Reproductive System

• egg cells are produced in two almond-shaped organs  known as the ovaries
• during the process of ovulation, a mature egg (ovum) is released and enters one of the fallopian tubes
• for few days the egg cell travels towards the pear-shaped uterus
• the lining of this organ thickness in preparation for fertilized egg
• if the egg is not fertilized by the male sperm cell, it will leave the body together with the lining of the uterus and a small amount of blood called menstruation
• the lower portion of the uterus is called cervix and is a common site for cancer in women
• the female organ of intercourse is the vagina
• a circular fold of skin is usually present at the entrance to the organ and is called hymen
• outside of this organ are folds of skin covered with pubic hair known as the labia
• between these skin folds is a small, round sensitive area of skin called clitoris
• the development of the female reproductive system is triggered by the hormones: estrogen & progesterone, which causes many physical changes in a girl
• sperm cell are produced in a small seminiferous tubules of the testicles
• these oval shaped glands are protected by a sac called the scrotum
• after the sperm cells are produced, they stored in a large coiled tube on the outer surface of each testicle called the epididymis
• from this tube the sperm go into a larger tube called seminal vesicle
• which eventually carries them to the external male reproductive organ, the penis
• along the way sperm is nourished by a sugary fluid from the prostate gland which is the most common site for cancer in men
• fluid from cowper's gland which are two small glands located near the bladder
• these fluids, plus sperm cell combine to form semen
• the fluid ejaculated from the penis during orgasm
• before the male can ejaculated the spongy tissue surrounding the penis becomes engorged with blood causing the penis to become still and hard known as erection
• the tube that carries the semen from the body is the urethra
• urethra also carries urine from the bladder
• male can also have uncontrollable ejaculations during sleep, which are called nocturnal emissions
• the development of the male reproductive system is triggered by the hormone: testosterone, which cause many physical changes in a boy
• • Acts as a channel for signals between the brain and the rest of the body
  • Controls simple musculoskeletal reflexes without input from the brain
• Central Nervous System (CNS):

  • Serves as the main processing center for the entire nervous system
  • Brain functions as the organizer and distributor of information
  • Cerebrum (Forebrain):
  • Large, upper part of the brain
  • Controls activity and thoughts
  • Cerebellum (Hindbrain):
  • Located under the cerebrum
  • Controls posture, balance, and coordination
  • Brain Stem:
  • Connects the brain to the spinal cord
  • Controls automatic functions like breathing, digestion, heart rate, and blood pressure
  • Spinal Cord:
• Peripheral Nervous System (PNS):

  • Connects the CNS to the organs and limbs
  • Somatic Nervous System:
  • Allows voluntary control of body movements
  • Spinal Nerves:
  • Carry motor and sensory signals between the spinal cord and the body
  • Cranial Nerves:
  • Nerve fibers that carry information into and out of the brain stem
  • Autonomic Nervous System:
  • Involuntary control of body movements
  • Sympathetic:
  • Activated during dynamic roles or stress
  • Increases heart rate and breathing, dilates pupils, and causes sweating
  • Parasympathetic:
• • Maintains body function and restores the body to a normal or relaxed mode
• Nerve Cell (Neurons):

  • Basic unit of the nervous system
  • Carry messages through an electrochemical process
  • Billion neurons in the body, some exist alone, others form organs like the brain and spinal cord
  • Dendrites:
  • Root-like structures projecting from the cell body
  • Carry impulses towards the cell body
  • A cell may have as many as 200 dendrites, with a single dendrite reaching over one meter long
  • Axon:
  • Grouped together into cable-like bundles called nerves
  • Carry impulses away from the cell body
• • Pass impulses to the dendrites of other neurons or the cell body of muscle cells
• • Sense organs constantly receive information from the environment and send messages to the brain
  • Stimulus:
  • Any factor in the environment that triggers a nerve impulse or influences behavior
  • Response:
  • Reaction to a condition or stimulus
  • Organism:
  • Must be able to respond to a stimulus to survive
  • Reaction time:
  • Length of time between the application of a stimulus and the detection of a response
• Control of Body Processes Through the Nervous System:

  • Nerve impulse:
  • An electromagnetical signal moving along a neuron
  • Cannot jump from one neuron to another
  • Neurons:
  • Cells with the special ability to carry signals or impulses for thoughts, emotions, learning, and more
  • Neurotransmitter:
  • Produced at the end of an axon when a nerve impulse arrives
  • Synapse:
  • Space between neurons where chemicals cross to stimulate the next dendrite
  • Nervous System:
  • Assisted by five sense organs (Eyes, Ears, Nose, Tongue, Skin)
• How does the Nervous System Work?

  • Acts like a network that relays messages
  • Information transmitted through the spinal cord linking the brain to every organ and bodily portion
  • Brain commands the body to respond to messages
  • Nerve cells process information and pass it to other cells
  • Neurons:
  • Handle information, passing it to other cells
  • Motor Neurons:
  • Transmit impulses from the brain to muscles, glands, or other neurons in the PNS
  • Sensory Neurons:
  • Transmit impulses from sensory nerves to the CNS
  • Brain messages sent through motor neurons
• Endocrine System:

  • Controls slow-acting mechanisms like cell growth
  • Nervous system controls body movement and breathing
• Major Glands of the Endocrine System:

  • Hypothalamus:
  • Connects the nervous system with the endocrine system
  • Controls the secretions of the pituitary gland
  • Pituitary Gland:
  • Secretes 9 hormones, involved in various functions like sperm and egg production
  • Parathyroids:
  • Secretes Parathyroid Hormone (PTH) to regulate calcium levels in the blood
  • Thyroid:
  • Regulates the body's metabolism
  • Adrenals:
  • Responsible for the "fight or flight" response, releasing epinephrine and norepinephrine
  • Pancreas:
• • Contains exocrine and endocrine glands, releasing digestive enzymes and hormones like insulin and glucagon
  • Ovaries (female):
  • Produce estrogen and progesterone
  • Testes (male):
  • Produce testosterone
• Hormones:

  • Chemical substances released by cells or glands
  • Coordinate organ functions in the body
  • Endocrine glands:
  • Where hormones are made
  • Release hormones directly into the bloodstream
  • Classified into four types: Peptides, Steroid Hormones, Amino Acid Derivatives, Fatty Acid Derivatives
• Symptoms of Hormonal Imbalance:

  • Irregular periods
  • Sore or tender breasts
  • Weight gain and slowed metabolism
• Reproductive System:

  • Organ system primarily for reproduction