sympathetic vs Parasympathetic
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
Effects from these systems (parasympathetic & sympathetic) can be antagonistic, such as:
- Increasing (sympathetic) or decreasing (parasympathetic) heart rate
- Inhibiting (sympathetic) or maintaining (parasympathetic) digestion and
elimination
