Human Anatomy: Hormones, Nervous System, and Organs
Hormones and Endocrine System
Hormones: Influences metabolic activities of cells.
Pituitary gland: Hangs by a stalk from the hypothalamus in the brain. Protected by the sphenoid bone. Has two functional lobes:
- Anterior pituitary—glandular tissue
- Posterior pituitary—nervous tissue
Often called the “master endocrine gland”.
Endocrinology: Study of hormones and endocrine organs.
Central and Peripheral Nervous System
Central Nervous System (CNS): Components: brain and spinal cord. Functions: receives, processes, and transfers information.
Sensory neurons: Carry information toward the CNS.
Motor neurons: Carry information away from CNS.
Spinal Nerves: Part of the peripheral nervous system—carry impulses to and from the spinal cord.
Peripheral Nervous System: Components: nerves outside CNS.
Neurons and Brain Structure
Neuron: Specialized cells to transmit messages:
- Axon: Sends info, size varies (up to 1 meter), 1 per neuron. Axon hillock: area of body from which axon arises, sends signals away.
- Dendrites: Receive info, branching structures that receive signals, 100’s per neuron, short distance signals.
Brain: In Central Nervous System.
Cerebrum: Cerebral cortex: higher function. Paired (left and right) superior parts of the brain. Includes more than half of the brain mass. The surface is made of:
- Gyrus – ridges
- Sulcus – grooves
Lobes of the Cerebrum: Fissures (deep grooves) divide the cerebrum into lobes. Surface lobes of the cerebrum:
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
Cerebellum: Controls balance and equilibrium. Timing for skeletal muscle activity. Coordination of body movement, coordinates basic movements.
Reproductive System
Fallopian tubes:
- Receive the ovulated oocyte
- Site for fertilization
- Does not physically attach to the ovary
- Fimbriae – finger-like projections receive oocyte
- Cilia inside the tube
Spinal Cord and Urinary System
Spinal cord: Extends from skull to lumbar vertebra. Provides 2-way conduction pathway to and from brain. Cauda equina: collection of spinal nerves.
Kidney: Dorsal wall, abdominal cavity. Renal vessels. Located along the posterior wall of the abdominal cavity. Blood flow in/out: -> Renal artery <- Renal vein. Anatomy:
- Renal capsule
- Renal cortex
- Renal medulla
- Nephrons
- Renal pelvis
Ureter: Tubes that transport urine from kidney to urinary bladder. Tissue composed of transitional epithelium, smooth muscle and connective.
Urinary bladder: Can increase 6x size. Transitional epithelium and smooth muscle.
Reproductive and Urinary System Details
Diploid: First cell of a new individual.
Urethra male: Extends from the base of the urinary bladder to the tip of the penis.
- Prostatic Urethra
- Spongy Urethra
Carries both urine and sperm. Sperm enters from the ejaculatory duct.
Nephron: Functional unit of the kidney. Produces urine. Composed of hollow tube of epithelial cells (tubule) & blood vessels. Removes lots of fluid from blood and then returns almost all of it to the blood. Glomerular capsule (Bowman’s capsule): surrounds glomerulus. Formation of urine: Plasma fluid is filtered out of capillaries into the capsule. Continues to tubule:
- Proximal tubule
- Loop of Henle
- Distal tubule
Collecting ducts drain urine into renal pelvis.
Testes: Seminiferous tubules: tightly coiled structures. Function as sperm-forming factories. Sperm travels to the epididymis. Interstitial cells produce androgens such as testosterone.