chapter 6 - Nervous and Endocrine Systems Flashcards
The Role of the Nervous System?
The role of the nervous system I to control and coordinate body activities in a rapid and precise mode of action.
The nervous system is composed of central and peripheral nervous system.
The Central Nervous System - CNS
The CNS is enclosed within the cranium (skull), and vertebral canal (Spinal) and consists of, respectively, of the brain and spinal cord.
The peripheral Nervous System – PNS – Two types of PNS?
The PNS is outside of the bony encasements and is composed of peripheral nerves, which are branches or continuations of the spinal or cranial nerves.
The PNS can be divided into the somatic nervous system and the autonomic nervous system.
The Somatic Nervous System
The somatic nervous system contains sensory fibers that bring information back to the CNS and motor fibers that innervate skeletal muscles.
The Autonomic Nervous System – 2x types of ANS?
The ANS contains motor fibers that innervate smooth muscle, cardiac muscle and glands.
The ANS is then divided into the sympathetic and parasympathetic which generally act against each other.
Sympathetic acts to prepare the body for emergency situations (Fight or flight)
Parasympathetic acts to conserve energy and restore the body to resting level (Rest & Digest)
Three types of Neurone
Afferent Neurons – Carry information from the environment to the brain or spinal cord.
Efferent Neurons – Carry motor commands from the brain or spinal cord to different parts of the body.
Interneurons Neurons - Connect sensory and motor neurons in neural pathways.
The spinal Cord
Long cylinder structure with a hollow core – core is called the central canal.
Central canal is surrounded by grey matter which in turn surrounded by white matter.
(The reverse is true of the brain)
White & Grey Matter
Basically the grey matter consists of cell bodies of neurons and the white consists of the nerve fibers – axons and dendrites
Sensory Receptors
Any type of nerve ending in the body that can be stimulated by some physical or chemical stimulus either outside or within the body.
e.g. rods or cones of the eye, cochlear nerve endings in the ear.
An Organ
In biology, an organ (from the Latin “organum” meaning an instrument or tool) is a collection of tissues that structurally form a functional unit specialized to perform a particular function. Your heart, kidneys, and lungs are examples of organs.
The effector receptors
These include every organ that can be stimulated by nerve impulses. An important example would be the skeletal muscle.
Effector
The term effector in biology refers to n organ, cell or molecule that acts in response to a stimulus.
Reflex Arc
A basic method of controlling the functions in the body is the reflex arc.
A stimulus excites a receptor, appropriate impulses are transmitted into the CNS. Where various reactions take place and then appropriate effector impulses are transmitted to an effector organ to cause a reflex effect
e.g take your and off the stove.
The Endocrine System
Responsible for the secretion of hormones directly into the circulatory
Hormones transported by the blood system.
Hormones controlling many of the boy’sin one of the following 3 ways.
1) By controlling transport of substances through cell membranes
2) By controlling the activity of some of the specific genes
3) By controlling directly some metabolic systems of cells
Pituitary Gland
Pituitary glad secretes hormones responsible for a variety of functions in the body.
